The effect of diethyldithiocarbamate on antioxidant enzyme activities in the blood of rats

Diethyldithiocarbamate (DDC) exhibits a variety of effects including neurotoxic, radioprotective and sensitizing activity. It is a potent copper chelating agent used for the treatment of oxygen toxicity, as an imunomodulator in cancer therapy, as well as in HIV infected patients. In this study we examined the effect of DDC, a superoxide dismutase (SOD) inhibitor, on the activities of copper-zinc containing superoxide dismutase (CuZn SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR) and glutathione-S-transferase (GST). Three hours after diethyldithiocarbamate treatment (1 g/kg b.m, i.p.) a significant decrease of SOD and increase of GR and GST activities were found in the blood of rats. A negative correlation between SOD and OR and a positive correlation between OR and GST activities were also obtained. DDC induced a concentration dependent increase of OR activity and NADPH consumption in an enzymatic assay in vitro. The obtained results may be interpreted to indicate that a decrease in SOD activity in the blood of rats, after DDC administration, may be compensated for by changes in the activity of some other compounds suggesting that regulation of antioxidative defence is very complex.