The Temporal Relationship Between the Secretion of Luteinizing Hormone and Testosterone in Man

Rowe, Philip H.; Racey, Paul A.; Lincoln, G. A.; Ellwood, M.; Lehane, J. R.; Shenton, J. C.

doi:10.1677/joe.0.0640017

Cited by 66 publications

(24 citation statements)

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“…Testosterone levels generally follow those of LH (Rowe et al, 1975). In the present study propranolol lowered testosterone levels while not altering LH.…”

Section: Discussionsupporting

confidence: 58%

The effects of propranolol and acebutolol on the overnight plasma levels of anterior pituitary and related hormones.

Mj¹,

Groom²,

Barber³

et al. 1981

Brit J Clinical Pharma

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1 The effects of single evening doses of the beta‐adrenoceptor blocking agents propranolol (80 mg orally) and acebutolol (200 mg orally) on plasma levels throughout the night of prolactin, growth hormone, luteinising hormone, follicle stimulating hormone, cortisol and testosterone have been studied in seven healthy male volunteers. 2 Three way analysis of variance showed that acebutolol significantly reduced circulating levels of prolactin and follicle stimulating hormone, but did not alter the levels of the other hormones studied. 3 Propranolol significantly reduced follicle stimulating hormone and testosterone, and significantly increased circulating levels of cortisol, but caused no change in the other hormones studied. 4 Prolactin, luteinising hormone, testosterone and cortisol showed a significant variation with time indicating the existence of a diurnal rhythm in the pattern of their secretion. 5 There was a significant inter‐subject variability in all the hormones studied. 6 There was a significant between‐subject variation in response to both propranolol and acebutolol. 7 Different subjects showed significant variations with respect to time in prolactin, growth hormone and cortisol levels. 8 Neither propranolol nor acebutolol significantly altered the time course of secretion of any of the hormones studied. 9 Possible relationships of these beta‐adrenoceptor blocker‐induced changes in anterior pituitary and related hormones to the antihypertensive mechanism of acebutolol and propranolol are discussed.

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“…Testosterone levels generally follow those of LH (Rowe et al, 1975). In the present study propranolol lowered testosterone levels while not altering LH.…”

Section: Discussionsupporting

confidence: 58%

The effects of propranolol and acebutolol on the overnight plasma levels of anterior pituitary and related hormones.

Mj¹,

Groom²,

Barber³

et al. 1981

Brit J Clinical Pharma

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“…However, in the ram, bull, rat, monkey, and peri-pubertal or, in occasional cases, in the adult human, episodic increases in immunoactive LH concentrations have been correlated with subsequent presumptive pulses of testosterone secretion (8,(47)(48)(49)(50)(51)(52)(53)(54)(55)(56)(57)(58). In the present work, we found 3.5±1.0 statistically significant fluctuations in serum testosterone concentrations per 8 h. Nonetheless, we cannot make any definitive inference that these represent true "pulses" of testosterone release.…”

Section: Discussioncontrasting

confidence: 55%

Endogenous opiates modulate the pulsatile secretion of biologically active luteinizing hormone in man.

Veldhuis¹,

Rogol²,

Johnson³

1983

J. Clin. Invest.

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A B S T R A C T We studied the secretion of physiological pools of immunoreactive and biologically active luteinizing hormone in response to endogenous pulses of gonadotropin-releasing hormone (GNRH) in eugonadal men. Concentrations of immunoactive and bioactive luteinizing hormone (LH) were determined in blood drawn at 20-min intervals for 8 h in eight normal men under two conditions: (a) after placebo, in order to evaluate spontaneous LH pulsations in the basal state, and (b) after administration of the opiate-receptor antagonist, naltrexone, which is believed to amplify the pulsatile release of endogenous GNRH. Spontaneous and naltrexone-stimulated secretion of LH occurred in pulses of high biological activity, as measured in the RICT (rat interstitial cell testosterone bioassay), i.e., bioactive:immunoactive LH ratios within both spontaneous and naltrexone-stimulated LH pulses were higher than corresponding interpulse ratios (P < 0.001). Quantitative characterization of the pulsatile release of bioactive LH revealed the following specific effects of opiate-receptor blockade: increased 8-h mean and integrated serum concentrations of bioactive LH (P < 0.002), enhanced pulse frequency of bioactive LH release (P < 0.001), and augmented peak amplitude of bio-LH pulses (P < 0.01). Moreover, this increase in episodic secretion of bioactive LH was associated with increased 8-h mean and integrated serum testosterone concentrations in these men (P < 0.05).We conclude the following: (a) LH is normally released in spontaneous pulses of high biological activity in men; (b) when the endogenous GNRH signal is amplified by opiate-receptor blockade, the pituitary gland releases more frequent bioactive LH pulses, which are of high amplitude and contain a high bioactive:immunoactive LH ratio. This increase in pulsatile release of bioactive LH quantitated in the RICT assay in vitro is reflected by acutely increased serum testosterone concentrations in vivo. We infer that modulation of the episodic GNRH signal by endogenous opiates provides another significant mechanism by which the hypothalamus can alter the biological activity of circulating gonadotropic hormone in man. Moreover, observed alterations in the pulsatile pattern of bioactive LH release were associated in turn with significant changes in testosterone concentrations. Thus, we hypothesize that alterations in the properties of the bioactive LH pulse signal can provide an important mechanism for regulating target-cell function within the gonad in states of health or disease.J. Clin. Invest.

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“…T fluctuations in the peripheral blood of monkeys (6,21), rams (4,22), bulls (23), dogs (5), deer (24), rabbits (25), and mice (7) vary in amplitude from 2 to 30 ng/ml, compared with much smaller variations of < 1-3 ng/ml in men (8)(9)(10)(11)(12). We are unaware of any other species in which moment-to-moment changes in testicular vein steroid levels have been studied.…”

Section: Discussionmentioning

confidence: 99%

“…T fluctuations in peripheral blood in men are of low amplitude and occur at irregular intervals (8)(9)(10)(11)(12). In one study, T increments in men were generally preceded by LH rises, but Portions of these data were published in abstract form (Clin.…”

Section: Introductionmentioning

confidence: 99%

Testosterone and estradiol are co-secreted episodically by the human testis.

Winters¹,

Troen²

1986

J. Clin. Invest.

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In spite of a striking pulsatile pattern of luteinizing hormone (LH) secretion, testosterone (T) fluctuations in peripheral blood in normal adult men are irregular and of low amplitude. To determine whether T secretion by the human testis is episodic, T was measured in blood samples drawn at 15-min intervals for 4 h through a catheter placed in the testicular vein of six men with varicocele-associated infertility. Estradiol (E2) concentrations were also determined in each sample. Each subject released testosterone in well-defined pulses. Gonadal vein T levels ranged from 1 to 1,540 ng/ml. Mean (±SE) pulse amplitude was 176±42 ng/ml, with a frequency of 4.0±03 pulses per 4 h. Testicular vein E2 levels ranged from 0.01 to 6.8 ng/ml. E2 secretory episodes were generally coincident with T pulses, and their amplitudes were highly positively correlated (r = 0.90, P < 0.01).These results indicate that T secretion by the adult human testis is pulsatile, and suggest a functional relationship between intermittent LH secretion and normal testicular steroidogenesis in men. The failure to appreciate these fluctuations as hormone pulses in peripheral blood may relate to their absolute amplitude and frequency. The concordance between E2 and T pulses suggests that the Leydig cell, under LH control, is the source of most of the E2 secreted by the adult human testis.

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The Temporal Relationship Between the Secretion of Luteinizing Hormone and Testosterone in Man

Cited by 66 publications

References 0 publications

The effects of propranolol and acebutolol on the overnight plasma levels of anterior pituitary and related hormones.

The effects of propranolol and acebutolol on the overnight plasma levels of anterior pituitary and related hormones.

Endogenous opiates modulate the pulsatile secretion of biologically active luteinizing hormone in man.

Testosterone and estradiol are co-secreted episodically by the human testis.

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