Chlorpyrifos induces oxidative stress in rats

This study was carried out in male Wistar rats to determine the potential effects of chlorpyrifos (CHP) on oxidative stress, as was reported for organophosphorus (OP) pesticides. Following an acute, daily 3- or 14-day exposure with CHP at doses of 2.5, 5, or 25 mg kg-1 data showed significant increases in malondialdehyde levels at both exposure durations and at all doses, except for 2.5 mg kg-1, in hepatic and aorta, kidney, and plasma samples. The nitrites (NO) showed elevation at 25 mg kg-1 in aorta, at 3- and 14-day exposure, in hepatic tissue with all doses at 3-day exposure, but not at 14-day with a 5 mg kg-1 dose. In plasma, increases occurred only at 25 mg kg-1 at both exposure times, and in kidney at all doses and both exposure durations. Superoxide dismutase (SOD) enzyme activity in the aorta sample was statistically significant at all doses at 3 days and at 14 days, except at 2.5 mg kg-1; and in hepatic tissue only at 25 mg kg-1 dose at both durations. In plasma SOD activity was elevated at all doses at 3 days, but at 14 days only at 25 mg kg-1. Data suggests that oxidative stress may be involved in the effects of CHP on rats.