Mediation of oxidative stress in HCH-induced neurotoxicity in rat.

Effect of repeated oral administration of hexachlorocyclohexane (HCH) (10 and 20 mg/kg body weight/day for 7 and 30 days) on the antioxidant defense system and lipid peroxidation (LPX) of rat cerebral hemisphere (CH) was evaluated. The level of LPX was elevated after 7 days of treatment in crude homogenate (endogenous and FeSO(4)- and ascorbic acid-stimulated) and subcellular fractions except the nuclear fraction in which induction was seen after 30 days. The pesticide elicited a significant decrease in the activities of cytosolic total and CN(-)-sensitive superoxide dismutase (SOD) after 7 and 30 days of HCH treatment, but failed to evoke any change in CN(-)-resistant SOD. Catalase activity decreased throughout the treatment period. Cerebral glutathione peroxidase activity (both selenium-dependent and -independent isoenzymes) and the level of glutathione content were decreased after 7 and 30 days of treatment, respectively. Activity of glutathione reductase and content of ascorbic acid, however, were enhanced following the pesticide exposure. The results suggest that repeated HCH administration induced oxidative stress in rat CH.