RELATION BETWEEN CIRCULATING LEVELS OF TESTOSTERONE, LH AND FSH IN INTACT AND CASTRATED, ADULT, MALE RATS AFTER TESTOSTERONE ADMINISTRATION

1975 ◽  
Vol 79 (2) ◽  
pp. 380-386 ◽  
Author(s):  
H. L. Verjans ◽  
H. J. van der Molen ◽  
K. B. Eik-Nes
Keyword(s):  
Adult Male ◽  
Serum Testosterone ◽  
Serum Levels ◽  
Male Rats ◽  
Male Rat ◽  
Normal Male ◽  
Serum Lh ◽  
Adult Male Rat ◽  
Normal Rat ◽  
Testosterone Administration

ABSTRACT Serum levels of LH, FSH and testosterone were measured by radioimmunoassay in intact and castrated, adult, male rats after testosterone was administered subcutaneously for seven days in doses ranging from 25 to 200 μg per 100 g body weight per day. Such treatment increased circulating testosterone both in intact and castrated rats, but its effects on serum gonadotrophins were different in these animal groups. All doses of testosterone suppressed serum LH and FSH in the normal rat. In the castrates, treatment with the lowest dose of testosterone resulted in serum LH levels significantly above the high castrate levels, while serum FSH tended to drop. Administration of the highest doses of testosterone did not depress serum LH and FSH in the castrates to those of intact, normal animals, though serum testosterone in these castrates was much higher than in normal, male rats. It is concluded, that the sensitivity of the hypothalamic-pituitary system for daily, subcutaneous testosterone administration during seven days is not the same in the intact and castrated, adult, male rat and that testicular factors different from testosterone may play a role in regulating production and/or secretion of gonadotrophins by the hypophysis in male animals.

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

EFFECTS OF TESTOSTERONE PROPIONATE, 5α-DIHYDROTESTOSTERONE PROPIONATE AND OESTRADIOL BENZOATE ON SERUM LEVELS OF LH AND FSH IN THE CASTRATED ADULT MALE RAT

1974 ◽  
Vol 77 (4) ◽  
pp. 643-654 ◽  
Author(s):  
H. L. Verjans ◽  
K. B. Eik-Nes ◽  
J. H. Aafjes ◽  
F. J. M. Vels ◽  
H. J. van der Molen
Keyword(s):  
Adult Male ◽  
Testosterone Propionate ◽  
Serum Levels ◽  
Seminal Vesicles ◽  
Male Rats ◽  
Male Rat ◽  
Low Doses ◽  
Serum Lh ◽  
Oestradiol Benzoate ◽  
Adult Male Rat

ABSTRACT The influence of treatment with various doses of testosterone propionate, 5α-dihydrotestosterone propionate or oestradiol benzoate on serum levels of LH and FSH (measured by radioimmunoassay) and on weights of ventral prostates and seminal vesicles was investigated in castrated, adult, male rats. For depression of the high, castrate levels of serum gonadotrophins with either of these steroid esters, the inhibition curves were different for LH and for FSH. Serum LH was kept at levels encountered in intact, adult, male rats by lower doses of steroid ester than was serum FSH. Oestradiol benzoate was the most potent suppressor of the serum gonadotrophins among the steroid esters tested, testosterone propionate the least. Treatment with low doses of oestradiol benzoate, however, resulted in serum FSH levels significantly above those of castrates treated with vehicle only. Finally, administration of a synthetic LH-releasing factor to testosterone propionate, 5α-dihydrotestosterone propionate or oestradiol benzoate treated, castrated, adult, male rats resulted in a further release of both LH and FSH. The latter effect was more pronounced in oestradiol benzoate treated castrates than in testosterone propionate or 5α-dihydrotestosterone propionate treated castrates.

EFFECT OF OESTRADIOL BENZOATE ON PITUITARY AND TESTIS FUNCTION IN THE NORMAL ADULT MALE RAT

1974 ◽  
Vol 77 (4) ◽  
pp. 636-642 ◽  
Author(s):  
H. L. Verjans ◽  
F. H. de Jong ◽  
B. A. Cooke ◽  
H. J. van der Molen ◽  
K. B. Eik-Nes
Keyword(s):  
Adult Male ◽  
Subcutaneous Administration ◽  
Serum Levels ◽  
Testicular Tissue ◽  
Male Rats ◽  
Normal Adult ◽  
Ventral Prostate ◽  
Male Rat ◽  
Oestradiol Benzoate ◽  
Adult Male Rat

ABSTRACT The effects of subcutaneous administration of oestradiol benzoate (EB) on the weights of sex organs and on levels of testosterone and gonadotrophins in normal adult male rats have been studied. Doses of EB varied from 0.01 to 100 μg and were administered daily for seven days. Administration of 100 μg EB resulted in suppression of pituitary LH, while serum LH levels were already decreased after treatment with EB ≧ 1 μg. Pituitary and serum FSH levels were suppressed after administration of 100 and 10 μg EB respectively. Testicular tissue and serum levels of testosterone decreased after treatment with amounts of EB ≧ 1 μg. These decreased androgen levels were also reflected in a concomitant decrease in the weights of the ventral prostate and seminal vesicles. A decrease in the weight of the testes was obtained following a dose of EB ≧ 10 μg.

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.

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.

scholarly journals Evaluation of The Effect of Pasak Bumi (Eurycoma longifolia Jack) to Increase Androgen Levels

INSIST ◽  
2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Hurip Pratomo
Keyword(s):  
Serum Testosterone ◽  
Female Rats ◽  
Male Rats ◽  
Male Rat ◽  
Testosterone Levels ◽  
Eurycoma Longifolia ◽  
Testosterone Administration ◽  
Eurycoma Longifolia Jack ◽  
Boiled Water ◽  
Androgen Levels

Abstract—Background:The ability of reproductive disorders in men and experimental male rat is characterized among other things by a decrease in androgen such as testosterone levels. Materials of pasak bumi root (Eurycoma longifolia Jack) increased libido behavior of experimental male rat. Libido associated with higher levels of testosterone, it is therefore necessary to evaluate the effect of pasak bumi on androgen levels such as testosterone. Methods: Male rats at 9.00 am treated controls and pasak bumi, then at 14.00 pm tempted with estrus female rats 10 minutes. Then, both control and pasak bumi blood  samples were collected from male rat heart on day 1st  and day 3rd  at 14.15 pm. Measurement of testosterone levels were calculated using radioimmunoassay (RIA). Results: An increase in serum  testosterone levels in the blood on day-3rd  administration pasak bumi boiled water 18 mg/200 g dose  significantly different than the  control within day 1st to 3rd. The average levels of testosterone administration control (boiled water of aquades) day 1st = 0.50 ng/ml, day 3rd = 2.46 ng / ml, increased markedly on pasak bumi treatment day 1st = 4.00 ng / ml and day 3 = 9.73 ng / ml, (Duncan test, α=0.05). Conclusions: Testosterone levels can be increased markedly after the consumption of the pasak bumi boiled water for 3 days.Keywords—Pasak bumi, a dose of  18 mg/200 g, testosterone.

scholarly journals Some effects of dietary dextrose, fructose, liquid glucose and sucrose in the adult male rat

1966 ◽  
Vol 20 (2) ◽  
pp. 339-347 ◽  
Author(s):  
R. J. L. Allen ◽  
J. S. Leahy
Keyword(s):  
Adult Male ◽  
Body Weight Gain ◽  
Plasma Cholesterol ◽  
Liver Fat ◽  
Male Rats ◽  
Male Rat ◽  
Liver Protein ◽  
Cholesterol Levels ◽  
Adult Male Rat ◽  
The Mean

1. For 26 weeks, adult male rats were fed on diets containing about 80 % of carbohydrate, given as dextrose, fructose, liquid glucose, or sucrose; their performance was compared with that of rats receiving a standard laboratory cubed diet (41 B) containing 60 % of carbohydrate, mainly as starch. 2. More of diet 41 B was eaten than of any of the diets containing sugars, but only with dextrose was the mean body-weight gain significantly lower than with diet 41 B. 3. No significant differences in body length or girth were produced by the different diets. 4. Compared with those of rats given diet 41B, plasma cholesterol levels were significantly in- creased by fructose and sucrose and to a lesser extent by dextrose, but not by liquid glucose. 5. Compared with those given diet 41 B, the rats given fructose had heavier hearts, kidneys and livers, those given sucrose had heavier hearts and livers, and those given dextrose had heavier hearts. Those given fructose had the heaviest kidneys and livers, and heavier hearts than those given liquid glucose. The organ weights of those given liquid glucose and those given diet 41 B were not significantly different. 6. Compared with the values on diet 41B, carcass and liver fat were both significantly increased by sucrose and fructose but not by dex- trose or liquid glucose. With fructose, liver fat was almost double that with dextrose or liquid glucose. 7. Dry-matter contents of whole carcass and liver followed substantially the same pattern as did the fat contents. 8. Liver protein content was significantly lower on the 80 % carbohydrate diets. The reductions were greatest with fructose and sucrose.

Reproductive toxicity of DDT in adult male rats

2001 ◽  
Vol 20 (8) ◽  
pp. 393-397 ◽  
Author(s):  
K Ben Rhouma ◽  
O Tébourbi ◽  
R Krichah ◽  
M Sakly
Keyword(s):  
Adult Male ◽  
Pesticide Exposure ◽  
Reproductive Toxicity ◽  
Male Rats ◽  
Male Rat ◽  
Seminiferous Tubules ◽  
Serum Lh ◽  
Testicular Weight ◽  
Hypothalamic Pituitary Axis ◽  
Dose Dependent

The reproductive toxicity of DDT was investigated in adult male rats exposed to 50 and 100 mg/kg body weight (b.wt) day 1 for 10 successive days. Compared with control animals, administration of DDT led to a dose-dependent reduction of testicular weight and the number as well as the percentage of motile spermatozoa in the epididymis. Testicular histological observationsrevealed alsoamarkedloss of gametes in the lumen of seminiferous tubules. In DDT treated rats, the seminal vesicles weights dropped significantly, resulting from a decrease of testosterone production by testes, whereas serum LH and FSH increased after pesticide exposure. This increase of gonadotrophin levels may be related to an impairment of the negative feedback exerted by the steroid on the hypothalamic–pituitary axis. It is concluded that DDT induced adverse effects on male rat fertility by acting directly on the testes and altering the neuroendocrinefunction.

Influence of pinealectomy on the suppression of gonadotrophin secretion induced by hyperprolactinaemia in the adult male rat

1983 ◽  
Vol 97 (3) ◽  
pp. 401-407 ◽  
Author(s):  
A. S. McNeilly ◽  
D. W. Lincoln
Keyword(s):  
Pineal Gland ◽  
Adult Male ◽  
Male Rats ◽  
Male Rat ◽  
Gonadotrophin Secretion ◽  
Adult Male Rat ◽  
Pituitary Glands ◽  
Hypothalamic Pituitary Axis

To investigate the role of the pineal gland in the long-term suppression of gonadotrophin secretion induced by prolactin, the effects of pinealectomy were studied in adult male rats with hyperprolactinaemia produced by the transplantation of two pituitary glands under the kidney capsule. Pinealectomy had no effect on basal levels of LH, FSH or prolactin. The presence of pituitary transplants induced a significant twofold increase in prolactin levels and a prolonged suppression in both LH and FSH. These changes were not affected by pinealectomy. Castration resulted in a similar rise in plasma levels of LH and FSH in rats with and without pituitary transplants. In control rats this rise in LH and FSH was reduced by testosterone-containing silicone elastomer implants (s.c) of 10 mm in length and delayed by implants of 30 mm. These rises in LH and FSH were significantly delayed (10-mm implant) or abolished (30-mm implant) in rats with pituitary transplants indicating an increase in sensitivity of the hypothalamic-pituitary axis to the negative feedback effects of testosterone in these animals compared to controls. These responses were not affected by pinealectomy. These results suggest that the pineal gland is not involved in the mechanism whereby pituitary grafts, possibly through their secretion of prolactin, cause long-term suppression of gonadotrophin secretion.

The effect of Δ1·testolactone on serum testosterone and estradiol in the adult male rat**Supported in part by NIH grant 2-R01-AM 16735.

1983 ◽  
Vol 40 (6) ◽  
pp. 818-822 ◽  
Author(s):  
Harris M. Nagler ◽  
Ralph deVere White ◽  
Inge Dyrenfurth ◽  
Wylie C. Hembree
Keyword(s):  
Adult Male ◽  
Serum Testosterone ◽  
Male Rat ◽  
Adult Male Rat
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