The Effect of Luteinizing Hormone-Releasing Hormone in Hypogonadotrophic Eunuchoidism

Wj, Bremner; Nn, Fernando; Ca, Paulsen

doi:10.1530/acta.0.0860001

Cited by 24 publications

(9 citation statements)

References 7 publications

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“…It is also documented that basal and LRH-stimulated LH secretion is more dependent on previous LRH stimulation than is FSH secretion (Bremner et al -1977;Jacobson et al -1979). The differences, shown in our experiments, between the LH and FSH response to LRH after administration of tamoxifen, support the concept of different sites of negative feedback action of estrogens on LH and FSH secretion.…”

Section: Discussionsupporting

confidence: 82%

Interaction of Inhibin and Estrogens on Basal and LRH-stimulated Gonadotropin Levels

et al. 2009

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In order to study the action of estrogens and inhibin and their interaction with gonadotropin secretion in men, we measured basal and LRH-stimulated gonadotropin secretion before and after six weeks' administration of tamoxifen in two groups of men.A) Six men with impaired spermatogenesis with basal levels of FSH, LH, testosterone and estradiol within the range of reference values in our laboratory. B) Six men with severely impaired spermatogenesis. LH, testosterone and estradiol levels were within reference values, whereas FSH was at least 100% above the upper limit of reference values.Mean testosterone and estradiol levels were not different in either groups. Inhibin levels were presumed to be normal in group A and decreased in group B.Although within reference values, basal LH levels in group B were slightly but significantly higher than in group A.The response of LH to LRH in group B exceeded that of group A. This suggests that inhibin has a slightly inhibitory effect on basal LH and even more so on LRH-induced LH secretion.After tamoxifen administration basal FSH levels rose far more in group B than in group A. The LRH-induced LH release increased in both groups, the LRH-stimulated FSH release, however, increased only in group A.We conclude that estrogens and inhibin have a strongly synergistic negative feedback action on basal FSH secretion, and to a limited extent on basal LH secretion. In the presumed presence of inliibin (group A) the FSH additionally synthesized through the action of anti-estrogens, can be released by LRH administration, whereas FSH is probably spontaneously released in the presumed deficiency of inhibin (group B). With LH this phenomenon is less obvious. Die lnteraktion von lnhibin mit Ostrogenen und deren EinfluR auf die basalen und von LRH stimulierten GonadotropinspiegelZusammenfassung: Ziel dieser Untersuchung war es, die Wirkung von Ostrogenen und Inhibin und ihre Wechselbeziehung auf die Gonadotropinsekretion beim Mann zu iiberpriifen. Dazu wurden die basalen und die von LRH stimulierten Gonadotropinspiegel vor und nach sechswochiger Behandlung mit Tamoxifen bei 2 Gruppen von Mannern gemessen. andrologia 16 (1984) 412 L. J. G. Gooren et al. A) Sechs Manner mit beeintdchtigter Spermatogenese: die basalen Spiegel von FSH, LH, Testosteron und Ostradiol waren im Normalbereich unseres Labors. B) Sechs Manner mit stark gestorter Spermatogenese: LH, Testosteron und Ostradiol waren im Normalbereich, wahrend FSH mindstens 100% uber der Obergrenze lag.Die Mittelwerte der Testosteron-und Ostradiolspiegel waren in den beiden Gruppen nicht unterschiedlich. Es wurde angenommen, daB die Inhibinspiegel normal waren in Gruppe A und herabgesetzt in Gruppe B.Die basalen LH-Spiegel in Gruppe B, obwohl noch im Normalbereich, waren hoher als in Gruppe A. Die Reaktion von LH auf LRH in Gruppe B ubertraf die der Gruppe A. Das konnte darauf hinweisen, daB Inhibin einen geringen hemmenden Effekt aut die basale und einen stiirkeren Effekt auf die von LRH induzierte LH-Sekretion hat.Nach Tamoxifengaben stie...

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Section: Discussionsupporting

confidence: 82%

Interaction of Inhibin and Estrogens on Basal and LRH-stimulated Gonadotropin Levels

et al. 2009

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“…Serum levels of FSH were undetectable in a radioimmunoassay that is sufficiently sensitive to differentiate reliably between the low end of the normal adult range and the values found in prepubertal boys or hypogonadotropic subjects (28). Serum levels of FSH in this assay were always undetectable in basal sampling in the men during hCG plus T administration in this study, even when sampling was at 20-min intervals for 6 h. Infusion of LHRH demonstrated that even with 4 h of stimulation, four of five subjects failed to increase their FSH levels into the detectable range, whereas the fifth man had a slight increase late in the infusion.…”

Section: Resultsmentioning

confidence: 94%

Follicle-stimulating Hormone and Human Spermatogenesis

Bremner¹,

Matsumoto²,

Sussman³

et al. 1981

J. Clin. Invest.

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110

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A B S T R A C T The role of follicle-stimulating hormone (FSH) in the control of spermatogenesis is not well established in any species, including man. We studied the effect of an experimentally-induced, selective FSH deficiency on sperm production in normal men. After a 3-mo control period, five normal men received testosterone enanthate (T) 200 mg i. m. weekly to suppress luteinizing hormone (LH) and FSH, until three successive sperm counts revealed azoospermia or severe oligospermia (sperm counts <3 million/ml). Then, while continuing T, human chorionic gonadotropin (hCG) 5,000 IU i. m. three times weekly was administered simultaneously to replace LH activity, leaving FSH activity suppressed. The effect of the selective FSH deficiency produced by hCG plus T administration on sperm production was determined.Sperm counts (performed twice monthly throughout the study) were markedly suppressed during T administration alone (1.0+1.0 million/ml mean± SE, compared with 106±28 million/ml during the control period, P < 0.001). With the addition of hCG to T, sperm counts returned toward normal (46±16 million/ ml, P < 0.001 compared with T alone). In two subjects, sperm counts during hCG plus T returned into the individual's control range. Sperm motility and morphology were consistently normal in all men during hCG plus T. Serum FSH levels by RIA were normal (110±10 ng/ml) in the control period and were suppressed to undetectable levels (<25 ng/ml) in the T alone and hCG plus T periods. markedly suppressed in the T alone (60±15 mIU/h2nd IRP, P < 0.01) and hCG plus T (37±9 mIU/h, P < 0.01) periods compared with the control period (334±78 mIU/h).We conclude that spermatogenesis as assessed by sperm counts, motilities, and morphologies may be reinitiated and maintained at normal levels in men with undetectable blood FSH levels and urinary excretion of FSH less than that of prepubertal children. This conclusion implies that, although FSH may exert effects on human testicular function, maintenance of normal spermatogenesis and reinitiation of sperm production after short-term suppression by exogenous steroids can occur in spite of nearly absent FSH stimulation.

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“…A possible explanation of these data is that there may be a relatively high production of endogenous LHRH in neonatal animals, which leads to an increase in the acutely releasable pool of LH (15,16). These responses in the youngest animals were greater than those in older prepubertal animals, and for LH, were as great as those found in adults.…”

Section: Discussionmentioning

confidence: 93%

Endocrine Correlates of Sexual Development in the Male Monkey, Macaca fascicularis*

1981

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To increase our understanding of the physiology of sexual maturation in the primate, we have studied various endocrine correlates of reproductive development in the male monkey, Macaca fascicularis. In a cross-sectional study, we examined 80 monkeys, ranging in age from 2 weeks to more than 8 yr. We weighed, measured testis size, and obtained a single morning blood sample from all animals. Serum LH and testosterone (T) levels were measured by bioassay and RIA, respectively. Based on the criteria of age and testis size, we classified the monkeys into five study groups: neonates, older infants, juveniles, peripubertals, and adults. To characterize hormone secretory patterns and to search for evidence of episodic LH and T secretion during development, we selected animals at random (n > 6) from each study group and bled them at 20-to 30-min intervals during evening hours (between 1900-2300 h). To assess pituitary responsiveness to LHRH during development, we administered LHRH (5 /ig/kg, iv bolus) to groups of neonatal, older infant, juvenile, and adult animals (n > 4). LH and T concentrations were integrated over the 90-min postinfusion period. Analysis of serum LH and T levels measured in single morning blood samples showed significantly higher levels of both LH and T in

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The Effect of Luteinizing Hormone-Releasing Hormone in Hypogonadotrophic Eunuchoidism

Cited by 24 publications

References 7 publications

Interaction of Inhibin and Estrogens on Basal and LRH-stimulated Gonadotropin Levels

Interaction of Inhibin and Estrogens on Basal and LRH-stimulated Gonadotropin Levels

Follicle-stimulating Hormone and Human Spermatogenesis

Endocrine Correlates of Sexual Development in the Male Monkey, Macaca fascicularis*

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