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.

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.

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

SEXUAL DIFFERENTIATION IN THE PHASE OF THE CIRCADIAN RHYTHM OF [35S]METHIONINE INCORPORATION INTO CEREBRAL PROTEINS, AND OF SERUM GONADOTROPHIN LEVELS

1974 ◽  
Vol 62 (2) ◽  
pp. 257-265 ◽  
Author(s):  
M. B. ter HAAR ◽  
P. C. B. MacKINNON ◽  
M. G. BULMER
Keyword(s):  
Circadian Rhythm ◽  
Circadian Rhythms ◽  
Adult Male ◽  
Anterior Pituitary ◽  
Male Rats ◽  
Normal Adult ◽  
Adult Males ◽  
Serum Luteinizing Hormone ◽  
Serum Lh ◽  
The Brain

SUMMARY The incorporation of [35S]methionine into protein in various regions of the brain and in the anterior pituitary, and serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels were measured at 6 h intervals throughout a 24 h period in the following groups of Wistar rats: (1) normal adult males and females; (2) adult genetic males or females which had been respectively 'feminized' or 'masculinized' by androgen deprivation or administration in neonatal life. Similar measurements were made at 12 h intervals in adult male rats which had been castrated at 7 or 15 days of age. Serum LH levels showed a circadian rhythmicity in normal adult animals of both sexes, with peak levels in the male occurring 6 h earlier than those in the female. There was no statistically significant circadian rhythm in FSH levels in any group of animals. In all groups of castrated animals LH and FSH levels were raised but no circadian rhythms were observed. Incorporation of [35S]methionine into protein in all cerebral areas showed circadian rhythms, the peak values of which, in the adult males, were almost 8 h (120°) out of phase with those of the adult females. In the 'feminized' genetic males or 'masculinized' genetic females the rhythmic phase was reversed to that of the opposite genetic sex. Animals castrated at 7 days or 15 days of age did not appear to show a rhythm. A 12 h rhythm of incorporation was apparent in the anterior pituitary of the normal adult male and the adult 'masculinized' female; no significant rhythm was seen in the normal adult female and the 'feminized' male. It is suggested that a 'female type' rhythm of incorporation in the brain may be associated with the maintenance of oestrous cycles.

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

COMPARISON OF EFFECTS OF C19 (ANDROSTENE OR ANDROSTANE) STEROIDS ON SERUM GONADOTROPHIN CONCENTRATIONS AND ON ACCESSORY REPRODUCTIVE ORGAN WEIGHTS IN GONADECTOMIZED, ADULT MALE RATS

1977 ◽  
Vol 84 (4) ◽  
pp. 829-841 ◽  
Author(s):  
H. L. Verjans ◽  
K. B. Eik-Nes
Keyword(s):  
Adult Male ◽  
Subcutaneous Administration ◽  
Serum Levels ◽  
Reproductive Organs ◽  
Reproductive Organ ◽  
Seminal Vesicles ◽  
Male Rats ◽  
High Potency ◽  
Feedback Effects ◽  
Organ Weights

ABSTRACT The effect of subcutaneous administration of graded doses of C19 (androstene or androstane) steroids on serum levels of LH and FSH and on weights of accessory reproductive organs in gonadectomized, adult male rats were investigated. The C19 steroids were administered during 7 days in doses of 100, 50, 25, 12.5 or 6.25 μg per 100 g body weight per day. With the amounts of steroids used, 5α-dihydrotestosterone and 5α-androstane-3α,17β-diol had a high potency in preventing the rise of serum gonadotrophin concentrations and in curbing the decrease of weights of ventral prostates and seminal vesicles following orchidectomy. 5α-Androstane-3β,17β-diol showed no such effects. Positive feedback effects on serum gonadotrophins in castrates were observed following injection of certain doses of some steroids. Effects of steroids on accessory reproductive organs did not always correlate with those on gonadotrophic function of the hypothalamic-pituitary unit.

Effects of Testosterone Metabolites on Serum Gonadotropin Concentrations in Immature Male Rats

1975 ◽  
Vol 53 (5) ◽  
pp. 839-844 ◽  
Author(s):  
William H. Moger
Keyword(s):  
Body Weight ◽  
Testosterone Propionate ◽  
Male Rats ◽  
Ventral Prostate ◽  
Male Rat ◽  
Control Group ◽  
Immature Male ◽  
Serum Lh ◽  
Serum Gonadotropin ◽  
Testosterone Metabolites

The ability of testosterone, androsterone, 5α-androstane-3α,17β-diol, and 5α-androstane-3β,17β-diol to prevent the castration-induced rise in serum gonadotropin levels was investigated in immature male rats. Rats castrated at 30 days of age were treated once per day by subcutaneous injection of 12.5–100 μg of the steroid per 100 g body weight per day for 3 days, beginning on the day of castration. The animals were sacrificed 24 h after the last injection. Testosterone propionate, androsterone propionate, and 5α-androstane-3α,17β-diol dipropionate were also tested at the approximate molar equivalent of 100 μg of the free alcohol form per 100 g body weight per day.Testosterone propionate and 5α-androstane-3α,17β-diol were the only compounds tested that prevented the castration induced rise in luteinizing hormone (LH) concentrations. Testosterone propionate also inhibited the rise in follicle stimulating hormone (FSH) concentrations whereas 5α-androstane-3α,17β-diol inhibited the rise in FSH in one but not in another experiment. These were the only compounds tested that affected serum FSH concentrations.The lower doses of testosterone tested significantly increased serum LH, but not FSH concentrations compared to castrate control animals. The highest dose tested partially inhibited the rise in serum LH concentrations.Both androsterone and androsterone propionate maintained ventral prostate weights. Although neither compound prevented the castration induced rise in serum LH, two groups receiving androsterone had serum LH concentrations significantly lower than the castrate control group.5α-Androstane-3β,17β-diol and 5α-androstane-3α,17β-diol dipropionate failed to maintain ventral prostate weights or prevent the rise in serum gonadotropin levels.These results indicate that 5α-androstane-3α,17β-diol is capable of preventing the castration induced rise in serum LH concentrations in the immature male rat and thus may participate in the regulation of LH secretion in these animals.

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.

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.

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.

EFFECTS OF ANDROSTENES, 5α-ANDROSTANES, 5β-ANDROSTANES, OESTRENES AND OESTRATRIENES ON SERUM GONADOTROPHIN LEVELS AND VENTRAL PROSTATE WEIGHTS IN GONADECTOMIZED, ADULT MALE RATS

1976 ◽  
Vol 83 (1) ◽  
pp. 201-210 ◽  
Author(s):  
H. L. Verjans ◽  
K. B. Eik-Nes
Keyword(s):  
Adult Male ◽  
Standard Dose ◽  
Subcutaneous Administration ◽  
Serum Levels ◽  
Inhibitory Effect ◽  
Male Rats ◽  
Ventral Prostate ◽  
Male Rat ◽  
Regulatory Processes ◽  
Organ Systems

ABSTRACT The effects of subcutaneous administration of steroids from the androstene, 5α-androstane, 5β-androstane, oestrene and oestratriene series on serum levels of LH and FSH and on ventral prostate weights were investigated in gonadectomized, adult male rats. Each steroid was administered for seven days in a standard dose of 100 μg per 100 g body weight per day. 5α-Androstanes disubstituted with oxygen in the positions 3 (3-keto or 3α-hydroxy) and 17 (17-keto or 17β-hydroxy) were effective in suppressing either one or both serum gonadotrophins. 5β-Androstanes and androstenes exhibited very little inhibitory effect in this respect. Potent suppression of serum gonadotrophins was observed following treatment with oestratrienes, the presence of only a phenolic A-ring in these oestrogens appeared sufficient for such suppression. 3 or 3β and 17 or 17β disubstituted (keto or hydroxyl) androstenes could entirely or partly prevent ventral prostate weight decrease post-gonadectomy. 5α-Androstane-3α,17β-diol, 5α-androstane-3α,11β,17β-triol and 5α-androstan-17β-ol-3-one were most potent, while 5β-androstanes and oestratrienes had no effect on this decrement. Regulatory processes by steroids at the hypothalamic-pituitary and at the ventral prostate level were not parallel. The results indicate, however, that 3 or 3α and 17 disubstituted (keto or hydroxyl) 5α-reduced testosterone metabolites, of which 5α-androstan-17β-ol-3-one might be the principal one, are the main steroids directing androgenic regulation at both organ systems tested in the mature male rat.

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