The role of testosterone in the feedback control of male FSH and LH secretion

1975 ◽  
Vol 53 (5) ◽  
pp. 237-239 ◽  
Author(s):  
G. B�rsch ◽  
J. Mauss ◽  
E. Richter ◽  
K. Bormacher ◽  
G. Leyendecker ◽  
...  
Keyword(s):  
Feedback Control ◽  
Lh Secretion

Suppression of LH secretion by oestradiol, dihydrotestosterone and trenbolone acetate in the acutely castrated bull

1984 ◽  
Vol 100 (1) ◽  
pp. 107-112 ◽  
Author(s):  
T. W. Gettys ◽  
M. J. D'Occhio ◽  
D. M. Henricks ◽  
B. D. Schanbacher
Keyword(s):  
Feedback Control ◽  
Pituitary Gland ◽  
Treated Group ◽  
Primary Site ◽  
Trenbolone Acetate ◽  
Releasing Hormone ◽  
Serum Lh ◽  
Lh Releasing Hormone ◽  
Lh Secretion

ABSTRACT Twenty acutely castrated bulls were used to investigate the role of androgenic and oestrogenic steroids in the feedback control of LH secretion. The effects of 5α-dihydrotestosterone (DHT) or the growth stimulants trenbolone acetate (TBA) or oestradiol-17β (OE2) on serum LH secretory profiles were measured. In addition, pituitary LH responses to exogenous LH releasing hormone (LHRH) were determined to differentiate between hypothalamic and pituitary sites of steroid action. At the time of castration, two groups of animals were given implants of either 45 mg OE2 or 200 mg TBA. Another group received equivalent to 30 mg daily injections of DHT. Control steers showed an increase in LH from 2·4 ± 0·5 (s.e.m.) μg/l to 7·0 ± 0·5 μg/l during the week after castration. Treatment with DHT and TBA prevented the post-castration rise in serum LH. In contrast, steers given implants of OE2 showed a significantly greater increase in LH than controls 1 day after castration, but by day 5 LH declined in the OE2-treated group to precastration values. Five weeks after castration control steers secreted LH in pulses at intervals of 40–50 min and with an amplitude of 4·2± 0·4 μg/l. Pulses were not detected in the LH profiles of the steroid-treated steers. Dihydrotestosterone and TBA significantly reduced pituitary LH responses to exogenous LHRH, whereas steers receiving OE2 showed LH responses to LHRH which were similar to those observed in castrated controls. These results support the hypothesis that androgenic and oestrogenic components participate separately in the feedback control of LH secretion in the bull. A similar LH response to exogenous LHRH in control and OE2-treated animals suggests that the primary site of oestrogen feedback is at the level of the hypothalamus. Conversely, the small LH response to LHRH in androgen-treated animals suggests that androgen feedback is, in part, imposed at the level of the pituitary gland. Interestingly, LH secretion is regulated by dosages of androgenic and oestrogenic steroids which are available commercially as growth stimulants for cattle. J. Endocr. (1984) 100, 107–112

FEEDBACK CONTROL OF LH-SECRETION IN THE CASTRATED ADULT MALE MINIATURE PIG

1975 ◽  
Vol 80 (1_Suppla) ◽  
pp. S76
Author(s):  
N. Parvizi ◽  
F. Elsaesser ◽  
D. Smidt ◽  
F. Ellendorff
Keyword(s):  
Feedback Control ◽  
Adult Male ◽  
Miniature Pig ◽  
Lh Secretion

scholarly journals Influence of sex and gonadal status of sheep on cortisol secretion in response to ACTH and on cortisol and LH secretion in response to stress: importance of different stressors

2002 ◽  
Vol 173 (1) ◽  
pp. 113-122 ◽  
Author(s):  
AI Turner ◽  
BJ Canny ◽  
RJ Hobbs ◽  
JD Bond ◽  
IJ Clarke ◽  
...  
Keyword(s):  
Sex Differences ◽  
Sex Difference ◽  
Restraint Stress ◽  
Cortisol Response ◽  
Blood Samples ◽  
Response To Stress ◽  
Lh Secretion ◽  
Gonadal Status ◽  
Major Mediator

There are sex differences in the response to stress and in the influence of stress on reproduction which may be due to gonadal steroids but the nature of these differences and the role of the gonads are not understood. We tested the hypotheses that sex and the presence/absence of gonads (gonadal status) will influence the cortisol response to injection of ACTH, insulin-induced hypoglycaemia and isolation/restraint stress, and that sex and gonadal status will influence the secretion of LH in response to isolation/restraint stress. Four groups of sheep were used in each of three experiments: gonad-intact rams, gonadectomised rams, gonad-intact ewes in the mid-luteal phase of the oestrous cycle and gonadectomised ewes. In Experiment 1 (n=4/group), jugular blood samples were collected every 10 min for 6 h; after 3 h, two animals in each group were injected (i.v.) with ACTH and the remaining two animals were injected (i.v.) with saline. Treatments were reversed 5 days later so that every animal received both treatments. Experiment 2 (n=4/group) used a similar schedule except that insulin was injected (i.v.) instead of ACTH. In Experiment 3 (n=5/group), blood samples were collected every 10 min for 16 h on a control day and again 2 weeks later when, after 8 h of sampling, all sheep were isolated and restrained for 8 h. Plasma cortisol was significantly (P<0.05) elevated following injection of ACTH or insulin and during isolation/restraint stress. There were no significant differences between the sexes in the cortisol response to ACTH. Rams had a greater (P<0.05) cortisol response to insulin-induced hypoglycaemia than ewes while ewes had a greater (P<0.05) cortisol response to isolation/restraint stress than rams. There was no effect of gonadal status on these parameters. Plasma LH was suppressed (P<0.05) in gonadectomised animals during isolation/restraint stress but was not affected in gonad-intact animals, and there were no differences between the sexes. Our results show that the sex that has the greater cortisol response to a stressor depends on the stressor imposed and that these sex differences are likely to be at the level of the hypothalamo-pituitary unit rather than at the adrenal gland. Since there was a sex difference in the cortisol response to isolation/restraint, the lack of a sex difference in the response of LH to this stress suggests that glucocorticoids are unlikely to be a major mediator of the stress-induced suppression of LH secretion.

Plasma testosterone surge and luteinizing hormone beta (LH-β) following parturition: lack of association in the male rat

1995 ◽  
Vol 133 (3) ◽  
pp. 366-374 ◽  
Author(s):  
Robert F McGivern ◽  
Ralph HM Hermans ◽  
Robert J Handa ◽  
Lawrence D Longo
Keyword(s):  
Luteinizing Hormone ◽  
Cesarean Section ◽  
Gnrh Antagonist ◽  
Male Rat ◽  
Plasma Testosterone ◽  
Treatment Groups ◽  
Natural Birth ◽  
Males And Females ◽  
Lh Secretion

McGivern RF, Hermans RHM, Handa RJ, Longo LD. Plasma testosterone surge and luteinizing hormone beta (LH-β) following parturition: lack of association in the male rat. Eur J Endocrinol 1995; 133:366–74. ISSN 0804–4643 Studies examining the role of luteinizing hormone (LH) in the initiation of the postnatal surge of testosterone in the male rat have produced ambiguous results. We examined the pattern of postnatal LH secretion in the newborn male rat, coincident with plasma testosterone levels, using a specific monoclonal antibody for LH-β. In some males, we attempted to block LH secretion and the postnatal testosterone surge by injecting males with a gonadotropin-releasing hormone (GnRH) antagonist, an LH antibody or progesterone immediately after delivery by cesarean section on day 22. Following injection, animals were immediately sacrificed (time 0) or housed in a humidified incubator maintained at 30°C until sacrifice at 60, 120, 240, 360 or 480 min after delivery. Plasma from individual animals was measured subsequently for LH-β and testosterone by radioimmunoassay. Results revealed a postnatal surge of testosterone which peaked at 2 h after delivery in males from all treatment groups. This testosterone surge was not accompanied by a postnatal rise in plasma LH-β in any group. Administration of the GnRH antagonist or the ethanol vehicle produced a transient drop of approximately 25% in LH-β levels at 60 min but did not decrease the postnatal testosterone surge in the same animals. Additional studies in untreated males and females born by cesarean section or natural birth also failed to reveal a postnatal rise in plasma LH-β during the first 3 h after birth. Plasma levels in both sexes were significantly lower in animals delivered by cesarean section compared to natural birth. Overall, these results indicate that the postnatal surge of testosterone occurs without a corresponding surge of detectable LH-β in the male rat. Robert F McGivern, 6363 Alvarado Ct, Suite 200H. San Diego, CA 92120, USA

scholarly journals Pengaruh Pemberian Kedelai terhadap Sistem Reproduksi

2019 ◽  
Vol 1 (1) ◽  
pp. 53-60
Author(s):  
Rizky Aprilia Wikayanti ◽  
Andre Parmonangan Panjaitan
Keyword(s):  
Menstrual Cycle ◽  
Reproductive System ◽  
Experimental Studies ◽  
Review Literature ◽  
Follicular Phase ◽  
Free Concentration ◽  
Human Reproductive ◽  
17Β Estradiol ◽  
Lh Secretion

Kedelai merupakan tanaman Leguminoceae, yang mengandung senyawa isoflavon. Struktur kimianya menyerupai 17β-estradiol yang memiliki kemampuan untuk berikatan dengan reseptor estrogen yang dapat berpengaruh terhadap sistem reproduksi manusia. Tujuan literatur review ini untuk mengetahui efek kedelai terhadap sistem reproduksi manusia. Metode yang digunakan adalah metode literatur review dari 50 artikel PubMed NCBI, Elsevier dan BMJ Journal yang diperoleh hanya 38 artikel yang digumakan dari tahun 2000 sampai dengan tahun 2018. Berbagai penelitian eksperimental yang dilakukan menunjukkan bahwa kedelai memiliki efek terhadap sistem reproduksi manusia. Kedelai dapat menyebabkan sekresi FSH, sekresi LH menurun dan meningkatkan konsentrasi estradiol bebas. Penurunan FSH dan LH dapat menyebabkan gangguan dalam siklus menstruasi terutama pada fase folikular dan  ovulasi, jika fase folikular terganggu maka siklus menstruasi akan menjadi  tidak teratur. Selain itu fitoestrogen yang terkandung dalam kedelai diketahui dapat menghambat 17-β hidroksisteroidoksidoreduktase sehingga mengakibatkan penurunan kadar testosteron.   Kata kunci: kedelai, manusia, reproduksi   THE ROLE OF SOYBEAN FOR REPRODUCTIVE SYSTEM   ABSTRACT Soybean is a Leguminoceae plant, which contains isoflavone compounds. Its chemical structure resembles 17β-estradiol which has ability to bind to estrogen receptors which can affect the human reproductive system. The purpose of this review literature is to determine the effect of soy on the human reproductive system. Using research articles and books related to the effect of soy on the reproductive system from 2000 to 2018. Various experimental studies conducted showed that soy has an effect on the human reproductive system. Soy can cause FSH secretion, decreased LH secretion and increasing the free concentration of estradiol. Decreased FSH and LH can cause disruption in the menstrual cycle, especially in the follicular phase and ovulation, if the follicular phase is disrupted then the menstrual cycle will become irregular. In addition, phytoestrogens contained in soy are known to inhibit 17-β hydroxysteroidoxidoreductase, resulting in a decrease in testosterone levels.   Keywords : human, reproductive, soybean

scholarly journals Role of Internal Ca2+ Stores in KCa Channel Feedback Control of Human Uterine Contractions

2021 ◽  
Vol 35 (S1) ◽  
Author(s):  
Bri Kestler ◽  
Chung‐Sik Choi ◽  
Mark Taylor
Keyword(s):  
Feedback Control ◽  
Uterine Contractions ◽  
Channel Feedback

scholarly journals Release of Norepinephrine in the Preoptic Area Activates Anteroventral Periventricular Nucleus Neurons and Stimulates the Surge of Luteinizing Hormone

Endocrinology ◽  
2013 ◽  
Vol 154 (1) ◽  
pp. 363-374 ◽  
Author(s):  
Raphael E. Szawka ◽  
Maristela O. Poletini ◽  
Cristiane M. Leite ◽  
Marcelo P. Bernuci ◽  
Bruna Kalil ◽  
...  
Keyword(s):  
Positive Feedback ◽  
Preoptic Area ◽  
Lh Surge ◽  
Ovx Rats ◽  
Selective Lesion ◽  
Periventricular Nucleus ◽  
Reverse Microdialysis ◽  
Fos Expression ◽  
Lh Secretion

The role of norepinephrine (NE) in regulation of LH is still controversial. We investigated the role played by NE in the positive feedback of estradiol and progesterone. Ovarian-steroid control over NE release in the preoptic area (POA) was determined using microdialysis. Compared with ovariectomized (OVX) rats, estradiol-treated OVX (OVX+E) rats displayed lower release of NE in the morning but increased release coincident with the afternoon surge of LH. OVX rats treated with estradiol and progesterone (OVX+EP) exhibited markedly greater NE release than OVX+E rats, and amplification of the LH surge. The effect of NE on LH secretion was confirmed using reverse microdialysis. The LH surge and c-Fos expression in anteroventral periventricular nucleus neurons were significantly increased in OVX+E rats dialyzed with 100 nm NE in the POA. After Fluoro-Gold injection in the POA, c-Fos expression in Fluoro-Gold/tyrosine hydroxylase-immunoreactive neurons increased during the afternoon in the A2 of both OVX+E and OVX+EP rats, in the locus coeruleus (LC) of OVX+EP rats, but was unchanged in the A1. The selective lesion of LC terminals, by intracerebroventricular N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine, reduced the surge of LH in OVX+EP but not in OVX+E rats. Thus, estradiol and progesterone activate A2 and LC neurons, respectively, and this is associated with the increased release of NE in the POA and the magnitude of the LH surge. NE stimulates LH secretion, at least in part, through activation of anteroventral periventricular neurons. These findings contribute to elucidation of the role played by NE during the positive feedback of ovarian steroids.

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