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S. PATHAK and A. FISK

SUMMARY

Typical histological and ultrastructural changes that occur in the pars distalis of the rabbit pituitary after different periods of organ culture are described. The best technique for the maintenance of the maximum proportion of the explant was assessed by comparing cultures grown under different conditions. Explants in air with a medium buffered with N-2-hydroxyethylpiperazine-N 1-2-ethanesulphonic acid (HEPES), not previously used in organ culture, proved more satisfactory than explants in carbogen with bicarbonate-buffered 199, and cultures were maintained for more than 3 weeks.

The survival of cells was assessed on the basis of their cytological integrity; DNA- and RNA-fluorescence with acridine orange was a valuable indicator. Prolactin cells, which were few in uncultured controls, became the most common type of granular cell in long-term cultures.

Cell modifications during culture included the development of a peripheral epithelioid layer and the appearance of numerous microvilli. Microfibrils, coated or smooth vesicles, lytic bodies, desmosomes and intranuclear rods became more common and intranuclear rodlets (fibrous or membranous structures) were identified. Cells often became more electron dense during long-term culture.

Though there was an increase in the number of agranular cells during culture, identifiable granules were retained by many cells throughout culture.

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HIN-CHING LIU and R. B. MANEELY

SUMMARY

The adrenal histology of Chelonia amyda is described and emphasis placed upon the interpenetration of the interrenal and chromaffin tissues and on their structural relationships with the vascular endothelium. Diastase-resistant polysaccharide complexes are present within the chromaffin-reactive cells. Alkaline glycerophosphatase is absent from the interrenal tissues but present in the chromaffin tissues, especially in the intercellular material.

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KATHLEEN HALL

1. The effect on the symphysis pubis of oöphorectomized mice of oestrone (1·5 μg./day) and progesterone (1·0 mg./day) injected separately and simultaneously for 8–20 days has been investigated histologically.

2. A brief course of treatment with oestrone had a definite effect on the pelvis, greater than appears on X-ray photographs, but not comparable in intensity with that which follows the addition of relaxin.

3. The action of oestrone affected the dorsal bony walls of the two innominates, and started at the anterior symphysial borders. Simultaneous resorption of the outer or periosteal surfaces, and deposition of new bone on the endosteal surfaces occurred, until the marrow cavities were obliterated at least in the medial parts of the two innominates. Resorption then continued so that the solid symphysial borders of the bones gradually disappeared. No ligament proliferation occurred.

4. A vascular, richly nucleated tissue replaced the resorbed dorsal surfaces of the bones, and was thought to be derived mainly from the marrow. Many osteoclasts were present along the eroding surfaces but the origin and function of these enigmatic cells is still undecided.

5. When progesterone was given for periods up to 20 days the histological structure of the symphysis pubis was similar to that of untreated control animals.

6. When oestrone and progesterone were given simultaneously for periods up to 20 days changes were produced of the same type as, but much less pronounced than, those produced by oestrone alone.

7. The results of histological investigation support the conclusion that progesterone is not only ineffective in producing relaxation of the pelvis in the mouse but that, at least in certain dose ratios, it inhibits the action of oestrone on the symphysis.

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H. HELLER, ELENA FERRERI and D. H. G. LEATHERS

SUMMARY

The effect of neurohypophysial hormones has been tested in vitro on oviducts of four species of urodele and three species of anuran Amphibia. Contractile responses were obtained with all the hormones used but 8-arginine oxytocin (vasotocin) was usually most potent. The sensitivity of the oviducts varied widely from species to species; there were also pronounced seasonal differences within a species. Histological investigations yielded some information on the abundance and arrangement of muscle fibres in amphibian oviducts. A simple and sensitive (magnification up to × 1000) recording system for isotonic contractions is described.

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D. R. IDLER and M. J. O'HALLORAN

SUMMARY

Yellow bodies scattered throughout the kidney tissue and posterior cardinal veins of the American Atlantic sturgeon Acipenser oxyrhynchus Mitchill were examined by histological and histochemical methods. Their histology resembled that of interrenal tissue, rather than that of corpuscles of Stannius.

The tissue was assayed histochemically for 3β-, 3α-, 11β-, 20β- and 20α-hydroxysteroid dehydrogenase (HSD) activity. Intense 3β-HSD activity was observed in the yellow bodies when dehydroepiandrosterone and pregnenolone were employed as substrates. Very weak 3α-HSD activity was observed with androsterone as a substrate. No 11β-HSD activity was observed with cortisol and corticosterone as substrates, and no 20α- or 20β-HSD activity when 20α- or 20β-hydroxyprogesterone respectively were employed as substrates.

These studies suggest that the yellow bodies found in the posterior cardinal veins and kidney tissue of A. oxyrhynchus Mitchill are true interrenal tissue.

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ARUNA KULSHRESHTHA and C. J. DOMINIC

It is well established that administration of hypertonic saline brings about characteristic histological changes in the hypothalamic neurosecretory system (HNS), which are regarded as morphological manifestations of augmented secretion of the anti-diuretic hormone (ADH) (see Gabe, 1966). Reserpine is reported to stimulate (Chaudhury, Chaudhury & Lu, 1962; Guzek & Leśnik, 1968), inhibit (Moses, 1964; Bridges & Thorn, 1970), or to have no effect (Boris & Stevenson, 1967) on ADH secretion. The amount of neurosecretory material (NSM) after reserpine treatment has been found to be unchanged (Eränkö, Hopsa, Kivalo & Telkkä, 1957) or diminished (e.g. Gabe, Tuchmann-Duplessis & Mercier-Parot, 1961). The present study reports the effect of reserpine on the histology of the HNS of the musk shrew after treatment with hypertonic saline.

Animals were divided into six groups with 12 adults of either sex in each, and treated as follows: Group I: 3% NaCl solution (2 ml/day, i.p.) for 3–5

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KUNWAR BAHADUR SINGH and C. J. DOMINIC

It is well established that in mammals ethanol is a potent chemical inhibitor of the release of the antidiuretic hormone (ADH), including the antidiuresis that follows the administration of hypertonic saline (see Kleeman & Cutler, 1963; Heller & Ginsburg, 1966). Ethanol also inhibits histological changes in the mammalian hypothalamic neurosecretory system (HNS) that normally follow treatment with hypertonic saline (Raiha, 1960; Kulshreshtha & Dominic, 1972). However, very few studies are available on the effect of ethanol on the neurohypophysis of birds and other non-mammalian vertebrates. The present report deals with the effect of ethanol on the HNS of the spotted owlet after treatment with hypertonic saline.

Birds weighing 120–140 g were divided into four groups with 25 individuals of either sex in each group, and were given the following treatments, Group 1: 3% NaCl solution (1 ml/animal/day) for 3–5 days; Group 2:3% NaCl solution (1 ml/animal/day), and 15% ethanol

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A. HOWE and A. J. THODY

SUMMARY

The changes in the content of melanocyte-stimulating hormone (MSH) and histology of the neuro-intermediate (n.i.) lobe were followed in rats which drank 2% sodium chloride for periods from 1–15 days.

The pars intermedia showed a biphasic response. During the initial phase of 1–4 days there was a rapid rise in the MSH content, by 153% in the first day, falling back to control level by 4 days. These fluctuations were paralleled by an increase in the normally small numbers of Type 2 cells and at the same time numerous Type I cells showed hypertrophy and degranulation.

After 4 days on saline there was a second rise in the MSH content, which was still evident at 15 days; during this second period the number of Type 2 cells declined to normal levels. The degranulated Type 1 cells also disappeared, most of Type 1 being smaller in size and intensely PAS-positive.

After the ingestion of saline it apparently takes several days before the pars intermedia adapts to a new level of activity.

The likely significance of these changes and the possibility of a relationship between the pars intermedia and the neurohypophysis are discussed.

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S. Carreau, M. A. Drosdowsky and M. Courot

ABSTRACT

The androgen-binding protein (ABP) and the cytosol androgen receptor (Rc) were measured in the epididymis of sheep aged 50, 120 and 200 days. Specific binding protein was not detected at 50 days (infantile); near puberty (120 days), ABP was more concentrated in caput and cauda epididymal cytosols (117 and 183 fmol/mg protein respectively) than in corpus (53 fmol/mg) although Rc levels were low (3–5 fmol/mg). In postpubertal rams (200 days), ABP and Rc concentrations were higher in caput and cauda than in corpus epididymis. Testosterone concentrations at 50 days were not statistically different along the epididymis and varied from 0·3 to 0·8 pmol/mg protein. In 120-day-old animals, testosterone was more concentrated in caput and corpus (0·45 and 0·41 pmol/mg) than in cauda (0·17 pmol/mg); at 200 days, the testosterone contents were low (0·10–0·17 pmol/mg) in all parts of the epididymis. A ten-fold increase in plasma testosterone concentrations was observed between 50 and 200 days (1·31 to 11·71 nmol/l). Histological studies of the epididymis in the three groups of animals showed that the cell differentiation started in the cauda where the principal epithelial cells were higher (47–56 μm) than in the caput (31–38 μm) at 50 days. The principal cells of the caput were two- to threefold higher in postpubertal rams than in infantile lambs, a finding which is correlated with the levels of ABP and Rc. This may suggest an important physiological role of this region in the induction of sperm maturation.

J. Endocr. (1984) 103, 281–286

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J. A. FINDLAY, K. A. ROOKLEDGE, ANNE BELOFF-CHAIN and J. D. LEVER

SUMMARY

The biochemical parameters of blood glucose, serum insulin and pancreatic insulin and glucagon were determined after single injections of the diabetogenic agent streptozotocin and in untreated animals from a strain of genetically obese mice and their lean litter-mates. Histological observations on α and β islet cells were also made in these animals by employing the phosphotungstic acid—haematoxylin and aldehyde—fuchsin staining techniques.

In untreated obese mice, endocrine hyperactivity was indicated by the presence of exceptionally large, highly vascular islets and by duct cell-islet metaplasia.

After streptozotocin injection, approximately half of the lean mice showed extensive β-cell necrosis and these animals became hyperglycaemic and hypoinsulinaemic with a much reduced pancreatic insulin over a long term. The remaining treated lean mice, whose biochemical parameters did not differ significantly from normal, showed little or no evidence of islet damage. The response of obese mice to streptozotocin treatment was less clear-cut than that of lean animals. Essentially similar histological changes were observed, though these were not consistently correlated with biochemical data. There was histological and biochemical evidence of islet cell recovery from the effects of the drug both in lean and in obese mice, and in all hyperglycaemic animals with initial severe islet damage a marked α-cell response was observed, namely an increased proportion of α cells and their random deployment throughout the islets.