Redox regulation & sperm function: A proteomic insight

Infertility affects nearly 15 per cent of all couples within the reproductive age worldwide, with about 50 per cent being exhibited in the male, called male factor infertility. Successful reproduction is dependent on sperm chromatin integrity. Spermatozoa are highly specialized cells that aim to transmit the paternal genomic blueprint to the oocyte. The spermatozoon is regulated by redox mechanisms during its epididymal transit to acquire fertilizing ability. While, at physiological levels, the production of reactive oxygen species (ROS) supports the spermatozoon to acquire its fertilizing ability, at high concentrations, it affects sperm function leading to infertility. Emerging proteomic technologies provide an opportunity to address these key issues that may solve many fertility-associated problems resulting from oxidative stress (OS). This review highlights the need for an efficient therapeutic approach to male infertility with the application of high-throughput OS-mediated proteomic technology, and also addresses the question as to whether targeting these altered sperm-specific proteins may help in designing an efficient and reversible male contraceptive.

Age-related differences of hexachlorocyclohexane effect on hepatic oxidative stress parameters of chicks.

Acute hexachlorocyclohexane (HCH; 50 mg/kg body wt, i.p.) treatment in young (30-day-old) chicks resulted in elevation of lipid peroxidation (LPX) only in nuclear fractions of livers while the same treatment in immature (7-day-old) chicks resulted in elevation of LPX in various liver subcellular fractions. Treatment of various subcellular fractions of livers with HCH in vitro stimulated increased LPX in young chicks than in immature ones. Hepatic cytoplasmic CN-sensitive and -resistant superoxide dismutase activities in immature chicks were inhibited significantly by HCH but no effect was observed in case of young chicks. The pesticide treatment in both immature and young chicks did not influence hepatic catalase activity. The level of glutathione in the liver of young chicks increased in response to the pesticide treatment but remained unaffected in the case of immature chicks. The results of the present study show that HCH-induced changes in hepatic oxidative stress parameters in chicks are age dependent.

Hexachlorocyclohexane-induced changes in lipid peroxidation, superoxide dismutase and catalase activities and glutathione content in chick liver.

An elevation in the level of lipid peroxides in nuclear, mitochondrial and microsomal fractions of chick liver was recorded 6 hr after hexachlorocyclohexane (HCH; 50 mg/kg body wt., ip) treatment. The magnitude of increase remained more or less same even 24 hr after the pesticide treatment. Total glutathione content also increased by 6 hr of HCH treatment and did not change even 24 hr after the pesticide treatment. Protein content of crude homogenate and 10000 g supernatant decreased significantly 6 hr after the pesticide treatment. The magnitude of decrease was more or less same even 24 hr after the pesticide treatment. Although cytoplasmic superoxide dismutase and catalase activities (expressed as units/mg protein) did not change 24 hr after HCH treatment, a small but significant increase in superoxide dismutase activity was recorded 6 hr after HCH treatment. On the other hand when activities were expressed as units/mg tissue wt., a significant decrease in the activities of both the enzymes was recorded 6 and 24 hr after HCH treatment. Therefore, the decrease in the activities of both the enzymes in response to HCH in chick liver may be due to decrease in tissue protein content in general rather than specific decrease in the activities of the enzymes.