Male Reproduction Health

Testosterone and estrogen are no longer considered male only and female only hormones. Both hormones are important in both sexes. It was known as early as the 1930's that developmental exposure to a high dose of estrogen causes malformation of the male reproductive tract, but the early formative years of reproductive biology as a discipline did not recognize the importance of estrogen in regulating the normal function of the adult male reproductive tract. In the adult testis, estrogen is synthesized by Leydig cells and the germ cells, producing a relatively high concentration in rete testis fluid. Estrogen receptors are present in the testis, efferent ductules and epididymis of most species. However, estrogen receptor-alpha is reported absent in the testis of a few species, including man. Estrogen receptors are abundant in the efferent ductule epithelium, where their primary function is to regulate the expression of proteins involved in fluid reabsorption. Disruption of the alph...

There is considerable variation, both within and between species, in reports of nuclear steroid receptor localizations in the male reproductive tract. In this study, androgen receptor (AR) and estrogen receptors ER and ERß were visualized by immunohistochemistry in adult male ...

A study was conducted to form a unified hypothesis regarding the gonadotropin-related mechanisms that underlie alterations in the male reproductive system in individuals with diabetes. Streptozotocin-induced diabetes resulted in reduced fertility, prolificacy, and libido. Testes showed a marked decrease in the number and function of Leydig cells, the latter manifested as changes in the expression of biochemical markers, including the GLUT-3 hexose transporter, c-kit, insulin-like growth factor I (IGF-I), androgen receptors, and overall tyrosine phosphorylation, as assessed by Western blot and immunocytochemical analyses. The expression of c-kit, IGF-I, insulin, and follicle-stimulating hormone (FSH) receptors in the seminiferous tubules was also affected. Serum levels of luteinizing hormone (LH), FSH, and testosterone significantly decreased. There was a significant (P <.05) correlation between the serum levels of insulin and FSH. No significant correlation was found between the ...

The understanding of estrogen's function in the male reproductive tract is limited, and estrogen receptor (ER) lo- calization in the reproductive tract of the adult male rat has not been described. In the present study, ERcs was localized by im- munohistochemistry using ER21 antibody, which recognizes only ERa. Strongest immunoreactivity was seen in epithelia of ductuli efferentes and the initial

Antioxidant supplementation during cooling was assayed to improve the motility of frozen-thawed (FT) boar spermatozoa from two different fractions of the ejaculate, the first component of the sperm-rich fraction (Fraction I) and the rest of the bulk ejaculate (Fraction II). Using a split-sample design, addition of two different concentrations (100 and 200 μM l−1) of the water-soluble Vitamin E analogue Trolox (6-hydroxy –2,5,7,8-tetramethylchroman –2-carboxylic acid) was evaluated for an effect on sperm motility (measured both subjectively and by means of a computer assisted motility assessment (CASA)), and on mitochondrial membrane potential using flow cytometry after cell-loading with JC-1. The effect of the Vitamin E analogue was clearly dose-dependent and varied with the fraction of the ejaculate considered. Motility was significantly higher in Trolox-treated spermatozoa (200 μm), from either ejaculate fraction, albeit the effect was more evident in spermatozoa from Fraction II (P<0.05) for any Trolox-concentration. Antioxidant supplementation resulted, also dose-dependent, in a higher number of spermatozoa showing high mitochondrial activity as assessed by the JC-1 staining, in both ejaculate fractions. In the present trial, exogenous Trolox positively affected post-thaw sperm viability (as motility and mitochondrial membrane potential) in both fractions of the ejaculate. The magnitude of the effect appeared, however, to be dependent of the fraction of the ejaculate considered.

Endosulfan (6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin-3-oxide) is a broad-spectrum insecticide and acaricide first regis-tered for use in the United States in 1954 to control agricultural insect and mite pests on a variety ...

Evidence supporting a role for estrogen in male reproductive tract development and function has been collected from rodents and humans. These studies fall into three categories: i) localization of aromatase and the target protein for estrogen (ER-alpha and ER-beta) in tissues of the reproductive tract; ii) analysis of testicular phenotypes in transgenic mice deficient in aromatase, ER-alpha and/or ER-beta gene; and, iii) investigation of the effects of environmental chemicals on male reproduction. Estrogen is thought to have a regulatory role in the testis because estrogen biosynthesis occurs in testicular cells and the absence of ERs caused adverse effects on spermatogenesis and steroidogenesis. Moreover, several chemicals that are present in the environment, designated xenoestrogens because they have the ability to bind and activate ERs, are known to affect testicular gene expression. However, studies of estrogen action are confounded by a number of factors, including the inabilit...

Sperm competition is a pervasive selective force in evolution, shaping reproductive anatomy, physiology and behaviour. Here, we present comparative evidence that varying sperm competition levels account for variation in the male reproductive anatomy of rodents, the largest and most diverse mammalian order. We focus on the sperm-producing testes and the accessory reproductive glands, which produce the seminal fluid fraction of the ejaculate. We demonstrate a positive association between relative testis size and the prevalence of within-litter multiple paternity, consistent with previous analyses in which relative testis size has been found to correlate with sperm competition levels inferred from social organization and mating systems. We further demonstrate an association between sperm competition level and the relative size of at least two accessory reproductive glands: the seminal vesicles and anterior prostate. The size of the major product of these glands—the copulatory plug—is a...