Effect of Glutathione Depletion on Antioxidant Enzymes in the Epididymis, Seminal Vesicles, and Liver and on Spermatozoa Motility in the Aging Brown Norway Rat1

Abstract

Reactive oxygen species (ROS) play a role in male infertility, where excessive amounts impair spermatozoal motility. Epididymal antioxidant enzymes protect spermatozoa from oxidative damage in the epididymal lumen. Antioxidant secretions from the seminal vesicle protect spermatozoa after ejaculation. As it is known that with age there is increased generation of ROS, the goals of this study were to determine how aging affects the response of antioxidant enzymes in the epididymis, seminal vesicles, and liver to l-buthionine-S,R-sulfoximine (BSO) mediated glutathione (GSH) depletion, and to examine the impact of GSH depletion on motility parameters of spermatozoa from the cauda epididymidis in young (4-mo-old) and old (21-mo-old) rats. Levels of GSH and glutathione disulfide (GSSG), as well as activities of glutathione peroxidase, glutathione reductase, catalase, and superoxide dismutase, were measured in the caput, corpus and cauda epididymidis, seminal vesicles, and liver. Spermatozoal motility was assessed by computer-assisted sperm analysis. Significant age-related changes in antioxidant enzyme activities were found in the liver and cauda epididymidis. Glutathione depletion clearly affected tissues in both young and old. The compounding effect of age was most evident in the cauda epididymidis, seminal vesicles, and liver, where antioxidant enzyme activities changed significantly. Additionally, spermatozoa motility was adversely affected after BSO treatment in both age groups, but significantly more so in older animals. In summary, the male reproductive tissues and liver undergo age-related changes in antioxidant enzyme activities and in their response to GSH depletion.

Antioxidant enzyme expression of mRNA and protein in the epididymis of finasteride-treated male rat offspring during postnatal development

“…The results of this study confirm the changes in antioxidant enzyme expression of mRNA and proteins during postnatal maturation, being different in immature rats (PND 7,14,21,28) than in mature animals (PND 90), in agreement with other reports [62] that demonstrated changes in antioxidant enzymes' (GPX, GR, CAT, SOD) activity in male reproductive tissues (such as the cauda epididymidis) in young (4-month-old) rats when compared to older (21-month-old) rats. Some authors [16] consider CAT one of the most controversial enzymes within the epididymis, such as when CAT mRNA expression is extremely low, undermining its potential role as a major antioxidant in the tissue.…”

Terazosin-induced alterations in catalase expression and lipid peroxidation in the rat seminal vesicles

“…Seminal vesicle fluid also provides a series of antioxidants that protect spermatozoa in oxidising environments (Zubkova & Robaire, 2004); any increase in its lipid peroxidation or decrease in its antioxidant capacity (i.e. by increased consumption of antioxidant enzymes) might contribute to impaired fertilisation.…”

Effects of Chronic Exposure to an Environmentally Relevant Mixture of Brominated Flame Retardants on the Reproductive and Thyroid System in Adult Male Rats

“…Spermatozoal motility was measured by CASA using our previously published method (Zubkova and Robaire, 2004). Briefly, spermatozoa from the cauda epididymidis were collected into 3 ml of motility buffer (Hanks Balanced Salt Solution, 0.35 mg/ml sodium bicarbonate, 0.1 mg/ml sodium pyruvate, 0.025 mg/ml soybean trypsin inhibitor, 2 mg/ml bovine serum albumin, pH 7.4 [Gibco Invitrogen, Burlington, ON], 4.2 mg/ml 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid, 0.9 mg/ml d -glucose [Sigma Chemical Co.], prewarmed to 37°C) and were allowed to disperse for 3 min.…”