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.

Effect of short-term starvation on reproductive hormone gene expression, secretion and receptor levels in male rats

1989 ◽  
Vol 121 (3) ◽  
pp. 409-417 ◽  
Author(s):  
M. Bergendahl ◽  
A. Perheentupa ◽  
I. Huhtaniemi
Keyword(s):  
Male Rats ◽  
Ventral Prostate ◽  
Male Rat ◽  
Testicular Function ◽  
Mrna Levels ◽  
Short Term ◽  
Α Subunit ◽  
Gnrh Receptors ◽  
Androgen Synthesis ◽  
Serum Lh

ABSTRACT The effects of 4–6 days of food deprivation on the pituitary-testicular function of adult male rats were studied. Fasting decreased body weights on average by 23% (P<0·01) and those of seminal vesicles by 55% (P<0·01) in 4 days. No consistent changes were found in testicular and ventral prostate weights. The pituitary levels of gonadotrophin-releasing hormone (GnRH) receptors decreased by 50% (P<0·01). Serum and pituitary levels of LH, FSH and prolactin decreased by 25–50% (P<0·01 for all). Testicular and serum levels of testosterone decreased by 70–80%, testicular LH receptors by 26%, those of prolactin by 50% (P<0·01 for all), but those of FSH remained unaffected. Acute (2 h) stimulation by a GnRH agonist (buserelin, 10 μg/kg i.m.) resulted in similar LH, FSH and testosterone responses in the fasted and control animals, and human chorionic gonadotrophin (hCG) stimulation (30 IU/kg i.m.) in similar increases in testosterone. A 42% decrease was found in pituitary content of mRNA of the common α subunit (P<0·05), but the mRNAs of the LH- and FSH-β chains and prolactin were unaffected by fasting for 4 days. When the same mRNAs were measured after 6 days of fasting, the decrease of the mRNA of FSH-β also became significant (50%, P<0·01). In contrast, the mRNA of LH-β was increased twofold (P<0·01) at this time and serum LH levels were similar in control and starved animals. It is concluded that during short-term starvation of male rats: (1) the decrease in gonadotrophin and prolactin synthesis and secretion is first noticed on the level of translation (protein synthesis), and the mRNA levels of these hormones may respond more slowly to starvation, (2) decreased pituitary GnRH receptors indicate decreased GnRH release from the hypothalamus, (3)the gonadotrophin and prolactin loss results secondarily in decreased testicular androgen synthesis and LH and prolactin receptor levels, (4) no decrease occurs during starvation in acute gonadotrophin response to GnRH, or testicular testosterone response to hCG, (5) the primary response to starvation in male rat pituitary-testicular function is the loss of normal hypothalamic support of gonadotrophin and prolactin secretion, rather than direct nutritional effects on the pituitary and testis, and (6) when starvation is continued beyond 4 days, a recovery is seen in pituitary mRNA on the LH-β chain and in serum LH, most probably because the starvation-associated decrease serum testosterone is a more potent positive stimulus of LH synthesis than the direct hypothalamic-pituitary inhibition. Journal of Endocrinology (1989) 121, 409–417

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.

MODIFICATION OF MALE RAT REPRODUCTIVE TRACT DEVELOPMENT BY A SINGLE INJECTION OF TESTOSTERONE PROPIONATE SHORTLY AFTER BIRTH

1965 ◽  
Vol 50 (2) ◽  
pp. 310-316 ◽  
Author(s):  
H. E. Swanson ◽  
J. J. van der Werff ten Bosch
Keyword(s):  
Reproductive Tract ◽  
Testosterone Propionate ◽  
Pubertal Development ◽  
Testicular Tissue ◽  
Male Rats ◽  
Ventral Prostate ◽  
Male Rat ◽  
Androgenic Activity ◽  
Reduced Rate ◽  
And Control

ABSTRACT Administration of 500 μg testosterone propionate (TP) to male rats within a few days of birth was followed by a reduced rate of growth of the testes and, after initial stimulation, of the seminal vesicles and ventral prostate. While the testes and accessory organs remained permanently smaller in TP-treated rats than in controls, their growth rates showed pubertal accelerations which coincided with those in the controls. On the basis of these criteria, as well as the criterion of spermatogenesis, the time of puberty was not altered by early TP-administration. The weights of the accessory organs considered in relation to the weights of the testes were identical in TP-treated and control rats; testis tubule diameters in TP-treated rats were normal for the age. It is concluded that early TP-administration caused a reduction in the volume of testicular tissue, which involved both tubules and Leydig cells. There were no indications that TP had caused any qualitative changes in the testes: the timing and the pattern of pubertal development (spermatogenesis and androgenic activity) appeared to be normal.

Testosterone metabolites do not participate in the control of hypothalamic LH-releasing hormone

1986 ◽  
Vol 109 (2) ◽  
pp. 291-296 ◽  
Author(s):  
M. Zanisi ◽  
F. Celotti ◽  
P. Ferraboschi ◽  
M. Motta
Keyword(s):  
Testosterone Propionate ◽  
Male Rats ◽  
Free Form ◽  
Releasing Hormone ◽  
Specific Radioimmunoassay ◽  
Serum Lh ◽  
Oestradiol Benzoate ◽  
Lh Release ◽  
Testosterone Metabolites ◽  
Lh Releasing Hormone

ABSTRACT To determine whether the ability of testosterone to increase intrahypothalamic LH-releasing hormone (LHRH) in orchidectomized rats might be explained by the conversion of the hormone into either its 5α-reduced or oestrogenic metabolites, testosterone, 5α-androstan-17β-ol-3-one (DHT), 5α-androstane-3α, 17β-diol (3α-diol) and 5α-androstane-3β,17β-diol (3β-diol) (2 mg/rat per day for 6 days) and oestradiol (0·1, 0·5, 1·0 and 5·0 μg/rat per day for 6 days) were injected into castrated male rats. After 6 days the rats were killed and serum LH levels and intrahypothalamic LHRH stores measured using specific radioimmunoassay procedures. Testosterone and its 5α-reduced metabolites were used in either the free alcohol or the propionate form (dipropionates in the case of the diols); oestradiol was used as oestradiol-17β or in the benzoate form. Treatment with testosterone, DHT, 3α-diol and 3β-diol resulted in a significant decrease in serum LH levels; all the 5α-reduced testosterone derivatives were more effective than testosterone in this respect. Testosterone and DHT propionates suppressed LH release following orchidectomy totally; 3α-diol and 3β-diol dipropionates were less effective. Testosterone increased intrahypothalamic LHRH stores, this effect being much higher after testosterone propionate, i.e. when intrahypothalamic LHRH stores were restored to pre-castration levels. None of the 5α-reduced steroids was capable of modifying the low intrahypothalamic levels of LHRH found following orchidectomy; only 3α-diol dipropionate exhibited some activity, but this was much lower than that of testosterone propionate. Oestradiol-17β was totally ineffective in decreasing serum LH in orchidectomized animals; in contrast, oestradiol benzoate progressively decreased serum LH. Oestradiol in the free form was unable to increase LHRH stores, as was oestradiol benzoate except at the highest dose. The results suggest that the effect exerted by testosterone on hypothalamic LHRH is due to the hormone as such and does not involve its conversion into either 5α-reduced or oestrogenic metabolites. J. Endocr. (1986) 109, 291–296

scholarly journals 6. Administration of Centella Leaf Extract (Centella asiatica (L.) Urban) for Decreasing cAMP Responsive Element Modulator (CREM) Expression in Testicular Seminiferous Tubule of Male Rats (Rattus norvegicus)

2016 ◽  
Vol 1 (2) ◽  
pp. 31-37
Author(s):  
Susi Darmayanti ◽  
Sri Wahyuni ◽  
Muslim Akmal ◽  
Tongku Nizwan Siregar ◽  
Sugito Sugito
Keyword(s):  
Body Weight ◽  
Rattus Norvegicus ◽  
Leaf Extract ◽  
Centella Asiatica ◽  
Male Rats ◽  
Male Rat ◽  
Seminiferous Tubules ◽  
Control Group ◽  
Responsive Element ◽  
Neutral Formalin

The objective of this study was to determine the effect of centella leaf extract administration on decreased of the molecule cAMP responsive element modulator (CREM) expression in the testicular seminiferous tubules of male rats (Rattus norvegicus). Eight rats, aged 3.5 months with 150-250 grams of body weight (BW) were used in this study. All rats were divided randomly into four groups as if K0 as a control group whereas K1, K2, and K3 were given the centella leaf extract with doses 125, 250, and 500 mg / kg body weight respectivelly that given once daily for 30 days. At the end of the treatment, rats were sacrificed and their testes were collected and subsequently fixed in buffered neutral formalin (BNF) 10% as fixative solution for histological preparation. The CREMs expressions were detected using immunohistochemical methods. The results showed that the number of CREM expression in the seminiferous tubules significantly differ (P <0.05) between K0 and the treatment group (K1, K2, and K3). Conclusion, the administration of centella leaf extract with of the dose 125, 250, and 500 mg/kg BW can decreased CREM expression spermatids of testicular seminiferous tubules in male rat.

Ontogeny of serum and pituitary gonadotrophins in male rats treated with low doses of 5α-dihydrotestosterone

1986 ◽  
Vol 108 (3) ◽  
pp. 369-375 ◽  
Author(s):  
S. Karanth ◽  
M. K. Gill ◽  
A. Dutt ◽  
N. Lehri ◽  
H. S. Juneja
Keyword(s):  
Body Weight ◽  
Male Rats ◽  
Male Rat ◽  
Low Doses ◽  
Releasing Hormone ◽  
Serum Lh ◽  
Lh Releasing Hormone

ABSTRACT The effect of s.c. daily injections of 10 or 1000 ng 5α-dihydrotestosterone (DHT)/100 g body weight from birth to day 21, or from days 26 to 117 of age, on the changes in concentration of serum and pituitary gonadotrophins was investigated in male rats. Treatment with 10 ng DHT from days 1 to 21 depressed serum FSH, but not LH, at day 7, while 1000 ng DHT depressed both serum LH and FSH. Treatment with both doses of DHT reduced pituitary levels of LH and FSH at day 7, with FSH being more depressed than LH. Treatment with 10 ng DHT from days 26 to 117 increased serum FSH from days 82 to 117, while 1000 ng DHT did not have this effect. Treatment with 1000 ng, but not 10 ng, DHT between days 26 and 117 reduced pituitary levels of LH and FSH at day 40. Rats treated with the two doses of DHT from days 26 to 117 showed a difference in the responsiveness of the pituitary to LH-releasing hormone (LHRH). Treatment with 10 ng DHT enhanced LHRH-induced release of LH without affecting FSH release, while 1000 ng DHT depressed LHRH-induced release of FSH but not of LH. These findings support the view that DHT may play a modulatory role in the ontogeny of serum gonadotrophins and the responsiveness of the pituitary to LHRH during the onset of puberty in the male rat. J. Endocr. (1986) 108, 369–375

EFFECT OF MELATONIN UPON THYROID HORMONE SECRETION RATE IN FEMALE HAMSTERS AND MALE RATS

1972 ◽  
Vol 69 (1) ◽  
pp. 35-40 ◽  
Author(s):  
D. V. Singh ◽  
C. W. Turner
Keyword(s):  
Body Weight ◽  
Thyroid Hormone ◽  
Hormone Secretion ◽  
Secretion Rate ◽  
Male Rats ◽  
Male Rat ◽  
Maximum Effect ◽  
Control Group ◽  
Sprague Dawley ◽  
The Mean

ABSTRACT Thyroid hormone secretion rate (TSR) of female golden hamsters and male Sprague-Dawley-Rolfsmeyer rats at 25 days of age were estimated as 0.75 μg L-T4/100 g body weight and 1.41 μg L-T4/100 g body weight respectively. The mean TSR of control group of both hamster and male rat reduced at 55 days (0.60 and 1.20 μg L-T4/100 g body weight, respectively) gives further evidence of aging. In hamsters, melatonin treatment at higher levels had no greater depressing effect upon TSR than the lower level, but had greater effect on food consumption. However, in male rats, melatonin depressed TSR at the higher level only. It seems that hamster is more sensitive to melatonin than rats. Thus the lower level exerts a maximum effect whereas in the rat, higher levels are required for maximum effect.

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.

Sexual Development in Male Rats Treated With Cortisone

1957 ◽  
Vol 188 (2) ◽  
pp. 281-286 ◽  
Author(s):  
Russell O. Hanson ◽  
Ben B. Blivaiss ◽  
Robert E. Rosenzweig
Keyword(s):  
Body Weight ◽  
Male Rats ◽  
Ventral Prostate ◽  
Prostate Weight ◽  
Immature Male ◽  
End Of Treatment ◽  
Feeding Regimes ◽  
Pituitary Glands ◽  
Ad Libitum ◽  
Ad Libitum Feeding

Immature male rats were treated with 1.0 mg cortisone acetate daily for 2 or 4 weeks starting at 23 days of age and were maintained on paired or ad libitum feeding regimes. Body, adrenal and thymus weights were reduced as compared to control animals. Actual testes weights were usually reduced less than body, liver or kidney weights. The ratios of testicular to body weight were significantly increased in the animals autopsied at the end of treatment. Histological examination of the testes revealed no significant alterations from normal. The ratios of seminal vesicle and ventral prostate weight to body weight were significantly decreased in all groups of ad libitum-fed animals and in pair-fed group autopsied at the end of 2 weeks of treatment. There were no significant changes in the other pair-fed groups. No modifications were observed in the histology of these organs. Pituitary glands removed from pair-fed animals at end of treatment with cortisone for 2 weeks appeared to have a higher GTH content than in the controls as indicated by the growth of the ovaries of immature rats injected with suspensions of these glands. Pituitary glands taken from other pair-fed groups and from all ad libitum-fed groups usually showed a lesser GTH content than in controls.

RESPONSE OF THE PITUITARY-TESTICULAR AXIS TO LUTEINIZING HORMONE-RELEASING HORMONE IN THE IMMATURE MALE RAT

1977 ◽  
Vol 84 (2) ◽  
pp. 254-267 ◽  
Author(s):  
H. Edward Grotjan ◽  
Donald C. Johnson
Keyword(s):  
Luteinizing Hormone ◽  
Control Level ◽  
Serum Testosterone ◽  
Male Rats ◽  
Male Rat ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Immature Male ◽  
Serum Lh ◽  
Lh Rh

ABSTRACT Follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone and androstenedione were measured by radioimmunoassays in the sera of immature male rats treated with luteinizing hormone-releasing hormone (LH-RH). A single dose of 10, 20, 40 or 80 ng of LH-RH produced a prompt increase in serum LH: significant changes in FSH were found only with the two larger doses. Serum testosterone increased to peak levels in 20 to 40 min and returned to control level by 120 min. Changes in androstenedione were temporally similar but smaller in magnitude. Four doses of 20 or 40 ng LH-RH given at 20 min intervals did not increase serum LH or testosterone concentrations above those found with a single injection; FSH was slightly higher after the fourth dose. However, 40 ng LH-RH given every 20 min for 2 h produced a dramatic increase in serum LH and FSH: serum and testicular androgens were also much higher during the second hour. A 2 h stimulation with 80 ng LH-RH given ip at 30 min intervals did not alter the response to the same treatment given 24 h later; i. e., neither the pituitary nor the gonad was primed by previous exposure to increased levels of LH-RH or gonadotrophins. These results suggest that a single pulse of LH-RH produces a predictable response in the animal, but multiple episodic stimuli produce variable responses: testes, on the other hand, produce androgens as long as gonadotrophins are available.

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