Pituitary–testicular interrelationships during germinal involution in the vitamin A deficient rat

1984 ◽  
Vol 100 (1) ◽  
pp. 33-41 ◽  
Author(s):  
H. F. S. Huang ◽  
P. Zaidi ◽  
E. Nieschlag
Keyword(s):  
Vitamin A ◽  
Vitamin A Deficiency ◽  
Serum Testosterone ◽  
Normal Serum ◽  
Male Rats ◽  
Total Testosterone ◽  
Cell Nuclei ◽  
Serum Lh ◽  
Testicular Weight ◽  
Lh Secretion

ABSTRACT Pituitary–testicular relationships in mature male rats were investigated during the period of germinal involution after the induction of vitamin A deficiency (VAD). Vitamin A deficiency caused a decrease in testicular weight, a gradual increase in the incidence of delayed spermiation, increased phagocytosis of spermatids and pyknosis of germ cell nuclei in rats aged 80 to 110 days. Both basal and gonadotrophin releasing hormone (GnRH)-stimulated serum FSH concentrations were increased by 100 days of age. During the same period, the per cent increment in GnRH-stimulated FSH secretion, pituitary FSH concentration and LH secretion remained unchanged. These results suggest that the increased serum FSH may mark specifically an alteration in the germinal epithelium. By 140 days of age, spermatogenic activity in the rats with VAD was limited to the spermatogonial proliferations so that only Sertoli cells, spermatogonia and preleptotene spermatocytes remained. At this time hypersecretion of FSH persisted while the per cent increment of GnRH-stimulated FSH secretion decreased. Concomitantly, basal and GnRH-stimulated LH concentrations were also increased in the presence of normal serum testosterone. These results indicate that a complete cessation of spermatogenesis beyond preleptotene spermatocytes is associated with a change in the secretion of both FSH and LH. The relationship between serum LH and testosterone was normal until at least 110 days of age. By 140 days the ratio between basal LH and basal testosterone, and between total LH and total testosterone, after GnRH administration, increased in the rats with VAD. These changes may be caused by a hyporesponsiveness of the Leydig cells which may, in turn, be attributed to the cessation of spermatogenesis. J. Endocr. (1984) 100, 33–41

Effects and Mechanisms of Acupuncture and Moxibustion on Reproductive Endocrine Function in Male Rats with Partial Androgen Deficiency

2016 ◽  
Vol 34 (2) ◽  
pp. 136-143 ◽  
Author(s):  
Yi Ren ◽  
Xiaoguang Yang ◽  
Yu Zhang ◽  
Ying Wang ◽  
Xuezhi Li
Keyword(s):  
Protein Expression ◽  
Mrna Expression ◽  
Serum Testosterone ◽  
Hydroxysteroid Dehydrogenase ◽  
Endocrine Function ◽  
Male Rats ◽  
Acupuncture Points ◽  
Total Testosterone ◽  
Androgen Deficiency ◽  
Serum Lh

Objectives Partial androgen deficiency of the aging male (PADAM) is characterised by a deficiency in serum androgen levels. Both electroacupuncture (EA) and mild moxibustion (MM) can raise serum testosterone levels in PADAM. We investigated the mechanisms underlying the use of EA and MM in a rodent model of PADAM. Methods Fifty rats received cyclophosphamide injection over 5 consecutive days to induce PADAM, which was verified by comparing total testosterone (TT) and free testosterone (FT) levels with 10 non-PADAM healthy control rats (CON). Successful modelling was confirmed in 43 of 50 rats, 40 of which were randomly divided into untreated (PADAM), EA-treated (PADAM+EA), MM-treated (PADAM+MM), and androlin (AD)-treated (PADAM+AD) groups (n=10 each). EA and MM were administered at BL23 and CV4 acupuncture points for 8 weeks, and no treatment was given to rats in the PADAM and CON groups. Serum levels of luteinising hormone (LH) and follicle-stimulating hormone (FSH), mRNA expression of cytochrome P450c17 (P450c17) and 3β-hydroxysteroid dehydrogenase 1 (3β-HSD1), and protein levels of cytochrome P450 side chain cleavage (P450scc), 17β-hydroxysteroid dehydrogenase 3 (17β-HSD3) and steroidogenic factor 1 (SF-1) were evaluated after 8 weeks. Results Both EA and mild MM significantly increased serum TT and FT levels with MM displaying superiority. P450scc, 17β-HSD3 and SF-1 protein expression, and P450c17 and 3β-HSD1 mRNA expression, were significantly increased and serum LH and FSH levels were significantly decreased in PADAM+EA and PADAM+MM relative to PADAM rats. Moreover, serum LH and FSH levels were significantly lower and 17β-HSD3 protein expression significantly higher in PADAM+MM relative to PADAM+EA rats. Conclusions EA and MM at the BL23 and CV4 acupuncture points appear to be effective treatments for PADAM, and MM displays superior efficacy to EA.

HYPOTHALAMIC-PITUITARY-TESTICULAR SYSTEM FOLLOWING TESTICULAR X-IRRADIATION

1976 ◽  
Vol 83 (1) ◽  
pp. 190-200 ◽  
Author(s):  
H. L. Verjans ◽  
K. B. Eik-Nes
Keyword(s):  
Interstitial Cell ◽  
Serum Testosterone ◽  
Male Rats ◽  
Ventral Prostate ◽  
Testis Weight ◽  
X Ray ◽  
Serum Lh ◽  
Testicular Weight ◽  
Unknown Factor ◽  
X Irradiation

ABSTRACT Testes of adult, male rats were exposed to a total dose of 1500 R of X-irradiation. Testicular weight decreased from day 8 after X-ray treatment. This decrease was, however, preceded by an increment of the testis weight on day 4 following treatment. X-ray treatment of testes was associated with significant increases in serum FSH. Testicular irradiation had, however, no effect on ventral prostate and seminal vesicles weights. Serum testosterone increased only on day 1, 2 and 4 after irradiation, while serum LH levels tended to increase from day 8 post-irradiation. These changes were not significant, however, when compared with non-irradiated controls. At 7, 13 and 20 days following 1500 R of bilateral, testicular X-irradiation, the hypothalamic-pituitary unit was still capable of responding to exogenous gonadotrophin releasing factor. Serum FSH may in male rats be regulated at least partly by circulating steroids of testicular origin and partly by an unknown factor of non-interstitial cell nature.

scholarly journals Letrozole once a week normalizes serum testosterone in obesity-related male hypogonadism

2008 ◽  
Vol 158 (5) ◽  
pp. 741-747 ◽  
Author(s):  
Sandra Loves ◽  
Janneke Ruinemans-Koerts ◽  
Hans de Boer
Keyword(s):  
Hypogonadotropic Hypogonadism ◽  
Serum Testosterone ◽  
Free Testosterone ◽  
Total Testosterone ◽  
Male Hypogonadism ◽  
Serum Lh ◽  
Long Term Effect ◽  
Starting Dose ◽  
Severely Obese ◽  
Lh Secretion

ObjectiveIsolated hypogonadotropic hypogonadism (IHH) is frequently observed in severely obese men, probably as a result of increased estradiol (E2) production and E2-mediated negative feedback on pituitary LH secretion. Aromatase inhibitors can reverse this process. This study evaluates whether letrozole once a week can normalize serum testosterone in severely obese men and maintain its long term effect.DesignOpen, uncontrolled 6-month pilot study in 12 severely obese men (body mass index>35.0 kg/m2) with obesity-related IHH and free testosterone levels <225 pmol/l, treated with 2.5 mg letrozole once a week for 6 months.ResultsSix weeks of treatment reduced total E2 from 123±11 to 58±7 pmol/l (P<0.001, mean±s.e.m.), and increased serum LH from 4.4±0.6 to 11.1±1.5 U/l (P<0.001). Total testosterone rose from 5.9±0.5 to 19.6±1.4 nmol/l (P<0.001), and free testosterone from 163±13 to 604±50 pmol/l (P<0.001). Total testosterone rose to within the normal range in all subjects, whereas free testosterone rose to supraphysiological levels in 7 out of 12 men. The testosterone and E2 levels were stable throughout the week and during the 6-month treatment period.ConclusionLetrozole 2.5 mg once a week produced a sustained normalization of serum total testosterone in obese men with IHH. However, free testosterone frequently rose to supraphysiological levels. Therefore, a starting dose <2.5 mg once a week is recommended.

Investigations upon the mechanism of inhibition of spermatogenesis in the rat by a dimeric ethynodiol-testosterone ester

1988 ◽  
Vol 117 (4) ◽  
pp. 536-544 ◽  
Author(s):  
Hans-Joachim Born ◽  
Petra Hörster-Poschmann ◽  
Wilfried Stoll ◽  
Jürgen Sandow ◽  
Hans-Dieter Taubert ◽  
...  
Keyword(s):  
Serum Testosterone ◽  
Normal Serum ◽  
Male Rats ◽  
Serum Testosterone Level ◽  
Intact Male ◽  
Strong Suppression ◽  
Mechanism Of Inhibition ◽  
Serum Lh ◽  
Minor Significance ◽  
Androgen Binding

Abstract. The combination of androgens and progestogens has been shown to be a suitable male contraceptive. Previous experiments revealed that injection of a dimeric testosterone-ethynodiol ester into rats and monkeys induces azoospermia for several weeks. In order to investigate the mechanism of action, we compared the endocrine effects of a single injection of 10 mg of the dimeric ester into intact male rats with that of 6 mg of norethisterone enanthate + 6 mg of testosterone enanthate. After the injection of the dimer there was a transitory reduction of serum FSH and a strong suppression of serum LH and testosterone, of testicular testosterone and of androgen-binding protein (ABP) in the testis and epididymis for at least 8 weeks, whereas spermatogenesis was totally depressed between the 4th and 8th week. Contrary to this, the enanthates caused only a slight suppression of spermatogenesis, although serum LH, testicular testosterone and ABP were profoundly reduced. The only conspicuous difference in the endocrine pattern of both groups during the first 4 weeks was in the serum testosterone level which remained normal in the rats treated with the enanthates. The results suggest that testicular testosterone and ABP concentrations are of minor significance for an intact spermatogenesis, and that some other factors produced by Sertoli cells might be involved and possibly maintained by normal serum testosterone levels.

Effect of food restriction on 24-h serum and pineal melatonin content in male rats

1987 ◽  
Vol 115 (4) ◽  
pp. 507-513 ◽  
Author(s):  
C. L. Chik ◽  
A. K. Ho ◽  
G. M. Brown
Keyword(s):  
Body Weight ◽  
Food Restriction ◽  
Serum Testosterone ◽  
The Body ◽  
Male Rats ◽  
Organ Weights ◽  
Pineal Melatonin ◽  
Serum Lh ◽  
Testicular Weight ◽  
Male Wistar Rats

Abstract. Food restriction (50%) effects on the 24-h rhythm of serum and pineal melatonin (MT) were studied in 260–300 g male Wistar rats under a lighting regimen of 14 h light and 10 h dark. Body weight, testicular weight, accessory organ weights, serum LH, serum testosterone, and 24-h rhythms of serum and pineal MT were determined. One week of food restriction caused a decrease in body weight (18%), accessory organ weights (18%), and serum LH (50%), but had no effect on serum or pineal MT. Three weeks of food restriction suppressed the body weight and accessory organ weights further (35% and 39%, respectively), reduced serum LH (68%) and serum testosterone (53%), reduced pineal MT (12%) and raised serum MT (34%). The increased serum MT may play a role in the reported potentiation of pineal action in food deprived rats.

Non-responsiveness of serum gonadotropins and testosterone to pulsatile GnRH in hemochromatosis suggesting a pituitary defect

1993 ◽  
Vol 128 (4) ◽  
pp. 351-354 ◽  
Author(s):  
Lise Duranteau ◽  
Philippe Chanson ◽  
Joelle Blumberg-Tick ◽  
Guy Thomas ◽  
Sylvie Brailly ◽  
...  
Keyword(s):  
Single Pulse ◽  
Serum Testosterone ◽  
Pulse Amplitude ◽  
Pulse Frequency ◽  
Gonadotropin Secretion ◽  
Pulsatile Gnrh ◽  
Serum Lh ◽  
Before And After ◽  
Gnrh Therapy ◽  
Lh Secretion

We investigated the potential pituitary origin of gonadal insufficiency in hemochromatosis. Gonadotropin secretion was studied in seven patients with hemochromatosis and hypogonadism, before and after chronic pulsatile GnRH therapy. Pulsatile LH secretion was studied before (sampling every 10 min for 6 h) and after 15-30 days of chronic pulsatile GnRH therapy (10-12 μg per pulse). Prior to GnRH therapy, all the patients had low serum testosterone, FSH and LH levels. LH secretion was non-pulsatile in four patients, while a single pulse was detected in the remaining three. Chronic pulsatile GnRH administration did not increase serum testosterone levels; similarly, serum LH levels remained low: neither pulse frequency nor pulse amplitude was modified. We conclude that hypogonadism in hemochromatosis is due to pituitary lesions.

Hypergonadotropism in Peripubertal Boys with Chronic Renal Failure

PEDIATRICS ◽  
1983 ◽  
Vol 72 (3) ◽  
pp. 384-389
Author(s):  
Harold K. Marder ◽  
Laxmi S. Srivastava ◽  
Stephen Burstein
Keyword(s):  
Renal Failure ◽  
Chronic Renal Failure ◽  
Elevated Serum ◽  
Serum Testosterone ◽  
Normal Serum ◽  
Adult Men ◽  
Testicular Dysfunction ◽  
Serum Luteinizing Hormone ◽  
Serum Lh ◽  
Serum Gonadotropin

Serum gonadotropin and testosterone concentrations were measured in ten peripubertal boys to assess the effects of uremia on pubertal maturation. Serum luteinizing hormone (LH) concentrations were elevated for stage of puberty in eight boys, whereas in most boys serum follicle-stimulating hormone and testosterone concentrations were normal. Serum LH concentrations correlated with the severity of uremia. LH levels declined when measured 1 year after the initial measurements in four boys who received renal allografts, but were further elevated in two boys who were treated conservatively. Elevated serum LH concentrations in the presence of normal serum testosterone concentrations imply limited testicular sensitivity to the effects of LH in these peripubertal boys, as has been documented for adult men with chronic renal failure. Alternatively, there may be accumulation of an immunoreactive LH molecule that lacks bioactivity. A testicular dysfunction may explain the pubertal delay experienced by some uremic adolescent boys.

scholarly journals Testosterone immunoreactivity in the seminiferous epithelium of rat testis: effect of treatment with ethane dimethanesulfonate.

1989 ◽  
Vol 37 (11) ◽  
pp. 1667-1673 ◽  
Author(s):  
R Schulz ◽  
F Paris ◽  
P Lembke ◽  
V Blüm
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Time Course ◽  
Seminiferous Epithelium ◽  
Male Rats ◽  
Plasma Testosterone ◽  
Seminiferous Tubules ◽  
Treatment Level ◽  
Cell Nuclei ◽  
Testicular Weight

Androgens drive spermatogenesis by processes that are largely unknown. Direct effects on germ cells and indirect effects mediated via testicular somatic elements are currently under consideration, and specific localization of androgens in seminiferous tubules may provide information as regards this. Adult male rats were injected with ethane dimethanesulfonate (EDS; 75 mg/kg body weight) or vehicle. Testes were fixed and paraffin-embedded for localization of testosterone immunoreactivity 1 and 2 weeks after treatment, using the unlabeled antibody (PAP) technique. Plasma testosterone dropped from a pre-treatment level of 2.3 ng/ml to below 0.2 ng/ml 3 days after EDS injection and remained at low levels until the end of observation, accompanied by a progressive decrease in testicular weight. In the seminiferous tubules of vehicle-injected males, testosterone immunoreactivity was found in nuclei of spermatocytes and spermatids and in nuclei and the cytoplasm of Sertoli cells, and showed typical variations according to the stage of spermatogenesis. One week after EDS treatment, immunoreactivity had disappeared from the seminiferous epithelium. Two weeks after treatment, staining of germ cells was detected in two out of four males. The disappearance and reappearance of immunoreactivity coincided with the time course of EDS effects on rat Leydig cells, and we conclude that it corresponds to androgen specifically localized in fixed, paraffin-embedded tissue. Because staining of germ cell nuclei varied with the stage of spermatogenesis, the technique may detect a physiologically relevant androgen fraction; its location suggests that androgens may also directly affect certain germ cell stages.

Acute and short-term actions of serotonin administration on the pituitary-testicular axis in the adult rat

1995 ◽  
Vol 7 (5) ◽  
pp. 1101 ◽  
Author(s):  
MP Hedger ◽  
S Khatab ◽  
G Gonzales ◽  
Kretser DM de
Keyword(s):  
Serum Testosterone ◽  
Fold Increase ◽  
Significant Inhibition ◽  
Male Rats ◽  
Minor Role ◽  
Testis Weight ◽  
Serum Concentrations ◽  
Adult Rat ◽  
Serum Lh ◽  
A Minor

In this study, adult male rats were injected intraperitoneally with a single dose of serotonin (5-hydroxytryptamine, 5HT; 10 mg kg-1 bodyweight) for 2 h or 18 h, or daily with graded doses of 5HT (0.1-10 mg kg-1) for four days before being killed. Serum and testicular interstitial fluid (IF) concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone and immunoreactive-inhibin were measured by radioimmunoassay, and one testis was removed for histological examination. At 2 h after a single injection, 5HT caused a significant inhibition of serum concentrations of LH and inhibin, recovered IF volume and intratesticular testosterone concentrations; testis weight and serum concentrations of testosterone and FSH were unaffected. At 18 h after injection, all parameters had returned to normal, with the exception of intratesticular testosterone concentration which remained lower than normal. The lowest 5HT dose (0.1 mg kg-1) had no effect on any parameter following four daily injections. At a dose of 1.0 mg kg-1 5HT, there was a four-fold increase in the concentration of serum LH, but testis weight, recovered IF volume, testosterone and inhibin concentrations and serum concentrations of FSH were not significantly affected. At the highest dose of 5HT (10 mg kg-1) after four daily injections, testis weight decreased, and IF volume increased nearly three-fold. Testis concentrations of inhibin and serum testosterone were reduced, whereas serum concentrations of both LH and FSH were elevated; intratesticular testosterone concentrations did not differ from controls. Only at the highest dose of 5HT was disruption to the seminiferous epithelium observed, with focal damage ranging in severity from increased degeneration of spermatogenic cell profiles, to complete loss of the germinal epithelium; however, many tubule profiles displayed completely normal spermatogenesis. The acute IF volume reduction and spermatogenic disruption in 5HT-treated rats were consistent with localized ischaemia due to constriction of the testicular arterial supply. The eventual increase in IF volume observed after 5HT treatment appeared to be secondary to the loss of germ cells. Although 5HT also inhibited pituitary LH release and Leydig cell steroidogenesis, these effects appeared to play only a minor role in the induction of spermatogenic damage.

EFFECT OF SYNTHETIC THYROTROPHIN RELEASING FACTOR ON PROLACTIN AND LUTEINIZING HORMONE SECRETION IN MALE AND FEMALE RATS DURING VARIOUS REPRODUCTIVE STATES

1975 ◽  
Vol 67 (3) ◽  
pp. 425-430 ◽  
Author(s):  
R. P. DEIS ◽  
NIA ALONSO
Keyword(s):  
Hormone Secretion ◽  
Female Rats ◽  
Male Rats ◽  
Serum Prolactin ◽  
Serum Prolactin Level ◽  
Luteinizing Hormone Secretion ◽  
Male And Female Rats ◽  
Serum Lh ◽  
The Mean ◽  
Lh Secretion

SUMMARY The effect of synthetic thyrotrophin releasing factor (TRF) on serum prolactin and LH concentrations was determined by radioimmunoassay in male, cyclic and pseudopregnant female rats. A solution of TRF (0·1, 0·25, 0·5 and 1 μg/rat) was injected i.v. at 17.00 h into rats pretreated with sodium pentobarbitone at 13.00 h. A group of male rats was also treated with TRF at 11.00 h after pretreatment with sodium pentobarbitone at 07.00 h. Fifteen minutes after TRF administration, blood samples were obtained by heart puncture. Doses of 0·25, 0·5 and 1 μg TRF significantly increased the serum prolactin concentration in pro-oestrous rats. The mean serum prolactin level after the injection of 0·5 and 1 μg into oestrous rats and 0·5 μg TRF into dioestrous day 2 rats, was significantly greater than the control values. Injection of TRF on day 1 of dioestrus had no effect. Serum LH concentration was not significantly modified by the various doses of TRF administered. On day 3 of pseudopregnancy a significant increase of serum prolactin values was obtained with 0·5 and 1 μg TRF. On day 7 of pseudopregnancy a dose of 0·5 μg produced the same effect, but on day 10 of pseudopregnancy only 1 μg TRF significantly increased serum prolactin levels when compared with the control rats. In male rats serum prolactin concentration was significantly greater than the control values after TRF treatment either in the morning or the afternoon. The response was similar to that obtained in pro-oestrous rats. The results suggest that the ability of synthetic TRF to stimulate prolactin release exists in both female and male rats and that TRF does not affect LH secretion.

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