scholarly journals Postnatal development of growth hormone and prolactin cells in male and female rat pituitary. An immunocytochemical light and electron microscopic study.

1987 ◽  
Vol 35 (3) ◽  
pp. 335-341 ◽  
Author(s):  
G Smets ◽  
B Velkeniers ◽  
E Finne ◽  
A Baldys ◽  
W Gepts ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Cell Types ◽  
Female Rats ◽  
Male Rats ◽  
Intermediate Lobe ◽  
Female Rat ◽  
Electron Microscopic ◽  
Adult Rats ◽  
Gh Cells ◽  
Immature Rats

Localization and ultrastructural maturation of prolactin (PRL) and growth hormone (GH) cells were studied in pituitaries from neonatal, immature (4-6 weeks old), and adult rats (2-3 months old) by light and electron microscopic immunocytochemistry. The distribution pattern of these cells did not change with age. Both cell types were concentrated laterodorsally, with PRL cells adjacent to the intermediate lobe and GH cells nearer the center of the pars distalis. Labeling density of the immunogold reaction was highest for both hormones in immature rats. In neonatal and immature rats, one PRL cell type with granules 200 nm in diameter was present. In adult rats, two types of PRL cells were present: one containing polymorphous granules measuring about 500 nm (prevalent in female rats), the other with spherical granules about 200 nm (prevalent in male rats). No changes were detected in GH cells during maturation.

scholarly journals CLASSIFICATIONS OF ANTERIOR PITUITARY CELL TYPES WITH IMMUNOENZYME HISTOCHEMISTRY

1970 ◽  
Vol 18 (1) ◽  
pp. 9-20 ◽  
Author(s):  
PAUL K. NAKANE
Keyword(s):  
Anterior Pituitary ◽  
Cell Types ◽  
Male Rats ◽  
Intermediate Lobe ◽  
Prolactin Cells ◽  
Electron Microscopic ◽  
Thyrotropic Hormone ◽  
Gonadotropic Cells ◽  
Gh Cells ◽  
Tsh Cells

Peroxidase-labeled antibody method was used to localize the six hormones of the anterior pituitary gland of male rats both at the light and electron microscopic levels. Growth hormone (GH), adenocorticotropic hormone (ACTH), prolactin and thyrotropic hormone (TSH) were found in separate cells. Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were frequently found in the same cell. TSH cells were scarce and were located at the periphery of the gland. The anterior-ventral portion of the gland contained few or no GH cells, ACTH cells, prolactin cells and TSH cells, but was filled with gonadotropic cells. In an area near the intermediate lobe, GH cells, ACTH cells and TSH cells were not found. GH cells and prolactin cells may be identified in electron micrographs without the aid of immunocytochemistry; however, ACTH cells and TSH cells may not be distinguished by their ultrastructural characteristics alone. Gonadotropic cells may be identified but their hormone content cannot be determined. The positive identification of these latter four cell types requires immunocytochemical methods.

scholarly journals Sex-dependent expression and growth hormone regulation of class alpha and class mu glutathione S-transferase mRNAs in adult rat liver

1993 ◽  
Vol 294 (1) ◽  
pp. 159-165 ◽  
Author(s):  
P K Srivastava ◽  
D J Waxman
Keyword(s):  
Growth Hormone ◽  
Continuous Infusion ◽  
Rat Liver ◽  
Female Rats ◽  
Male Rats ◽  
Female Rat ◽  
Glutathione S Transferase ◽  
Gh Treatment ◽  
Adult Rat ◽  
Hypophysectomized Rats

The sex-dependent expression and growth hormone (GH) regulation of rat liver glutathione S-transferase (GST) was examined using oligonucleotide probes that distinguish between closely related class Alpha (Ya1, Ya2, Yc) and class Mu (Yb1, Yb2, Yb3) GST mRNAs [Waxman, Sundseth, Srivastava and Lapenson (1992) Cancer Res. 52, 5797-5802]. Northern-blot analysis revealed that the steady-state levels of GST Ya1, Yb1 and Yb2 mRNAs are 2.5-3-fold higher in male as compared with female rat liver. In contrast, GST Yc and Ya2 mRNAs were expressed at a 2-3-fold higher level in female rat liver. Microsomal GST mRNA did not exhibit significant sex-dependent differences in rat liver. Treatment of male rats with GH by continuous infusion suppressed expression of the male-dominant GST Ya1, Yb1 and Yb2 mRNAs to levels at or below those found in female rat liver. This suppressive effect of GH was liver-specific, insofar as GH treatment did not alter kidney GST Ya1 mRNA levels. Hypophysectomy increased expression of the male-dominant GSTs, particularly in female rats (e.g. 8-fold elevation of GST Ya1 mRNA). GST Yc mRNA was increased approx. 2-fold in hypophysectomized males, indicating that this mRNA is subject to negative regulation by one or more pituitary-dependent factors. Continuous GH treatment of the hypophysectomized rats suppressed the expression of mRNA of GSTs Ya1, Yb1 and Yb2 when given as a continuous infusion, but not when given by an intermittent (twice daily) GH-injection schedule. Combination of continuous exposure to GH with thyroxine treatment resulted in a more complete suppression of GSTs Ya1, Yb1 and Yb2. In contrast, thyroxine increased the expression of GST Yc in hypophysectomized rats. These studies establish that several Alpha and Mu class GSTs are expressed in a sex-dependent fashion in adult rat liver, where they are regulated by multiple pituitary-dependent hormones through pretranslational mechanisms.

AN ELECTRON MICROSCOPIC STUDY OF NORMAL AND NEOPLASTIC ACIDOPHIL CELLS OF THE RAT PITUITARY

1971 ◽  
Vol 67 (1) ◽  
pp. 29-39 ◽  
Author(s):  
U. Schelin ◽  
P. M. Lundin
Keyword(s):  
Electron Microscopy ◽  
Secretory Granules ◽  
Female Rats ◽  
Male Rats ◽  
Cell Type ◽  
Prolactin Cells ◽  
Electron Microscopic ◽  
Gh Cells ◽  
Rat Pituitary ◽  
Close Relationship

ABSTRACT The morphology of normal and neoplastic acidophil cells of the rat pituitary has been studied by electron microscopy with special reference to the size and shape of the secretory granules. In the female rats, pregnant or non-pregnant, growth hormone (GH) cells and prolactin cells are easily separated, but in the male rats this separation is very uncertain. Acidophil tumours with granules similar to the GH type or to the prolactin type can be induced with stilboestrol treatment. These results indicate a close relationship between the two types of acidophil cells. They may be derived from a common progenitor which can be differentiated into either GH or prolactin cell or they may represent one cell type capable of producing both hormones.

Single exposure to testosterone in adulthood rapidly induces regularity in the growth hormone release process

2000 ◽  
Vol 278 (5) ◽  
pp. E933-E940 ◽  
Author(s):  
Jean-Claude Painson ◽  
Johannes D. Veldhuis ◽  
Gloria S. Tannenbaum
Keyword(s):  
Growth Hormone ◽  
Adult Life ◽  
Approximate Entropy ◽  
Female Rats ◽  
Female Rat ◽  
Adult Rats ◽  
Release Process ◽  
Intact Group ◽  
Gh Secretion ◽  
Plasma Gh

The neonatal gonadal steroid milieu is known to be important in imprinting the striking sexual dimorphism of growth hormone (GH) secretion; however, the influence of the sex steroids on GH control in adult life and their mechanism/site of action are largely unknown. In the present study, we tested the hypothesis that testosterone (T) subserves the gender-specific regularity of the GH release process in adulthood. The approximate entropy statistic (ApEn) was used to quantify the degree of regularity of GH release patterns over time. Eighteen hours after a single subcutaneous injection of 1 mg T, both sham-operated and ovariectomized (OVX) female adult rats displayed plasma GH profiles that were strikingly similar to the regular male-like ultradian rhythm of GH secretion. The highest ApEn values, denoting greater disorderliness of GH secretion, were observed in the ovary-intact group, and T injection significantly ( P < 0.001) reduced this irregularity whether or not the ovaries were present. Serial intravenous injections of GH-releasing hormone (GHRH) caused a similar increase in plasma GH levels in sham-operated females independently of time of administration. In contrast, female rats administered T exhibited a male-like intermittent pattern of GH responsiveness to GHRH, the latter known to be due to the cyclic release of endogenous somatostatin. These results demonstrate that acute exposure to T during adult life can rapidly and profoundly “masculinize” GH pulse-generating circuits in the female rat. Our findings suggest that the enhanced orderliness characteristic of the GH release process in males, compared with females, is regulated by T. We postulate that this T-induced regularity is mediated at the level of the hypothalamus by inducing regularity in somatostatin secretion, which in turn governs overall GH periodicity.

Pars distalis cell quantification in normal adult male and female rats

1984 ◽  
Vol 101 (1) ◽  
pp. 87-NP ◽  
Author(s):  
M. O. Dada ◽  
G. T. Campbell ◽  
C. A. Blake
Keyword(s):  
Adult Male ◽  
Cell Types ◽  
Volume Density ◽  
Female Rats ◽  
Male Rats ◽  
Pars Distalis ◽  
Prolactin Cells ◽  
Male And Female ◽  
Gh Cells ◽  
Male And Female Rats

ABSTRACT We analysed cell types in the pars distalis of normal young adult male and female rats with respect to their percentages and the relative volumes they occupy. In male rats the percentages of the cell types were: prolactin 49·80, GH 22·67, LH 5·04, FSH 4·22, ACTH 2·93 and TSH 2·09, The volume densities were: prolactin 20·48, GH 20·95, LH 7·34, FSH 6·73, ACTH 3·75 and TSH 3·19. In female rats the percentages of the cell types were: prolactin 52·40, GH 20·30, LH 5·89, FSH 4·06, ACTH 2·53, TSH 2·40 and the volume densities were: prolactin 28·09, GH 20·86, LH 8·11, FSH 5·46, ACTH 3·49 and TSH 2·91. The percentages of pars distalis cells which did not stain with the antisera to the six classical hormones were 17·47 in male and 16·48 in female rats. The results suggest that (1) in both sexes the number (N) of prolactin cells > N of GH cells > N of gonadotrophs > N of TSH or ACTH cells, (2) the percentage of each cell type was similar in both sexes, (3) the volume density (Vv) of prolactin cells was greater than the Vv of GH cells in female but not in male rats and in both sexes the Vv of GH cells > the Vv of gonadotrophs > the Vv of TSH or ACTH cells, (4) in both sexes the volume (V) of prolactin cells < the V of GH cells < the V of gonadotrophs, the V of TSH cells or the V of ACTH cells, (5) the V of prolactin cells was greater in female than in male rats and (6) approximately 17% of the cells in the pars distalis of both sexes did not contain 'immunoreactive' prolactin, GH, LH, FSH, TSH or ACTH. J. Endocr. (1984) 101, 87–94

Endogenous testosterone enhances growth hormone (GH)-releasing factor-induced GH secretion in vitro

1987 ◽  
Vol 113 (2) ◽  
pp. 249-253 ◽  
Author(s):  
L. Ohlsson ◽  
O. Isaksson ◽  
J.-O. Jansson
Keyword(s):  
Growth Hormone ◽  
Basal Medium ◽  
Dry Weight ◽  
Female Rats ◽  
Male Rats ◽  
Testosterone Replacement Therapy ◽  
Female Rat ◽  
Gh Secretion ◽  
Male And Female Rats

ABSTRACT The influence of endogenous gonadal steroids in male and female rats on basal and growth hormone-releasing factor (GRF)-stimulated GH secretion from perifused anterior pituitaries was studied. After 75 min of perifusion with basal medium, freshly dissected pituitaries were exposed to human GRF(1–44) (10 nmol/l) for 15 min. Neonatal (day 1–2) or prepubertal (day 25) gonadectomy of male rats suppressed baseline GH release (ng/min per mg dry weight) as well as GRF-stimulated GH release by 40–70%. This effect was slightly more pronounced in neonatally gonadectomized animals. In prepubertally gonadectomized male rats, the suppression of GH release was completely reversed by testosterone replacement therapy. In female rats, prepubertal gonadectomy did not affect GH secretion from perifused pituitaries. However, treatment of ovariectomized female rats with oestradiol reduced baseline and GRF-induced GH release to levels lower than those observed in sham-operated or vehicle-treated ovariectomized animals. The data suggest that testicular androgen secretion in adult male rats increases the pituitary GH release in response to GRF in vitro, whereas ovarian oestrogen secretion is of less importance for the GRF responsiveness of female rat pituitaries. J. Endocr. (1987) 113,249–253

INDUCTION OF GOITRE BY PTU OR KClO4 IN MALE AND FEMALE RATS. EFFECT OF GONADECTOMY

1973 ◽  
Vol 74 (1) ◽  
pp. 88-104 ◽  
Author(s):  
T. Jolín ◽  
M. J. Tarin ◽  
M. D. Garcia
Keyword(s):  
Iodine Content ◽  
High Plasma ◽  
Disc Electrophoresis ◽  
Female Rats ◽  
Male Rats ◽  
Adult Rats ◽  
Male And Female ◽  
Glucose Levels ◽  
Male And Female Rats ◽  
Tsh Levels

ABSTRACT Male and female rats of varying ages were placad on a low iodine diet (LID) plus KClO4 or 6-propyl-2-thiouracil (PTU) or on the same diet supplemented with I (control rats). Goitrogenesis was also induced with LID plus PTU in gonadectomized animals of both sexes. The weight of the control and goitrogen treated animals, and the weight and iodine content of their thyroids were determined, as well as the plasma PBI, TSH, insulin and glucose levels. The pituitary GH-like protein content was assessed by disc electrophoresis on polyacrylamide gels. If goitrogenesis was induced in young rats of both sexes starting with rats of the same age, body weight (B.W.) and pituitary growth hormone (GH) content, it was found that both the males and females developed goitres of the same size. On the contrary, when goitrogenesis was induced in adult animals, it was found that male rats, that had larger B.W. and pituitary GH content than age-paired females, developed larger goitres. However, both male and female rats were in a hypothyroid condition of comparable degree as judged by the thyroidal iodine content and the plasma PBI and TSH levels. When all the data on the PTU or KClO4-treated male and female rats of varying age and B.W. were considered together, it was observed that the weights of the thyroids increased proportionally to B.W. However, a difference in the slope of the regression of the thyroid weight over B.W. was found between male and female rats, due to the fact that adult male rats develop larger goitres than female animals. In addition, in the male rats treated with PTU, gonadectomy decreased the B.W., pituitary content of GH-like protein and, concomitantly, the size of the goitre decreased; an opposite effect was induced by ovariectomy on the female animals. However, when goitrogenesis was induced in weight-paired adult rats of both sexes, the male animals still developed larger goitres than the females. Among all the parameters studied here, the only ones which appeared to bear a consistent relationship with the size of the goitres in rats of different sexes, treated with a given goitrogen, were the rate of body growth and the amount of a pituitary GH-like protein found before the onset of the goitrogen treatment. Moreover, though the pituitary content of the GH-like protein decreased as a consequence of goitrogen treatment, it was still somewhat higher in male that in female animals. The present results suggest that GH may somehow be involved in the mechanism by which male and female rats on goitrogens develop goitres of different sizes, despite equally high plasma TSH levels.

OXYDATION DES ANABOLIKUMS 1-METHYL-ANDROST-1-EN-17β-OL-3-ON MIT WASSERSTOFFTRANSFER AUF ÖSTRON

1971 ◽  
Vol 67 (3) ◽  
pp. 517-530 ◽  
Author(s):  
Martin Wenzel
Keyword(s):  
Rat Liver ◽  
Anabolic Steroid ◽  
Female Rats ◽  
Male Rats ◽  
Female Rat ◽  
Liver Slices ◽  
Androgen Effects ◽  
Biochemical Difference

ABSTRACT With the aid of metenolon-17α-T a tritium-transfer to oestrone in rat liver slices was demonstrated. This tritium-transfer from metenolon17α-T to oestrone yielding tritium-labelled oestradiol had a higher efficiency in male than in female rat liver. Correspondingly in the presence of metenolon the relation of oestrone to oestradiol is changed more in male than in female rat liver. Looking for biochemical differences between the anabolic steroid metenolon and testosterone the oxydation at C17 was measured in different organs of the rat using 17α-T-labelled steroids. The highest oxydation rate was found for both steroids in the liver. In the sexual organs of male rats the oxydation rate of testosterone was 50–10 times higher than that of the anabolic steroid. This difference was less in sexual organs of female rats. This result of a greater biochemical difference between both steroids in males than in females leads to the question, whether the dissociation between the anabolic and the androgen effects is higher in males than in females.

scholarly journals Increased bioactivation of dihaloalkanes in rat liver due to induction of class Theta glutathione S-transferase T1-1

1998 ◽  
Vol 335 (3) ◽  
pp. 619-630 ◽  
Author(s):  
Philip J. SHERRATT ◽  
Margaret M. MANSON ◽  
Anne M. THOMSON ◽  
Erna A. M. HISSINK ◽  
Gordon E. NEAL ◽  
...  
Keyword(s):  
Western Blotting ◽  
Rat Liver ◽  
Female Rats ◽  
Male Rats ◽  
Male Rat ◽  
Female Rat ◽  
Glutathione S Transferase ◽  
Chemopreventive Agents ◽  
Cytoplasmic Staining ◽  
Potent Inducer

A characteristic feature of the class Theta glutathione S-transferase (GST) T1-1 is its ability to activate dichloromethane and dibromoethane by catalysing the formation of mutagenic conjugates. The level of the GSTT1 subunit within tissues is an important determinant of susceptibility to the carcinogenic effects of these dihaloalkanes. In the present study it is demonstrated that hepatic GST activity towards these compounds can be elevated significantly in female and male Fischer-344 rats by feeding these animals on diets supplemented with cancer chemopreventive agents. Immunoblotting experiments showed that increased activity towards the dihaloalkanes is associated with elevated levels of the GSTT1 subunit in rat liver. Sex-specific effects were observed in the induction of GSTT1 protein. Amongst the chemopreventive agents tested, indole-3-carbinol proved to be the most potent inducer of hepatic GSTT1 in male rats (6.2-fold), whereas coumarin was the most potent inducer of this subunit in the livers of female rats (3.5-fold). Phenobarbital showed significant induction of GSTT1 only in male rat liver and had little effect in female rat liver. Western blotting showed that class Alpha, Mu and Pi GST subunits are not co-ordinately induced with GSTT1, indicating that the expression of GSTT1 is determined, at least in part, by mechanisms distinct from those that regulate levels of other transferases. The increase in amount of hepatic GSTT1 protein was also reflected by an increase in the steady-state level of mRNA in response to treatment with chemopreventive agents and model inducers. Immunohistochemical detection of GSTT1 in rat liver supported the Western blotting data, but showed, in addition to cytoplasmic staining, significant nuclear localization of the enzyme in hepatocytes from some treated animals, including those fed on an oltipraz-containing diet. Significantly, the hepatic level of cytochrome P-450 2E1, an enzyme which offers a detoxification pathway for dihaloalkanes, was unchanged by the various inducing agents studied. It is concluded that the induction of GSTT1 by dietary components and its localization within cells are important factors that should be considered when assessing the risk dihaloalkanes pose to human health.

Hypothalamo-pituitary regulation of the c-myc gene in rat liver

1990 ◽  
Vol 5 (3) ◽  
pp. 267-274 ◽  
Author(s):  
I. Porsch Hällstöm ◽  
J.-Å. Gustafsson ◽  
A. Blanck
Keyword(s):  
Rat Liver ◽  
Female Rats ◽  
Male Rats ◽  
Female Rat ◽  
Continuous Administration ◽  
Gh Secretion ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Female Wistar Rats ◽  
Myc Gene

ABSTRACT Expression of the c-myc gene was studied in the livers of male and female Wistar rats. Furthermore, the effects on hepatic c-myc expression of neonatal and adult castration, with or without testosterone supplementation, as well as of continuous administration of GH to intact males, were analysed. Expression of c-myc was low in 6-day-old animals of both sexes, reached a maximum at 35 days of age and declined to the level of adult animals at 70 days. In prepubertal animals, expression was higher in females, but was higher in males after the onset of puberty, the postpubertal female rat liver exhibiting 50–70% of the expression in males. Treatment of adult male rats with bovine GH in osmotic minipumps for 1 week reduced c-myc expression to the level of female rats. Castration, both neonatally and of adults, also feminized hepatic c-myc expression. Testosterone supplementation of the castrated animals increased the expression towards the level in sham-operated controls. These results indicate that the c-myc gene is regulated by the hypothalamo-pituitary-liver axis via the sex-differentiated pattern of GH secretion, in analogy with other sex-differentiated hepatic functions, such as metabolism of steroids and xenobiotics. Neuroendocrine regulation of a gene such as c-myc, which is involved in the control of cell proliferation and differentiation, represents another aspect of the complex influence of GH on various somatic functions.

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