Effects of Cd and Pb on the activities of SOD in hepatopancreas of Carassius auratus

This article is intended to present our findings on the effects of Cd and Pb on the activities of SOD in the hepatopancreas of Carassius auratus,which is a kind of enzyme that tends to catalyze the destruction of the O_2-free radical to form oxygen and hydrogen peroxide.As is known,SOD is a kind of chemical compound widely existing in nature to prevent cellular damage by excessive oxygen free radicals generated in the process of metabolism.As a matter of fact, the activity of SOD can be affected by the metal ions,especially,the heavy metal ones,e.g.Cd and Pb.In our research,we have discovered that the concentrative effects of Cd and Pb on the activities of SOD from hepatopancreas of Carassius auratus through our toxicity tests.Statistically speaking,after 24 h,48 h or 96 h of post-exposure treatments in the presence of Cd~(2+) (0.5 mg/L,2.0 mg/L,6.0 mg/L),Pb~(2+) (10 mg/L,20 mg/L,40 mg/L) or both of them,the activity of SOD would have changed.The results have thus shown that within the experimental dose range,the activities of SOD were found to have accelerated by 0.5 mg/L of Cd~(2+).However,high concentrations of Cd~(2+),Pb~(2+) and the mixture tend to obviously suppress the activities of SOD.What is more,synergetic effect of the toxicity can be detected in the presence of both Cd~(2+) and Pb~(2+).Such results prove to be useful for the evaluation of the risk of Cd~(2+) and Pb~(2+),in monitoring the environmental pollution.