Effect of dihydrotestosterone on serum concentrations of α2u-globulin and on spermatogenesis in melatonin-treated rats

1990 ◽  
Vol 126 (3) ◽  
pp. 431-435 ◽  
Author(s):  
H. Mandal ◽  
P. K. Ghosh ◽  
N. M. Biswas
Keyword(s):  
Body Weight ◽  
Adult Male ◽  
Serum Levels ◽  
Hydroxysteroid Dehydrogenase ◽  
Male Rats ◽  
Testicular Function ◽  
Serum Concentrations ◽  
Melatonin Treatment ◽  
Accessory Sex Organs

ABSTRACT Adult male rats were given s.c. injections of melatonin (400 μg/100 g body weight per day) for 14 days. On day 15, the weights of the testis and accessory sex organs were less, testicular 17β-hydroxysteroid dehydrogenase (17β-HSD) activity was inhibited, spermatogenesis was suppressed and serum levels of gonadotrophins, testosterone and α2u-globulin were decreased compared with control animals injected with vehicle. In a third group of rats given the same dose of melatonin for 14 days, administration of dihydrotestosterone (DHT) at a dose of 25 μg/100 g body weight per day on days 8–14 resulted in serum levels of α2u-globulin, FSH, LH and testosterone and testicular 17β-HSD activity similar to those seen in vehicle-injected control animals. Weights of the testes and accessory sex organs and spermatogenesis were normal after administration of DHT in melatonintreated rats. In another group of rats, the depressive effects of melatonin treatment on plasma gonadotrophins were reversed by the administration of α2u-globulin on days 8–14. It was concluded that treatment with DHT prevents the depressive action of melatonin on testicular function by inducing the synthesis of α2u-globulin. Journal of Endocrinology (1990) 126, 431–435

Effect of α2u-globulin on serum concentration of gonadotrophins and testicular activity in oestrogen-treated rats

1983 ◽  
Vol 96 (2) ◽  
pp. 321-327 ◽  
Author(s):  
N. M. Biswas ◽  
P. K. Ghosh ◽  
K. K. Ghosh ◽  
O. W. Neuhaus
Keyword(s):  
Serum Concentration ◽  
Adult Male ◽  
Serum Levels ◽  
Hydroxysteroid Dehydrogenase ◽  
Organ Weight ◽  
Male Rats ◽  
Testicular Function ◽  
Accessory Sex Organs ◽  
Testosterone Synthesis

Adult male rats were given injections of oestradiol-17β (50 μg/100 g body wt per day) for 7 days. When they were killed 14 days after the last injection, serum levels of gonadotrophins and testosterone and weights of accessory sex organs were less, testicular 17β-hydroxysteroid dehydrogenase 17β-HSD activity was suppressed and spermatogenesis was inhibited. Administration of α2u-globulin (1·5 mg/day) for 14 days to oestrogen-treated rats and for 10 days to control rats resulted in increased concentrations of gonadotrophins and testosterone in the serum. Accessory sex organ weight and spermatogenesis appeared to be normal while 17β-HSD activity increased in oestrogen-treated rats after treatment with α2u-globulin. It was concluded that α2u-globulin has an effect on testicular function in oestrogenized rats by inducing gonadotrophin and testosterone synthesis.

Effect of thyroidectomy, and thyroxine and α2u-globulin replacement therapy on testicular steroidogenic and gametogenic activities in rats

1994 ◽  
Vol 140 (3) ◽  
pp. 343-347 ◽  
Author(s):  
N M Biswas ◽  
P K Ghosh ◽  
R Biswas ◽  
D Ghosh
Keyword(s):  
Body Weight ◽  
Thyroid Hormone ◽  
Replacement Therapy ◽  
Serum Levels ◽  
Male Rats ◽  
Testicular Function ◽  
Serum Concentrations ◽  
Hydroxysteroid Dehydrogenases ◽  
Accessory Sex Organs ◽  
Hormone Control

Abstract Adult male rats were thyroidectomized and killed after 22 days of treatment. Thyroidectomy lowered the weights of testes and accessory sex organs, decreased the activities of testicular Δ5-3β- and 17β-hydroxysteroid dehydrogenases (HSD), and diminished spermatogenesis, serum levels of testosterone and α2u-globulin. Supplementation with thyroxine at a dose of 5 μg/100 g body weight per day for 21 days or supplementation with α2u-globulin at a dose of 1·5 mg/rat per day for 21 days in thyroidectomized animals partially reversed the decrease in HSD activities and serum concentrations of testosterone and α2u-globulin, while spermatogenesis was restored to normal. The weights of testes and accessory sex organs were also reinstated after supplementation with thyroxine or α2u-globulin in thyroidectomized rats in comparison with thyroidectomized animals. It was concluded that α2u-globulin may be an intermediary in the thyroid hormone control of testicular function. Journal of Endocrinology (1994) 140, 343–347

GONADOTROPHIN SUPPRESSION BY STEROIDS IN NORMAL, ADULT MALE RATS

1977 ◽  
Vol 84 (4) ◽  
pp. 842-849 ◽  
Author(s):  
H. L. Verjans ◽  
K. B. Eik-Nes
Keyword(s):  
Body Weight ◽  
High Activity ◽  
Adult Male ◽  
Subcutaneous Administration ◽  
Serum Levels ◽  
Steroid Treatment ◽  
Male Rats ◽  
Normal Adult ◽  
Serum Lh ◽  
Testosterone Metabolites

ABSTRACT Effects of subcutaneous administration of various doses of different steroids on serum levels of LH and FSH in normal, adult male rats were investigated. Each steroid was injected daily during 7 days in doses of 50, 25, 12.5 or 6.25 μg per 100 g body weight. Ring A 5α-reduced testosterone metabolites exerted high activity in suppressing serum LH and FSH levels. 5α-Androstane-3β,17β-diol had in the doses tested, however, no such effects on serum gonadotrophins. Serum LH concentrations in normal rats appeared more sensitive to steroid treatment than serum FSH concentrations.

The contribution of corticosterone and testosterone to the suppression of serum LH in hyperprolactinaemic adult male rats with pituitary transplants

1987 ◽  
Vol 113 (1) ◽  
pp. 111-116 ◽  
Author(s):  
R. F. A. Weber ◽  
M. P. Ooms ◽  
J. T. M. Vreeburg
Keyword(s):  
Adult Male ◽  
Serum Testosterone ◽  
Serum Levels ◽  
Male Rats ◽  
Male Rat ◽  
Serum Concentrations ◽  
Testosterone Secretion ◽  
Accessory Sex Glands ◽  
Serum Lh ◽  
Stimulation Of

ABSTRACT The effects of hyperprolactinaemia on serum levels of LH were investigated in adult male rats of the R × U strain. Hyperprolactinaemia was induced by three pituitary grafts under the kidney capsule, transplanted on day 0 of each experiment. Special attention was paid to the contribution of prolactin-stimulated testes, adrenals and corticosterone. In experiment 1, hyperprolactinaemia significantly reduced the serum concentrations of LH in intact rats. In spite of a significant increase in the serum levels of corticosterone, serum testosterone was not significantly affected by hyperprolactinaemia. The weights of both the adrenals and accessory sex glands were significantly increased at autopsy. In experiment 2, treatment with 10 mg corticosterone s.c. daily from day 14 to day 28 after pituitary grafting significantly reduced serum levels of both LH and testosterone. The suppression of testosterone in the hyperprolactinaemic corticosterone-treated animals was significantly less than in the corticosterone-treated control animals. The weights of the accessory sex glands were significantly increased in the hyperprolactinaemic animals. In experiment 3, rats were adrenalectomized and half of them were substituted with corticosterone. Serum testosterone levels significantly increased in both hyperprolactinaemic adrenalectomized rats and in adrenalectomized corticosterone-treated animals without any significant effect on serum LH. Again the weights of the accessory sex glands were significantly increased in the hyperprolactinaemic animals. In experiment 4, rats were adrenalectomized, gonadectomized and corticosterone treated on day 0 and then implanted with a 2, 1·5 or 1 cm silicone elastomer capsule containing testosterone. On day 28 after pituitary grafting, LH levels were significantly suppressed in animals with a 2 or 1·5 cm testosterone implant. The weights of the accessory sex glands were not increased in the hyperprolactinaemic animals. These results show that in the male rat the inhibitory effects of hyperprolactinaemia on serum LH levels may be due to (1) increased sensitivity of the hypothalamic-pituitary axis to the negative feedback action of testosterone by prolactin and by the prolactin-stimulated corticosterone secretion and (2) stimulation of testicular testosterone secretion by prolactin, which can also explain the increased weights of the accessory sex glands. Even in the presence of high serum concentrations of corticosterone, stimulation of testicular testosterone secretion by prolactin was observed. J. Endocr. (1987) 113,111–116

SHORT-TERM EFFECTS OF CASTRATION AND STARVATION UPON PITUITARY AND SERUM LEVELS OF LUTEINIZING HORMONE AND FOLLICLE STIMULATING HORMONE IN MALE RATS

1972 ◽  
Vol 70 (4) ◽  
pp. 665-675 ◽  
Author(s):  
Allen W. Root ◽  
R. David Russ
Keyword(s):  
Luteinizing Hormone ◽  
Adult Male ◽  
Follicle Stimulating Hormone ◽  
Serum Levels ◽  
Male Rats ◽  
Serum Concentrations ◽  
Short Term ◽  
Serum Lh ◽  
Total Starvation ◽  
Stimulating Hormone

ABSTRACT Serum and pituitary levels of luteinizing hormone (LH) and follicle stimulating hormone (FSH) were measured by radioimmunoassay in intact and castrated juvenile (21 days) and adult male rats. The effect of total starvation upon the gonadotrophin response to castration was also investigated in adult animals. In rats castrated at 21 days of age, serum and pituitary levels of LH were elevated by 7 days and increased progressively for 4 weeks. Serum concentrations of FSH also increased within 7 days and remained stable thereafter. Pituitary FSH levels initially declined and then increased. In adult animals serum LH and FSH concentrations increased after castration. Pituitary LH values also increased, while FSH levels remained stable for 14 days after operation. Serum FSH concentrations were consistently decreased in starved-intact animals. Starvation partially inhibited castration-induced release of LH without affecting pituitary LH or FSH synthesis or FSH release.

HYPOTHALAMIC-PITUITARY-TESTICULAR SYSTEM AND ADRENOCORTICAL FUNCTION

1976 ◽  
Vol 81 (1) ◽  
pp. 198-207 ◽  
Author(s):  
H. L. Verjans ◽  
K. B. Eik-Nes
Keyword(s):  
Adrenal Gland ◽  
Blood Serum ◽  
Adult Male ◽  
Serum Levels ◽  
Male Rats ◽  
Intramuscular Administration ◽  
Adrenocortical Function ◽  
Male Rat ◽  
Pituitary Secretion ◽  
Slight Elevation

ABSTRACT Effect of intramuscular administration of ACTH or dexamethasone on blood serum levels of testosterone, LH and FSH was examined in intact and castrated, adult, male rats. Six IU ACTH or 1 mg dexamethasone were given daily for 7 days. Corticotrophin treatment had no influence on circulating testosterone, LH and FSH in intact or castrated male rats. Dexamethasone administration resulted in a slight elevation of serum FSH in intact animals but not in castrates. LH and testosterone remained normal in both intact and castrated animals injected with dexamethasone. Under our conditions of study the secretions from the adrenal gland appear to be insignificant for the regulation of pituitary secretion of gonadotrophins in the male rat.

Dietary fat and adiposity: a dose-response relationship in adult male rats fed isocalorically

1995 ◽  
Vol 268 (4) ◽  
pp. E546-E550 ◽  
Author(s):  
C. N. Boozer ◽  
G. Schoenbach ◽  
R. L. Atkinson
Keyword(s):  
Body Weight ◽  
Body Fat ◽  
Adult Male ◽  
Dietary Fat ◽  
Male Rats ◽  
Control Group ◽  
Low Fat Diet ◽  
Mesenteric Fat ◽  
Total Body Fat ◽  
Total Body

This study examined the effects of increasing levels of dietary fat fed isocalorically on body weight, body composition, and adipose distribution. Adult male rats were weight matched into four groups. One group that was fed a low-fat diet (12%) served as reference controls. The other three groups were fed diets of 24, 36, or 48% fat in amounts to equal the energy intake of the control group. After 6 wk, body weights of the four groups were not significantly different. Intrascapular brown fat did not differ between groups. Total body fat and adipose depot weights, however, increased in proportion to the level of fat in the diet. Total body fat and retroperitoneal and mesenteric depot weights of the 48% fat group were greater than controls (P < 0.05). Mesenteric fat in this group was also significantly increased over all other groups (P < 0.05). These results show that high-fat diets fed to adult animals cause increased body fat in the absence of significant changes in body weight and that mesenteric fat is increased disproportionately.

Correlation between Serum and Tissue Levels of Adipokines in Obesity in Adult Male Rats with and without Antioxidant

QJM ◽  
2020 ◽  
Vol 113 (Supplement_1) ◽  
Author(s):  
M M Elshawwa
Keyword(s):  
Insulin Resistance ◽  
Adult Male ◽  
Fasting Glucose ◽  
Density Lipoprotein ◽  
Serum Levels ◽  
Lipoprotein Cholesterol ◽  
Male Rats ◽  
Control Group ◽  
Tissue Levels ◽  
Group I

Abstract Background Obesity is associated with insulin resistance, type2 diabetes, dyslipidemia and cardiovascular diseases. Apelin and chemerin are identified as adipokines and adipose tissue markers. Several adipose-derived peptides are known to influence food intake, including apelin, whose expression is regulated by insulin and chemerin. Oxidative stress thought to be involved in the development of complications associated with obesity. Objective To study the nature of correlation between serum and liver levels of apelin, chemerin and oxidative parameters in obese rats with and without antioxidant. Aiming to clarify the pathophysiology of obesity. Material and Methods Thirty adult male albino rats, divided into three equal groups. Group I (control), group II (obese) and group III (obese and Lepidium sativum (LS) as an antioxidants). At the end of the experiment, blood samples were collected for estimation of the serum levels of chemerin, apelin, fasting glucose, insulin, insulin resistance (IR), lipid profile, reduced glutathione (GSH) and malondialdehyde (MDA). In addition to tissue homogenous extracts of liver were taken for the levels of MDA, CAT, chemerin and apelin. Results After eight weeks, high fat diet group showed a significant increase in serum levels of apelin, chemerin, fasting glucose, insulin, IR, total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C) & MDA and a significant decrease in high-density lipoprotein cholesterol (HDL-C) & GSH. HFD also caused a significant increase in tissue levels of MDA, CAT & chemerin and a significant decrease in apelin, compared to control group. While addition of LS to HFD caused a significant decrease in serum levels of apelin, chemerin, fasting glucose, insulin, IR, TC, TG, LDL-C & MDA and a significant increase in HDL-C & GSH. LS also caused a significant decrease in tissue levels of MDA, chemerin & insignificant decrease in CAT and a significant increase in apelin, compared to HFD group. Conclusion This study showed a significant positive correlation between liver & serum chemerin and between liver and serum MDA. On the other hand, it showed a significant negative correlation between liver and serum apelin and liver CAT and serum GSH

scholarly journals In vitro pituitary and testicular effects of the leptin-related synthetic peptide leptin(116-130) amide involve actions both similar to and distinct from those of the native leptin molecule in the adult rat

2000 ◽  
pp. 406-410 ◽  
Author(s):  
M Tena-Sempere ◽  
L Pinilla ◽  
LC Gonzalez ◽  
J Navarro ◽  
C Dieguez ◽  
...  
Keyword(s):  
Body Weight ◽  
Adult Male ◽  
Body Weight Gain ◽  
Biologically Active ◽  
Male Rats ◽  
Male Rat ◽  
Gh Secretion ◽  
Adult Rat ◽  
Testosterone Secretion

The obese gene (ob) product, leptin, has recently emerged as a key element in body weight homeostasis, neuroendocrine function and fertility. Identification of biologically active, readily synthesized fragments of the leptin molecule has drawn considerable attention, as they may provide a powerful tool for detailed characterization of the biological actions of leptin in different experimental settings. Recently, a fragment of mouse leptin protein comprising amino acids 116-130, termed leptin(116-130) amide, was shown to mimic the effects of the native molecule in terms of body weight gain and food intake, and to elicit LH and prolactin (PRL) secretion in vivo. As a continuation of our previous experimental work, the present study reports on the effects of leptin(116-130) amide on basal and stimulated testosterone secretion by adult rat testis in vitro. In addition, a comparison of the effects of human recombinant leptin and leptin(116-130) amide at the pituitary level on the patterns of LH, FSH, PRL and GH secretion is presented. As reported previously by our group, human recombinant leptin(10(-9)-10(-7)M) significantly inhibited both basal and human chorionic gonadotrophin (hCG)-stimulated testosterone secretion in vitro. Similarly, incubation of testicular tissue in the presence of increasing concentrations of leptin(116-130) amide (10(-9)-10(-5)M) resulted in a dose-dependent inhibition of basal and hCG-stimulated testosterone secretion; a reduction that was significant from a dose of 10(-7)M upwards. In addition, leptin(116-130) amide, at all doses tested (10(-9)-10(-5)M), significantly decreased LH and FSH secretion by incubated hemi-pituitaries from adult male rats. In contrast, in the same experimental protocol, recombinant leptin(10(-9)-10(-7)M) was ineffective in modulating LH and FSH release. Finally, neither recombinant leptin nor leptin(116-130) amide were able to change basal PRL and GH secretion in vitro. Our results confirm the ability of leptin, acting at the testicular level, to inhibit testosterone secretion, and map the effect to a domain of the leptin molecule that lies between amino acid residues 116 and 130. In addition, we provide evidence for a direct inhibitory action of leptin(116-130) amide on pituitary LH and FSH secretion, a phenomenon not observed for the native leptin molecule, in the adult male rat.

Effects of Insulin, Metrazol, and Electroconvulsive Shocks upon Learning to Learn 30 Successive Reversal Problems by Rats

1970 ◽  
Vol 26 (2) ◽  
pp. 551-558 ◽  
Author(s):  
Loh Seng Tsai ◽  
Vernon J. Perez ◽  
Jefferson M. Koonce
Keyword(s):  
Body Weight ◽  
Potassium Chloride ◽  
Electric Current ◽  
Adult Male ◽  
Male Rats ◽  
Learning To Learn ◽  
Successive Reversal ◽  
Insulin Group ◽  
Weight One ◽  
Better Than

To determine the relative effects of insulin, metrazol and electroconvulsive shocks upon learning to learn 30 successive reversal problems by rats, an enclosed square T-maze was used, with water as incentive after 23 hr. of deprivation. S had to achieve 9 correct out of 10 daily trials before a problem was reversed. 40 adult male rats were equally divided into a control and 3 differently shocked groups. Shocks were administered on 3 alternate days followed by 2 days of rest. Each time, Ss of the 4 groups received respectively 0.5 cc. of saline, 55 mg. of metrazol per kg. of body-weight, one unit of insulin per 20 gm. of body-weight, and an electric current of 50 ma. at 25 v for 150 msec. Convulsion in the insulin group was prevented by an injection of dextrose and potassium chloride. The control was significantly superior to the 3 shocked groups which were remarkably similar or practically identical in their performance during the initial 6 problems. Thereafter, both the non-convulsive (saline and insulin) groups did better than the 2 convulsive groups either in terms of error, day, or one-trial reversal score.

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