Effect of Luteinizing Hormone on Leydig Cell Structure and Testosterone Secretion*

Ewing, Larry L.; Wing, Tung-Yang; Cochran, Roger C.; Kromann, N.; Zirkin, Barry R.

doi:10.1210/endo-112-5-1763

Cited by 86 publications

(44 citation statements)

References 18 publications

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“…LH in particular affects the secretion of testosterone by Leydig cells in the testis (Ewing et al 1983), The average testosterone concentration of the C group of the present study increased over the 8 weeks of the experiment, coinciding with the seasonal (photoperiodic) stimulation of GnRH secretion and increase in sexual behaviour at that time of year (Delgadillo et al 2004). Improvac suppressed testosterone concentrations by the end of the 8-week experiment, even in the face of the normal seasonal increase.…”

Section: Discussionsupporting

confidence: 44%

Immunisation against gonadotrophin-releasing hormone (GnRH) reduces agonistic behaviours in male rangeland goats

et al. 2016

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Rangeland goat bucks were used to evaluate the efficacy of a commercially available antigonadotrophin-releasing hormone vaccine, Improvac (Zoetis Australia, West Ryde, NSW, Australia). The hypothesis tested was that immunisation would suppress testosterone secretion by the testis and agonistic behaviour between male goats. We also compared intervals of 2 and 4 weeks between primary and booster immunisations and monitored responses over a 2-month period. The 45 goats were split into three groups (n = 15): one group receiving the vaccination booster on Day 14, one group receiving the vaccination booster on Day 28, and the Control group receiving sterile saline injections. Body mass, body condition score and scrotal circumference were measured fortnightly, and blood was collected at 2-week intervals and analysed for testosterone concentration. Behavioural interaction tests of 2-min duration were also conducted fortnightly. There was a significant decrease in paired testicular circumference (P < 0.05) and testosterone concentration (P < 0.01) in both vaccination groups by the end of the experiment at Day 60, compared with the Control group. Agonistic interactions measured at Day 60 were significantly reduced in both vaccination groups (P < 0.05) compared with the Control group. These results support the efficacy of Improvac in reducing agonistic behaviours in rangeland goat bucks and suggest that the use of the vaccine may assist in reducing social stress and possible injury in groups of confined male goats.

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Section: Discussionsupporting

confidence: 44%

Immunisation against gonadotrophin-releasing hormone (GnRH) reduces agonistic behaviours in male rangeland goats

et al. 2016

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“…Ultrastructural changes in the Leydig cells of rat (Lording and de Kretser, 1972), rabbit (Gondos et al, 1976) and the monkey, Cercopithecus aethiops , suggest that the ability to synthesize testosterone may vary during postnatal development, but distinct correlations between these two processes were not demonstrated. Only morphometric analysis has been able to show that the ability of the testis to synthesize testosterone is correlated with the amount of smooth endoplasmic reticulum (SER) of the Leydig cells (Zirkin et a / ., 1980 ;Ewing et al, 1983).…”

Section: Introductionmentioning

confidence: 99%

“…Correlations with whole-cell or cytoplasmic volume were still more significant : r = 0.56, P < 0.001 (n = 30). Most of the enzymes involved in testosterone synthesis are sequestered in mitochondria and SER membranes of Leydig cells (Christensen, 1975), but it has been shown that the ability to synthesize testosterone is only correlated with the SER content of adult cells (Zirkin et al, 1980 ;Ewing et al, 1983 (Christensen, 1975 Le niveau moyen de la testostérone plasmatique est 2 ng/ml chez les nouveaux-nés ; 0,4 ng/ml chez les enfants, il monte à 3 ng/ml pendant l'initiation de la méiose et atteint 10 ng/ml chez les adultes. Le profil évolutif de la testostérone est corrélé positivement et significativement avec le volume total et le nombre total des cellules de Leydig (P < 0,01 et P < 0,02, respectivement), une corrélation plus forte est observée avec les changements de volume cytoplasmique (P < 0,0011.…”

Section: Introductionunclassified

Relationships between Leydig cell morphometry and plasma testosterone during postnatal development of the monkey, Macaca fascicularis

Fouquet¹,

Meusy-Dessolle²,

Dang³

1984

Reprod. Nutr. Dévelop.

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The mean level of plasma testosterone was 2 ng/ml in neonates and 0.4 ng/ml in infants ; it increased to 3 ng/ml during onset of meiosis and reached 10 ng/ml in adults. The profile of testosterone was positively and significantly correlated with the total volume and total number of Leydig cells (P <0.01 and P < 0.02, respectively) and with changes in their cytoplasmic volume (P < 0.0011. Moreover, plasma testosterone levels were positively and significantly correlated with changes in Leydig cell SER content i.e. SER volume density and mean absolute volume per cell (P < 0.001), total SER in the whole testis (P < 0.011. ).Introduction.

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“…Hypothalamic control of gonadotropin secretion is exerted via the GnRH receptor in gonadotropes (8). Leydig cells are the only binding sites for luteinizing hormone (LH) in the testis, and LH is the primary tropic hormone that stimulates Leydig cell function in the postnatal testis (9). We previously observed simultaneous elevations in serum LH and testosterone (T) levels and increased Leydig cell steroidogenesis in rats that were treated with 10 and 100 mg͞kg per day DEHP for 28 days (10).…”

mentioning

confidence: 99%

Phthalate-induced Leydig cell hyperplasia is associated with multiple endocrine disturbances

Akingbemi

Klinefelter

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

315

197

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The possibility that exposures to environmental agents are associated with reproductive disorders in human populations has generated much public interest recently. Phthalate esters are used most commonly as plasticizers in the food and construction industry, and di-(2-ethylhexyl) phthalate (DEHP) is the most abundant phthalate in the environment. Daily human exposure to DEHP in the U.S. is significant, and occupational and clinical exposures from DEHP-plasticized medical devices, e.g., blood bags, hemodialysis tubing, and nasogastric feeding tubes, increase body burden levels. We investigated the effects of chronic exposures to low environmentally relevant DEHP levels on testicular function. Our data show that prolonged exposures to this agent induced high levels of the gonadotropin luteinizing hormone and increased the serum concentrations of sex hormones [testosterone and 17␤-estradiol (E2)] by >50%. Increased proliferative activity in Leydig cells was evidenced by enhanced expression of cell cycle proteins, as determined by RT-PCR. The numbers of Leydig cells in the testis of DEHP-treated rats were 40 -60% higher than in control rats, indicating induction of Leydig cell hyperplasia. DEHP-induced elevations in serum testosterone and E2 levels suggest the possibility of multiple crosstalks between androgen, estrogen, and steroid hormone receptors, whereas the presence of estrogen receptors in nonreproductive tissues, e.g., cardiovascular system and bones, implies that the increases in serum E2 levels have implications beyond reproduction, including systemic physiology. Analysis of the effects of phthalate exposures on gonadotropin and steroid hormone levels should form part of overall risk assessment in human populations. R eports of a higher incidence of urogenital anomalies of the newborn, such as cryptorchidism, hypospadias, and reproductive abnormalities in wild life exposed to high levels of chemicals in the environment, have generated public concern that these agents may impair human reproductive health (1, 2). Phthalates are used as plasticizers in certain infant toys and consumer products (e.g., containers for soaps, shampoos, and perfumes) and medical devices such as tubings and catheters. The U.S. Department of Health and Human Services in 1985 (3) estimated the total daily human consumption of di-(2-ethylhexyl) phthalate (DEHP) from all sources of exposure at 5.8 mg in the U.S. In a report just published by the Center for Disease Control and Prevention, the urinary levels of mono-(ethylhexyl) phthalate (MEHP) (micrograms per liter), which is the chief metabolite of DEHP, ranged from 3.26 to 4.15 in males and 2.93 to 3.51 in females; these levels are thought to represent only one-tenth of the ingested DEHP dose within the previous 24 h (4). In a recent review of laboratory studies, the U.S. National Toxicology Program's Center for the Evaluation of Risks to Human Reproduction Expert Panel concluded that DEHP has the potential to produce adverse reproductive effects in humans (5). Indeed, several propo...

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Effect of Luteinizing Hormone on Leydig Cell Structure and Testosterone Secretion*

Cited by 86 publications

References 18 publications

Immunisation against gonadotrophin-releasing hormone (GnRH) reduces agonistic behaviours in male rangeland goats

Immunisation against gonadotrophin-releasing hormone (GnRH) reduces agonistic behaviours in male rangeland goats

Relationships between Leydig cell morphometry and plasma testosterone during postnatal development of the monkey, Macaca fascicularis

Phthalate-induced Leydig cell hyperplasia is associated with multiple endocrine disturbances

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