The changes of serum SOD activity and MDA content in rats induced by lead

Objective To study the change of superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in serum of rats exposed to lead, and the dose effect relationship between lead and SOD, MDA respectively. Methods SOD activity in serum was measured by nitrite coloration and MDA contents were determined by TBA method. Results Compared with control groups, the activities of serum SOD were markedly decreased in low dose groups after 60 days lead exposure, and 30 days in high dose groups( P 0.05 ). Serum MDA contents in high dose groups were higher than those of control groups after 30 days. There were negative correlation( r =-0.479, P 0.01) and negative dose effect relationship between SOD in serum and lead in blood; there were positive correlation( r=0.496,P0.01) and positive dose effect relationship between MDA and lead. Conclusion SOD activity appeared to be significantly decreased and MDA content significantly increased during sub chronic lead exposure and there was dose effect relationship between them. It suggested that lipid peroxidation could be one of molecular mechanism in lead poisoning.