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  • Rat  (27)
  • Animals
  • Kinetics
  • Pregnancy
  • Springer  (36)
  • 1980-1984  (36)
  • 1925-1929
  • 1982  (36)
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  • 1980-1984  (36)
  • 1925-1929
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  • 1
    Electronic Resource
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    Springer
    Colloid & polymer science 260 (1982), S. 641-642 
    ISSN: 1435-1536
    Keywords: Kinetics ; Nucleation ; Water ; Emulsion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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  • 2
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    Monatshefte für Chemie 113 (1982), S. 1087-1092 
    ISSN: 1434-4475
    Keywords: Dissolution ; Kinetics ; Pyrrhotite ; Rotating disc
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die Auflösungsgeschwindigkeit von natürlichem monoklinen Pyrrhotin, FeS1.14, wurde in sauerstofffreien LösungenS([H+]=0.1, [Na+]=0.9, [ClO 4 − ]=1.0 mol kg−1) mit Hilfe der Methode der rotierenden Scheibe bestimmt. Im Temperaturbereich von 40–90° erfolgt die Auflösungsreaktion kinetisch kontrolliert, wobei eine Aktivierungsenergie von 14±1 kcal mol−1 (59±5 kJ mol−1) gefunden wurde.
    Notes: Abstract Using the rotating disc method, the rates of dissolution of natural monoclinic pyrrhotite, FeS1.14, in oxygen-free aqueous solutionsS([H+]=0.1, [Na+]=0.9, [ClO 4 − ]=1.0 mol kg−1) were determined. In the temperature range 40–90 °C the dissolution reaction occurs under kinetic control; the activation energy being 14±1 kcal mol−1 (50±5 kJ mol−1).
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  • 3
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    Monatshefte für Chemie 113 (1982), S. 1239-1244 
    ISSN: 1434-4475
    Keywords: Allyl alcohol ; Kinetics ; Mechanism ; Oxidation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die Kinetik der Oxidation von Allylalkohol mitN-Bromsuccinimid (NBS) wurde bei 35 °C in wäßrigem Medium untersucht. Die Reaktion zeigt erste Ordnung gegenüberNBS und Allylalkohol. Bei relativ hoher Säurekonzentration zeigt sich keine Änderung der Reaktionsgeschwindigkeit, bei niedriger Säurekonzentration wird die Reaktionsgeschwindigkeit beträchtlich erhöht. Es wurde kein primärer Salzeffekt festgestellt. Bei varriierender Quecksilberacetatkonzentration bleibt die Reaktionsgeschwindigkeit gleich, bei Abwesenheit von Quecksilberacetat wird jedoch die Geschwindigkeitskonstante erhöht. Die kinetischen Parameter,E a, derArrheniusfaktorA, ΔH ≠, ΔG ≠ und ΔS ≠ wurden bestimmt. Ein Geschwindigkeitsgesetz in Übereinstimmung mit den experimentellen Befunden wurde abgeleitet und ein Mechanismus vorgeschlagen.
    Notes: Abstract The kinetics of oxidation of allyl alcohol byN-bromosuccinimide (NBS) has been studied at 35 °C in aqueous medium. The reaction shows first order dependence on bothNBS and allyl alcohol. In fairly high acid concentration, there is no change in the rate of the reaction but at low acid concentration, the rate is considerably enhanced. There is no primary salt effect. At varying mercuric acetate concentrations, the rate constant remains the same. But in the absence of mercuric acetate, the rate is enhanced. The kinetic parameters,E a,Arrhenius factorA, ΔH≠, ΔG≠ and ΔS≠ have been calculated. A rate law in agreement with experimental results has been derived. A mechanism is proposed.
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  • 4
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    Monatshefte für Chemie 113 (1982), S. 887-893 
    ISSN: 1434-4475
    Keywords: Diazotation ; Kinetics ; α-Naphthylamine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Optimal diazotation conditions were determined by means of extinction measurements at various experimental conditions. The optimal conditions found arep H=9,5, the amount of phenol is 1 250 times the amount of α-naphthylamine.
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  • 5
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    Monatshefte für Chemie 113 (1982), S. 3-14 
    ISSN: 1434-4475
    Keywords: Graphite ; Kinetics ; Reduction ; Thoria ; Thoriumcarbide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die Reduktion von Thoriumoxid mit Graphit im Überschuß wurde mittels einer Thermowaage zwischen 1620 und 1920 K im Vakuum untersucht. Ab ThO2:C=1:50 war die Reaktionsgeschwindigkeit vom Mischungsverhältnis unabhängig; das Endprodukt war immer ThC2. Der logarithmische Gewichtsverlust war direkt proportional der Zeit, und dieArrheniusgerade zeigte einen Knickpunkt bei 1710 K: unterhalb dieser Temperatur ergab sich eine Aktivierungsenergie von 440 kJ, oberhalb eine solche von 260 kJ. Die Temperatur des Knickpunkts entspricht der Umwandlungstemperatur von monoklinem in tetragonal raumzentriertes ThC2.
    Notes: Abstract The reduction of thoria with excess graphite was studied with a thermo-balance in vacuum between 1620 and 1920 K. From Th02:C=1:50 the rate of reaction was independent of the ratio of the reactants; the endproduct was always ThC2. The logarithmic weight loss was directly proportional to the time, and theArrhenius plot showed a break at 1710 K: below this temperature the activation energy was found to be 440 kJ, above 260 kJ. The temperature corresponding to the break coincides with the transition temperature of monoclinic to body-centered tetragonal ThC2.
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  • 6
    ISSN: 1434-4475
    Keywords: Kinetics ; Ligand-transfer ; Thallium (III)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The transfer of oxinate ions from thallium (III)oxinate to trivalent Fe(DMF) 6 3+ in propylenecarbonate takes place via rearrangements within a rapidly formed binuclear thallium(III)—iron(III) complex. In a last rapid step this rearranged complex reacts with excess reactants to the final products whose composition accordingly depends on the ratio of the reactant concentrations.
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  • 7
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    Calcified tissue international 34 (1982), S. 211-213 
    ISSN: 1432-0827
    Keywords: Rat ; incisor ; ameloblasts ; enamel ; 45Ca autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Rats were injected with45Ca and horseradish peroxidase to determine the patterns of45Ca incorporation into incisor enamel and the morphological types of the overlying maturation ameloblasts.45Ca autoradiography showed no differences in the patterns of incorporation into enamel between routinely embedded and freeze-dried specimens. Enamel overlaid by ruffle-ended ameloblasts was much more heavily labeled while that overlaid by smooth-ended ameloblasts showed only moderate labeling. The observations lend further support to the hypothesis that the ruffle-ended cells are very active in mineralizing enamel and that the smooth-ended cells are in a passive, restorative phase.
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  • 8
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    Calcified tissue international 34 (1982), S. 9-12 
    ISSN: 1432-0827
    Keywords: Parathyroid hormone ; Pregnancy ; Nephrogenous cAMP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Parathyroid hormone (PTH) metabolism in pregnancy has not been clearly defined. Studies have reported either increased or unchanged values of immunoreactive PTH (iPTH). However, iPTH levels do not necessarily correlate with hormonal bioactivity due to the presence of immunoreactive but nonbioactive PTH fragments. In this study we evaluated PTH metabolism in the third trimester of pregnancy by determining iPTH blood levels as well as the biological effects of PTH, assessed by tubular maximum phosphate reabsorption (TmP) and nephrogenous cAMP (ncAMP) excretion, in 10 young, healthy pregnant patients (mean gestational age 35 weeks) and 10 young, healthy age-matched female controls. Pregnancy was associated with a significant increase in creatinine clearance (146±13 vs 106±9 ml/min,P〈0.01), and a significant decrease in total fasting serum calcium (8.4±0.1 vs 9.0±0.1 mg/dl,P〈0.001) and serum albumin (3.6±0.1 vs 4.2±0.1 g/dl,P〈0.001). There was no significant difference in iPTH (3.7±0.4 vs 4.3±0.5 µlEq/ml), serum phosphorus (3.6±0.1 vs 3.8±0.2 mg/dl), TmP (3.61±0.13 vs 3.75±0.25 mg/100 ml GFR), or ncAMP (1.68±0.20 vs 1.88±0.23 nmoles/100 ml GFR) between the two groups. Pregnancy was attended by a significant increase in fasting urinary calcium to creatinine ratio (0.14±0.03 vs 0.06±0.01,P〈0.05), an index of bone resorption. The data suggest that the biological effects of PTH are unchanged in pregnancy, and that reported increments in 1,25(OH)2 vitamin D in pregnancy are not regulated by changes in either PTH, calcium, or phosphate.
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  • 9
    ISSN: 1432-0827
    Keywords: Vitamin D ; Vitamin D deficiency ; Bone ; Pregnancy ; Lactation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The effect of vitamin D on bone changes during the reproductive cycle in female rats has been investigated. One group of female rats was maintained on a vitamin D-deficient diet and another group on a vitamin D-replete diet from weaning. Both groups were mated with normal males and changes in their bones were determined histomorphometrically during pregnancy, lactation, and after weaning. All vitamin D-deficient rats had bone changes typical of rickets. Pregnancy caused significant reductions in mineralized tissue of trabecular and cortical bone in the vitamin D-deficient rats. Lactation caused further significant reductions in mineralized tissues of cortical and trabecular bone in both the vitamin D-deficient and vitamin D-replete animals, with the greatest changes seen at weaning. Some restoration of mineralized tissues occurred following weaning. There was an increase in tetracycline-labeled bone surface in the vitamin D-replete animals during lactation, likely due to an increase in bone formation rates. In the vitamin D-deficient animals during lactation, there was a decrease in tetracyclinelabeled bone surface, likely due to severely depressed bone mineralization. These results indicate that the mobilization of calcium from bone to maintain pregnancy and lactation occurs by a mechanism independent of vitamin D.
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  • 10
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    Calcified tissue international 34 (1982), S. 376-381 
    ISSN: 1432-0827
    Keywords: Matrix vesicles ; Bone ; Actin ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Preliminary indications of the occurrence of actin and myosin in crude matrix vesicle preparations have been reported previously. In the present study extracellular matrix vesicles from rat alveolar bone were isolated. They were further purified by a sucrose density gradient. SDS-polyacrylamide gel electrophoresis of the purified vesicles revealed the presence of a polypeptide with a molecular weight of 43 K daltons and with electrophoretic mobility identical to that of blood platelet actin. The limited proteolysis of both 43 K dalton vesicular polypeptide and actin byStaphylococcus aureus-V8-protease revealed three fragments with identical electrophoretic mobility. In addition, the vesicular preparations inhibited the activity of DNase I, a property typical of actin monomers. Filamentous material extracted from matrix vesicles showed ultrastructural features of F-actin. Reaction of this material with heavy meromyosin resulted in arrowhead formation, which is characteristic of acto-heavy meromyosin. The occurrence of actin in extracellular matrix vesicles may account for their budding from the osteoblastic plasma membrane, their possible motility in the matrix, and maintenance of the spherical shape.
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  • 11
    ISSN: 1573-5036
    Keywords: Ammonification ; Cadmium ; Heavy metals ; Kinetics ; Lead ; Nitrification ; Perfusion incubations ; Polluted soils ; Selection ; Toxicity ; Zinc
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The sensitivity of the mineralization of nitrogen by a range of soils contaminated with heavy metals (up to 340 μg Cd g−1, 7500 μg Pb g−1 and 34000 μg Zn g−1) to the addition of heavy metals in solution were studied using pot incubations (ammonification) and a soil perfusion technique (nitrification). The ammonification of peptone showed little correlation between treatments with Cd, Zn (1000 and 5000 μg g−1) and Pb (10000 and 20000 μg g−1) and origin of the soil. Nitrification was considerably more sensitive to heavy metals than ammonification. All the soils had active, often large, populations of ammonifying and nitrifying organisms which showed substantial similarities between the soils. The rate of nitrifying activity (NO3−N production) was logrithmic in most cases. The presence of tolerant populations of nitrifying organisms in the contaminated soils was demonstrated. Tolerance was also eventually acquired after a longer lag phase, by the non-contaminated soil populations although the rate of activity was often reduced. Metals added in solution were adsorbed by the soil within 4 hours. Differences in toxicity between metal salts (chlorides, sulphates and acetate) were attributed to the amount left in solution. However, in many instances, acetate was found to stimulate all the stages in the mineralisation of nitrogen.
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  • 12
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    Cell & tissue research 225 (1982), S. 229-234 
    ISSN: 1432-0878
    Keywords: Preovulatory follicle ; Cell division ; Age ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pattern of follicular development during the estrous cycles of aged rats was examined and compared with that of mature rats. In both, preovulatory follicles are derived from a select group of small pre-Graafian follicles which begin to develop at estrus and reach the preovulatory size by the morning of proestrus, but the rate of growth, as judged by an increase in the percentage of granulosa cells incorporating 3H-thymidine, is accelerated in the follicles of aged rats. A second mechanism, which accounts for preovulatory follicles in aged rats, involves the rescue from atresia of pre-Graafian and preovulatory follicles. The existence of this mechanism is supported by the observation that at metestrus in aged rats virtually all follicles, regardless of their state of atresia, possess a high percentage of granulosa cells incorporating 3H-thymidine, indicating that the follicles are growing rapidly. However, some of these rapidly growing follicles show signs of atresia such as pyknotic nuclei within their granulosa cell layers. Since follicles in the initial stage of atresia contain defective oocytes (Peluso et al. 1979b), their rescue and development into preovulatory follicles would result in the ovulation of defective oocytes, a fact which accounts in part of the lower fertility in these older animals.
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  • 13
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    Cell & tissue research 225 (1982), S. 469-485 
    ISSN: 1432-0878
    Keywords: Microglial cells ; Postnatal development ; Enzyme histochemistry ; NDPase, TPPase ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The postnatal development of microglial cells was investigated in the neonatal rat brain by use of light- and electron microscopy, including enzyme-histochemical techniques. Microglial cells were selectively stained by demonstration of their nucleoside diphosphatase (NDPase) activity and classified into three types: 1) In the early postnatal period, “primitive microglial cells” showing scantily ramified processes were found in the cerebral cortex, the hippocampal formation, and the hypothalamus. During the course of the first postnatal week the processes of this cell type developed gradually and the cells were transformed into typical ramified microglial cells, called “resting microglial cells”. 2) “Amoeboid microglial cells” showing typical features of macrophages were characteristic of the cerebral white matter. 3) “Round microglial cells” possessing a round soma and few pseudopodia but no characteristic processes occurred in large numbers in the sub ventricular zone of the lateral ventricle and as single elements in the vicinity of blood vessels. Histochemically, thiamine pyrophosphatase (TPPase) was demonstrated only in the fully developed, ramified microglial cells (“resting microglial cells”), which could be readily observed in the central nervous tissue from the age of 14 day. “Round and amoeboid microglial cells” did not show TPPase activity and disappeared after 14 days of postnatal life. By use of electron microscopy, in neonatal rats NDPase activity was apparent in the plasma membrane of the three types of microglial cells (“primitive, round, and amoeboid” types). They showed basically similar submicroscopic characteristics, i.e., well-developed Golgi apparatus, long strands of roughsurfaced endoplasmic reticulum, single dense bodies and vacuoles, and numerous ribosomes. “Amoeboid microglial cells” were characterized by their well-developed cytoplasmic vacuoles and phagocytic inclusion bodies. The present study strongly suggests a mesodermal origin for these microglial elements.
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  • 14
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    Cell & tissue research 222 (1982), S. 359-378 
    ISSN: 1432-0878
    Keywords: Axon terminals ; Substantia gelatinosa ; Spinal cord ; Noradrenaline ; Ultrastructure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The noradrenergic terminals in the substantia gelatinosa of the dorsal horn of the cervical spinal cord of the rat were investigated by means of the histofluorescence technique and electron-microscopic cytochemistry using the glyoxylic acid-KMnO4 fixation technique. In accordance with the topographical distribution of fluorescent catecholaminergic fibers, noradrenergic terminals containing small granular vesicles were frequently observed electron microscopically in the outer layer of the substantia gelatinosa. These terminals were most frequently found to appose without showing typical synaptic features, small-caliber dendrites, spine apparatus, and rarely, large caliber dendrites. Only in a few cases, the noradrenergic terminals exhibited typical synaptic contacts with dendritic elements of small size. In addition, noradrenergic terminals apposed non-noradrenergic terminals containing small agranular vesicles. In rats bearing surgical lesions of the dorsal roots, no noradrenergic terminal were found in contact with the degenerated axon terminals in the substantia gelatinosa. These findings suggest that the noradrenergic afferents to the substantia gelatinosa may exert their influence on sensory transmission via dorsal horn cells.
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  • 15
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    Cell & tissue research 222 (1982), S. 629-634 
    ISSN: 1432-0878
    Keywords: Calcitonin cells ; Anomaly ; Thymus ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In a study of the effect of pinealectomy on thyroid C-cell number, 8 animals out of 66 were found to have thymic tissue in close association with the thyroid. Cells containing immunoreactive calcitonin were found in all of the thyroids but in only one of the 8 pieces of thymus. These cells found in a piece of thymic tissue associated with the right thyroid lobe were located immediately under the capsule and did not form or associate with follicles. Unlike the other animals the rat with thymic calcitonin cells had an unequal distribution of C-cells between the left and right thyroid lobes, but the total number of thyroidal C-cells was the same as that of the other rats. Since the thymus proper was not examined in these 66 animals, ten additional rats were taken for such a study. Thyroid-associated thymic tissue was found in three of these, but none of these thymi showed any immunoreactive cells.
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  • 16
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    Cell & tissue research 222 (1982), S. 691-693 
    ISSN: 1432-0878
    Keywords: Jugular vein ; Histochemistry ; Adrenergic innervation ; Cholinergic innervation ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The autonomic innervation of rat jugular vein was studied using glyoxylic acid fluorescence and acetylcholinesterase histochemical methods. The rat jugular vein is provided with both adrenergic and cholinergic nerve fibers organized in plexuses located at the adventitial-medial border. The existence of these nerve plexuses does not seem to support biochemical findings that suggest a lack of innervation in the rat jugular vein and which propose this blood vessel as a model for the analysis of drug-smooth muscle cell interaction without the interference of neuronal uptake mechanisms.
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  • 17
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    Cell & tissue research 223 (1982), S. 493-506 
    ISSN: 1432-0878
    Keywords: Microglial cells ; TPPase ; NDPase ; Synapse ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron-microscopic survey of selectively stained microglial cells in the cerebral cortex of the rat reveals that the processes of this cell type often encircle axo-dendritic synapses. Enzyme-histochemical methods for thiamine pyrophosphatase (TPPase) or nucleoside diphosphatase (NDPase) were used for the selective marking of the microglial cells; TPPase and NDPase activities were observed in the plasma membrane of microglial cells. The synapses encircled by microglial processes displayed presynaptic structures containing round clear vesicles (50 nm in diameter) and a prominent thickening of the postsynaptic membrane. In vitro, the above-mentioned enzymatic activities were completely suppressed by neuroactive agents such as catecholamines and phenothiazine derivatives. Examination using enzyme-histochemical techniques suggests that a single enzyme may be responsible for both above-mentioned enzymatic reactions. The functional significance of microglial cells in the normal central nervous tissue is discussed.
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  • 18
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    Cell & tissue research 223 (1982), S. 603-614 
    ISSN: 1432-0878
    Keywords: Kidney ; Medullary collecting duct ; Rat ; Rabbit ; Tight junctions ; Freeze ; fracture electron microscopy ; Urinary concentration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The tight junctions along the medullary collecting duct in the kidneys of the rat and the rabbit were studied with freeze-fracture electron microscopy and quantitated according to the number of strands and the apico-basal depth (nm) of the junctions. The most elaborate tight junctions were found in the inner stripe of the outer medulla; rat: 10.6±0.8 strands and 205±24nm; rabbit: 11.6±2.4 strands and 291±55 nm. The elaboration of the tight junctions decreased continuously towards the papillary tip. Inner zone I; rat: 9.3±2.6 strands and 186±38nm, rabbit: 9.5±2.3 strands and 247±59nm. Inner zone II; rat: 7.1±2.2 strands and 129±32nm, rabbit: 8.5±1.4 strands and 199±26nm. Inner zone III; rat: 6.0±1.6 strands and 111 + 19 nm, rabbit: 7.0±1.5 strands and 183±43 nm. In the inner zone III comprising the papillary tip tight junctions with only 1–3 strands were not infrequently seen. Preliminary findings in the kidney of the golden hamster indicate a similar decline of junctional tightness along the collecting duct. These morphological observations suggest that the permeability of the paracellular pathway of the medullary collecting duct increases towards the tip of the papilla, especially in the rat. The functional implications for the medullary recycling of urea and electrolytes, and for the urinary concentrating mechanism are discussed. In addition, the tight junctions of the papillary epithelium are described.
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  • 19
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    Cell & tissue research 223 (1982), S. 695-698 
    ISSN: 1432-0878
    Keywords: Pineal gland ; Luteinizing hormone-releasing hormone (LHRH) ; Immunocytochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Immunoreactive luteinizing hormone-releasing hormone (LHRH)-like material has been demonstrated in the pineal gland of the adult rat. The objective of the present study was to examine the ontogenetic development of this LHRH-like substance in the rat pineal with the peroxidase-antiperoxidase (PAP) method of Sternberger. LHRH-like immunoreactive material was not observed in pineal glands of newborn rats. The amount of material increased progressively from the 6th–12th day of postnatal development. On day 12, the amount of LHRH-like immunoreactivity was consistent and comparable in all pineal glands of male and female animals examined.
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  • 20
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    Cell & tissue research 224 (1982), S. 195-206 
    ISSN: 1432-0878
    Keywords: Pinealocytes ; Nucleolus ; Rat ; Ultrastructure ; Twenty-four-hour changes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An ultrastructural and morphometric analysis was made of the nucleolar components in pinealocytes of 40 male Fischer rats sampled at eight times in an LD 12∶12 photoperiod cycle. Comparisons of results from the eight times showed variation in estimated mean volume of the granular component of ±29%, and of the fibrillar component ±11%, in relation to daily means. Peaks in mean volume of total nucleolus and its granular component occurred at 1 h of light. Near maximal and minimal mean volumes of the fibrillar component both occurred during both light and dark. Fibrillar centers (nucleolar organizer regions) of different sizes were found at all sampling times. It is concluded that temporal patterns in 24-h changes in the nucleolar components are most prominent in the granular component, and are more complex than suggested by changes in total nucleolar size or mean dimensions, and than represented by a simple biphasic circadian rhythm. Examples of different stages in the migration of the granular component, and of possible sites of nucleo-cytoplasmic transfer of nucleolar material, are described.
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  • 21
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    Cell & tissue research 224 (1982), S. 647-653 
    ISSN: 1432-0878
    Keywords: hCG binding sites ; Endocytosis ; Ovary ; Ultrastructural immunocytochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Localization of hCG binding sites and the process of endocytosis in pseudopregnant rat ovaries were investigated by indirect electron-microscopic immunocytochemistry. Immature female rats were treated with pregnant-mare serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG) to induce ovarian luteinization. Eight days after priming with PMSG-hCG and 1–6 h before sacrifice the animals were given another injection of hCG to bind the receptors. Receptor sites to hCG localized by reaction product were present in most luteal cells, but not in primary follicular cells. The receptor sites were distributed on luteal cell surfaces facing interstitial spaces. Endocytotic pits containing hCG binding sites were rarely seen 1 h after hCG injection. At 2 h, hCG and presumably its receptor were taken up within endocytotic vesicles with the evidence of reaction product coated on the vesicle wall. With time, fusion of endocytotic vesicles with lysosome occurred and the reaction product appeared in phagolysosomes. The reaction product was localized on phagolysosomal inner surface or in free granular form. These findings suggest that hCG and its receptors were internalized through endocytotic pits and endocytotic vesicles and delivered to lysosomes probably for degradation. An additional experiment for localization of acid phosphatase was also performed to delineate the lysosomes and phagolysosomes.
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  • 22
    ISSN: 1432-0878
    Keywords: Pudendal nerve ; Sensory neurones ; Spinal ganglion ; Transganglionic labelling (HRP) ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The morphology and distribution of the sensory neurones of the pudendal nerve within the spinal ganglia of rats were investigated by use of horseradish peroxidase (HRP). The labelling was visualized in diaminobenzidine (DAB) or tetramethyl-benzidine (TMB)-stained sections. Injection of HRP directly into the pudendal nerve labelled perikarya predominantly in the sixth lumbar DRG (L6). Following injection of HRP into the scrotal skin, however, additional cells were labelled in L5 and SI. Labelling was invariably unilateral. Approximately equal numbers of small (〈30 μm) and large neurones (〉40 μm) were labelled following subcutaneous injections although injections into the nerve marked twice as many small cells as large cells. This suggests that, in the rat, most of the small-diameter fibres within the pudendal nerve ascend through L6. Although a cluster of neurones was observed in one experiment, the remaining 25 experiments did not reveal any somatotopic arrangement since the labelled perikarya were distributed evenly throughout the ganglion. Similar numbers of retrogradely labelled neurones (somatopetal transport of the tracer) were observed in both DAB- and TMB-stained sections, although TMB allowed the demonstration of anterograde (somatofugal) HRP transport by terminal labelling in the superficial laminae of the lumbar spinal cord, extending into laminae II–IV.
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  • 23
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    Cell & tissue research 227 (1982), S. 93-112 
    ISSN: 1432-0878
    Keywords: Neurophysins ; Immunocytochemistry ; Age-dependent changes ; Hypophysectomy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The hypothalamo-extrahypophyseal neurophysin pathways (HEH) and the three hypothalamic nuclei secreting neurophysins, the supraoptic (SON), paraventricular (PVN) and suprachiasmatic (SCN) nuclei, of normal and hypophysectomized rats were studied by application of the immunoperoxidase procedure. Eight well-defined HEH pathways were recognized. Their main sites of projection were: lateral septum and subfornical organ (1 and 2); tractus diagonalis (3); medial nucleus of the amygdala and lateral ventricle (4); nucleus periventricularis thalami, nucleus habenulae lateralis and periaqueductal gray (5); periaqueductal gray, pineal organ, collicular recess and subependymal region of the fourth ventricle (6); dorsomedial nucleus and premammillary area (7); perimammillary region, corpus trapezoideum, ventral surface of medulla oblongata, nucleus tractus solitarii, nucleus commissuralis, substantia gelatinosa and formatio reticularis lateralis of the medulla oblongata and spinal cord (8). Neurophysin fibers of unknown origin were found in the frontal cerebral cortex. It was noted that in pathway 5 the amount of immunostainable material undergoes changes with age. The three neurophysin-secreting nuclei reacted differently following hypophysectomy. Among the HEH pathways the only one that seemed to be affected by hypophysectomy was that innervating the lateral septum. It is suggested that the neurons that survive hypophysectomy either do not project to the neural lobe or, alternatively, display axon collaterals projecting outside the neural lobe. Such a neuronal population could be the origin of the HEH pathways.
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  • 24
    ISSN: 1432-0878
    Keywords: Luteinizing hormone ; releasing hormone ; Immunocytochemistry ; Distribution ; Forebrain ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of luteinizing hormone-releasing hormone (LHRH)-immunoreactive perikarya and processes was examined, in the untreated rat, with the unlabeled antibody enzyme method of immunocytochemistry on thick 50 μm vibratome sections. LHRH neurons were primarily observed in the preoptico-anterior hypothalamic and septal areas. Projections from these cell bodies to the median eminence form three distinct pathways, one laterally along the course of the optic tracts, one medially through the periventricular stratum of the third ventricle, and one through the tractus infundibularis. In addition, some of these cell bodies project to the organum vasculosum of the lamina terminalis (OVLT) and the subfornical organ (SFO). LHRH immunoreactive neurons were also noted in the anterior olfactory regions; they project along the medial olfactory tract to the olfactory bulb.
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  • 25
    ISSN: 1432-0878
    Keywords: Splenic implants ; Non-lymphoid cells ; Trapping ; Enzyme histochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Regeneration of splenic tissue after autologous subcutaneous implantation provides a useful model for studying the development of splenic tissue. The development of the various non-lymphoid cells of the white pulp in the rat is described. It appears that regeneration of the implants is initiated by ingrowing vessels and a newly formed reticulum, which forms the microenvironment for the homing lymphocytes. Marginal metallophils are found at their characteristic location at the inner border of the marginal sinus five weeks after implantation. Trapping of antigen-antibody complexes reappears when the first primary follicles can be recognized.
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  • 26
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    Cell & tissue research 222 (1982), S. 223-226 
    ISSN: 1432-0878
    Keywords: Kainic acid ; Reactive microglia ; Autoradiography ; Hippocampus ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Autoradiographic studies showed that in the rat hippocampus “microglia-like reactive cells” (MRC) and astrocytes are capable of proliferation in response to kainic acid (KA)-induced lesions. A marked increase in the number of labeled MRC was observed during the first four days after the induction of the KA-lesion. A proliferative response of astrocytes occurred at two days after the KA-lesion. After the induction of a KA-lesion brain macrophages and oligodendrocytes were only slightly labeled with 3H-thymidine. It appears likely that MRC is the main cellular element responding to this type of lesion.
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  • 27
    ISSN: 1432-0878
    Keywords: Uterus ; Epithelial cells ; Tight junctions ; Pregnancy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of tight junctions between uterine luminal epithelial cells of the pregnant rat was studied by the freeze-fracture technique. On day 5 of pregnancy, the day of implantation, the region of tight junctions extended three times as far down the lateral cell membrane as on day 1 of pregnancy, and the strands of the complex interlinked more frequently. These observations suggest that tight junctions on day 5 may be more efficient in preserving the contents of the uterine lumen from dilution or escape than at earlier times of pregnancy.
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  • 28
    ISSN: 1432-0878
    Keywords: Cholecystokinin ; Spinal cord ; Immunocytochemistry ; Rat ; Neuropeptides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cholecystokinin-like immunoreactivity has been demonstrated by radioimmunoassay and immunocytochemistry in the spinal cord of various mammals, in particular in nerve fibers of the superficial layers of the posterior column, but had not been detected in neuronal cell bodies. We report immunohistochemical evidence for the presence of a group of cholecystokinincontaining neuronal cell bodies in the lumbar spinal cord of the rat. This group of cells is only visualized after direct injection of colchicine into the spinal cord and is located near the central canal in the intermedio-medial nucleus of area X of Rexed.
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  • 29
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    Cell & tissue research 224 (1982), S. 25-31 
    ISSN: 1432-0878
    Keywords: Spleen ; Ig-containing cells ; Immunocytochemistry ; Germinal center ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The morphology and localisation of IgM- and IgG-containing cells in the spleen of rats immunized with sheep red-blood cells (SRBC) were studied by combining immunohistochemical reactions with routine histological and histochemical methods. It was shown that IgM cells occur only in the outer periarteriolar lymphocyte sheath (PALS), whereas IgG cells are present throughout the whole PALS. It has been concluded that these cell types have different routes of migration. Both IgM- and IgG-containing cells were found in the germinal center in close relation with the extracellular immune complexes. The significance of this localisation is discussed.
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  • 30
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    Cell & tissue research 224 (1982), S. 247-267 
    ISSN: 1432-0878
    Keywords: Serotonin ; Brainstem ; Immunohistochemistry ; Rat ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The morphological characteristics and distribution of the somata of serotonin-containing neurons in the brainstem of rats and cats were studied by use of the peroxidase-anti peroxidase (PAP) immunohistochemical method employing highly specific antibodies to serotonin. Antibodies were raised in rabbits against an antigen prepared by coupling serotonin to bovine thyroglobulin and using formaldehyde as the coupling reagent. The distribution pattern of serotonin neurons observed in the present material is essentially in agreement with that described by other investigators who used the Falck-Hillarp method. In addition, this immunohistochemical technique revealed serotonin-containing perikarya in the following regions: 1) the periaqueductal gray, especially lateral to the nucleus raphe dorsalis, 2) the nucleus interpeduncularis, 3) the nucleus parabrachialis ventralis and dorsalis, 4) the field of the lemniscus lateralis, and 5) the reticular formation of the pons and medulla oblongata. The described immunohistochemical procedure makes it possible to study central serotonin neurons in detail without pharmacological pretreatment. The wide distribution of serotonin neurons demonstrated in this study should be considered when interpreting experiments dealing with the serotonin system.
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  • 31
    ISSN: 1432-0878
    Keywords: ACTH/β-endorphin neurons ; Synapse ; Hypothalamus ; Immunohistochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the preinfundibular portion of male rat hypothalamus, the arcuate-median eminence region was examined after staining with anti-porcine ACTH 1-39 serum. In several cases, anti-β-endorphin serum was also employed. Both sera stain the same cell bodies. The cell bodies of the immunoreactive neurons are scattered in the subependymal layer, arcuate nucleus and lateral tuberal region. Fibers originating from these cell bodies are distributed extensively throughout these regions. They make synaptic contacts on immunonegative fibers in the arcuate nuclei, or terminate directly in the perivascular space in the internal layer of the median eminence. The fibers, however, are very scarce in the external layer of the median eminence, and do not directly terminate on the neurovascular contact surface. These findings suggest that the ACTH/β-endorphin neuronal system may serve neuronally and humorally as an intrahypothalamic constituent of the hypothalamic pituitary regulation system.
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  • 32
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    Cell & tissue research 224 (1982), S. 455-458 
    ISSN: 1432-0878
    Keywords: Intravagal paraganglia ; Paraganglion supracardiale vagi ; Recurrent nerve ; Vagus nerve ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the Ham-Wistar rat, a paraganglion was found within the vagus nerve at the site of branching of the recurrent laryngeal nerve. Due to its location the name “paraganglion supracardiale vagi” is suggested. Fluorescence microscopy of the paraganglionic cells displays an intense yellow-green fluorescence indicating the presence of biogenic amines. Ultrastructurally, chief cells containing dense-core vesicles form three kinds of synaptic contacts (afferent, efferent and reciprocal) with enlarged, mitochondria-rich nerve endings.
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  • 33
    ISSN: 1432-0878
    Keywords: Rat ; Cold adaptation ; Skeletal muscle ; Mitochondria ; Fat ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Growing rats (4 weeks old) were kept for 3 weeks at 11° C and 24° C respectively. The cold-adapted animals showed a significantly higher oxygen consumption (64%). Volume density of subsarcolemmal and interfibrillar mitochondria as well as volume density of fat droplets were estimated in M. soleus and the diaphragm of both groups. In cold-adapted animals, the total volume of mitochondria was significantly increased by 24% in diaphragm and 37% in M. soleus. The volume of subsarcolemmal mitochondria was almost doubled in each muscle, but the volume of interfibrillar mitochondria did not change significantly. The surface of the inner mitochondrial membranes per unit volume of mitochondrion in M. soleus was significantly increased both in interfibrillar and subsarcolemmal mitochondria, whereas the surface of the outer mitochondrial membranes per unit volume of mitochondrion was increased only in the subsarcolemmal mitochondria. The volume of fat droplets in the diaphragm and M. soleus of cold adapted animals increased significantly by 62% and 150% respectively.
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  • 34
    ISSN: 1432-0878
    Keywords: Monoadrenalectomy ; Compensatory adrenal growth ; Zona fasciculata ; Rat ; Stereology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructural changes associated with the compensatory hypertrophy of the zona fasciculata cells on monoadrenalectomized rats were investigated by stereological techniques. It was found that these subcellular changes display a different pattern from those underlying the ACTH-induced adrenocortical cell growth in the intact rats. This result supports the view that compensatory adrenal hypertrophy does not involve activation of the hypothalamo-hypophyseal-adrenal axis.
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  • 35
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    Cell & tissue research 226 (1982), S. 1-12 
    ISSN: 1432-0878
    Keywords: Serotonin-immunoreactive nerve fibers ; Cerebellum ; Cat ; Rat ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The localization of serotonin (5-HT)-immunoreactive nerve fibers in the cerebellum of the rat and cat was investigated by means of the peroxidase-anti-peroxidase (PAP) method using highly specific antibodies to 5-HT. Serotonin-containing nerve fibers were distributed throughout the entire cerebellum including the deep cerebellar nuclei, while 5-HT-positive neuronal somata were not detected in the cerebellum of either species. A different pattern of 5-HT innervation was found among the three layers of the cerebellar cortex. There were also interspecific differences in the pattern of distribution of 5-HT. In the rat, the pool of 5-HT nerve fibers mainly consisted of tangential elements, which were predominant in the molecular layer, while in the cat only a few 5-HT fibers were found in the molecular layer of the cerebellar cortex; dense networks of 5-HT nerve fibers were present in the granular layer. Some differences are evident in the pattern of distribution of 5-HT fibers in cerebellar regions classified on an anatomical and functional basis.
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  • 36
    ISSN: 1432-0878
    Keywords: Carotid body ; Glomus cells ; Endocytosis ; Cationized ferritin ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Glomus cells from carotid bodies of adult rats dissociated by means of collagenase or collagenase + trypsin were used to study by electron microscopy the endocytotic uptake of cationized ferritin (CF) tracer into subcellular compartments. The glomus cells were incubated with the tracer (1) in a basic salt medium (BM), or (2) in the BM into which calcium ionophore A23187 had been added, or (3) in a potassium-rich medium. Incubation of the cells in BM containing CF for 30 min resulted in attachment of the tracer to the cell membrane and uptake of a few solitary tracer particles into small vesicles and multivesicular bodies. No uptake into the cisternae of the Golgi apparatus was observed. Further incubation in BM containing CF for another 30 min resulted in increased uptake of the tracer into small vesicles and multivesicular bodies. A similar pattern of uptake was observed when the dissociated glomus cells were first preincubated in BM with CF for 30 min and then incubated for 1 min or 30 min in the BM solution containing both the ionophore and CF. Upon such incubation, CF particles were seen to penetrate into coated pits and sites of exocytosis at the cell surface. When the 30-min preincubation in BM was followed by incubation in a CF-containing potassium-rich medium for 15–30 min, uptake into vesicles, small lysosomes and occasionally also into profiles of the smooth endoplasmic reticulum was seen. Endocytotic mechanisms of the glomus cells are outlined.
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