Effect of Luteinizing Hormone Releasing Hormone on Plasma Levels of Luteinizing Hormone, Oestradiol and Testosterone in the Male Dog

Jones, Gwyneth E.; Baker, K. D.; Fahmy, D; Boyns, A. R.

doi:10.1677/joe.0.0680469

Cited by 15 publications

(9 citation statements)

References 18 publications

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“…It has been reported that the plasma LH peak in the ndrmal dog occurs 15-20 min after injection of a LHRH-A (Jones, 1976). These reports are consistent with the results of this study.…”

Section: Discussionsupporting

confidence: 93%

Effects of LHRH‐analogue treatment of spermatogenic dysfunction in the dog

et al. 1991

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Three male dogs, aged 2-4 years, which exhibited a high percentage of sperm with abnormal tails in their semen and low levels of peripheral plasma LH and testosterone were given two injections of 400 micrograms an LHRH analogue (LHRH-A) 3 h apart. The semen quality of all three dogs and the peripheral plasma levels of LH and testosterone were examined in two of the dogs. Plasma levels of LH and testosterone in both dogs peaked at 30 and 90 min respectively, after the injection of LHRH-A. The semen quality of all three dogs had improved temporarily 20 days after the injection. To be specific, although the mean percentage of sperm with abnormal tails in the three dogs was 19, 26 and 32% respectively before injection of LHRH-A, these values had decreased to 10, 16 and 13%, respectively, 20-40 days later. Thereafter, however, the percentage sperm abnormalities increased again. The testes and epididymides of two of the dogs were examined histologically at the end of 90 days. Sloughed germ cells were observed in the seminiferous tubules of the testes, and pyknotic epithelial cells were noted in some of the epididymal ducts. The other dog, which had a history of three unsuccessful matings was treated again with LHRH-A and mated with three bitches 30, 75, and 110 days later, respectively. Only the bitch mated with this dog 30 days after a second series of injections conceived. It is assumed that the semen quality of the three dogs improved because of a temporary rise in plasma LH and testosterone levels after the injection of LHRH-A. It is concluded that the fertility of dogs with a high percentage of sperm with abnormal tails can be improved approximately 30 days after treatment with an LHRH-A.

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“…It has been reported that the plasma LH peak in the ndrmal dog occurs 15-20 min after injection of a LHRH-A (Jones, 1976). These reports are consistent with the results of this study.…”

Section: Discussionsupporting

confidence: 93%

Effects of LHRH‐analogue treatment of spermatogenic dysfunction in the dog

et al. 1991

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“…Similarly, when LRH is administered to normal men, although pronounced increments in circulating LH levels occur, there are only slight increases in circulating T levels (1 1, 29). Again, T pulses accompany LH rises after acute LRH administration to lower animals, including monkeys (24,(30)(31)(32)(33). The production of testosterone by human and rat Leydig cells after exposure to hCG in vitro has also been compared (34).…”

Section: Discussionmentioning

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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“…A limited number of studies exist in the literature concerning the mechanisms regulating the neuro¬ endocrine axis of the male dog (Jones & Boyns, 1974Jones, Baker, Fahmy & Boyns, 1976).…”

Section: Introductionmentioning

confidence: 99%

Plasma concentrations of testosterone and LH in the male dog

DePalatis¹,

Moore²,

Falvo³

1978

Reproduction

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Blood samples were withdrawn every 20 min from 3 conscious intact and 2 castrated mature males during non-consecutive periods of 12 h during the light and dark phases of the lighting schedule (intact dogs) and of 11 h during the light period (castrated dogs). In the intact dogs testosterone concentrations ranged from 0.4 to 6.0 ng/ml over the 24-h period. LH concentrations varied from 0.2 to 12.0 ng/ml. In all animals, LH peaks were clearly followed, after about 50 min, by corresponding testosterone peaks, but no diurnal rhythm could be established. LH concentrations in the castrated dogs were high (9.8 +/- 2.7 (s.e.m.) ng/ml), and still showed an episodic pattern in spite of the undetectable plasma testosterone levels.

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Effect of Luteinizing Hormone Releasing Hormone on Plasma Levels of Luteinizing Hormone, Oestradiol and Testosterone in the Male Dog

Cited by 15 publications

References 18 publications

Effects of LHRH‐analogue treatment of spermatogenic dysfunction in the dog

Effects of LHRH‐analogue treatment of spermatogenic dysfunction in the dog

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

Plasma concentrations of testosterone and LH in the male dog

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