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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Entomologia experimentalis et applicata 44 (1987), S. 187-193 
    ISSN: 1570-7458
    Keywords: Calosoma sycophanta ; Carabidae ; Coleoptera ; emigration ; gypsy moth ; Lymantria dispar ; spatial dispersion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé L'étude par capture-recapture de Calosoma sycophanta L. (Carabidae) a été effectuée dans deux parcelles de 4 ha en utilisant des pièges distribués sur une grille de 10 sur 10. Pendant la première année d'échantillonnage, Lymantria dispar L. (Lymantriidae) était abondant et les calosomes se sont reproduits, tandis que la seconde année les papillons étaient beaucoup moins nombreux. La distribution des larves de carabes a été examinée aussi pendant la première année sur l'une des stations, et celle des chenilles pendant les deux années avec des toiles d'emballage sur l'autre station. Les dispersions des adultes et larves de calosomes et des chenilles de Lymantria ont été calculées en utilisant la régression du logarithme naturel de la variance de l'échantillon sur le logarithme naturel de la moyenne (méthode de Taylor) et la régression de l'indice de Lloyd d'agrégation moyenne sur la moyenne (méthode d'Iwao). La méthode de Taylor a donné les résultats les plus logiques, et les pentes ont servi à mesurer le degré d'agrégation. Les recaptures de calosomes adultes ont été analysées par les méthodes de Fisher-Ford et Jolly-Seber, associées à la méthode de Jackson pour séparer survie et migration. De même, une nouvelle méthode pour déterminer directement la migration en découvrant combien d'insectes recapturés ont abandonné les microparcelles s'est révélée comme la plus cohérente avec le procédé Fisher-Ford-Jackson. La tendance à l'agrégation est plus forte chez les mâles (d'après la pente du logarithme de la moyenne par rapport au logarithm e de la variance de l'échantillon). La migration et le degré d'agrégation paraissent varier ensemble dans une station, tandis que dans l'autre une telle relation n'apparaît pas clairement. Les femelles malgré des taux de migration variés mais généralement faibles, n'ont jamais pr'esenté de tendance significative à l'agrégation. A l'opposé, les larves de calosomes et de Lymantria ont presenté des distributions agrégatives.
    Notes: Abstract Mark-release studies of Calosoma sycophanta L. (Carabidae) in two 40000 m2 areas were done using traps deployed in 10 by 10 grids. In both areas, gypsy moths, Lymantria dispar L. (Lymantriidae), were abundant the first but not the second year of sampling. The distribution of carabid larvae was also investigated in the first year at one of the sites and the distribution of gypsy moth larvae found under burlap bands determined for 2 years at the other site. Dispersions of beetles and prey were evaluated by Taylor's logarithmic meanvariance method and Iwao's mean-mean crowding method. Taylor's method gave the most consistent results, and the slopes of the regression lines were used to determine degree of clumping. To evaluate dispersal of adult beetles, recapture data were analysed using the Fisher-Ford and Jolly-Seber methods in conjunction with Jackson's method for separating survival and emigration. A new method for estimating emigration was found to be most consistent with the Fisher-Ford-Jackson procedure. The tendency of the beetles to aggregate (measured via Taylor's method) was generally highest for males. In one site, emigration and degree of aggregation for males appeared to vary together, while at the other site no relationship was evident. Females showed few tendencies to aggregate. Both beetle larvae and gypsy moth larvae had clumped distributions.
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  • 2
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    Entomologia experimentalis et applicata 45 (1987), S. 102-104 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Carabidae ; Bembidion ; Trechus ; Agonum ; sex determination ; adhesion ; male setae ; tarsomere
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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  • 3
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    Entomologia experimentalis et applicata 45 (1987), S. 23-27 
    ISSN: 1570-7458
    Keywords: Coléoptère ; Bruchidae ; Olfactométrie ; phéromone sexuelle ; plante hôte ; régulation de la réproduction ; Coleoptera ; Bruchidae ; olfactometer ; sex pheromone ; host plant ; reproductive regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Summary In order to meet its sexual partner, Zabrotes subfasciatus must rely on the olfactory signals emitted either by the female or the male insect. The attractiveness of male and female odours were therefore studied and compared in an olfactometer. The behaviour of virgin and inseminated females and males, left in contact with the host plant's seeds or not, was studied in terms of the age of the imagos. In all cases examined, male odours did not attract female insects. Virgin females kept without seeds of the host plant did not attract males. On the other hand, the odour of virgin females left in contact with bean seeds significantly attracted virgin males. The females' attractive power varied according to their age: older females released a chemical cue that was more attractive for the males. Emission of the sex-pheromone stops after insemination of the females but begins again after a certain period of time. Results are discussed in terms of what is known on the reproductive regulation of this bruchid.
    Notes: Abstract Pour rechercher son partenaire sexuel Zabrotes subfasciatus doit utiliser les signaux olfactifs émis soit par les mâles ou par les femelles. Le pouvoir attractif de l'odeur des mâles et des femelles sont donc étudiés et comparés par olfactométrie. Le comportement de mâles et de femelles vierges et inséminées, mis en contact des graines de la plante hôte ou non, est observé en fonction de l'âge des imagos. En aucun cas, les odeurs des mâles n'exercent une attraction sur les femelles. Les femelles vierges en absence de graines de haricot (Phaseolus vulgaris) n'exercent pas d'attraction sur les mâles vierges. Par contre les odeurs des femelles vierges mises en contact avec les graines de haricot sont très attractives pour les mâles vierges et varie en fonction de l'âge: il est plus affirmé chez les femelles plus âgées. L'émission de la phéromone sexuelle est interrompue après l'insémination des femelles mais reprend au bout d'un certain temps après celle-ci.
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  • 4
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    Entomologia experimentalis et applicata 43 (1987), S. 205-208 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Chrysomelidae ; Diabrotica virgifera ; corn rootworms ; prehatch development ; posthatch development ; protandry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé L'observation, au laboratoire, pendant une période d'éclosion de dix jours, des oeufs de D. v. virgifera LeConte, a montré que les oeufs mâles prédominent les deux premiers jours d'éclosion, que les oeufs des deux sexes, avec des fréquences 0,5/0,5, ont éclos les troisième et quatrième jours, et que les oeufs éclos du cinquième au dixième jour étaient presque tous femelles. Globalement, les oeufs femelles ont éclos en moyenne 2,9 jours plus tard que les oeufs mâles. De plus, la durée du développement post-embryonnaire des femelles a demandé 1,8 jour en plus. Une éclosion plus tardive et un développement post-embryonnaire plus long ont entrainé une émergence des femelles en moyenne 4,7 jours après les mâles. La période d'émergence des adultes s'est étalée sur 14 jours; les mâles ayant dominé pendant les 5 premiers jours et les femelles pendant les 9 derniers. Les mâles de D. v. virgifera semblent avoir évolué vers la protandrie en acquerant, tant une diapause post-embryonnaire que des stades de développements larvaire et nymphal plus brefs.
    Notes: Abstract Laboratory tests with eggs of Diabrotica virgifera virgifera LeConte showed that during a 10-day hatching period, hatch of male eggs predominated on the first and second days, eggs of mixed sex, with ca. 1:1 ratio, hatched on the third and fourth days, and eggs hatching from the fifth to the tenth days were nearly all female. Overall, female eggs hatched a mean of 2.9 days later than male eggs. Not only did female eggs hatch later, but the time for posthatch development to the adult stage was 1.8 days longer for females. The later egg hatch and longer posthatch development for females resulted in female adults emerging a mean of 4.7 days later than male adults. Total adult emergence lasted 14 days; of this, males predominated during the first 5 days, and females predominated during the last 9 days. Males of D. v. virgifera appear to have evolved protandry (the tendency for males to emerge before females) by developing both a postdiapause embryonic stage and a combined larval and pupal stage of shorter duration.
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  • 5
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    Entomologia experimentalis et applicata 44 (1987), S. 15-21 
    ISSN: 1570-7458
    Keywords: Callosobruchus maculatus ; Coleoptera ; Bruchidae ; intraspecific competition ; oviposition strategies ; resource exploitation ; vibrations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Lors de la compétition, les larves réagissent l'une par rapport à l'autre, même lorsque leurs galeries sont séparées. L'une est inhibée, tandis que l'autre se comporte comme si elle était seule. Le signal provoquant ces réactions, qui peut traverser du papier métallique, est dû vraisemblablement aux vibrations de mastication des larves; ces dernières perçoivent ces signaux tout au long de leur vie active. La larve la plus âgée ne l'emporte pas obligatoirement, ce qui signifie que le signal indique plus que l'âge. Les conditions expérimentales peuvent inverser les réponses des unes et des autres, bien que la larve la plus âgée puisse souvent mourir de ces conditions anormales de compétition. L'avantage potentiel associé à l'inhibition du futur perdant est mis en évidence en collant ensemble des graines. Quand la larve dominante se nymphose, la larve inhibée recommence à s'alimenter et achève son développement. En ayant eu son alimentation interrompue et en restant dans une galerie superficielle, la larve inhibée évite les affrontements et peut se développer lorsque la larve dominante meurt ou se nymphose, puisque la galerie de la larve inhibée n'avait pas été sectionnée. La stratégie de ponte réduit la fréquence de la compétition en uniformisant la distribution des oeufs; elle augmente les chances de survie des larves vaincues avec l'addition des oeufs sur les graines les plus grosses quand les disponibilités sont limitées. L'étude de l'évolution de ces adaptations a été possible puisque, comme on le sait, C. maculatus est génétiquement polymorphe pour les caractères déterminant le comportement de ponte des femelles et la compétition larvaire.
    Notes: Abstract Larvae of the bean weevil C. maculatus feeding in a single bean apparently respond to vibrations from each other's chewing: one larva feeds normally, the other is inhibited. If the burrows of the larvae intersect, the inhibited larva dies. If the dominant larva pupates or dies without the burrows intersecting, the inhibited larvae then feeds and matures if enough food remains. Since females add second eggs to the largest beans after most beans carry a single egg, competition is most common in the largest available beans, precisely where inhibited larvae can benefit from avoiding a contest.
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  • 6
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    Entomologia experimentalis et applicata 44 (1987), S. 53-58 
    ISSN: 1570-7458
    Keywords: Tomicus piniperda ; Coleoptera ; Scolytidae ; host recognition ; host volatiles ; attraction ; low vigor trees ; attacked trees
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Der Anflug von Tomicus piniperda (L.) (Coleoptera: Scolytidae) an Kiefern in schlechtem oder besserem Gesundheitszustand, mit oder ohne vorherigen Befall, wurde mit Hilfe von Leimfallen untersucht. An Bäumen in schlechtem Zustand wurden etwas mehr Käfer gefangen als an Bäumen in besserem Gesundheitszustand. Das deutet auf Unterschiede in Geruchsreizen zwischen den beiden Klassen des Baumzustands hin. An Kiefern, die von T. piniperda befallen waren oder simulierte Einbohrungen (von Hand gebohrte Löcher) hatten, wurden viel mehr Käfer gefangen als an Kontrollbäumen ohne oder mit sehr geringem Befall. Der starke Anflug von Käfern an befallene Bäume wird gedeutet als Reaktion auf Duftstoffe des Wirts, die aus den Borkenkäfergängen abgegeben werden.
    Notes: Abstract The attraction of Tomicus piniperda (L.) (Coleoptera: Scolytidae) to Scots pine trees of low and higher vigor with and without previous attacks was monitored with sticky traps. Somewhat higher numbers of beetles were caught on low vigor trees than on trees of higher vigor, indicating differences in olfactory stimuly between the two classes of trees. Many more beetles were caught on trees attacked by T. piniperda and on trees with simulated bark beetle galleries (manually drilled holes) than on control trees with no or only a few attacks. The strong attraction of beetles to attacked trees is attributed to the beetles responding to host volatiles released from the galleries.
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  • 7
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    Journal of molecular evolution 24 (1987), S. 260-271 
    ISSN: 1432-1432
    Keywords: Mouse ; Rat ; Two-dimensional electrophoresis ; Quantitative variability of proteins ; Qualitative variability of proteins ; Protein classes ; Membrane proteins ; Organ-specific proteins ; Regulatory genes ; Speciation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Proteins of membranes and cytosols were extracted from the livers and brains of mice (inbred strain DBA/6J) and rats (inbred strain DA/Han) and separated by two-dimensional electrophoresis (2-DE). The 2-DE patterns were compared with regard to qualitative (spot position) and quantitative (spot intensity) characteristics of the proteins of these two species. The following results were obtained: (1) Brain had more (higher percentage) conservative proteins (proteins found in both mice and rats) than liver; (2) plasma membranes had more conservative proteins than the cytosols; (3) organ-unspecific proteins contained more conservative proteins than relatively organ-specific proteins; (4) the pattern of distribution of genetic variability among different classes of proteins represented by findings 1–3 was the same for the qualitative and quantative characteristics of the proteins; and (5) some observations indicated that quantitative variability occurred more frequently among proteins than did qualitative variability. Our conclusion is that regulatory sequences in the DNA (regulatory genes) are subjected to functional constraints that differ in strength among different classes of proteins by the same ratios as the constraints acting on the structural genes. The overall effect of the selective pressure is, however, less stringent for regulatory genes than for structural genes. The results obtained here by comparing two different species are very similar to previous results we obtained by studying different subspecies (inbred strains of the mouse). From this finding arises a new concept: the study of molecular evolution on the basis of different classes of proteins. Our results were compared with data from the literature that were obtained in part from studies on cultured cells. The comparison suggested that cultured cells have lost their tissue-specific proteins, and so generate predominantly extremely conservative proteins.
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  • 8
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    European journal of nutrition 26 (1987), S. 43-51 
    ISSN: 1436-6215
    Keywords: Dietary protein ; Vitamin A ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Es wurde der Einfluß von Qualität und Quantität von Nahrungsproteinen auf die Verteilung einer einzigen massiven Dosis von Vitamin A in verschiedenen Organen wachsender Wistar-Ratten untersucht. Die Untersuchungen wurden mit Casein- und Bengal-Gram-Diäten mit 20 % und 10 % Proteingehalt und auch mit radioaktiv markiertem Retinylacetat durchgeführt. Die Ergebnisse zeigen, daß die Leberspeicherung sowohl von Vitamin A aus der Nahrung als auch die einer einzigen starken Vitamin-A-Gabe (20 000 I.U.) stark herabgesetzt war bei Ratten, die nach der Bengal-Gram-Diät gefüttert wurden, verglichen mit Ratten, die auf Casein-Diät gesetzt waren. Im Gegensatz zur Leberspeicherung ist das Vitamin-A-Niveau im Plasma in allen Gruppen vergleichbar. Füttern niedriger Protein-Qualität reduzierte die Gewebeverteilung von [3H]-Retinylacetat sowohl bei Kontrollratten als auch bei solchen, denen eine massive Dosis Vitamin A gegeben wurde. Diese Untersuchung läßt vermuten, daß sowohl schlechte Qualität als auch unzureichende Mengen von Nahrungsproteinen nachteilige Einflüsse auf den Vitamin-A-Zustand wachsender Ratten haben.
    Notes: Summary The influence of the quality and the quantity of dietary proteins on the distribution of a single massive dose of vitamin A in various organs of growing Wistar strain rats has been studied by using casein and bengal gram diets at 20 % and 10 % protein levels. The distribution of [3H]-retinyl acetate in various tissues was also investigated in these dietary conditions. The results show that the hepatic storage of dietary as well as a single massive dose (20,000 I.U.) of vitamin A was profoundly decreased in the rats fed on bengal gram diets as compared to those fed on casein diets. Regardless of hepatic stores, the plasma vitamin A levels were comparable in all the groups. Feeding of low quality of protein reduced the tissue distribution of [3H]-retinyl acetate in control as well as rats given a massive dose of vitamin A. This study suggests that both the poor quality and the inadequate quantity of dietary protein are detrimental influences on the vitamin A status of the growing rats.
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  • 9
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    Cellular and molecular life sciences 43 (1987), S. 458-460 
    ISSN: 1420-9071
    Keywords: Defensive secretions ; glands ; Chrysomelidae ; Coleoptera ; phenylethanol ; linalool ; 6-methyl-5-hepten-2-one ; 6-methyl-5-hepten-2-ol ; 2-hexenal ; chemotaxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The leaf beetle larva ofGonioctena (Phytodecta) viminalis L. has been shown to produce five volatile constituents within its paired abdominal defensive gland reservoirs. It is the first time that these compounds have been reported to occur in coleopteran defensive glands (linalool, phenylethanol) and Chrysomelidae larvae (6-methyl-5-hepten-2-one, 6-methyl-5-hepten-2-ol, 2-hexenal). In addition to the gross morphology of theGonioctena gland and its discharge behavior, the natural products found are discussed in terms of chemotaxonomy.
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  • 10
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    Cellular and molecular life sciences 43 (1987), S. 460-462 
    ISSN: 1420-9071
    Keywords: Biosynthesis ; cardenolides ; Coleoptera ; chrysomelid beetles ; [23-14C]-cholesterol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Labeling experiments have shown that the chrysomelid beetleChrysolina coerulans is able to biosynthesize its own defensive cardenolides from cholesterol, via a pathway involving a C21 intermediate, as in plants.
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  • 11
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    Calcified tissue international 25 (1978), S. 75-83 
    ISSN: 1432-0827
    Keywords: Rat ; Fluorosis ; Enamel ; Scanning electron microscopy ; Low temperature incineration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Sixteen 58-day-old male rats of Wistar strain, with a mean body weight of 179 g, were divided into two equal groups. Each group of eight animals was maintained for 70 days on drinking water, ad lib., containing no fluorine (control group) and 100 ppm of fluorine (experimental group). All specimens examined were obtained from the incisal portions of the incisors. The following types of enamel specimens were prepared for scanning electron microscopy: (1) acid-etched specimens; (2) acid-etched specimens followed by low temperature microincineration; and (3) fractured specimens. The enamel formed during high fluoride exposure showed marked hypocalcification, that is, the crystallite density in the prism core and interprismatic region was lower than that of control animals. The organic substances appeared to increase in these regions. These changes were prominent in the outer and middle enamel layers. Such changes following fluoride administration appear to indicate an inhibition of enamel maturation, that is, an inhibition of the mineral deposition and/or an inhibition of organic matrix withdrawal.
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  • 12
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    Journal of chemical ecology 13 (1987), S. 219-226 
    ISSN: 1573-1561
    Keywords: Ablation ; egg dispersion ; oviposition deterrent ; foretarsi ; palpi ; antennae ; Coleoptera ; Bruchidae ; Callosobruchus maculatus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Females ofCallosobruchus maculatus (F.) avoid ovipositing on host seeds already bearing conspecific eggs, and thus distribute eggs evenly among seeds. This behavior was presumed to be mediated by an ether-soluble “oviposition marker” that is deposited with the egg and can be extracted from egg-laden artificial hosts (glass beads). Ablation experiments revealed that the true factors promoting an even dispersion of eggs were perceived by the maxillary and labial palpi. In contrast, receptors on the antennae were largely responsible for avoidance of seeds treated with “oviposition marker.” Taken together, these results suggest that a careful distinction should be drawn between factors that promote spacing of eggs under natural conditions and general oviposition deterrents that may be isolated from both sexes.
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  • 13
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    Journal of chemical ecology 13 (1987), S. 2009-2022 
    ISSN: 1573-1561
    Keywords: Leptinotarsa decemlineata ; Coleoptera ; Chrysomelidae ; Colorado potato beetle ; deterrent receptor ; feeding deterrents ; alkaloids ; sugar receptor ; amino acid receptor ; chemoreception ; steroidal alkaloids ; antifeedants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The galeal chemosensory system of the adult Colorado potato beetle was used as a model to study the effects of alkaloids on insect gustation. Nine alkaloids, representing a wide range of structural types, were used. Their ability to stimulate chemosensory cells when presented in isolation and their ability to interfere with normal chemosensory processes were emphasized. None of the alkaloids stimulated chemosensory cells in a dose-dependent manner, although a few stimulated low-level activity from some cells. There was no evidence for a general “deterrent receptor” in these beetles. Some of the alkaloids had a marked inhibitory effect on normal chemosensory responses. Tomatine, solanine, papaverine, and sparteine significantly inhibited responses to amino acids (represented by GABA) while quinine and papaverine inhibited responses to sucrose. An attempt was made to correlate neurophysiological action of some alkaloids with their effects on feeding behavior. It was clear from this correlation that even a dramatic inhibition of sensory input by an alkaloid does not necessarily lead to measurable effects on behavior. The results are discussed in the context of current theories on the mode of action of alkaloids and other secondary plant compounds which may be involved in host recognition by phytophagous insects.
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  • 14
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    Journal of chemical ecology 13 (1987), S. 35-38 
    ISSN: 1573-1561
    Keywords: Coleoptera ; Silphidae ; Silpha novaboracensis ; steroids ; pregnanes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Two novel steroids, 3α,7β-dihydroxy-14β-pregn-4-en-15,20-dione (1) and 3α,7β, 20ξ-trihydroxy-14β-pregn-4-en-15-one (4), have been characterized from the rectal gland ofSilpha novaboracensis (Coleoptera: Silphidae). Judging from the function of comparable pregnanes in another species ofSilpha, the compounds may play an antipredator role.
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  • 15
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    Journal of chemical ecology 13 (1987), S. 39-46 
    ISSN: 1573-1561
    Keywords: Solanum ; glycoalkaloid ; Leptinotarsa decemlineata ; protein ; growth ; Coleoptera ; Chrysomelidae ; α-tomatine ; α-solamarine ; β-solamarine ; α-solamine ; α-chacomine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Growth of larvae of the Colorado potato beetle,Leptinotarsa decemlineata (Say), as measured by weight gain, was determined when larvae were reared on synthetic diets containing measured quantities of protein and one of fiveSolanum glycoalkaloids. Data were analyzed to determine if growth was affected by these two aspects of phytochemical variation independently, or if there was a significant interaction component in larval weight gain to simultaneous variation in protein and glycoalkaloid concentration. For four of the five glycoalkaloids examined, a bivariate regression model without interaction accurately accounted for growth ofL. decemlineata larvae. For alpha-tomatine, however, a regression model with the addition of a (protein × glycoalkaloid) interaction term more accurately accounted for larval growth. The influence of this interaction was less than either protein or glycoalkaloid concentration alone. The variation in protein concentration accounted for most of the variation in larval growth, and high protein concentrations could more than offset the effect of high concentration of any of the five glycoalkaloids.
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  • 16
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    Journal of chemical ecology 13 (1987), S. 335-344 
    ISSN: 1573-1561
    Keywords: Kairomone ; parasite ; host finding ; host acceptance ; behavior ; Edovum puttleri ; Hymenoptera ; Eulophidae ; Colorado potato beetle ; Leptinotarsa decemlineata ; Coleoptera ; Chrysomelidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract When females of the eulophid parasiteEdovum puttleri were exposed to ann-hexane wash of eggs of the Colorado potato beetle,Leptinotarsa decemlineata, their responses indicated that the eggs contained a kairomone which elicited host-finding and host-acceptance behaviors. The hostfinding responses included an increased amount of time searching glass beads treated with kairomone, and drumming on the beads with the flagellum of the antennae. Host-acceptance responses included grasping of the beads with the legs, raising of the abdomen, and probing the kairomone-treated surface with the ovipositor. None of these responses were noted in females on beads treated only with hexane, or in males exposed to kairomone-treated beads. When kairomone was applied to a flat surface, filter paper disks, few episodes of drumming and no episodes of probing with the ovipositor were noted. Responses ofE.puttleri to eggs of Colorado potato beetle were similar to those on kairomone-treated beads, but females normally drilled into eggs and fed on host fluids after retracting the ovipositor. The kairomone is volatile, and responsiveness was reduced in parasites exposed to beads treated several hours previously.
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    Journal of chemical ecology 13 (1987), S. 2143-2157 
    ISSN: 1573-1561
    Keywords: Dendroctonus brevicomis ; Coleoptera ; Scolytidae ; pheromone ; synergism ; plumes ; exo-brevicomin ; frontalin ; myrcene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The relationships between catch ofD. brevicomis LeC. at sources of the synergistic pheromone components,exo-brevicomin (E) and frontalin (F), and increasing distance of separation of sources were investigated in the forest. The two components were each released with the host monoterpene, myrcene (M), in trap pairs. The traps of each pair were spaced apart at various distances (0–16 m) in either horizontal or vertical lines that were perpendicular to the mean wind direction. Both sexes were most strongly attracted when the two components were released from the same source, and increasing distance of separation between components caused exponential decreases in trap catch for all trap configurations. Males were significantly more attracted to traps with E, M alone than to corresponding traps with F, M alone, while females exhibited a preference for F, M. The theoretical relationships and properties of two coalescing plumes of individual components and their intersecting “active space” are presented and discussed. It is proposed that “confusion” or “communication disruption” techniques for insect control may be more successful if components are released individually from many points rather than released similarly in blends.
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  • 18
    ISSN: 1573-1561
    Keywords: 2-Methyl-3-buten-2-ol ; cis-verbenol ; trans-verbenol ; myrtenol ; trans-myrtanol ; 2-phenylethanol ; ipsdienol ; subtractive assay ; Ips typographus ; Coleoptera ; Scolytidae ; Picea abies ; host volatiles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Six compounds previously identified from hindguts of unmated maleIps typographus (L.) during host colonization: 2-methyl-3-buten-2-ol (MB),cis-verbenol (cV),trans-verbenol (tV), myrtenol (Mt),trans-myrtanol (tM), and 2-phenylethanol (PE), were tested for their attractivity in the field with a subtractive method. The amounts of MB and cV released from a pipe trap were similar to those given off from the commercial bait Ipslure as well as that from a Norway spruce tree,Picea abies (L.) Karst., under mass attack. The blend of the compounds became nonattractive when either MB or cV was subtracted, while subtraction of any of the other four compounds had no effect. Addition of ipsdienol (Id) to the blend did not significantly increase the attraction. In a second comparative test, the addition of three compounds as a group (tV + Mt + PE) to MB + cV again had no effect on the attraction, but the addition of Id increased the catch somewhat. Addition of host logs to a bait releasing MB + cV at a rate lower than in previous experiments did not influence the attraction to pipe traps. Sticky traps containing natural pheromone sources (50 males in a log), which released 1–5 mg/day of MB as determined by aerations with deuterated MB as internal standard, were less attractive than a synthetic source releasing similar amounts of MB.
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  • 19
    ISSN: 1573-1561
    Keywords: Diabrotica ; Coleoptera ; Chrysomelidae ; western com rootworm ; southern corn rootworm ; northern corn rootworm ; attractants ; semiochemicals ; veratrole ; estragole ; trans-anethole ; indole ; eugenol ; phenylacetaldehyde
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract During the summers of 1984 and 1985, a variety of structurally related benzenoid compounds was evaluated in sweet corn plots as attractants for adult southern corn rootworms (SCR), western com rootworms (WCR), and northern corn rootworms (NCR). Field response to the volatiles was measured by beetle counts on baited cylindrical sticky traps placed inside the corn plots at a height of l m above ground level. SCR adults were attracted late in the season (last week of August through September, 1984 and 1985) to numerous aromatic compounds, including phenylacetaldehyde, benzyl acetone, phenethyl alcohol, phenyl acetate, indole, veratrole, methyl eugenol, methyl isoeugenol, eugenol, and isoeugenol. Although many compounds attracted SCR adults late in the season, only veratrole, phenylacetaldehyde, and chavicol were significantly active in early and middle August 1985. WCR adults were attracted to a different group of compounds, namely estragole,trans-anethole, and indole. Estragole (4-methoxy-1-allylbenzene) was an effective WCR attractant from corn tasseling in early August 1985, until the end of the trapping period in late September and early October 1985. Indole andtrans-anethole (4-methoxy-1-propenylbenzene) were less effective attractants than estragole and were most active at the beginning and/or end of the corn season. Traps baited with 100 mg of estragole caught an average of 20 times more WCR adults than unbaited control traps, and the females outnumbered the males in the baited traps. Estragole dosage tests were conducted in three sweet corn plots on different dates in 1985 and the minimum effective dose ranged between 5 and 30 mg/trap. Field tests with structural analogs revealed the importance of the site of unsaturation in the allylic side chain of estragole and the effect of different ring substituents on WCR response. The phenylpropanoids, eugenol and isoeugenol, significantly attracted NCR adults, even though these beetles were in low abundance in the test corn plots. Field tests indicate there is no cross-species response by WCR and NCR adults to their related phenylpropanoid attractants. However, in late August, SCR adults do respond to some WCR and NCR attractants (indole and several eugenol analogs). Electroantennographic analysis of SCR males revealed they can perceive peripherally a wide range of benzenoid compounds.
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  • 20
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    Journal of chemical ecology 13 (1987), S. 1087-1097 
    ISSN: 1573-1561
    Keywords: Boll weevil ; Anthonomus grandis Boh. ; Coleoptera ; Curculionidae ; Rose-of-Sharon ; Hibiscus syriacus L. ; feeding deterrent ; unsaturated fatty acids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The Rose-of-Sharon,Hibiscus syriacus (L.), can be a significant alternate host plant for the boll weevil,Anthonomus gradis (Boh.). Boll weevils are known to be deterred from feeding and ovipositing in the buds unless the calyx is removed. This investigation was initiated to identify calyx allelochemicals that deter feeding with the eventual strategy of breeding for cotton lines high in these allelochemicals in the appropriate tissues. The feeding deterrency of calyx tissue from the buds of Rose-of-Sharon for the boll weevil was confirmed. The most active deterrent fraction was found to contain mostly fatty acids and their methyl esters. Saturated fatty acids and their methyl esters were generally found to be stimulatory, while the unsaturated species were found to be deterrent. Higher quantities of the fatty acids, particularly the unsaturated species, were found in Rose-of-Sharon calyx tissue than in the buds without calyx. This supports the hypothesis developed through the isolational work and testing of standards that the unsaturated fatty acids are significant deterrents of boll weevil feeding.
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  • 21
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    Journal of chemical ecology 13 (1987), S. 1279-1292 
    ISSN: 1573-1561
    Keywords: Diabrotica sp ; kinetic resolution ; lipase ; methyl carbinol ; Mucor miehei ; pheromone ; western corn rootworm ; Coleoptera ; Chrysomelidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The relative rates of enzyme-catalyzed esterification of the enantiomers of 2-octanol with various acids were determined for several commercial lipases. Interesterifications and hydrolyses of racemic 2-octanol esters catalyzed by these enzymes were also examined. Novo'sMucor miehei lipase exhibited considerable enantioselectivity and was therefore employed to prepare 8-methyl-2-decanols with high configurational purity at the carbinol carbon. Esters of these alcohols had been previously identified as sexually attractive to several rootworm (Diabrotica) species, and the stereochemistry of those esters had been shown to be critical to the attraction. The enzymatic resolution provides a convenient method to obtain such esters in a desired state of configurational purity.
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  • 22
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    Journal of chemical ecology 4 (1978), S. 409-423 
    ISSN: 1573-1561
    Keywords: Coleoptera ; Dermestidae ; diel behavioral patterns ; 14-methyl-8-hexadecenal ; pheromone ; reproductive isolation ; Trogoderma glabrum ; T. inclusum ; T. variabile ; trogodermal
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract AdultTrogoderma glabrum, T. inclusum, andT. variabile exhibit diel periods of exposure-concealment behavior, the frequency and duration of which are age-dependent, and the temporal placement of which is species-dependent. Exposure periods correspond with daily maxima in male sensitivity to the most active female-released sex pheromone component, 14-methyl-8-hexadecenal, and with respective periods of sex pheromone release in females. Exposure-concealment behavior may be a factor in reproductive isolation between these species, since potential communication distances are greatly reduced when either males or females are concealed.
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  • 23
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    Journal of chemical ecology 4 (1978), S. 451-461 
    ISSN: 1573-1561
    Keywords: Coleoptera ; Dermestidae ; Attagenus megatoma ; canadensis ; japonicus ; schaefferi spurcus ; bicolor ; rufipennis ; elongatulus ; behavior ; sex pheromone ; calling ; bioassay ; black carpet beetle ; megatomoic acid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Females of severalAttagenus species demonstrated calling behaviors similar to those previously reported forA. elongatulus. Attagenus rufipennis females did not call until they were 12–14 days old. OtherAttagenus species called at approx. 4 days of age. All species exhibited diurnal periods of calling activity. Interspecific pheromone responses were tested, withA. megatoma megatoma, A. megatoma canadensis, A. megatoma japonicus, andA. schaefferi spurcus showing equal cross-responses. Male response to females was demonstrated inA. rufipennis andA. bicolor. Attagenus rufipennis, bicolor, andelongatulus males responded only to female extracts of their own species.
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  • 24
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    Cell & tissue research 189 (1978), S. 155-166 
    ISSN: 1432-0878
    Keywords: Levator ani muscle ; Rat ; Neuromuscular junction ; Castration ; Testosterone effect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the neuromuscular junction (n.m.j.) of the androgen-sensitive levator ani muscle was studied in normal adult male rats, in 8-month-old rats castrated at the age of one month and in castrated rats treated with testosterone propionate (TP). Castration does not result in significant changes of the n.m.j. The density of synaptic vesicles and the postsynaptic junctional folds remain practically normal in spite of marked atrophy of the muscle. TP administration for 7 days results in marked changes in preand postsynaptic structures. There is slow progressive depletion of synaptic vesicles, appearance of cisternae and coated vesicles in axon terminals, and coalescence of coated vesicles with the plasma membrane. Coated vesicles are also found inside Schwann cells and among junctional folds. Dense core vesicles appear both in the axon terminals and in the postsynaptic area. Collateral sprouting of terminal axons with the formation of new immature junctions is observed. After 35 days of TP administration depletion of synaptic vesicles continues. Glycogen β-particles, mostly freely dispersed, occasionally seen in axon terminals 7 days after TP administration, subsequently increase in number. In the endplate zone of the muscle fibre increased protein synthesis is indicated by a rapid increase in ribosomes and irregularly located myofilaments and myofibrils. The appearance of n.m.j. after testosterone administration resembles that described after nerve stimulation; the degree of change is however less pronounced.
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  • 25
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    Cell & tissue research 189 (1978), S. 277-286 
    ISSN: 1432-0878
    Keywords: Maternal adrenalectomy ; Rat ; Influence on the adrenals of newborn animals ; Electron microscopy
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    Topics: Biology , Medicine
    Notes: Summary Maternal adrenalectomy at 7 or 14 days of gestation produced increased cell necrosis within zona reticularis cells on the day of birth and at 24 or 48 h after birth. Small remnants or large portions of adrenocortical cells were present within macrophages. In otherwise normal adrenocortical cells, lipid droplets were incorporated within some mitochondria. Autophagocytosis of single mitochondria was observed within adrenocortical cells. Undoubtedly ultrastructural changes represent stimulation of adrenocortical cells in neonatal rats in response to maternal adrenalectomy.
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  • 26
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    Cell & tissue research 191 (1978), S. 501-506 
    ISSN: 1432-0878
    Keywords: Neurohypophysis ; Ultrastructure ; Perivascular space ; Hormonerelease ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Neural lobes from rats subjected to neurohypophysial hormone-releasing stimuli were examined electron microscopically following fixation in 4 % tannic acid in 2.5 % glutaraldehyde. This fixation allowed the delineation of the perivascular space in the neural lobe tissue. Measurement of the area of the perivascular space showed that it was significantly increased in the rats subjected to vagal stimulation and intraarterial calcium ions compared to the control rats. The rats which had been subjected to haemorrhage as a hormonereleasing stimulus did not show any significant change in the area of the perivascular space. The significance of these findings in relation to hormone release is discussed.
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  • 27
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    Cell & tissue research 191 (1978), S. 507-512 
    ISSN: 1432-0878
    Keywords: Odontoblasts ; Osteoblasts ; Cementoblasts ; Intercellular attachments ; Electron microscopy (SEM/TEM) ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Osteoblasts of the young rat cranium, and cementoblasts and odontoblasts of young rat molars were prepared by ethanol freeze-fracture prior to critical point drying for scanning electron microscopy (SEM) as well as conventional transmission electron microscopy (TEM) techniques. Critical point drying causes shrinkage which separates the lateral intercellular contacts between neighbours in the same sheet in the case of cementoblasts and osteoblasts, but not those between odontoblasts. These differences are considered to be of functional significance and need to be taken into consideration when formulating theories of calcium influx into the mineralizable matrix of the respective tissues.
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  • 28
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    Cell & tissue research 191 (1978), S. 513-523 
    ISSN: 1432-0878
    Keywords: Median eminence ; Rat ; Freeze-fracture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Nerve terminals in the palisade zone of the rat median eminence were investigated with freeze-fracture electron microscopy. Fracture face P of the specific terminals showed two populations of intramembranous particles (IMP): a large and a small variety. The large IMP-s often formed small irregular clusters. In nerve terminals the total number of both populations of IMP-s was considerably less than that found on P membrane faces of ependymal feet. On fracture face E of the nerve terminals, the number of IMP-s was about a quarter of that seen on fracture face P. On both fracture faces of most terminals a few small round impressions (or elevations respectively) were found which may be interpreted as broken necks of either exo- or endocytotic vesicles. Neither gap nor tight junctions occurred at lateral membranes of the specific axon terminals. Similarly, no membrane specializations were observed with freeze-fracturing on membrane areas adjacent to the basement membrane. The findings are discussed in relation to a possible exocytosis mechanism of the hypothalamic releasing and inhibiting hormones.
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  • 29
    ISSN: 1432-0878
    Keywords: Taste buds ; Circumvallate papillae ; Colchicine ; Rat
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    Topics: Biology , Medicine
    Notes: Summary It is believed that differentiation and maintenance of taste buds in vertebrates is dependent on the trophic function of their sensory nerve supply. In the present work colchicine was injected into the circumvallate papilla of the rat. This produced a reversible blockade of neuroplasmic transport and disappearance of taste buds. Colchicine inhibited the further differentiation of bud cells, but apparently did not change the life cycle of the cells present already at the time of injection. It is speculated that the neurotrophic factors in this particular cell system are effective to induce cell differentiation only.
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  • 30
    ISSN: 1432-0878
    Keywords: Cholecalcin (vitamin D-dependent calcium-binding protein) ; mRNA ; Uterus ; In situ hybridisation ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The molecular cloning of a cDNA fragment synthesised from rat duodenal mRNA coding for cholecalcin (calbindin), a 9000 Mr vitamin D-induced calcium-binding protein (CaBP), has been previously described. DNA/RNA hybridisation assays have been used to examine CaBP mRNA production in the uterine horns and duodena of pregnant (21 day) rats using the cloned CaBP cDNA. Northern hybridisation studies showed that the 32P cDNA sequence hybridised to a single 500–600 nucleotide species in both the uterus and the duodenum, thus demonstrating identical CaBP mRNA processing in both tissues. Dot blot hybridisation studies showed that the CaBP mRNA concentration was greatest in the duodenum while that of the uterine horns was about 10% of the duodenal level. The observed differences in CaBP mRNA levels correlate well with the in vivo CaBP concentrations. In situ hybridisation histochemistry using 3H cDNA revealed that CaBP mRNA visualised by silver grains was found in all the parts of the endometrium and the myometrium. However, CaBP mRNA was more concentrated in the outer and inner muscular fibres and in the luminal cells of the endometrium than in the stroma cells. These results demonstrate that the CaBP gene is expressed in specific cells of the rat uterus.
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  • 31
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Aminoglutethimide ; Corticosterone ; Morphometry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of a 7-day administration of aminoglutethimide (AG) on the adrenal zona fasciculata were examined in “normal” and dexamethasone/ACTH-treated rats. There was a 70–74% decrease in the concentration of corticosterone in blood, but no conspicuous qualitative changes suggesting cell degeneration occurred. Morphometry showed that AG induced a significant hypertrophy of the zona fasciculata and its parenchymal cells only in “normal” animals, which was due to an increase in the volume of the mitochondrial compartment and to proliferation of the smooth endoplasmic reticulum. This response to AG was considered to be non-specific and mediated by the enhanced secretion of ACTH following the decrease in the blood level of corticosterone. AG administration significantly increased the volume of the lipid-droplet compartment and the number of intramitochondrial lipid-like inclusions in both groups of animals. These changes were interpreted as the morphological counterpart of the AG-induced block of cholesterol utilization in steroid synthesis.
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  • 32
    ISSN: 1432-0878
    Keywords: Astrocytes ; Ependymal cells ; Circumventricular organs ; Tight junctions ; Orthogonal arrays of particles ; Freeze-fracturing ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ependymal cells in the ventricular wall and in several circumventricular organs of the rat were compared by means of freeze-fracturing. In principle, tight junctions and orthogonal arrays of particles (OAP) do not coexist in the cells bordering the ventricular wall: (1) Ordinary ependymal cells of the rat possess OAP and are devoid of tight junctions. (2) Epithelial cells of the rat choroid plexus are connected by tight junctions; OAP are lacking here. In some cases, however, tight junctions and OAP coexist in the same cell. In the boundary zone between choroid plexus and ependyma of the rat, the density of OAP is very low, whereas the tight junctions are well developed. In the subfornical and the subcommissural organ (SCO) of the rat both structures are poorly developed; in the SCO they occur segregated in different membranous areas. An overview of the literature confirms that tight junctions and OAP mostly exclude each other. The possibility that in astrocytes and ependymal cells tight junctions may have been replaced by OAP during phylogeny is briefly discussed.
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  • 33
    ISSN: 1432-0878
    Keywords: Teeth ; Dental pulp ; Periodontium ; Neurofilament protein ; Immunohistochemistry ; Rat
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    Topics: Biology , Medicine
    Notes: Summary The distribution of nerve fibers in molars, periodontal ligament and gingiva of the rat shows a complex pattern. Decalcified material including the alveolar bone was sectioned in three different planes and stained by means of immunohistochemistry for detection of the neurofilament protein (NFP); the immunoreactive neural elements were clearly visualized in three-dimensional analyses. NFP-positive nerve fibers formed a subodontoblastic plexus in the roof area of the dental pulp; some of them entered the predentin and dentin directly through the dentinal tubules. This penetration was found mainly in the pulp horn, and was limited to a distance of about 100 μm from the pulpo-dentinal junction. In the periodontal ligament, NFP-positive nerve fibers were found densely distributed in the lower half of the alveolar socket. Two types of nerve terminals were recognized in the periodontal ligament: free nerve endings with tree-like ramifications, and expanded nerve terminals showing button- or glove-like shapes. The former tapered among the periodontal fibers, some even reaching the cementoblastic layer. The latter were located, frequently in groups, within the ligament restricted to the lower third of the alveolar socket. A well-developed plexus of NFP-positive nerves was revealed in the lamina propria of the free gingiva, the innervation being denser toward the epithelium of the gingival crevice. The characteristic distribution of NFP-immunoreactive nerve fibers revealed in this study is discussed in relation to region-specific sensations in the teeth and surrounding tissues.
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  • 34
    ISSN: 1432-0878
    Keywords: Epididymis ; Ductus deferens ; Myosin ; Actin ; Fibronectin ; Rat
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Summary The postnatal maturation of regions of the epididymis and intragonadal segment of the deferens duct was studied in the rat by light-and transmission electron microscopy. Maturation of the genital duct starts in the distal cauda epididymidis and ductus deferens after one week of life, and one week later, in the more cranial segments of the epididymis. Epithelial principal cells and peritubular contractile cells are structurally mature 35 days after birth. The synchronous changes of these cells indicate that the same factors control their postnatal maturation. The epithelial principal cells obtain an endocytotic apparatus and long stereocilia, whereas peritubular cells acquire contractile features. These changes are associated with a progressive increase in the immunoreaction for smooth muscle actin in both cell types. Smooth muscle myosin is detected in the apical region of the epithelial cells and the peritubular cell cytoplasm by day one of postnatal development. The differentiation of contractile cells in the wall is accompanied by progressive organization of the pericellular matrix into a continuous basement membrane. Although fibronectin is visible at birth, it is gradually removed from the tubule wall.
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  • 35
    ISSN: 1432-0878
    Keywords: Cardiac muscle cells ; Extracellular matrix ; Collagen fibers and filaments ; Immunohistochemistry ; Rat ; Hamster
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    Notes: Summary The morphology, composition, and function of struts that interconnect the lateral surfaces of cardiomyocytes were examined in the hearts of rats and hamsters. Methods included brightfield and fluorescent light microscopy, secondary and backscatter scanning electron microscopy, and transmission electron microscopy in conjunction with silver stain, cationic dye, and antibody to type-I collagen. These studies reveal a twisted, beaded appearance and a complex substructure of collagen fibrils embedded in a ground substance that has a positive reaction with cationic dye. A hierarchy of patterns of branching and attachment was seen among intercellular struts ranging in diameter from 0.1 μm to several urn. The hypothesis that struts tether not only the surfaces but the contractile lattices of laterally adjacent myocytes is supported by the following: (a) the attachments of struts to the collagen weave of the sarcolemma, often lateral to the level of Z bands, (b) the presence of collagen type I in a composite material arrangement, (c) the relative dispositions and configurational changes of struts and myocyte surfaces in various physiological states and induced, non-physiological perturbations of cardiac muscle, (d) the corrugated sarcolemmas with infoldings near Z bands, and (e) the continuity of intracellular filaments from Z bands to the inner aspect of the sarcolemma in relaxed and contracted myocytes. Implications of struts acting as tethers and sites for storage of energy in the motions of myocytes during the cardiac cycle are discussed.
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  • 36
    ISSN: 1432-0878
    Keywords: GABA-treatment ; Superior cervical ganglion ; Synaptic plasticity ; Morphometry ; Rat
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    Notes: Summary The superior cervical ganglion (SCG) of adult rats was exposed to γ-aminobutyric acid (GABA) by means of long-term microapplication. Serial sections were cut from GABA-treated and control ganglia, and subsequently the fine structure of individual synapses was investigated. The quantitative analysis of structural parameters of studied synapses showed that significant changes consisting of (1) a reduction in size of presynaptic axon terminals, (2) a decrease in the number of synaptic vesicles, and (3) a diminution in the extent of the postsynaptic membrane thickening at the dendritic side developed as an effect of GABA-treatment. These results provide morphological evidence that long-term application of GABA to the SCG exerts a combination of effects on both presynaptic and postsynaptic elements. It is suggested that the structural changes observed in the fine structure of individual synapses within the SCG may play an integral role in the development of the synaptogenetic action of GABA.
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  • 37
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    Cell & tissue research 249 (1987), S. 325-329 
    ISSN: 1432-0878
    Keywords: Renin release ; Epithelioid cells ; Osmosensitivity of renin release ; Rat
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    Topics: Biology , Medicine
    Notes: Summary Superfusion with hypoosmotic solutions stimulates renin release from rat epithelioid cells adherent to isolated glomeruli. This stimulatory effect may be related to the observed swelling of the secretory granules; the swelling may markedly increase the probability of pre-exocytotic fusions between the granule and cell membranes, and consequently increase the frequency of exocytotic events.
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  • 38
    ISSN: 1432-0878
    Keywords: Exocrine pancreas ; Secretion granules ; Effect of feeding ; Carbachol ; Stereology ; Rat
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    Notes: Summary The size, number and volume per cell of secretion granules in rat exocrine pancreas have been measured using stereological techniques. The changes which occur as a result of feeding starved animals (90 min) or stimulating lobular fragments in vitro with carbachol are documented. In fasted animals mean acinar cell volume was estimated as 1670 μm3 and the cells contained an average of around 450 secretion granules with a corrected mean diameter of 0.70 μm. They occupied around 7% of cell volume. After feeding mean cell volume was about 1300 μm3 and the cells contained an average of about 190 granules per cell with a mean diameter of 0.58 μm. They occupied 3% of cell volume. A shift in the size frequency distribution of granule diameters occurred as a result of feeding. In vitro experiments in which lobules were induced to secrete with carbachol (10μM, 3 h, 37° C) had a similar effect. Mean cell volume was reduced from around 1760 μm3 to 1360 μm3, mean granule number from around 420 per cell to 180 per cell and the volume density of granules was reduced from about 8% to 3% of cell volume. There was no significant change in mean granule diameter or shift in the size-frequency distribution of granule diameters. Incubation of tissues with cycloheximide (1 mM, 3 h, 37° C) did not prevent secretion by carbachol but it prevented replacement of granules. As a consequence, depletion by carbachol was greater in the presence of cycloheximide, the granules being reduced to around 110 per cell and to only 2.5% of cell volume. We conclude that feeding causes a preferential loss of larger granules and that during secretion replacement of granules occurs. Some of these granules are smaller than those evident in the glands of starved animals.
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  • 39
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    Cell & tissue research 249 (1987), S. 443-449 
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    Keywords: Different strains ; Adrenal cortex ; Zonation ; Cellular composition ; Sex differences ; Rat
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    Topics: Biology , Medicine
    Notes: Summary The zonation and cellular composition of the adrenal cortex of intact mature male and female rats of different strains (Chbb Thomm, CFY) and three strains of Wistar rats (W1, W2 and W3) at the age of 84–90 days were compared using morphometry. Both absolute and relative adrenal gland weights were higher in female than male rats. Rats of W3 and Chbb Thomm strains had the largest adrenals. These differences depended upon the higher volume of the zona fasciculata (ZF) and zona reticularis (ZR) in the W3 and Chbb Thomm strains than in the remaining animals. Females had larger adrenocortical zones than corresponding males. The average volume of the ZF cell ranged in males from 1589 μm3 (W1 strain) to 2111 μm3 (Chbb Thomm) and in females from 2249 μm3 (W1 strain) to 2894 μm3 (W3 strain). The average nuclear volume of the ZF cells was higher in female rats whereas there were no strain-and sex-differences in the size of zona glomerulosa (ZG) and ZR cells. The total number of parenchymal cells per pair of adrenals varied markedly among the studied strains, with the highest number in W3 and Chbb Thomm females. W3, Chbb Thomm and CFY females had larger number of parenchymal cells than males; the reverse was true for W1 strain whereas no differences were found among W2 male and female rats.
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  • 40
    ISSN: 1432-0878
    Keywords: Macula densa ; Intercellular spaces ; Ultrastructure ; Frusemide ; Tubulo-glomerular feedback ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In situ drip-fixation of superficial glomeruli and tubules in the rat kidney verified the results obtained from high pressure perfusion fixation studies indicating that distinct spaces normally exist between the cells of the macula densa. Following treatment with frusemide these intercellular spaces between the macula densa cells became closed in both drip-fixed and perfusion-fixed kidneys. These findings suggest that the variability of extracellular compartmentation found in the macula densa is unlikely to be an artifact but most likely represents changes in the in vivo status of the macula densa.
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  • 41
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Liver ; Nucleolus ; 4-amino-pyrazolo(3,4-d)pyrimidine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The nucleolar ultrastructural changes produced in adrenal zona fasciculata cells and hepatocytes of rats by 4-aminopyrazolo(3,4-d) pyrimidine (4-APP), an inhibitor of the lipoprotein synthesis, are described. Male rats were injected intraperitoneally for three consecutive days with 4-APP in sodium phosphate buffer (50 mg/Kg/day). On the 4th day, the animals were sacrificed and their adrenals and liver were processed for EM. The nucleoli of the adrenal zona fasciculata cells showed nucleolar fragmentation with loss of their normal reticular appearance, separation of fibrillar and granular components, extensive vacuolization and evidence of fibrillar centers. The hepatocyte nucleoli also exhibited fragmentation. These changes seem to be the morphological counterpart of alterations in rRNA synthesis and processing, since 4-APP inhibits “de novo” purine synthesis and thus interferes with its incorporation into RNA and DNA.
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  • 42
    ISSN: 1432-0878
    Keywords: Brain ; Immunohistochemistry ; Natural killer cells ; Monocytes ; Granulocytes ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary This study reports a specific cross-reactivity of the three anti-human-hematopoetic-cell monoclonal antibodies, anti-Leu-7 (HNK-1), anti-Leu-11a (NKP-15), and anti-Leu-M1 (MMA), with different epitopes in the brain of the adult rat. The distribution of these epitopes in rat brain is determined by means of immunohistochemistry in paraffin-embedded frontal serial sections. The reaction pattern of anti-Leu-11a monoclonal antibody is very similar to that of polyclonal antibodies against the myelin basic protein. Both antisera give a specific reaction with myelinated fibers. Immunoreaction products with the anti-Leu-7 monoclonal antibody are found as diffuse, mostly punctiform material in the neuropil and even more evident as small granules coating the cell surface of many neurons. In the white matter anti-Leu-7 reveals a moderate reactivity, which occurs predominantly as spots and fine-stranded material within the myelinated fiber tracts. Anti-Leu-M1 immunoreactivity is present between myelinated fiber bundles of the white matter, where it has a reticulate appearance, and as fine-granulated material within the grey matter of the cortex and the nuclei. The characteristic feature in the grey matter is that of irregularly shaped immunopositive plaques, which are often located around small blood vessels. The cytoplasm of glial and neuronal cells appeared negative with this MAB. The exact topographical distribution of the Leu-7 and Leu-M1 epitopes throughout the rat brain is described. The present hypotheses concerning the nature of this shared antigenicity between hematopoetic cells and nervous tissue are discussed.
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  • 43
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    Cell & tissue research 250 (1987), S. 29-33 
    ISSN: 1432-0878
    Keywords: Pituitary gland, pars anterior ; Cysts ; Transplantation ; Differentiation ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Hemipituitary glands from 30 rats were isotransplanted under renal capsules. At 1, 2, 4, 7 and 20 days after transplantation, the grafts were examined by light and electron microscopy. Two days after transplantation, the central area of graft showed necrosis; however, the peripheral area, where marginal cells of Rathke's cleft were ingesting the remnants of necrotic glandular cells, survived. Four days after transplantation, mitotic figures of marginal cells were observed. Seven days after transplantation, the damaged area of the graft disappeared, and Rathke's cleft was completely lined by marginal cells. Remnants of necrotic glandular cells were not seen in intercellular spaces or in the cytoplasm of marginal cells. Cystlike structures formed in the grafts; some were connected to Rathke's cleft by narrow cavities. The cavity-lining cells of the cysts were agranular and similar to those that lined Rathke's cleft. At 20 days after transplantation, granular cavity-lining cells appeared. It is suggested that marginal cells of immature rats can differentiate into granular cells.
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  • 44
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    Cell & tissue research 250 (1987), S. 21-27 
    ISSN: 1432-0878
    Keywords: Glomus cell ; Acetylcholinesterase ; Catecholamines ; Carotid body ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The localization of acetylcholinesterase (AChE) was investigated at the cellular and subcellular levels in dissociated cell cultures of the carotid body of the neonatal rat, prepared by the methods of Fishman and Schaffner (1984). In the presence of iso-OMPA, which blocks non-specific cholinesterase, staining was confined almost exclusively to glomus-cell clusters and occasional isolated cells. These clusters grow as discrete islands scattered throughout the culture and display typical catecholamine (CA) fluorescence as in vivo. AChE staining was abolished or reduced by the cholinesterase inhibitors eserine (30–100 μM), or (the poorly lipid soluble) echothiophate (8 (μM). Processing of the same culture sequentially for the demonstration of both AChE and CA revealed that glomus-cell clusters and individual glomus cells were consistently positive for both. In electron micrographs AChE reaction product was associated intracellularly with the nuclear envelope and cytoplasm of glomus cells (identified by their characteristic dense cored granules), as well as extracellularly with the boundaries of contiguous glomus cells. Significantly, reaction product occurred in some glomus cell profiles that had both dense-cored and clear (cholinergic-like) vesicles. These findings are discussed in the context of a possible dual (adrenergic/cholinergic) function status of glomus cells in the rat's carotid body.
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  • 45
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    Cell & tissue research 250 (1987), S. 181-184 
    ISSN: 1432-0878
    Keywords: Prolactin cell ; Secretory granule ; Glycoconjugate ; Lectin ; Concanavalin A ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Prolactin granules in the anterior pituitary glands of male rats contain densely stained materials at the periphery of the matrix. These occur in both small spherical and large polymorphic types of granules. The presence of densely stained materials around secretory granules may be a useful criterion for identification of prolactin cells since the dense structure was observed in 95% of these cells after conventional staining by uranyl acetate and lead citrate. The localization of glycoconjugates in the prolactin granules was examined by applying concanavalin A (Con A) on the ultrathin sections. HRP-Con A or ferritinconjugated Con A bound specifically to the densely stained materials in the peripheral region of the prolactin granule matrix, indicating that this densely stained matrix contains glycoconjugates; the significance thereof is discussed with reference to the concentration and packaging of secretory product.
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  • 46
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    Cell & tissue research 188 (1978), S. 345-359 
    ISSN: 1432-0878
    Keywords: Hippocampal subfields ; Rat ; Volumes ; Timm stain
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The absolute volumes of the hippocampal and subicular cortical layers in the rat were determined. The boundaries of the various layers were defined on series of sections made through the entire hippocampal region of five rats and stained according to the Timm sulfide silver technique. Coordinates representing the boundaries of the layers on selected sections were fed into a mini-computer programmed to calculate the volume of the layers from the areas of the profiles and the distances between the sections. The distribution of the layers indicates that they constitute the same proportion of the volume of the dorsal and ventral divisions of the hippocampal region, with the exception of the structures lying in regio inferior and regio superior. Although the combined regio superior and regio inferior components of the layers of Ammon's horn occupy the same percentage of the volume of the dorsal and ventral hippocampal regions, the regio superior components occupy a larger percentage of Ammon's horn in the dorsal region than they do in the ventral region. The inter-animal variations in the volumes of the various layers indicate that it is possible to describe quantitatively the subdivisions of the hippocampal region with a precision that is compatible with comparative studies.
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  • 47
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    Cell & tissue research 188 (1978), S. 491-496 
    ISSN: 1432-0878
    Keywords: Castration ; LH-cells ; Rat ; Development ; Sex-steroids
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    Topics: Biology , Medicine
    Notes: Summary The effects of sex-steroids on the LH-cell development in neonatal rats were studied. The cells were stained immunohistochemically by applying anti-HCG serum. On the second day after birth some of the animals of both sexes were gonadectomized and simultaneously injected with testosterone or estradiol (50 or 200 μg). The remaining animals were either gonadectomized or injected with either one of the sex-steroids. The LH-cell numbers in each group were determined on the 12th day of age from serially cut histological sections of the pituitary. In castrated males the number of LH-cells was about twice that of the intact animals. In the so-called sex-zone, LH-cells tended to be hypertrophied in castrates. These alterations in the appearance of LH-cells did not occur after ovariectomy. In gonadectomized animals injected with sexsteroids (200 μg), the cells were markedly reduced in number and size, both in males and females. Testosterone injection (50 μg) into intact newborn animals also suppressed the numerical development of LH-cells, especially in females. These alterations were particularly evident in the sex-zone in both sexes. Thus the present findings show that sex-steroids may be involved in sexual differences in morphological development of LH-cells in newborn rats.
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  • 48
    ISSN: 1432-0878
    Keywords: Adrenal gland ; Rat ; Vinblastine ; Corticosterone ; Exocytosis
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    Topics: Biology , Medicine
    Notes: Summary Vinblastine treatment blocks corticosterone release from rat adrenal zona fasciculata without impairing hormone synthesis, and induces the formation of acid phosphatase-positive granular clumps at the juxta-sinusoidal pole of the cells. Autoradiography shows that ACTH administration to vinblastine-treated animals mobilizes the 3H-cholesterol stored in the lipid droplets and leads to a noticeable labelling of the granular clumps. The possible significance of these granules is discussed.
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  • 49
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    Cell & tissue research 247 (1987), S. 441-444 
    ISSN: 1432-0878
    Keywords: Growth hormone-releasing factor (GRF) ; Neuropeptide immunocytochemistry ; Trigeminal ganglion ; Spinal ganglion ; Development, ontogenetic ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Growth hormone-releasing factor (GRF)-like immunoreactivity has been demonstrated in the trigeminal and spinal ganglia of fetal, young and adult rats by use of peroxidase-antiperoxidase immunohistochemistry. GRF-like-immunoreactive cells first appear during the second half of embryonic life, as early as day 17. In untreated animals the GRF-immunoreactive elements form approximately 1% of all ganglion cells in the trigeminal and spinal ganglia; their numbers do not change significantly during development. The granular immunoreaction product is confined to perikarya, especially to the perinuclear region. Nerve fibers displaying GRF-like immunoreactivity were found neither in the ganglia, nor in the corresponding central and peripheral areas of termination. The possible role of GRF in sensory ganglia is discussed.
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  • 50
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    Cell & tissue research 247 (1987), S. 565-572 
    ISSN: 1432-0878
    Keywords: Synapses ; Perforated synapses ; Synaptic plasticity ; Serial section reconstructions ; Synaptic curvature ; Rat
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    Topics: Biology , Medicine
    Notes: Summary The morphology of perforated synapses in the molecular layer of rat parietal cortex has been studied in 28-day-old animals. Of the perforated synapses analyzed, 92% were axospinous and of these all had asymmetrical contacts. A spinule was present in 20% of them, and 63% had a negative curvature (concave with respect to the presynaptic terminal) overall. Up to 95% of perforated synapses had one or more negatively-curved segments. The perforated synapses studied were characterized by postsynaptic densities (PSD) with a mean length of 581 nm, compared with 233 nm for non-perforated synapses. A study of over 100 serially sectioned synapses demonstrated that, in perforated synapses, the PSD and perforations often had a highly irregular shape and arrangement, the site of the perforation frequently projected into the presynaptic terminal, and coated evaginations of membrane, or coated vesicles, were sometimes found at the site of a perforation or towards the periphery of perforated PSDs. Preliminary reconstructions of perforated synapses suggest that, for descriptive purposes, three types can be recognized. Criteria are formulated for determining, on the basis of a study of single sections, which non-perforated profiles belong to perforated synapses.
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  • 51
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    Cell & tissue research 248 (1987), S. 49-54 
    ISSN: 1432-0878
    Keywords: Enterochromaffin cells ; Serotonin ; Duodenum ; Immunocytochemistry ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Enterochromaffin cells of the rat duodenum have been studied immunocytochemically by use of a specific antiserum to serotonin. At the light-microscopic level serotonin immunoreactivity was observed in enterochromaffin cells located in the epithelium of the duodenal mucosa. Most of the serotonin-immunoreactive material was localized to the basal portion of the enterochromaffin cells, but small amounts of immunoreactive material were regularly observed in the apical portion. At the electron-microscopic level serotonin immunoreactivity in enterochromaffin cells was found to be concentrated over the dense cores of the cytoplasmic granules. The majority of these granules was located in the basal cytoplasm of the enterochromaffin cells, but serotonin-immunoreactive granules were also observed in the apical cytoplasm immediately beneath the microvilli. These observations indicate that duodenal enterochromaffin cells are bipolar and that they secrete serotonin both basally, to the circulation, and apically, to the gut lumen. Rat duodenal enterochromaffin cells thus appear to have an exocrine as well as an endocrine function.
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  • 52
    ISSN: 1432-0878
    Keywords: TRH ; Insulin ; Pancreas ; Streptozotocin ; Regeneration ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Streptozotocin treatment at birth induces, in the pancreas of rats, first depletion of insulin and thyrotropin-releasing hormone and then early regeneration ofβ cells and insulin, but not TRH. This study was undertaken to investigate whether the reduction in pancreatic TRH content can be associated with changes in the intensity and the distribution of TRH-immunoreactivity, and to follow the pattern of regeneration ofβ cells through insulin- and TRH-immunoreactivity. In control animals, strong TRH-immunoreactivity was seen in insulin-containing cells on days 1–4 after birth. At day 7, the TRH-immunoreactivity was already decreased. In contrast, insulin-immunoreactivity was present throughout the neonatal period. A sparse population of cells near ducts also contained both TRH- and insulin-immunoreactivity at 1–2 days age. In streptozotocin-treated animals, TRH-immunoreactivity is found only in a few scattered insulin-containing cells in altered islets on days 1–4. Near the ducts, there were new insulin-containing cells which did not contain TRH. From day 7 regeneration of endocrine cells was characterized by new, typical islets, but these contained insulin-, but not TRH-immunoreactivity. These findings suggest a differential control of the biosynthesis of insulin and TRH within the pancreas.
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  • 53
    ISSN: 1432-0878
    Keywords: Neuromuscular synapse ; Lectin histochemistry ; Dolichusbiflorus agglutinin ; Synaptogenesis ; Denervation ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The binding of agglutinin fromDolichus biflorus (DBA) and other lectins (Concanavalin A, agglutinin from wheat germ and lectin fromBandeiraea simplicifolid) to synaptic and extrasynaptic portions of the basal lamina of muscle fibers, was studied with histochemical methods. In rat muscle, DBA-binding is specifically detected at the basal lamina of neuromuscular junction. However, long-term (6 months) denervated end-plate in adult rat muscle failed to bind DBA. During normal development, synaptic DBA receptors appear later than acetylcholine receptors or acetylcholinesterase at the rat neuromuscular junction. Generalized DBA-binding to motor end-plates is first visualized in 3-day-old rats, but section of sciatic nerve in 1-day-old rats prevents the appearence of synaptic DBA-binding on the leg end-plates. It is suggested, therefore, that the synaptic DBA receptors could be related to the postnatal stabilization of rat neuromuscular synapses.
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  • 54
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    Cell & tissue research 248 (1987), S. 699-702 
    ISSN: 1432-0878
    Keywords: Albumin ; Ovarian follicles ; Granulosa cells ; Immunocytochemistry ; Rat
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    Topics: Biology , Medicine
    Notes: Summary The purpose of this study was to investigate whether albumin (Alb) can be detected in ovarian rat granulosa cells. Using immunocytochemistry and morphometrics, the percentages of Alb-positive follicles (follicle-index), of Alb-positive granulosa cells (granulosa-index), and of strongly reacting follicles (intensity-index) were evaluated in intact and regressing follicles of different diameter groups during different stages of the estrous cycle. In intact follicles, the follicle- and the granulosa-index increased from small-sized to large-sized follicles. Although the follicle-index did not change in any group during the stages of the estrous cycle, the granulosa-index was higher during proestrus than during the other stages. Intact follicles showed a stronger immunoreactivity than regressing follicles throughout the stages of the estrous cycle. Thus, Alb may be a requirement for the control of follicle growth in fertile rats. This Alb function may be attributable to Alb binding to specific cell-membrane components followed by the intracellular uptake of Alb-bound substances.
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  • 55
    ISSN: 1432-0878
    Keywords: Androgen ; Estrogen ; Pituitary ; Autoradiography ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Castrated male and female rats pretreated with dihydrotestosterone (DHT) were injected i.v. with 3H-estradiol (E2). Nuclear uptake and retention of 3H-E2 was measured in each of five cell types of the anterior pituitary gland using a combined quantitative autoradiographic and immunocytochemical procedure. In non-pretreated groups, each cell type bound a characteristic amount of ligand but no sex differences were apparent. DHT pretreatment, however, caused a significant decrease in 3H-E2 retention by gonadotrophs in both males and females. The treatment also caused a decrease in binding by lactotrophs and somatotrophs, but only in the females. No other cell types were altered. Thus, androgen appears to modulate E2 binding and retention by pituitary cells in both a cell-type and sexdependent manner. Our results also indicate that the inhibitory effects of androgens on E2 binding by the pituitary gland is more complex than can be explained by simple competition for the estrogen receptor.
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  • 56
    ISSN: 1432-0878
    Keywords: Lectin histochemistry ; Transport epithelia Immunolocalization: (Na++K+)-ATPase, carbonic anhydrase ; Kidney collecting ducts ; Rat
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Summary To identify precisely the structural and functional cell type in the collecting duct of the rat kidney expressing binding sites for Dolichos biflorus agglutinin (DBA), we stained serial paraffin sections of kidney with horseradish peroxidase-labeled DBA and with immunocytochemical methods for localizing (Na++K+)-ATPase and carbonic anhydrase II (CA II), enzymes found preferentially in principal and intercalated cells, respectively. Most principal cells expressing a strong basolateral staining for (Na+ + K+)-ATPase showed binding sites for DBA at their luminal surfaces. However, a minority of cells rich in CA II and showing morphologic characteristics of intercalated cells also expressed DBA binding sites at their luminal surface and apical cytoplasm. These data suggest that DBA cytochemistrycan provide a useful tool for studying the functional polarity of the main cell types of the collecting duct of the rat kidney.
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  • 57
    ISSN: 1432-0878
    Keywords: Immuno-electron microscopy ; Triple-immunogold-labeling ; CRF axon terminal ; Median eminence ; Rat
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Summary Ultrastructural appearances of axonal terminals containing corticoliberin (CRF) were examined in the rat median eminence prepared by a freeze-drying procedure. Immunolabeling was performed by using 5-, 8-, or 15-nm gold-antibody complexes for CRF, arginine vasopressin (VP) and methionine-enkephalin-octapeptide (Enk-8), singly or in combination. In intact animals, the CRF-containing secretory granules were only slightly labeled with goldanti-VP or -Enk-8. In adrenalectomized rats, granules within single axons appeared to be labeled with all the immunogold complexes. This intragranular colocalization of the three antigens was confirmed by using three neighboring sections of the same axon terminals which were stained separately with each one of the antibodies and visualized with the avidin-biotin-peroxidase complex method. The granules labeled for CRF had decreased 9 days after adrenalectomy but had increased again by day 21, while those labeled for VP steadily increased after adrenalectomy. However, this did not correspond with the appearances of cell bodies in the paraventricular nucleus; the cell bodies labeled for both CRF and VP steadily increased in number and in stainability. By contrast, Enk-8 immunoreactivity in the axonal terminals and cell bodies was not affected by adrenalectomy. These findings suggest that although the three peptides could be released simultaneously from the axonal terminals, VP may play some special role in the expression of CRF activity.
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  • 58
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    Cell & tissue research 249 (1987), S. 577-586 
    ISSN: 1432-0878
    Keywords: Parotid gland ; Duct cells ; Ferritin ; Endocytosis ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ability of the intralobular ducts of the rat parotid gland to take up protein from the lumen was examined after retrograde infusion of native and cationized ferritin. At high concentrations (3–10 mg/ml), cells of both intercalated- and striated ducts avidly internalized the tracers. No differences were noted in the mode of uptake or fate of native or cationized ferritin. Large, apical ferritin-containing vacuoles up to 5 μm in size were present in cells of the intercalated ducts after infusion for 15 min. Small, smooth-surfaced spherical or flattened vesicles and tubules containing ferritin were also observed, often in association with the large vacuoles. Ferritin uptake increased with increasing infusion time, up to 1 h. Uptake by the striated ducts was less consistent than by the intercalated ducts, and occurred mainly in small vesicles and tubules. Secondary lysosomes became labeled with ferritin in both cell types. Ferritin was not observed in the Golgi saccules, nor was it discharged from the cells at the basolateral surfaces. At low concentrations (0.3–1 mg/ml), uptake was reduced, especially by cells of intercalated ducts, and differences were noted in the behavior of the two tracers. Cationized ferritin was internalized mainly into vesicles and tubules of cells of striated ducts; little uptake of native ferritin occurred at low concentrations. These results demonstrate that the ductal cells of the salivary glands are capable of luminal endocytosis of foreign proteins. They also suggest that in addition to modifying the primary saliva by electrolyte reabsorption and secretion, and secretion of various glycoproteins, the ductal cells are able to reabsorb proteins secreted by the acinar cells.
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  • 59
    ISSN: 1432-0878
    Keywords: γ-Aminobutyric acid (GABA) ; Autoradiography ; Development, ontogenetic ; Duodenum ; Uptake sites ; Rat
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Summary The localization of high-affinity uptake sites for 3Hγ-aminobutyric acid (3H-GABA) was investigated in the rat duodenum during ontogenesis and also at the adult stage (from 15.5 days of fetal life up to 105 days post natum) by means of low- and high-resolution autoradiography. At all stages studied, specific endocrine cell types of the epithelium were labelled and an intense uptake was detected in the nervous tissue, especially in glial cells but also in scarce neurones. When the incubation medium was supplemented with β-alanine (1 mM), a blocker of the glial uptake for GABA, the labelling persisted only in endocrine cells and in few neurones. The intensity and the frequency of the labelling decreased at later periods compared to the earlier developmental stages. The GABA content of the duodenum as measured by a new ion-exchange column chromatography-HPLC-coupled method was higher in the early postnatal period compared to later stages. These observations suggest that GABA, in addition to being a neurotransmitter, may play an important role during development of the duodenum.
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  • 60
    ISSN: 1432-0878
    Keywords: 7B2 polypeptide ; Gastro-intestinal tract ; Endocrine cells ; Immunohistochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Summary Immunoreactivity to the polypeptide designated “7B2” recently isolated from human and porcine pituitary glands, appears to be consistently confined to neuroendocrine and endocrine cells in various tissues. In rat gut, immunoreactive 7B2 was found in endocrine-paracrine cells. Highly labeled cells were found in the antrum of the stomach and, cells with lower concentrations, in the fundus, duodenum, jejunum and ileum. Except for a few cells which were simultaneously positive for 5-hydroxytryptamine, and a few others showing Grimelius's reaction, “7B2” cells do not exhibit argentaffin and/or argyrophil character. The 7B2 polypeptide seems to be distributed amongst several different types of endocrine cells in the gut.
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  • 61
    ISSN: 1432-0878
    Keywords: Organum vasculosum laminae terminalis (OVLT) ; Capillaries ; Horseradish peroxidase ; Leptomeninges ; Blood-blood barrier ; Blood-cerebrospinal fluid barrier ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Using intravenously injected horseradish peroxidase (HRP) as tracer, we demonstrate, that — in contrast to other neurohemal regions — the organum vasculosum laminae terminalis (OVLT) is composed of two functionally different divisions. Both parts of the OVLT are endowed with fenestrated capillaries which, however, obviously differ in their permeability for HRP. In one of these portions the neurohemal region remains unlabeled under the experimental conditions used, while the other portion, in analogy to the majority of neurohemal regions, is labeled by the tracer. The functionally different divisions of the OVLT are separated from one another by tanycytic processes and meningeal cells establishing a barrier between the two hemal compartments. The meningeal elements penetrate the organ in the form of an uninterrupted layer; they are continuous with the pia mater and produce large amounts of basal lamina-like material. Furthermore, they provide the delineation of the OVLT against the outer cerebrospinal fluid-containing compartment, a structural feature that is characteristic of both divisions of the OVLT and corresponds to the arrangement of meninges in all other portions of the brain where a blood vessel penetrates its surface.
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  • 62
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    Cell & tissue research 250 (1987), S. 641-648 
    ISSN: 1432-0878
    Keywords: Kidney ; Interstitial cells ; Lysosomes ; Sulfated glycosaminoglycans ; Tilorone ; Mucopolysaccharidosis ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary This investigation provides histochemical evidence for lysosomal storage of sulfated glycosaminoglycans (GAGs) in the interstitial cells of the renal cortex and in macrophage-like cells of the renal medullary zones of rats chronically treated with the drug tilorone. This compound is known to interfere with lysosomal degradation of sulfated GAGs; therefore cells that develop GAG-storage can be assumed to be involved in the turnover of GAGs. In view of this consideration, the most remarkable and still unexplained finding was that the intrinsic interstitial cells in the papilla, which is known to be particularly rich in sulfated GAGs, did not show the cytological symptoms of lysosomal GAG-storage. The present findings may stimulate further studies focused on the cellular sites of turnover of the sulfated GAGs present in the renal medullary interstitium.
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  • 63
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    Cell & tissue research 188 (1978), S. 285-297 
    ISSN: 1432-0878
    Keywords: Pineal gland ; Rat ; Organ culture ; Indole metabolism ; Ultrastructural morphology
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    Topics: Biology , Medicine
    Notes: Summary In vitro indole metabolism and ultrastructural morphology of the pineal gland of male rats were examined. A comparison of the effect of norepinephrine stimulation on indole synthesis in whole cultured glands and preparations of dispersed pineal cells is discussed. Our studies on the performance of dispersed cells during the first 24 h after preparation indicate a strong dependence of pineal cells upon physical attachment to the culture dish and probably also on cell-to-cell contact.
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  • 64
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    Cell & tissue research 192 (1978), S. 285-297 
    ISSN: 1432-0878
    Keywords: Intestinal epithelium ; Rat ; Kinetics ; Autonomic denervation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effect of autonomic denervation upon the kinetics of the ileal epithelium of rats was studied by tracing 3H-thymidine labelled nuclei and counting mitotic figures and goblet cells. Counts of labelled nuclei and goblet cells provided information about cell migration along the intestinal epithelium. The mitotic index and turnover time of this population were calculated from the mitotic figures counts. Comparing denervated animals with sham operated controls, it was possible to conclude that autonomic denervation, either sympathectomy or parasympathectomy results in a decrease in mitotic activity. As a result of lower mitotic activity in the crypts, the turnover time increases and there is a delay in the migration of cells from the crypts towards the villi. Sympathectomy causes an early short-lived effect upon the kinetics of the crypt cell population, since after 27 h there is a tendency to normality. Parasympathectomy produces a slower but continuous decline in mitotic activity.
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  • 65
    ISSN: 1432-0878
    Keywords: Myocyte subpopulations ; Hypertension ; Cell volume ; Doubling time ; Tetraploid cells ; Rat
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    Topics: Biology , Medicine
    Notes: Summary Smooth muscle cells obtained from three distinct segments of the thoracic aorta of both Wistar Kyoto (WKY) and Spontaneously Hypertensive Rats (SHR) taken at different stages of development were studied in terms of their volume, DNA content in single cell suspensions, and doubling time in primary cultures. The proliferative activity and mean cell volume of myocytes from WKY rats increase along the thoracic aorta in a gradient from the aortic arch to the diaphragm. The slope of this gradient is increased in SHR because of an extension of the area that contains myocytes with low proliferative activity in primary cell culture and large cell volumes in suspension. Tetraploid myocytes are found in both strains and their proportions are larger in SHR than in WKY, specifically after the onset of hypertension. However, they appear to be evenly distributed along the thoracic aorta with a size distribution that is included in that of the diploid cells from the same area. It is suggested that changes in the structural properties of the aortic-cell compartment, associated with maturation and hypertension, reflect quantitative changes in the relative proportions of several myocyte subpopulations within the aorta of the rat.
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  • 66
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    Cell & tissue research 247 (1987), S. 215-225 
    ISSN: 1432-0878
    Keywords: Kidney ; Endoplasmic reticulum ; Ultrastructure ; Membrane transport ; Metabolism ; Rat
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    Topics: Biology , Medicine
    Notes: Summary The spatial organization of endoplasmic reticulum (ER) was examined in all segments of rat nephron. Tissues were fixed with glutaraldehyde, impregnated “en bloc” with osmium tetroxide, prepared for and examined by standard (80–100 kV) and high voltage (1 mEV) transmission electron microscopy. In all proximal tubule cells, ER forms a continuous and extensive network of canaliculi and abundant fenestrated saccules which surround mitochondria and cytoplasmic bodies; the cage-like structure of the fenestrated saccules was most evident around the spherical mitochondria of the S3 segment. In the cells of the distal straight and convoluted tubules, the network consists mostly of canaliculi with rare non-fenestrated saccules. The ER network of canaliculi is particularly rich in intercalated cells, in contrast with its rudimentary appearance in the adjacent principal cells of the collecting tubule. In fact, in these cells there are few isolated ER cisternae and they are rarely impregnated. The nuclear envelope is well impregnated in most cells throughout the various segments. Segmental variations in ER organization and its relative abundance are most likely related to the well, established functional heterogeneity of the nephron segments. Moreover, the extensive and unique organization among mitochondria, ER and the basolateral membrane suggests that these three organelles function as a unit which is related to active electrolyte transport. In addition, because of its transepithelial organization, ER may well constitute a transcellular pathway for molecules.
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  • 67
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    Cell & tissue research 247 (1987), S. 241-247 
    ISSN: 1432-0878
    Keywords: Somatomedin C ; Insulin-like growth factor I (IGF-I) ; Axoplasmic transport ; Sciatic nerve ; Schwann cell ; Trophic influence ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Somatomedin C (Sm-C; insulin-like growth factor I; IGF-I) is a polypeptide (Mr 7649), often dependent on growth hormone (GH), with trophic effects on several different tissues. Monospecific IGF-I antisera were used to investigate its localization in the sciatic nerve and corresponding nerve cells, as well as its possible axoplasmic transport in the adult rat. IGF-I-like immunoreactivity was demonstrated in anterior horn motor nerve cells in the spinal cord and in spinal- and autonomic ganglion nerve cells. Faint IGF-I immunoreactivity was under normal conditions observed in axons of the sciatic nerve and in the Schwann cells. Using crush technique, accumulation of IGF-I immunoreactivity was seen in dilated axons within 2 h, both proximal and distal to the crush. However, only a small fraction of the anterogradely transported IGF-I immunoreactive material could be demonstrated to be transported in retrograde direction. Colchicine injected proximal to a crush prevented accumulation of IGF-I immunoreactivity proximal to the crush, but not distal to it. IGF-I-immunoreactive material is synthesized in the cell bodies of peripheral sensory and motor nerve cells. It is transported at rapid rates in the axoplasm of the sciatic nerve of adult rats both in anterograde and retrograde directions. We propose that axonally transported IGF-I may be released and exert trophic influence on innervated cells, tissues and organs.
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  • 68
    ISSN: 1432-0878
    Keywords: CGRP ; Chromaffin cells ; Nerve fibers ; Adrenal gland ; Rat
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    Notes: Summary The present immunohistochemical study reveals that a small number of chromaffin cells in the rat adrenal medulla exhibit CGRP-like immunoreactivity. All CGRP-immunoreactive cells were found to be chromaffin cells without noradrenaline fluorescence; from combined immunohistochemistry and fluorescence histochemistry we suggest that these are adrenaline cells. In addition, all CGRP-immunoreactive cells simultaneously exhibited NPY-like immunoreactivity. CGRP-chromaffin cells were characterized by abundant chromaffin granules with round cores in which the immunoreactive material was densely localized. These findings suggest the co-existence of CGRP, NPY and adrenaline within the chromaffin granules in a substantial number of chromaffin cells. Thicker and thinner nerve bundles, which included CGRP-immunoreactive nerve fibers, with or without varicosities, penetrated the adrenal capsule. Most of them passed through the cortex and entered the medulla directly, whereas others were distributed in subcapsular regions and among the cortical cells of the zona glomerulosa. Here the CGRP-fibers were in close contact with cortical cells. A few of the fibers supplying the cortex extended further into the medulla. The CGRP-immunoreactive fibers in the medulla were traced among and within small clusters of chromaffin cells and around ganglion cells. The CGRP-fibers were directly apposed to both CGRP-positive and negative chromaffin cells, as well as to ganglion cells. Immunoreactive fibers, which could not be found close to blood vessels, were characterized by the presence of numerous small clear vesicles mixed with a few large granular vesicles. The immunoreactive material was localized in the large granular vesicles and also in the axoplasm. Since no ganglion cells with CGRP-like immunoreactivity were found in the adrenal gland, the CGRP-fibers are regarded as extrinsic in origin. In double-immunofluorescence staining for CGRP and SP, all the SP-immunoreactive fibers corresponded to CGRP-immunoreactive ones in the adrenal gland. This suggests that CGRP-positive fibers in the adrenal gland may be derived from the spinal ganglia, as has been demonstrated with regard to the SP-nerve fibers.
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  • 69
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    Keywords: Calcergy ; Calciphylaxis ; Cutaneous calcinosis ; Experimental calcification ; Ultrastructure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Skin calcification induced by topical calciphylaxis was provoked by a subcutaneous injection of iron chloride in rats previously sensitized by dihydrotachysterol. A cutaneous topical calcergy was induced by an injection of potassium permanganate. An electron-microscopical study of the long-term evolution of both these models of calcification was made. After the initial stages, mineralization of the connective tissue continued by a secondary nucleation process without matrix vesicles. The mineral composed of needle-like structures, apatite in nature, was mainly deposited between and around collagen fibrils, and showed various arrangements in calcified plaques. Intrafibrillar calcification was rarely observed and appeared only in the later stages. The extension of calcified deposits then stopped. Finally, there was a fragmentation of the mineralized area which was progressively surrounded by uncalcified collagen fibrils. A demineralization process, caused by cells such as macrophages and multinucleated giant cells, rather than a resorption of the calcified deposits, was noted. It is important to emphasize that, in both models of ectopic calcification, an evolution toward ectopic ossification was never observed, which is perhaps due to the absence of extensive resorption mechanisms.
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  • 70
    ISSN: 1432-0878
    Keywords: Goblet cells ; Small intestine ; Tight junctions ; Peroxidase ; Cholinergic drugs ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Crypt, but not villus, goblet cells in the ileum accelerate their secretion of mucus within 5 min following cholinergic stimulation. This study was done to determine whether the macromolecular permeability and structure of occluding junctions in the ileum are altered during accelerated secretion. Rats were injected intravenously with horseradish peroxidase followed by carbachol (250 μg/kg, subcutaneous) and the intestinal mucosa was fixed 3–12 min later. In control mucosa (saline-injected), peroxidase filled lateral intercellular spaces up to the occluding junctions of both crypt and villus epithelium, but did not enter occluding junctions or pass into the lumen. In 3 of 8 carbachol-stimulated rats, peroxidase was present within occluding junctions in crypt epithelium and in the crypt lumen, although all intermembrane junctional fusion sites appeared intact. Villus epithelial occluding junctions, in contrast, continued to exclude peroxidase. In freeze-fracture replicas of crypt cells prepared after carbachol stimulation, we detected no structural changes in strand networks of occluding junctions that could account for increased paracellular permeability.
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  • 71
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    Cell & tissue research 248 (1987), S. 393-398 
    ISSN: 1432-0878
    Keywords: Adrenaline ; Phenylethanolamine-N-methyl transferase ; Immunocytochemistry ; Electron microscopy ; Central nervous system ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of adrenergic axon terminals was examined in the paraventricular nucleus of the thalamus (PNT) and in the hypothalamic arcuate nucleus-median eminence (ARC-ME) complex by use of phenylethanolamine-N-methyl transferase (PNMT) immunocytochemistry. In the PNT, immunoreactive terminals formed a dense and well-circumscribed plexus. In the ARC, labeled varicosities were less numerous and more evenly distributed. In the ME, they were scarce and confined to the inner zone. In all these areas, the diameter of immunoreactive varicosities ranged between 0.2 and 1.3 μm; in the ME and in the transitional zone between the ARC and the ME, a population of larger boutons (〉2 μm) was also visible. All immunoreactive varicosities exhibited densely packed small, clear vesicles associated with a few large granular vesicles. In the PNT and the ARC, but not in the ME, they formed synaptic contacts with dendritic elements and were occasionally apposed to neuronal cell bodies. These axo-somatic appositions showed no junctional specializations. In the ME and transitional zone, immunoreactive terminals were frequently juxtaposed to, and occasionally established differentiated synaptic contacts with, tanycytes. These data support a transmitter role for adrenaline in the diencephalon and suggest that adrenaline plays a role in hypothalamo-hypophysiotropic regulation through interactions with neural and glial elements.
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  • 72
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    Cell & tissue research 248 (1987), S. 399-407 
    ISSN: 1432-0878
    Keywords: Synapses ; Perforated synapses ; Synaptic plasticity ; Synaptic density ; Morphometry ; Serial sections ; Section thickness ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The numerical density and frequency of perforated synapses in the molecular layer of rat parietal cortex have been determined using 4 procedures in an attempt to overcome problems associated with the size and complex three-dimensional shape of perforated synapses. The following procedures were compared: A, single-section analysis; B, adjacent-section analysis; C, semi-serial-section analysis; and D, complete serial-section analysis. All procedures made use of an unbiased counting rule. Estimates of the numerical density of perforated synapses ranged from 0.06 to 0.27×109 mm-3, and that of all synapses (non-perforated and perforated) from 1.88 to 2.50×109 mm-3. The frequency of perforated synapses varied from 4.5 to 18.0%. Procedures B (adjacent-section analysis) and D (complete serial-section analysis), neither of which utilize assumptions regarding the shape of synapses, produced comparable results (numerical density of perforated synapses 0.19–0.27×109 mm-3, and of all synapses 2.24–2.45×109 mm-3; frequency of perforated synapses 8.6–10.9%). The frequency of perforated synapses appeared to be underestimated by procedure A (single section analysis; 4.5%) and overestimated by C (semi-serial section analysis; 18%). It is concluded that adjacent-section analysis is the most efficient and effective procedure for determining the numerical density and frequency of complex particles, such as perforated synapses. There is, however, no significant difference in the performance of this procedure compared with that of single-section analysis, for determining the numerical density of synapses in general. Nevertheless, inherent problems of bias within the single-section procedure make the adjacent section method the procedure of choice.
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  • 73
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    Keywords: Cell membrane ; Transglutaminase ; Cysteine ; proteinase inhibitor ; Epithelium ; Rat
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    Topics: Biology , Medicine
    Notes: Summary The chemical nature of the thickened plasma membrane of cornified cells in stratified squamous epithelium was investigated in comparison with that in noncornified epithelium. Localizations of transglutaminase, molecular weight 92000 daltons, and detection of epidermal cysteine proteinase inhibitor were effected with a monoclonal antibody and a monospecific rabbit anti-inhibitor immunoglobulin, respectively, directed to the antigens. N-(7-dimethylamino-4-methylcoumarinyl) maleimide was used to demonstrate S-S cross-linking. In all keratinizing epithelia, the enzyme and inhibitor were deposited on membranes of granular cells. S-S bonds were formed in cornification with the appearance of electron-dense material by the inner leaflet. Both enzyme and inhibitors occurred on the corneal epithelium, but S-S linkage and the thickened plasma membrane did not form even at the last stage of maturation. On the other hand, the internal vaginal epithelium in the proestrous stage without keratinization contained the enzyme, but neither inhibitor nor S-S linkage. Both antigens and S-S bonds were detected when keratinization proceeded during estrus. The staining patterns in the epithelium near the vaginal introitus were identical to those in the skin. Cuboidal and simple epithelia exhibited none of those constituents. The findings indicated that heterogenous components contribute to modification of the plasma membrane of cornified cells, but S-S cross-linkages are associated exclusively with formation of the ultrastructurally unique membrane structure. In addition, findings suggested hormonal regulation in the chemical modification of the membrane in estrogen-sensitive internal vaginal epithelium.
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  • 74
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    Cell & tissue research 248 (1987), S. 169-180 
    ISSN: 1432-0878
    Keywords: M-band structure ; Fibre type ; Skeletal muscle ; Cryo ultramicrotomy ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of the M-band in soleus (SOL) and extensor digitorum longus (EDL) muscles in newborn and four-week-old rats was studied using electron-microscopic techniques. In newborn rats, all myotubes and fibres in both muscles had an identical myofibrillar appearance. A five-line M-band pattern was seen in longitudinal sections and distinct M-bridges in cross-sections. The Z-discs were of medium width. On the other hand, in four-week-old rats, different muscle fibre types were observed on the basis of their myofibrillar pattern. In SOL two fibre types were distinguished in longitudinal sections. One had a four-line M-band pattern and very broad Z-discs, whereas the other type had five lines in the M-band and broad Z-discs. In EDL, three different myofibrillar patterns were observed. The M-bands were composed of three, four or five lines. Fibres had either thin, broad or medium Z-disc widths, respectively. In cross-sections of the SOL muscle one group of fibres showed indistinct M-bridges, whereas distinct M-bridges were seen in the other fibres and in all observed EDL muscle fibres. We conclude that initially there seems to be a single intrinsic program for M-band genesis; this program becomes modified upon the induction of functionally differentiated fibres.
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  • 75
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    Cell & tissue research 248 (1987), S. 247-255 
    ISSN: 1432-0878
    Keywords: Collagen ; Slow and fast skeletal muscle ; Age ; Endurance training ; Endomysium ; Perimysium ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Intramuscular collagen in a slow (m. soleus) and a fast (m. rectus femoris) skeletal muscle was studied by biochemical, morphometric, and immunohistochemical methods. Wistar white rats of 1, 4, 10, and 24 months were used as experimental animals. Our aim was to evaluate the effects of life-long physical training (treadmill running, 5 days a week for 1, 3, 9, and 23 months depending on the age attained). The biochemical concentration of collagen was higher in m. soleus than in m. rectus femoris and it increased in youth and in old age in m. soleus. The trained rats had higher concentrations of collagen than the untrained rats at 10 and 24 months. The morphometrically measured area-fractions of both the endomysium and perimysium were higher in m. soleus than in m. rectus femoris. The age-related increase in intramuscular connective tissue was of endomysial origin. The immunohistochemical staining of type-I, -III, and -IV collagens indicated the more collagenous nature of m. soleus as compared with m. rectus femoris for all major collagen types; this was most marked for type-IV collagen of basement membrane. The results indicate that both age and endurance-type physical training further distinguish the slow and fast muscles with respect to their connective tissue.
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  • 76
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    Cell & tissue research 248 (1987), S. 297-303 
    ISSN: 1432-0878
    Keywords: Uterus (myometrium) ; Gap junctions ; Pregnancy ; Morphometry ; Freeze-fracturing ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In uterine smooth muscles, gap junction plaques rapidly form during the final stages of gestation. To investigate the related mechanisms, regional differences in myometrial gap junction development in rat uterus were examined quantitatively during delivery, using thin-section and freeze-fracture techniques in combination with light- and electron microscopy. Examination of implanted and nonimplanted horns in the unilaterally ligated rat bicornuate uteri, revealed no differences in the occurrence of gap junction plaques, but after 2 to 4 pups had been delivered, the contracted segments contained more gap junction plaques than did noncontracted segments examined immediately before delivery. In all segments, gap junctions were found more frequently in the circular muscle layers than in the longitudinal muscle layers. Gap junctions ranged in size from 0.002 μm2 to 0.52 μm2, but two-thirds were less than 0.1 μm2. The frequency of small gap junction plaques (less than 0.1 μm2) was higher in the noncontracted segment. These results suggest that gap junctions are dynamic structures, and that their formation is controlled not only by general hormonal factors, possibly involved in gap junction increases in the myometrium before delivery, but also by local factors, possibly related to the contraction, that may accelerate an increase in gap junction formation during delivery.
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  • 77
    ISSN: 1432-0878
    Keywords: Epididymis ; Basement membrane ; Anionic sites ; Differentiation ; Androgen ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Anionic binding sites in the lamina densa of the basement membrane of the rat epididymal epithelium were demonstrated ultrastructurally with the use of cationized polyethyleneimine (PEI). Enzyme digestion with heparitinase removed the anionic sites, indicating that they consist largely of heparan sulfates. The anionic sites are present as early as the 16th day of gestation on the interstitial face of the lamina densa; later during gestation they are localized on both faces of the lamina densa without further modification after birth. The distribution of the anionic sites was identical all along the epididymal duct. After castration and ligation of efferent ducts or in the state of cryptorchidism the sites were more numerous and located inside the thicker portion of the lamina densa. These alterations were more prominent in the initial segment compared to the distal segments, suggesting a differential androgen dependence of the reactive sites and their patterns of distribution.
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  • 78
    ISSN: 1432-0878
    Keywords: Osteogenesis ; Marrow stromal precursors ; Collagen ; Culture in vivo ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Diffusion chambers containing bone marrow cells from adult rats were implanted intraperitoneally into rat hosts and cultured in vivo for up to 64 days. Biochemical and histological analyses of the contents of the chambers demonstrate that a connective tissue consisting of bone, cartilage and fibrous tissues is formed by precursor cells present in marrow stroma. The amounts of osteogenic tissue and DNA are directly correlated with time of implantation and with number of cells inoculated. In the chambers there is initial formation of fibrous tissue which is strongly reactive to collagen type III, laminin and fibronectin. In areas of osteogenesis which appear later within this fibrous anlage, expression of collagen type III, laminin and fibronectin decrease and collagen types I and II increase in association with bone and cartilage respectively. Where osteogenesis does not develop, fibrous tissue continues to express collagen type III. The sequential expression of the different extracellular matrix components is similar to that previously observed during osteogenic differentiation in embryonic and adult developmental systems. It is concluded that the formation of fibrous and osteogenic tissues in diffusion chambers by precursor cells present in adult marrow, resembles the normal developmental process.
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  • 79
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    Cell & tissue research 250 (1987), S. 197-204 
    ISSN: 1432-0878
    Keywords: Third ventricle ; Intraventricular vessels ; Recess ; Development ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Light and electron microscopy of the hypothalamic ventricle in neonatal rats demonstrate morphological specializations of the ventricular wall at the level of the premammillary region of the third ventricle. The morphological features are: (1) A ventricular recess that we have called the “hypothalamic dorso-lateral recess” (HDR). (2) The presence of intraventricular capillaries near the dorsolateral recess. (3) The HDR possessing a specialized ependymal lining; this consists of non-ciliated cells with short microvilli and bleb-like processes. (4) The existence of cerebrospinal fluid-contacting neurons within the HDR. (5) The presence of numerous phagocytic supraependymal cells. The HDR is not found in adult rats. This indicates that the dorso-lateral recess may play a physiological role during development.
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  • 80
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    Cell & tissue research 250 (1987), S. 323-330 
    ISSN: 1432-0878
    Keywords: Tunicamycin ; β-Receptor ; Parotid gland ; Isoproterenol ; Secretion ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The morphological and functional effects of tunicamycin were studied in rat parotid glands at the stage of the reformation of secretory granules following secretory stimulation by isoproterenol. Tunicamycin inhibited the incorporation of (3H)-mannose into the acid-insoluble fraction but had no effect on total protein synthesis as determined by the incorporation of (14C)-leucine. Thus the administration of tunicamycin in vivo inhibits the synthesis of mannose-rich glycoproteins in a manner similar to that in an in vitro system. The ultrastructure of the acinar cell showed little change following treatment with this drug, except that the number of reaccumulated secretory granules was greater than in the control. Amylase secretion stimulated by isoproterenol was inhibited in tunicamycin-treated cells, but did not decrease following treatment with N6,2′-O-dibutyryladenosine 3′-5′-cyclic monophosphate, a secretory stimulator bypassing the β-receptor. A radio-receptor assay using (3H)-dihydroalprenolol and direct localization using the fluorescent β-adrenergic blocker 9-amino-acridin propranolol showed a marked reduction in the binding activity of β-receptor following treatment with tunicamycin. Thus the inhibition of N-linked glycosylation appears to produce profound effects on the β-adrenergic receptor-adenylate cyclase complex of acinar cells, although the steps of the transport and the exocytotic discharge of secretory materials are not affected.
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  • 81
    ISSN: 1432-0878
    Keywords: Neurofilaments ; Glial fibrillary acidic protein ; Sympathetic ganglia ; Intraocular transplantation ; Rat ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The presence of neurofilament (NF)-like and glial fibrillary acidic protein (GFAP)-like immunoreactivities was studied in sympathetic ganglia of adult rats and guinea pigs during normal conditions and after perturbation. In the superior cervical ganglion (SCG) of normal rats, many ganglion cells and nerve fibers show NF immunoreactivity. Some of these nerve fibers disappear after preganglionic decentralization of SCG; this indicates the presence of a mixture of preand postganglionic NF-positive nerves in the ganglion. Cuts in both preand postganglionic nerves result in a marked increase in GFAP immunoreactivity in SCG, whereas NF immunoreactivity increases in nerve cell bodies after preganglionic cuts. Only a few ganglion cells show NF immunoreactivity in the normal SCG of guinea pig. All intraganglionic NF-positive nerves are of preganglionic origin; decentralization abolishes NF immunoreactivity in these nerve fibers. The inferior mesenteric ganglion, the hypogastric nerves and colonic nerves in guinea pigs contain large numbers of strongly NF-immunoreactive nerve fibers. When the SCG of adult rat is grafted to the anterior eye chamber of adult rat recipients, both ganglionic cell bodies and nerve fibers, forming on the host iris from the grafted ganglion, are NF-positive. As only the perikarya of these neurons normally exhibit NF immunoreactivity, and the terminal iris arborizations are NF-negative, it appears that the grafting procedure causes NF immunoreactivity to become more widespread in growing SCG neurons.
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  • 82
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    Keywords: Serotonin ; Neuropeptide Y ; Suprachiasmatic nucleus ; Radioautography ; Immunocytochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The morphological substrate of putative serotonin (5-HT)/neuropeptide Y (NPY) interactions in thé suprachiasmatic nucleus (SCN) was investigated by combined radioautography and immunocytochemistry after intraventricular administration of (3H)5-HT in the rat. In the ventral portion of the SCN, the distribution of (3H)5-HT uptake sites overlapped closely the NPY-immunoreactive terminals. Previous investigations have shown that the dense 5-HT and NPY innervations of the SCN originate in different structures, i.e., the midbrain raphe nuclei and the ventral lateral geniculate nucleus, respectively. Accordingly, in the present study, destruction of 5-HT afferents by 5,7-dihydroxytryptamine was not found to induce any modification in NPY staining and, in ultrastructural immuno-radioautographic preparations, two distinct pools of axonal varicosities could be identified. Both 5-HT and NPY terminals established morphologically defined synaptic junctions, sometimes on the same neuronal target. Some cases of direct axo-axonic appositions between the two types of terminals were also encountered. These data constitute additional criteria for characterizing the cytological basis of the multiple transmitter interactions presumably involved in the function of the SCN as a central regulator of circadian biological rhythms.
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  • 83
    ISSN: 1432-0878
    Keywords: Anterior pituitary gland ; FSH cells ; LH cells ; Development ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Serum concentration of follicle-stimulating hormone (FSH) in the juvenile female rat increases independently from that of luteinizing hormone (LH). The objective of this study was to determine whether this increase in serum FSH is accompanied by a proliferation of FSH-cells greater than the proliferation of LH-cells. Thus, we measured circulating FSH and LH in female rats on days 3, 10, 13, 17, and 20, calculated the percentages of adenohypophyseal cells that contained FSH or LH on days 3, 10, and 20, and determined whether cells containing only FSH existed on day 10. Serum FSH concentrations on days 10 and 13 were significantly greater than those on days 3, 17, or 20. No differences existed in serum LH concentrations. Cells containing FSH or LH were distributed throughout the entire adenohypophyses of 3, 10, and 20-day-old females. Clusters of these cells were observed in the ventral regions of adenohypophyses of 3-day-old females. The percentages of adenohypophyseal cells containing FSH increased significantly from ∼9% in 3-day-old rats to ∼17% in 10-day-old rats and then decreased to ∼14% in 20-day-old animals. At all ages the percentages of adenohypophyseal cells containing FSH were similar to the percentages of cells containing LH. At 10 days of age, all cells containing FSH also contained LH and all cells containing LH also contained FSH. These data suggest that the increase in serum FSH in the juvenile female rat is associated with an increase in the percentage of adenohypophyseal cells containing FSH and that at this time all cells containing FSH also contain LH.
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  • 84
    ISSN: 1432-0878
    Keywords: Primary immune response ; Thymus-independent antigens ; Development, ontogenetic ; Lymph nodes ; Spleen ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary To examine the development of the postnatal immune response to thymus-independent type-1 (TI-type 1) and TI type-2 antigens, respectively, trinitrophenyl-lipopolysaccharide (TNP-LPS) or TNP-Ficoll was injected subcutaneously into the hind footpads of young rats of various ages. After 5 days the popliteal lymph nodes (PLNs) were removed and the localization pattern of specific anti-TNP antibody-containing cells was studied. The first specific antibody-containing cells elicited in rats by TNP-LPS appeared in animals at day 19 after birth. The results suggest that the development of these cells from lymphocyte to plasma cell occurs while they migrate from cortex to medulla. An unexpected finding was the low response to TNP-Ficoll in PLN; from 6 weeks after birth only very few specific antibody-containing cells were found. However, in the spleen numerous anti-TNP antibody-containing cells were found in the periarteriolar lymphocyte sheaths. To test the exclusive role of the spleen in the appearance of anti-TNP antibody-containing cells in lymph node after subcutaneous administration of TNP-Ficoll, the experiment was repeated in rats that had been splenectomized. Evidence from these experiments suggests that the spleen plays a major role in the appearance of the above-mentioned cells in lymph nodes.
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  • 85
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    Cell & tissue research 247 (1987), S. 179-185 
    ISSN: 1432-0878
    Keywords: Image analysis ; Morphometry ; Peroxisomes ; Catalase ; Cytochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The feasibility of the application of a television-based image analyzer, the Texture Analysis System (TAS, Leitz Wetzlar, FRG) in conjunction with a light microscope for morphometric studies of hepatic peroxisomes has been investigated. Rat liver peroxisomes were stained with the alkaline-DAB method for localization of catalase and semi-thin (0.25 and 1 μm) sections of plastic-embedded material were examined under an oil immersion objective. The TAS detected the peroxisomal profiles selectively and determined their morphometric parameters automatically. The same parameters were obtained also by morphometric analysis of electron micrographs from the same material. The volume density of peroxisomes determined by TAS in semithin sections of normal liver, after correction for section thickness, is quite close to the corresponding value obtained by morphometry of electron micrographs. The difference is approximately 20%. In animals treated with the hypolipidemic drug bezafibrate, which causes proliferation of peroxisomes, TAS detected readily the increase in volume density of peroxisomes in semithin sections. In comparison with electron microscopy, however, the light-microscopic approach seems to underestimate the proliferation. The lower resolution of the light microscope and overlapping of neighbouring particles in relatively thick sections used for lightmicroscopic analysis may account for the differences. The present study has demonstrated the usefulness of automatic image analysis in conjunction with selective cytochemical staining of peroxisomes for morphometry of this organelle in rat liver. The light-microscopic approach is not only faster but is also extremely economical by obviating the use of an electron microscope.
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  • 86
    ISSN: 1432-0878
    Keywords: Exocrine pancreas ; Proteinase inhibitor ; Feedback regulation ; Cholecystokinin ; Fine structure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Application of a single dose of a new type of proteinase inhibitor camostate (FOY-305) via orogastric tube was used in rats to study the dose-response relationship of resulting pancreatic stimulation. Doses up to 10 mg/ kg failed to elicit any response, while significant decrease in enzyme content and increase in serum CCK-levels were observed with doses ranging from 25 to 400 mg/kg. A single dose of 100 mg/kg was selected for a time-sequence analysis, which revealed a 60 to 70% depletion of enzyme stores persisting over 6 h and reverting to control levels by 12 h. Peak increases in serum CCK-levels (15-fold above the elevation observed after regular food intake) were found after 30 min and persisted as an 8-to 10-fold elevation for at least 3 h, then declined to control levels by 9 h. This prolonged endogenous hormone release and resulting pancreatic stimulation were also verified in a separate group of animals in which volume, protein, and enzyme output were measured after cannulation of the pancreatic duct. While volume secretion was not altered by feeding a single dose of 100 mg/kg FOY-305, protein and enzyme output increased 2-to 3-fold over a period of 7 h. Fine-structural analysis of the pancreas demonstrated efficient depletion of zymogen granules from acinar cells with all doses between 50 and 400 mg/kg, accompanied by the appearance of membrane material in the acinar lumina at 3 and 6 h. The same transient increase in the number of lysosomal bodies predominantly containing mitochondria with all doses above 50 mg/kg was interpreted as increased organelle turnover due to persisting hormonal stimulation.
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  • 87
    ISSN: 1432-0878
    Keywords: Exocrine pancreas ; Caerulein ; DNA synthesis ; Mitotic activity ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Previous studies from our laboratory indicate that the adaptive response of the exocrine pancreas of the rat to prolonged stimulation with optimal doses of caerulein (0.25 μg × kg-1 × h-1) follows a characteristic time course in which each step in the secretory pathway is activated. The immediate response is the depletion of zymogen-granule stores followed by coordinate and anticoordinate changes in individual rates of (pro-)enzyme synthesis after a lag period of 2 h. The sum of such changes leads to an increase in total rate of protein synthesis by 3 h which is combined with acceleration of intracellular transport packaging and granule discharge. In the present study the time course of DNA synthesis and the labeling index of five populations of pancreatic cells have been analyzed after caerulein stimulation for periods ranging from 6 to 72 h, using in vivo labeling with 1 μCi/g 3H-thymidine 1 h prior to sacrifice of the animals. DNA synthesis did not change during the initial 18 h in spite of persistent stimulation indicated by a 80% reduction of enzyme content. Following this lag period a sharp rise in DNA synthesis 20- to 25-fold above control levels was observed, which decreased by 48 h to reach control levels by 72 h. Increase in DNA synthesis was most pronounced in animals with lowest enzyme content in the pancreas. From the five cell populations studied by autoradiography interlobular duct cells and islet cells had no significant increase in labeling index at any time of stimulation. Acinar cells, intralobular duct cells and interstitial cells showed a marked increase in labeling index after a latent period of 18 h with peak values at 36 h 30 to 50 times higher in intralobular duct and acinar cells, respectively, and 4 times higher in interstitial cells. The increased labeling indices in all three cell populations reverted to lower values at 48 h and reached control values by 72 h. The data indicate a phasic and limited growth response of the rat exocrine pancreas to persistent stimulation with acinar cells as the major contributing cell population.
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  • 88
    ISSN: 1432-0878
    Keywords: Dorsal root ganglia ; Neuropeptides ; Coexistence ; Immunohistochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary By use of the indirect immunofluorescence technique the distribution of calcitonin gene-related peptide (CGRP)-like immunoreactivity (LI) has been analyzed in cervical and lumbar dorsal root ganglia of untreated and colchicine-treated rats. In addition, lumbar ganglia were examined 2 weeks after transection of the sciatic nerve. The occurrence of CGRP-positive cells in relation to ganglion cells containing substance P-, somatostatin-, galanin-, cholecystokinin (CCK)-, and vasoactive intestinal polypeptide (VIP)/peptide histidine isoleucin (PHI)-LI has been evaluated on consecutive sections as well as using elution-restaining and double-staining techniques. CGRP-LI was observed in many ganglion cells of all sizes ranging in diameter from 15 μm to 65 μm. Thus, this peptide occurs also in the large primary sensory neurons. In contrast to the sensory peptides described to date, CGRP-positive cells constituted up to 50% of all and 70% of the medium-sized neurons, thus being the most frequently occurring peptide in sensory neurons so far encountered. Subpulations of CGRP-positive neurons were shown to contain substance P-, somatostatin-, or galanin-LI and some CGRP-positive neurons contained both substance P- and galanin-LI. In fact, most substance P-, somatostatin- and galanin-positive cell bodies were CGRP-immunoreactive. The coexistence analysis further revealed that galanin and substance P often coexisted and that some cells contained both substance P- and somatostatin-LI, whereas no coexistence between galanin and somatostatin has as yet been seen. VIP/PHI-LI was only shown in a few cells in untreated or colchicine-treated rats. However, after transcetion of the sciatic nerve numerous VIP/PHI-positive cells were observed, some of which also contained CGRP-LI. The present results indicate that a CGRP-like peptide is present in a wide range of primary sensory neurons probably not related to specific sensory modalities. Often this peptide coexists with other biologically active peptides. Taken together these findings suggest that CGRP may have a generalized function.
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  • 89
    ISSN: 1432-0878
    Keywords: Cerebral aqueduct ; Ependyma ; Cystic ependymal cells ; Ectopic ependymal cells ; Ependymal ridge ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The wall of the cerebral aqueduct was examined in 20 male rats at the light- and electron-microscopic levels. Disorder in ciliary orientation was occasionally seen in ordinary ependymal cells. Ependymal cells possessing intracellular cysts of 5 to 30 urn in diameter were observed within and beneath the aqueductal ependyma in all animals examined. Light-microscopic reconstruction from serial, 10-μm thick frontal sections revealed an extensive distribution of cystic ependymal cells (CECs), especially along the ependymal ridges in the rostral half of the aqueduct, and along the dorsal region of the aqueductal lining in the caudal half. Both cystic and surface membranes of CECs bore microvilli and cilia. Ectopic ependymal cells (EECs) characterized by densely packed microvilli, well-developed intermediate junctions and cilia, but without cysts, were situated in the subependymal region adjacent to a CEC or another EEC. The ependymal ridges were long, narrow and sporadically stratified ependymal linings extending rostrocaudally and bilaterally along the aqueductal surface. Tanycyte-like cells filled the surface region of the ridge, and CECs and EECs were frequently seen in the core. Intraventricularly injected microperoxidase was detected among densely packed microvilli but not in the cystic lumina of CECs, indicating that EECs and CECs are distinct entities.
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  • 90
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    Cell & tissue research 248 (1987), S. 491-497 
    ISSN: 1432-0878
    Keywords: Intestine, small ; Collagen ; Submucosa ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Whole-mount preparations of the submucosa were made from the small intestine of rats, guinea-pigs, rabbits and sheep. In the distended intestine the collagen fibres ran straight and approximately parallel to the serosal surface. They formed a characteristic lattice, with two arrays of fibres running diagonally in a clockwise and an anticlockwise direction, and making an angle of 50°–55° with the longitudinal axis of the intestine. This collagenfibre lattice was flexible and changed with the movements of the intestinal wall; when the radial distension predominated, the angle between collagen fibres of the submucosa and longitudinal axis of the intestine increased to 60°–65°, and when the longitudinal distension predominated the angle decreased to about 30°.
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  • 91
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    Cell & tissue research 248 (1987), S. 505-510 
    ISSN: 1432-0878
    Keywords: Textile blood-vessel prosthesis ; Aorta ; Neointima formation ; Dog ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The formation of a neo-intima in textile prostheses implanted in the rat and dog aorta was studied by means of light- and scanning electron microscopy. Two independent cellular layers (the superficial and deep ingrowth layers) developed on the free surface and under the fibrin layer initially deposited on the inner surface of the prostheses. The superficial ingrowth layer invades the prosthesis from both the proximal and distal aortic stumps and extends over the primary fibrin layer, or replaces it. This layer consists mainly of smooth muscle cells of the triangular aortic type covered by endothelial-like cells. The deep ingrowth layer originates from cellular elements of the prosthetic bed. Fibroblasts, myofibroblasts and spindle-shaped smooth muscle cells invade the fibrin layer through the interstices of the fabric structure of the prosthesis. Precursors of endothelial cells, however, are absent from this population. The superficial and the deep ingrowth layers may become joined by progressive replacement of the fibrin layer, but remain distinguishable because of their different cellular components. When a continuous cellular layer is established on the inner surface of the prosthesis, and this is then covered by endothelial-like cells, the neo-intima formed remains stable during long-term studies.
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  • 92
    ISSN: 1432-0878
    Keywords: Gonadoliberin ; Pituitary gland, pars anterior ; Gonadotrophs ; Autoradiography ; Cryoultramicrotomy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary To identify anterior pituitary cell types containing GnRH binding sites and to study the internalization process of this peptide by target cells under physiological conditions, autoradiography was performed on rat anterior pituitaries removed at specific time intervals (2–60 min) after intravenous injection of mono-radioiodinated 125I-GnRH into intact males. At electron-microscopic level, gonadotrophs and lactotrophs appeared to contain silver grains. Concomitant administration of an excess of unlabeled GnRH with the radioiodinated hormone prevented this localization indicating the specificity of the reaction. The time-course study in gonadotrophs showed that 2 min after injection silver grains could be found over the plasma membrane, secretory granules and nuclear membrane. Similar results were observed 5 and 15 min after injection. Extensive label was observed over the nucleus and nuclear membrane 15 to 60 min after injection. The injection of a radioiodinated GnRH agonist [D-Trp6, Pro9 (Net), DesGly10]-GnRH produced comparable results. In contrast, the injection of 125I-[D-pGlu1, D-Phe2, Trp3,6]-GnRH, an antagonist of GnRH, produced positive labeling only at the plasma membrane without internalization. These results indicate that, after binding with receptors on the plasma membrane, GnRH is rapidly internalized, accumulating in secretory granules, and localizing over the nuclear membrane and later, in the nucleus. Association of radioactivity with secretory granules could be related to a specific action of GnRH at this level or to receptor recycling, and presence of label in the nucleus may be related to stimulation of neosynthesis of LH and GnRH receptors.
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  • 93
    ISSN: 1432-0878
    Keywords: Microtubules ; Terminal web ; Small intestine ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The terminal web (TW) region of mature absorptive cells in the small intestine of the rat contains an elaborate cytoskeleton which supports the apical microvillus membrane. In studies regarding the structural organization of the cytoskeleton and associated proteins in the small intestine, microtubules have not been mentioned as components of the TW. By transmission electron microscopy of conventional resin-embedded sections of rat small intestine, we observe many microtubule profiles in the TW of mature absorptive cells. These microtubules are found in various orientations, although most course parallel to the long axis of the cell, and many microtubule profiles are seen in close association with smooth-surfaced vesicles.
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  • 94
    ISSN: 1432-0878
    Keywords: Exocrine pancreas ; Proteinase inhibitor ; Cholecystokinin ; Protein synthesis ; Enzyme synthesis ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Oral application of a single dose of a new synthetic proteinase inhibitor Camostate (Foy-305) in male Wistar rats was carried out together with studies of in vitro amino acid incorporation followed by separation of proteins by two-dimensional gel electrophoresis. The aim of this experiment was to analyze changes produced by the inhibitor in total protein and individual enzyme biosynthesis. Administration of 100 mg/kg Foy-305 resulted in significant inhibition of total pancreatic protein synthesis, without changes in fractional rates for individual enzymes. 50 mg/kg Foy-305 induced a 10-fold elevation of cholecystokinin (CCK) levels in serum; this persisted for 3 h and led to a significant increase in the total rate of protein synthesis with peak values at 6 and 9 h (78% and 84% above control levels, respectively), returning to control by 15h. Changes in fractional rates of synthesis occurred with a latency of 6 h and were restricted to amylase and the anionic form of trypsinogen and chymotrypsinogen. Amylase biosynthesis decreased by about 40% from control levels at 9 h to return to control levels by 15 h. Increased synthesis of trypsinogen and chymotrypsinogen was observed; this was also phasic. The results show similar enzyme-specific regulation as previously described for exogenous CCK stimulation and for the adaptation of the pancreas to diets enriched in protein. They demonstrate the effectiveness of pulsatory endogenous hormone release in the regulation of protein synthesis.
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  • 95
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    Cell & tissue research 249 (1987), S. 215-220 
    ISSN: 1432-0878
    Keywords: X-ray microanalysis ; Thymocyte ; Mitosis ; Sodium ; Potassium ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Elemental concentrations of rat thymocytes in vivo were studied by X-ray microanalysis of freeze-dried sections. Cells from different regions, the subcapsular zone, the cortex and the medulla were studied in thymic tissue from a number of animals. Generally thymocytes situated in the medulla had higher concentrations of K compared to those in the subcapsular zone. The concentration of Na in the nucleus was constant in the medulla in all animals but some variation in this element was seen between animals in the subcapsular zone. The distribution of K/Na ratio in individual thymocytes was different in each region of the thymus. Cells with low K/Na ratio (〈5) were predominant in the subcapsular zone, whereas cells with higher values for K/Na ratio were found in the cortex and medulla. The subcapsular zone is the region where mitotic cells are mostly situated. The finding of thymocytes with higher concentrations of Na and low K/Na ratios in this region is in accord with in vitro studies on thymocyte stimulation.
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  • 96
    ISSN: 1432-0878
    Keywords: Liver ; LDL-gold conjugates ; Albumin-gold conjugates ; Endocytosis ; B, E receptor ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary To elucidate the participation of fetal rat liver cells in the receptor-mediated internalization of low-density lipoproteins (LDL), rat fetuses were injected with either LDL-gold or albumin-gold conjugates. The degree of binding and uptake of LDL-gold and albumin-gold by parenchymal and sinusoidal cells of the fetal rat liver differs markedly. Endothelial cells exhibit low LDL-gold uptake. In contrast, parenchymal cells internalize LDL-gold more actively (45 ± 8 LDL conjugates/100 μm2 cytoplasm within 60 min). Kupffer cells exceed this value by a factor of 20. The uptake of albumin-gold by endothelial and Kupffer cells is high, whereas it is extremely low in parenchymal cells. Estradiol pretreatment causes a significant doubling (p〈0.05) of the LDL-gold particle density/100 μm2 cytoplasm both in parenchymal and Kupffer cells, whereas estradiol has no effect on the albumin uptake. The results strongly indicate that LDL uptake by parenchymal and Kupffer cells in the fetal rat liver is mediated by estrogen-inducible receptors, which may correspond to B, E receptors in the adult liver.
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  • 97
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    Cell & tissue research 249 (1987), S. 235-239 
    ISSN: 1432-0878
    Keywords: Satellite nucleoli ; Normal, stimulated and malignant hepatocytes ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The present study was undertaken to provide information on the presence and frequency of satellite nucleoli in cells with increased nucleolar biosynthetic activity. The number of hepatocytes containing satellite nucleoli was analyzed in rat liver, regenerating liver 18 h after partial hepatectomy and in Novikoff hepatoma ascites cells. In comparison with hepatocytes of normal liver, the number of both stimulated hepatocytes and malignant hepatoma cells containing satellite nucleoli was significantly reduced. The results also indicated that whereas most satellite nucleoli contain protein C23, a smaller percentage contain protein B23.
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  • 98
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    Cell & tissue research 249 (1987), S. 367-377 
    ISSN: 1432-0878
    Keywords: Ethane dimethanesulphonate ; Leydig cells ; Destruction ; Regeneration ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ethane dimethanesulphonate (EDS) was used as a specific cytotoxin to eliminate the Leydig cell population of the adult rat testis. Ultrastructural, morphometric and serum gonadotrophin and testosterone analysis was used to study the response of the intertubular tissue of the testis from 1 day to 10 weeks after EDS treatment. In control animals, the testis contained approximately 28 million Leydig cells and 8 million macrophages. Three to seven days after EDS treatment, Leydig cells were absent and serum testosterone was undetectable. Macrophage numbers increased three-fold by 3 days and returned to pretreatment values thereafter. At 2 and 3 weeks post-EDS, foetal-type Leydig cells (∼1–2 million per testis) appeared in proximity to perivascular and peritubular tissues, a feature also observed at 4 weeks when numerous such cells (∼15 million per testis) formed prominent clusters in perivascular and peritubular locations. Between 6 and 10 weeks after EDS treatment, the foetal-type Leydig cells were transformed morphologically into adult-type Leydig cells, they occupied central intertubular positions and their numbers were restored to pretreatment values. Regeneration of Leydig cells was reflected by elevated serum testosterone levels which returned towards the normal range. The results demonstrate the regenerative capacity of the testicular intertubular tissue and indicate a dual site of origin of Leydig cells which initially resemble foetal-type Leydig cells prior to establishing the adult-type Leydig cell population. The morphological pattern of Leydig cell regeneration suggests that in addition to gonadotrophic stimulation, local testicular factors from the seminiferous tubules may stimulate Leydig cell growth.
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  • 99
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    Cell & tissue research 248 (1987), S. 103-110 
    ISSN: 1432-0878
    Keywords: Secretory ameloblast ; Ca++-ATPase ; Na+-K+-ATPase ; Ultracytochemistry ; Calmodulin blocker, trifluoperazine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of the calmodulin blocker, trifluoperazine (TEP), on membrane-bound Ca++ -ATPase, Na+ -K+ -ATPase (EC 3.6.1.3.) and the ultrastructure of the enamel organ were investigated in the lower incisors of normal and TFP-injected rats. The rats, of about 100 g body weight, were given either 0.2 ml physiological saline or 100 μg TFP dissolved in 0.2 ml physiological saline through a jugular vein and fixed by transcardiac perfusion with a formaldehyde-glutaraldehyde mixture at 1 and 2 h after TFP administration. Non-decalcified sections of the enamel organ less than 50 μm in thickness, prepared from dissected lower incisors, were processed for the ultracytochemical demonstration of Ca++-ATPase and Na+-K+ -ATPase by the one-step lead method at alkaline pH. In control saline-injected animals the most intense enzymatic reaction of Ca++-ATPase was demonstrated along the plasma membranes of the entire cell surfaces of secretory ameloblasts. Moderate enzymatic reaction was also observed in the plasma membranes of the cells of stratum intermedium and papillary layer. Reaction precipitates of Na+-K+-ATPase activity were localized clearly along the plasma membranes of only the cells of stratum intermedium and papillary layer. The most drastic effect of TFP was a marked disappearance of enzymatic reaction of Ca++-ATPase from the plasma membranes of secretory ameloblasts, except for a weak persistent reaction in the basolateral cell surfaces of the infranuclear region facing the stratum intermedium. The cells of stratum intermedium and papillary layer, however, continued to react for Ca++-ATPase even after TFP treatment. Similarly, Na+-K+-ATPase activity in these cells was not inhibited by TFP administration. Ultrastructural examination of secretory ameloblasts revealed that administration of TFP caused no considerable cytological changes and did not act as a cytotoxic agent. These results suggest that secretory ameloblasts may have an active Ca++ transport system, which is modulated by an endogenous calmodulin.
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  • 100
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    Cell & tissue research 248 (1987), S. 79-88 
    ISSN: 1432-0878
    Keywords: Bone resorption ; Implantation ; Osteoclasts ; Osteopetrosis ; Mononuclear phagocytes ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Faulty osteoclasts, characteristic of the incisors-absent (ia) rat mutation of osteopetrosis, cause a resorptive defect which results in the persistence of immature, highly mineralized bone matrix. We implanted osteopetrotic bone subcutaneously into normal andia rats to determine ifia bone could induce functionally active and morphologically identifiable osteoclasts at the implant surface. Assays of45Ca released from the preparations showed that normal andia recipients were capable of equivalent cell-mediated release of Ca over a 2-week implant period, indicating that theia resorptive defect was not reproduced at the subcutaneous site. Freeze-thawed osteopetrotic bone released twice as much45Ca as normal bone. This difference was eliminated by collagenase treatment. Cellular profiles were similar in both normal andia animals regardless of the implant preparation. At 3 days after implantation, both bone and suture were surrounded by mononuclear cells. By 14 days, multinucleated cells appeared at the implant surfaces. Morphological comparison of implant-induced multinucleated cells and tibial osteoclasts indicated that bone-elicited multinucleated cells lacked the ruffled borders characteristic of normal osteoclasts or the extensive clear zones typical ofia osteoclasts, but more closely resembled suture-induced macrophage-polykaryons. We conclude that ectopically implantedia bone as compared to normal bone elicits a different functional response from structurally similar cell populations. Bone-elicited multinucleated cells could not be classified as active osteoclasts despite evidence of release of45Ca. Release of labeled Ca was probably due to the action of mononuclear phagocytes and macrophage-polykaryons rather than to osteoclastic resorption.
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