Effect of antioxidant ascorbic acid, l-methionine or α tocopherol alone or along with chelator on cardiac tissue of lead-treated rats

An experiment was conducted using 42 IVRI 2CQ rats to evaluate the effects of three antioxidants, ascorbic acid, l methionine or α tocopherol alone, or chelator CaNa2EDTA alone or along with antioxidant α tocopherol, on lead accumulation, status of lipid peroxidation, and of copper and zinc concentration in cardiac tissue of lead-treated rats. Lead was given intraperitoneally as 1% lead acetate solution at the dose rate of 1mg of Pb2+/kg body mass for a period of 30 days. The lead was then withdrawn and the lead-exposed rats (n=36) were randomly divided into six groups, six lead-treated rats in each group. A further six rats were given no treatment, including lead exposure, to serve as negative controls. The rats were sacrificed under light anaesthesia one day after one week of treatment with antioxidant ascorbic acid, l-methionine or α tocopherol or with chelator CaNa2EDTA alone or along with antioxidant α tocopherol. Blood samples were collected and heart was quickly excised. Mean lead concentration in cardiac tissue was significantly higher in the lead-treated group, even after its withdrawal for a period of seven days (5.02 ± 1.06 vs. 0.40 ± 0.09 μg/gm). The treatment with chelator plus antioxidant α tocopherol lowered the cardiac lead burden but the level remained significantly higher than that of the negative control. There was a non-significant increase in lipid peroxide levels in the cardiac tissue of lead-exposed untreated rats and either of the antioxidants lowered the lipid peroxide level, but the differences between the different treatment groups remained statistically comparable at P>0.05. The mean concentration of copper and zinc in cardiac tissue remained statistically comparable among the different treatment groups.