Organochlorine pesticide-induced oxidative stress and immune suppression in rats.

Effects of subchronic DDT and lindane exposure were evaluated on lipid peroxidation, antioxidant mechanisms and humoral immune response in rats. Oral administration of DDT, (100 and 200 ppm) and lindane (40 and 80 ppm) dose dependently increased thiobarbituric acid reactive substance (TBARS) levels in serum after 8 wk of treatment. Superoxide dismutase (SOD) activity in red blood cells (RBC) was also dose dependently increased by these compounds. In addition, such DDT or lindane exposure markedly suppressed the humoral immune response as assessed by anti-sheep RBC antibody titres. Simultaneous treatment with ascorbic acid (100 mg/kg) markedly attenuated the effects of DDT and lindane on (a) lipid peroxidation, (b) SOD activity and (c) humoral immune suppression. These results indicate the possible involvement of free radicals in organochlorine-induced immunotoxicity.