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  • Rat  (16)
  • Springer  (16)
  • American Chemical Society
  • 1980-1984
  • 1970-1974  (16)
  • 1970  (16)
Collection
Keywords
Publisher
  • Springer  (16)
  • American Chemical Society
Years
  • 1980-1984
  • 1970-1974  (16)
Year
  • 1
    Electronic Resource
    Electronic Resource
    Fine structure of trypsin-dissociated rat adrenal cells (1970)
    Springer
    Cell & tissue research 107 (1970), S. 447-453 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Rat ; Trypsin-dissociation ; ACTH stimulation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron micrographs of trypsin-dissociated rat adrenal showed predominantly intact rounded cells without internal damage. The population contained cells from the glomerular, intermediary and fascicular zones with cells from the zona fasciculata predominant. The presence or absence of cells from the reticular zone could not be determined. Cells from the medullary zone were absent. The addition of adrenocorticotropic hormone (ACTH) to the cellular suspension for 2 hours produced corticosterone. However, these stimulated cells did not display any significant ultrastructural change.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00335433
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  • 2
    Electronic Resource
    Electronic Resource
    Quantitativ-morphologische Untersuchungen an Herzmuskelzellen von normalen und hypoxischen Ratten (1970)
    Springer
    Cell & tissue research 109 (1970), S. 384-397 
    Details
    ISSN: 1432-0878
    Keywords: Heart muscle cells ; Electron microscopy ; Quantitative ; Asphyxia ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Normale und hypoxische Herzmuskelzellen aus der Wand des linken Ventrikels der Ratte wurden quantitativ-morphologisch anhand von elektronenmikroskopischen Längsschnitten nach Perfusionsfixierung untersucht. In normalen Zellen waren alle Myofibrillen relaxiert, die mittlere Sarcomerlänge betrug 2,2 μm. Die Schnittfläche wurde zu 55% von Myofibrillen, zu 27% von Mitochondrien und zu 18% von Grundplasma und Reticulum eingenommen. Die zwischen den Myofibrillen liegenden Mitochondrien waren längsoval und im Mittel 2,3mal so lang wie breit. Es bestand kein Unterschied zwischen subendokardial und subepikardial gelegenen Zellen. 10 min nach Erstickung der Tiere waren in den sonst unauffälligen Muskelzellen die Glycogengranula vermindert. Nach 20 min führte die Hypoxie zu einer Zunahme der relativen Schnittfläche der Mitochondrien um etwa 16% und zu einer beginnenden Kontraktur der Myofibrillen (Sarcomerlänge 2,0 μm). 20 min Hypoxie in Hypothermie (25–30°C intrathorakal) veränderte die normale Zellstruktur dagegen kaum. Wenn die Herzen während der 20 min dauernden Hypoxie in Normothermie mit einer procainhaltigen sauerstoff- und glucosefreien Blutersatzlösung durchspült wurden, waren die Myofibrillen relaxiert, die Schwellung der Mitochondrien dagegen wurde nicht reduziert. 30 min nach Erstickung wurde die Kontraktur stärker (Sarcomerlänge 1,7 μm). Nach 60 min bildeten sich Superkontraktionsknoten, einzelne Myofibrillen waren in Höhe der I-Bänder unterbrochen. Die Cristae der Mitochondrien wichen auseinander, die Schnittfläche der Mitochondrien hatte um 27% zugenommen. Während in Normotherapie eine Asphyxie des Tieres bereits nach 10 min die Herzmuskelzellen funktionell schwer schädigt, ist die Schädigung morphologisch erst nach 20 min eindeutig. Das bedeutet, daß für die elektronenmikroskopische Präparation eine Hypoxie von unter 10 min bedeutungslos ist. Hinsichtlich der morphologischen Manifestationszeit für die Unterbrechung der Sauerstoffversorgung stimmen unsere Befunde an Herzmuskelzellen gut mit vergleichbaren Angaben an Leberzellen überein.
    Notes: Summary In heart muscle cells of the left ventricle of rats the distribution of cell organelles and their reaction to hypoxia were investigated by electron microscopy. In normal hearts fixed by perfusion with aldehydes, the mean sarcomere length was 2.2 μm. 27% of the longitudinal sectional area was occupied by mitochondria, 55% by myofibrils and 18% by sarcoplasmic reticulum and ground plasm. The mitochondria situated in rows between the fibrils were oval and measured 2.3 times more in length than in width. There was no difference between cells from subendocardial and subepicardial regions. 10 min hypoxia (complete occlusion of the trachea) did not affect the appearance of muscle cells but diminished the number of glycogen granules. After 20 minutes the area occupied by mitochondria was increased by 16%, the mitochondria between the myofibrils were more spherical and only 1.5 times longer than wide. The sarcomeres shortened to 2.0 μm. With hypothermia (25–30°C) hypoxia of 20 minutes duration did not affect the cell structure. Perfusion of the heart by a saline solution, which contained procaine but neither oxygen nor glucose, for 20 minutes prevented shortening of the sarcomeres but not swelling of the mitochondria. 30 minutes after occlusion of the trachea the myofibrils shortened to a sarcomere length of 1.7 μm. After 60 minutes irregularly and excessively contracted myofibrils appeared and some sarcomeres were interrupted at the level of the I-bands. In some of the swollen mitochondria the cristae were widely separated. The increase of the area occupied by mitochondria was 27%. Asphyxia affects heart muscle cells severely with respect to function within 10 min, but morphologically it takes 20 min before a definite effect can be noticed. As to the time after which lack of oxygen is manifested morphologically, our results are consistent with findings in liver cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02226910
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  • 3
    Electronic Resource
    Electronic Resource
    Zwei elektronenmikroskopisch unterscheidbare Formen sekundärer sensorischer Endigungen in einer Muskelspindel der Ratte (1970)
    Springer
    Cell & tissue research 110 (1970), S. 97-107 
    Details
    ISSN: 1432-0878
    Keywords: Muscle Spindles ; Different types of sensory endings ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung In einer Muskelspindel der Ratte, die an einer Serie alternierender Semidünn- und Ultradünnquerschnitte untersucht wurde, wurden zwei benachbart an „nuclear chain“-Fasern gelegene Nervenendformationen unterschiedlicher Bauweise festgestellt. Die beiden Endformationen sind mit ein und derselben Nervenfaser der Gruppe II verbunden und daher als Bestandteile einer sekundären sensorischen Endigung zu betrachten. Die Nervenendformation an einer der beiden „nuclear chain“-Fasern hat anulo-spirale Form. Die Nervenendformation an der anderen „nuclear chain“-Faser weist am Querschnittsbild eine Anzahl von Axonen auf, die zwischen Plasmalemm und Basalmembran der intrafusalen Muskelfaser eng aneinanderliegen. Nicht alle Axonquerschnitte stehen in direktem Kontakt mit der intrafusalen Faser. Das terminale Axon scheint sieh nach Eintritt unter die Basalmembran der intrafusalen Faser mehrfach in relativ dünne Äste unregelmäßigen Verlaufs zu teilen. Diese Form der Endigung könnte ein Korrelat der sog. „flower spray“-Endigung im Sinne Ruffinis (1898) darstellen. Die beiden morphologisch unterschiedlichen Endformationen innerhalb der sekundären Endigung gleichen einander und den Endformationen der primären Endigung bezüglich folgender Ultrastrukturmerkmale: 1. Es besteht synaptischer Kontakt zwischen Axon und intrafusaler Muskelfaser (synaptischer Spalt durchschnittlich 200 Å) ohne Zwischenlagerung von Basalmembranmaterial; 2. die terminalen Axonabschnitte liegen direkt unter der Basalmembran der intrafusalen Muskelfaser und sind nicht von Schwannschen Zellen bedeckt; 3. Mangel an synaptischen Bläschen; 4. desmosomenartige Verhaftungen zwischen Zellmembranen von Axon und intrafusaler Faser; 5. dyadenartige Anlagerungen des sarkoplasmatischen Retikulums an die Zellmembran der intrafusalen Faser im Bereich des synaptischen Spaltes. Nach unseren derzeitigen Vorstellungen sprechen diese Ultrastrukturmerkmale für eine rezeptorische Natur der beschriebenen Nervenendigungen.
    Notes: Summary In a rat muscle spindle transversally cut into a series of alternating semithin and ultrathin sections, two different forms of nerve terminations were found on two neighbouring nuclear chain fibres. The two nerve terminations were connected to the same group II nerve fibre and are consequently constituents of one particular secondary sensory ending. The nerve termination on one of the two nuclear chain fibres is of the anulo-spiral type. The nerve termination on the second nuclear chain fibre shows a number of axons lying closely together between plasma membrane and basement membrane of the intrafusal muscle fibre. Not all of these axons are in direct contact with the intrafusal fibre. The terminating nerve fibre seems to be divided into several branches of rather small diameters and irregular courses. It is suggested that this kind of termination could be a correlate of the so-called “flower spray” type of sensory endings in muscle spindles. The two morphologically different nerve terminations in the secondary ending have the following ultrastructural characteristics in common with those of the primary ending: 1) Synaptic contact between axon and intrafusal muscle fibre (synaptic gap about 200 Å) without interposition of basement membrane material; 2) terminal axons located beneath the basement membrane layer of intrafusal muscle fibres without covering by Schwann cells; 3) lack of synaptic vesicles; 4) desmosome-like structures between plasma membranes of axon and intrafusal muscle fibre, and 5) dyads of the sarcoplasmic reticulum adjacent to the synaptic cleft. According to present knowledge these features indicate that all of these endings are sensory ones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00343988
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  • 4
    Electronic Resource
    Electronic Resource
    Ultrastructure du lobe postérieur de l'hypophyse du rat et ses modifications au cours de l'excrétion de vasopressine (1970)
    Springer
    Cell & tissue research 108 (1970), S. 357-379 
    Details
    ISSN: 1432-0878
    Keywords: Neurohypophysis ; Rat ; Vasopressin release ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Le lobe postérieur de l'hypophyse a été examiné sur coupes ultrafines chez 45 rats (24 normaux, 17 déshydratés respectivement 1, 2 et 4 jours, et 4 anesthésiés à l'éther), après fixation au glutaraldéhyde ou selon la méthode de Karnovsky, post-fixation osmiée et double contraste à l'acétate d'uranyle et au citrate de plomb. Des fibres neurosécrétoires sombres et claires sont reconnaissables, mais les données manquent encore pour interpréter cette différence. Des densifications juxta-membranaires sont observées dans les terminaisons neurosécrétoires là où se trouvent des amas de microvésicules. Des fibres neurosécrétoires traversent parfois des pituicytes; il est aussi souvent observé des fibres, chargées de granules, libres dans un espace péricapillaire. Les espaces péricapillaires, ramifiés en tous sens loin des vaisseaux, développent une large surface de contact avec les extrémités nerveuses et les prolongements de pituicytes. Dans des conditions techniques bien contrôlées, la déshydratation n'entraîne pas de modifications appréciables des granules de neurosécrétat après 24 h. Ensuite les granules sont diminués en nombre, de façon très considérable le 4e jour; mais les granules restants ont un contenu dense normal; jamais il n'a été observé d'aspects de ≪granules vides ≫. Après anesthésie prolongée à l'éther, il n'y a aucune modification visible ni du nombre, ni de la densité des granules. Ces observations sont discutées quant au mécanisme de l'excrétion de vasopressine; elles sont en faveur de l'existence de deux pools hormonaux, l'un libre et rapidement disponible, l'autre plus fortement lié et certainement contenu dans les granules jouant le rôle de réserve. Toutefois un mécanisme d'exocytose granulaire ne peut être formellement exclu.
    Notes: Summary Hypophysial neural lobes of 45 rats (24 controls, 17 dehydrated resp. 1, 2 and 4 days, and 4 ether anesthetized) were fixed either with glutaraldehyde or according to Karnovsky and post-fixed in osmium tetroxyde; ultrathin sections were stained by uranyl acetate and lead citrate. Dark and clear neurosecretory fibres were observed, but sufficient data are still lacking for a valuable interpretation of these aspects. Juxta-membraneous densifications are visible in limited areas of neurosecretory terminals where clusters of microvesicles are present. Neurosecretory fibres happen to be completely encircled by pituioyte cytoplasm; fibres loaded with elementary granules are frequently encountered running free in a pericapillary space. Pericapillary spaces stretch out branching far away from vessels, resulting in a widespread contact with nerve terminals and pituicyte processes. In accurately controlled technical conditions, dehydratation does not result in any noticeable change of neurosecretory granules after 24 h. A decrease of the number of granules follows and is extremely conspicuous after 4 days; though, remaining granules keep a normal dense content, and aspects of “empty granules” have never been observed. After prolonged ether anesthesia, no visible change either in number or electron density of granules was observed. These findings are discussed in consideration of the mechanism of vasopressin release; they support the hypothesis of two hormonal pools, one of which would be free and rapidly available for release, the other being more tightly bound and certainly located in granules representing a storage site. Though granular exocytosis cannot be absolutely excluded.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00336525
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  • 5
    Electronic Resource
    Electronic Resource
    On the epithelium of the rat pituitary residual lumen (1970)
    Springer
    Cell & tissue research 108 (1970), S. 487-500 
    Details
    ISSN: 1432-0878
    Keywords: Pituitary gland ; Residual lumen ; Epithelial cells ; Fine structure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Histology, enzyme histochemistry, and electron microscopy of the epithelium covering the rat pituitary residual lumen was studied. The anterior and posterior epithelium have similar histological and histochemical appearance, although the posterior epithelium shows stronger enzyme reactions for an esterase and many dehydrogenases. Electron microscopic studies reveal that both epithelia form a continuous lining. Anterior epithelium is in immediate contact with the interstitial spaces of the anterior lobe, while the posterior epithelium is separated from the intermediate lobe by a continuous basement lamina. The cytological features of both epithelia are also remarkably similar with scanty rough-surfaced endoplasmic reticulum, inconspicuous Golgi apparatus, round or oval mitochondria, and moderate number of lysosomal bodies. The apical surface of these cells is covered by microvilli and in some, especially posterior epithelial cells, by numerous cilia. Anterior epithelial cells and the apical portions of the posterior epithelial cells contain a number of large vacuoles with material possibly related to the colloid within the residual lumen. Electron microscopic findings suggest that both epithelia are possibly active in transfer and/or disposal of the colloid material rather than being secretory themselves. Enzyme histochemical findings support the hypothesis of an active role of these cells in metabolic processes related to phagocytosis. Based on these observations the colloid seems to be the product of the anterior lobe function.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00339655
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  • 6
    Electronic Resource
    Electronic Resource
    Quantitative studies of postnatal changes in synapses in rat superficial motor cerebral cortex (1970)
    Springer
    Cell & tissue research 110 (1970), S. 559-568 
    Details
    ISSN: 1432-0878
    Keywords: Cerebral cortex ; Rat ; Synapses ; Postnatal ; Quantitation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Quantitation of synapses at different postnatal ages has been undertaken in the cerebral cortex of the rat. In this study axial ratios of presynaptic bags, proportion of cortex occupied by presynaptic bags and numbers of synapses per unit volume of cortex have been estimated. Observations on synaptic vesicle packing densities have also been made. Synaptic bags become increasingly spherical up to 7 days of age and become more elongated thereafter. The proportion of cortex occupied by presynaptic bags increases rapidly up to 7 days of age and then at a decelerated rate up to maturity. The number of synapses per unit volume increases slowly over the first four days after which there is a rapid increase to 14 days, followed by a decelerated rate. The average presynaptic bag shows marked changes in volume with increasing age which indicate the probability of two stages of synaptic development. This two stage development is further reflected in the estimates on vesicle packing densities. The implications of the results are discussed in relationship to changes in functional activity of the cortex during postnatal development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00330104
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  • 7
    Electronic Resource
    Electronic Resource
    Elektronenmikroskopische Untersuchungen zur Inselregeneration im Rattenpankreas nach subtotaler Pankreatektomie (1970)
    Springer
    Cell & tissue research 110 (1970), S. 569-587 
    Details
    ISSN: 1432-0878
    Keywords: Subtotal Pancreatectomy ; Rat ; Islet Regeneration ; Excretory Duct System
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Männliche Ratten wurden bei einem Gewicht von 80–100 g subtotal pankreatektomiert (5% Rest) und zu verschiedenen Zeitpunkten nach der Operation abgetötet. Bei diesen wie bei unbehandelten Kontrolltieren wurde die Neubildung von Inselgewebe aus dem exkretorischen Gangsystem elektronenmikroskopisch untersucht. — Es konnte gezeigt werden, daß die Inselneubildung von Gangzellen ausgeht, welche ein auffallend helles Zytoplasma besitzen und samt ihren Kernen größer und abgerundeter sind als ihre Nachbarzellen. Diese Zellen wandern vom Lumen ab, wobei die entstehende Lücke zum Lumen zu jeweils durch eine seitliche Ausdehnung des Zytoplasmas benachbarter Gangzellen geschlossen wird. Die abgewanderten hellen Zellen, die mit den lichtmikroskopisch beschriebenen „trüben Zellen“ identisch sein dürften, haben die Fähigkeit, sich zu Alpha-oder Beta-Zellen zu differenzieren. Dabei werden sie größer und das Zytoplasma dunkler. Sie behalten aber gleichzeitig einige Besonderheiten, die auf ihre Herkunft hinweisen. Die Regeneration des Inselgewebes, die vorwiegend von den zentroacinären Zellen ausgeht, setzt bald nach der Operation stark ein, schwächt sich dann aber kontinuierlich ab. In den immer ineffektiver werdenden Regenerationsvorgang werden zunehmend größere Gangabschnitte einbezogen. Die weitgehende Erschöpfung der Regenerationsfähigkeit fällt mit dem Auftreten eines manifesten Diabetes zwischen dem 40. und 60. Tag p.op. zusammen.
    Notes: Summary Male rats were subtotally pancreatectomized at a weight of 80–100 g according to the method of Foglia (5% of the total pancreas remaining). The animals were killed at different intervals after. In these rats, as well as in healthy controls, the new formation of islets out of the excretory duct system was studied by electron microscopy. Obviously the new formation of islets takes origin from certain cells of the ductular system which show a light cytoplasm and are larger and rounder than their neighbouring cells. The latter goes for their nuclei, too, even to a larger degree. These light cells migrate away from the ductular lumen and the gaps resulting from this are closed by long and thin processes of the cytoplasm of their neighbouring duct cells coming in contact with each other. The cells having migrated away seem to have an ability to differentiate into alphaor beta-cells. Most probably they are identical with the “trübe Zellen” described by light-microscopists. The higher the degree of differentiation in these cells is, the darker becomes their cytoplasm. But they still keep for some time morphological aspects indicating their origin from ductular cells. An intense regeneration of islet tissue starts soon after the operation from the centroacinar cells but it decreases continuously after. As the process of islet regeneration becomes more and more ineffective, an increasing number of larger excretory ducts are involved in it. The exhaustion of the ability for regeneration is correlated exactly in time with the onset of a manifest diabetes between the 40 th and 60 th day after operation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00330105
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  • 8
    Electronic Resource
    Electronic Resource
    Electron microscopic studies on the oocyte maturation in cultures of juvenile rat ovaries (1970)
    Springer
    Cell & tissue research 111 (1970), S. 364-378 
    Details
    ISSN: 1432-0878
    Keywords: Rat ; Oocyte maturation ; in vitro studies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary After cultivation in a modified Trowell-system (organ ciilture) oocytes of 12- to 40-day-old rats were studied under the light and electron microscope. The cultivation period was 72 hrs. Egg cells from primary and early secondary follicles which are characterized by the lack of a zona pellucida and by one or at most two very large Golgi's complexes located near the nucleus do not show any alterations. The other egg cells are characterized by membrane packages which can otherwise only be observed in mature egg cells right before or after the ovulation. Meiotic processes or the formation of polar bodies are only seldom to be seen. These egg cells are surrounded by a thick zona pellucida. From these findings the following conclusions can be drawn: 1. In organ cultures meiotic processes are prevented by the inhibitory influence of follicle cells (Foote and Thibault, 1969). 2. A cytoplasmic maturation proceeds independently. 3. In-vivo an inhibitory factor influences the cytoplasmic maturation. This inhibition is not observed in the organ culture. Thus we can be sure that it develops outside the ovary. 4. The synthesis of the zona pellucida continues in-vitro.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00342488
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  • 9
    Electronic Resource
    Electronic Resource
    Morphology of superficial postnatal cerebral cortex with special reference to synapses (1970)
    Springer
    Cell & tissue research 110 (1970), S. 540-558 
    Details
    ISSN: 1432-0878
    Keywords: Cerebral cortex ; Synapses ; Rat ; Postnatal differentiation ; Morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of layers I and II of the motor cerebral cortex of rat brain has been studied at birth, 4, 7 and 14 days postnatal and in the adult. Compared with the adult, neonatal rat motor cortex exhibited a large extracellular space which decreases with increasing age. At all stages studied the neurons were seen to contain the organelles usually found in adult neurons. Growth cones were present in decreasing numbers up to 14 days old. Synapses were detectable at birth and there was an obvious increase in their number throughout the postnatal development. At the earliest stages studied there was a lack of specialization characteristic of the adult. Many synapses were either avesicular or relatively so and lacked the high degree of modification of adult pre- and postsynaptic membranes. By 7 days after birth many synapses existed which in all morphological respects resembled those of the adult, and by 14 days, the majority were of the adult type. These findings, particularly with reference to the postnatal development of synapses, have been discussed in relation to the known electrophysiological findings.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00330103
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  • 10
    Electronic Resource
    Electronic Resource
    Origine embryonnaire et différenciation sécrétoire des cellules à calcitonine (cellules C) dans la thyroïde foetale du rat (1970)
    Springer
    Cell & tissue research 106 (1970), S. 251-268 
    Details
    ISSN: 1432-0878
    Keywords: C cells ; Thyroid ; Rat ; Ultimobranchial origin ; Differentiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Nos observations confirment l'origine ultimobranchiale des cellules C de la thyroïde du rat. L'évolution des corps ultimobranchiaux (C.U.B.) a été étudiée à partir du 16ème jour de gestation, stade où ils fusionnent avec l'ébauche thyroïdienne. Dès le 17ème jour, les premières cellules C se différencient dans le C.U.B. inclus dans la thyroïde. Au 18ème jour, elles sont plus nombreuses et commencent à se disperser dans les cordons thyroïdiens. La migration des cellules C est particulièrement importante au 19ème jour. A partir du 20ème jour, les signes d'activité sécrétoire s'intensifient très nettement. A la fin de la vie foetale, les cellules C sont comparables aux cellules C adultes. La differenciation des cellules parathyroïdiennes précède nettement celle des cellules C.
    Notes: Summary Our observations confirm the ultimobranchial origin of the C cells of the rat thyroid. We studied the development of the ultimobranchial body from the 16th day of pregnancy, when there is fusion with the thyroidian anlage, onwards. As early as the 17th day, the first C cells differentiate in the ultimobranchial body which is included into the thyroid. On the 18th day, they are more numerous and start to scatter throughout the thyroidian cords. The migration of the C cells is especially obvious on the 19th day. From the 20th day onwards, there is marked increase in secretory activity. At the end of the foetal life, the C cells resemble those of the adult. The differentiation of the parathyroid cells significantly precedes that of the C cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00335742
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  • 11
    Electronic Resource
    Electronic Resource
    Monoamine fluorescence in the median eminence of foetal, neonatal and adult rats (1970)
    Springer
    Cell & tissue research 104 (1970), S. 541-556 
    Details
    ISSN: 1432-0878
    Keywords: Median eminence ; Rat ; Monoamine fluorescence ; Output of pars distalis hormones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of monoamines in the median eminence of foetal, neonatal and adult rats has been studied with the Falck-Hillarp fluorescence histochemical technique in preparations in which the hypothalamus and pituitary gland were in continuity. In adult rats monoamine fluorescence is present throughout the median eminence, including the anatomical stem. In foetal rats a few sagittally-directed varicose fluorescent fibres are seen in the median eminence. In neonatal rats palisade layer fluorescence in appreciable amounts is first seen on the fourth day in the region of the anatomical stem. By the eighth day it has spread throughout the palisade layer of the entire median eminence, and by the end of the third week it has attained adult intensity. The appearance of monoamines in the median eminence, the development of a functional hypophysial portal system, and a changing pattern of development of function in both the hypothalamo-pituitary-adrenal and hypothalamo-pituitary-thyroid axes thus all appear to be contemporaneous events. It is suggested that the monoamines of the median eminence represent part of a neural system influencing the output of pars distalis hormones, in particular of ACTH and TSH secretion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00335377
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  • 12
    Electronic Resource
    Electronic Resource
    Cellular localization of 3H-oestradiol in the hypothalamus (1970)
    Springer
    Cell & tissue research 104 (1970), S. 572-581 
    Details
    ISSN: 1432-0878
    Keywords: Hypothalamus ; Rat ; Cellular Localization of 3H-Oestradiol ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The hypothalamus of male and female rats, given 0.3 μg/100 g body weight of 6.7-3H-oestradiol-17β and killed 1 hour after the injection, was examined by autoradiography in order to 1) localize the areas and the cells involved in the uptake of the hormone, and 2) study the intracellular localization of the labelled material. Only nerve cells contained radioactive material while glial and ependymal cells were not significantly labelled. In the anterior hypothalamus, labelled nerve cells were concentrated in areas corresponding to nucleus preopticus medialis and nucleus preopticus, pars suprachiasmatica. The nucleus supraopticus was unlabelled. In the medial basal hypothalamus, neurons corresponding to the nucleus arcuatus and the lateral part of the nucleus ventromedialis showed marked labelling. No significant labelling was observed in the nucleus paraventricularis, pars magnocellularis. Although the individual nerve cells varied in their extent of labelling, the major proportion of the silver grains were consistently concentrated over the nuclei. Castration was not found to influence the results. The findings were essentially the same in male and female rats and appear to suggest that oestradiol exerts a direct effect on nerve cells in certain hypothalamic areas.
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    URL: http://dx.doi.org/10.1007/BF00335379
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  • 13
    Electronic Resource
    Electronic Resource
    The uptake of 3H-oestradiol by the anterior hypophysis and hypothalamus of male and female rats (1970)
    Springer
    Cell & tissue research 104 (1970), S. 582-596 
    Details
    ISSN: 1432-0878
    Keywords: Anterior hypophysis ; Hypothalamus ; Rat ; Uptake of 3H-Oestradiol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The anterior hypophysis and hypothalamus of male and female rats given 3H-oestradiol were examined with regard to 1) the kinetics of the uptake of the radioactive material, 2) the chemical nature of the labelled material, and 3) the influence of non-labelled oestradiol-17β, oestradiol-17α and testosterone on the uptake of 3H-oestradiol. The anterior hypophysis was found to concentrate and retain oestradiol in basically the same manner in male and female rats. The pattern of the uptake was similar to that of the uterus and vagina, with a concentration peak 2 hours after the injection. Non-target tissues such as cerebral cortex, liver and blood attained their maximum uptake already 15 minutes after the injection. Thereafter the concentration gradually decreased. The ratio between the concentration of labelled material in the anterior hypophysis and brain cortex gradually increased until a peak was reached at 8 hours in both sexes. In the female, the concentration of labelled material in the anterior hypophysis was then 106.3 times greater than in the brain cortex, while in the male the ratio was 63.2. In the hypothalamus the uptake followed a pattern similar to that of the brain cortex. However, in the former the concentration of labelled material was consistently greater than in the latter. At maximum uptake, registered 4 hours after the injection, the concentration was about two times greater in the hypothalamus than in the cerebral cortex. The neurohypophysis contained, on an average, 1/6 of the amount of radioactive material registered in the anterior lobe one hour after the injection, but it was about two times greater than in the brain cortex. Isolation and identification of the radioactive material in the anterior hypophysis and hypothalamus showed that in both sexes nearly all of it was chemically unchanged oestradiol. Graded doses of non-labelled oestradiol-17β were found to decrease the uptake of 3H-oestradiol in the anterior hypophysis and hypothalamus almost linearly, while the concentration of labelled material in the brain was unaltered. Oestradiol-17α and testosterone were without significant effect on both the pituitary and hypothalamic accumulation of 3H-oestradiol. Therefore, a limited number of binding sites, with a high degree of specificity for oestradiol, appear to exist in both tissues. The results were essentially the same in male and female rats.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00335380
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  • 14
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    Ultrastructural changes in the median eminence of the rat following deafferentation of the basal hypothalamus (1970)
    Springer
    Cell & tissue research 105 (1970), S. 1-32 
    Details
    ISSN: 1432-0878
    Keywords: Median eminence ; Rat ; Deafferentation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary This report concerns a light and electron microscopic investigation of the median eminence and dorsal infundibular stem of the rat following surgical isolation (deafferentation). Using a modification of the Halász technique, the basal hypothalamus, including the arcuate nucleus and median eminence were surgically isolated from surrounding structures. Special attention was directed to the contact (external) zone of the median eminence and rostral infundibulum where tuberohypophyseal axons as well as ependymal cell processes abut upon the abluminal basement membrane of the portal perivascular space. The results of this study to date suggest that 9, 20, and 40 days following surgical isolation, there is a distinct increase in the population of tuberohypophyseal dense core vesicles. It is suggested that deafferentation abolishes inhibitory and excitatory input that serves to modify the cellular dynamics of tuberohypophyseal neurosecretory elements. Comments are also made on the presence of cistern-like structures in the lateral median eminence; the presence of vesicle-like inclusions in terminal ependymal processes is discussed in relationship to the role that ependyma may play in linking the third ventricle with the adenohypophysis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00340562
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  • 15
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    Electronic Resource
    Cellular localization of 3H-oestradiol in the hypophysis (1970)
    Springer
    Cell & tissue research 104 (1970), S. 597-614 
    Details
    ISSN: 1432-0878
    Keywords: Hypophysis ; Rat ; Localization of 3H-Oestradiol ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pituitaries of male and female rats given 0.3 μg of 6.7-3H-oestradiol-17β per 100 g body weight were examined by autoradiography in order to 1) identify the cells responsible for the uptake of the hormone, 2) determine the intracellular distribution of the hormone and quantify the proportions localized within the cytoplasm and nucleus by silver grain counting, and 3) see if sex differences existed in the cellular and intracellular distribution of the hormone. The animals were killed at intervals varying from 1 minute to 8 hours following intravenous or intramuscular injection. A large proportion of pituitary cells having the morphologic characteristics of acidophils, basophils and chromophobes contained radioactive material. Castration cells and acidophils of gonadectomized and lactating rats showed marked labelling. In male and female rats killed 10 minutes after intravenous injection, 84.4 and 83.6 per cent of the cells were labelled. One hour after intramuscular injection, 86.6 and 76.1 per cent of the cells were labelled in males and females, respectively. Thus, a small proportion of the cells remained unlabelled. Labelled cells showed silver grains both in the cytoplasm and over the cell nuclei, but the major proportion of the radioactive material was invariably associated with the cell nuclei in all cell types and at all time intervals. About 65 per cent of the radioactive material was associated with the cell nuclei in animals killed five minutes or one hour after intravenous or intramuscular injection of the hormone. The silver grains appeared to be randomly distributed in both the cytoplasm and over the cell nuclei. In the intermediate lobe and the neurohypophysis, only sparse labelling with random distribution was observed. At the border between the intermediate lobe and the neurohypophysis, labelling of single cells or clusters of cells similar to those in the adenohypophysis was found. The results, which were essentially the same in male and female rats, appear to indicate a direct effect of oestradiol at the pituitary level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00335381
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  • 16
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    Electronic Resource
    Altersabhängige Veränderungen im histochemischen Reaktionsmuster des Thymus bei Wistar-Ratten (1970)
    Springer
    Cell & tissue research 104 (1970), S. 138-148 
    Details
    ISSN: 1432-0878
    Keywords: Thymus ; Rat ; Involution ; Histochemical pattern
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Makrophagen und entodermale Retikulumzellen samt Ausläufern lassen sich im Thymus der Wistar-Ratte durch den histochemischen Nachweis der sauren Phosphatase und der unspezifischen Esterase selektiv darstellen, während die Lymphozyten nicht reagieren. Häufigkeit und Verteilung der Retikulumzellen und Makrophagen lassen altersabhängige Unterschiede erkennen: Auf Kosten der Retikulumzellen nimmt die Zahl der Makrophagen mit fortschreitendem Lebensalter zu. Bei geschlechtsreifen Tieren bilden sie einen Wall an der Mark-Rinden-Grenze. Die Bedeutung der sauren Phosphatase in entodermalen Retikulumzellen wird unter der Annahme diskutiert, daß es sich um lysosomengebundenes Ferment handelt. Lysosomen sind im involvierenden Thymus wahrscheinlich an autolytischen oder phagozytotischen Prozessen beteiligt. Es stellt sich die Frage, ob Lysosomen in entodermalen Retikulumzellen des Thymus neugeborener Tiere in die Abgabe einer humoral wirksamen Substanz eingreifen können.
    Notes: Summary Macrophages and entodermal reticulum cells in the thymus of Wistar rats contrast by their rich contents of acid phosphatase and unspecific esterase activity with the negativ reacting lymphocytes. Frequency and distribution of the cells vary according to different stages of age: at cost of the entodermal reticular cells the number of macrophages increases with progressive age. In sexually mature animals they form a typical layer at the corticomedullary junction. The functional meaning of acid phosphatase in the entodermal reticulum cells is discussed under the assumption that this enzyme is lysosomebound. In the involuting thymus lysosomes are involved in autolytic or phagocytic processes. The question arises wether lysosomes in entodermal reticulum cells in the thymus of newborn animals can take part in the control of an humoral function of the thymus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00340055
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