Effect of Cadmium on Activities of Catalase and Superoxide Dismutase from Hepatopancreas of Carassius auratus

In an acute toxicity test,Carassius auratus was exposed to a Cd2+ solution at 0.5,2.0 or 6.0 mg/L for 24,48,72 or 96 h,and the activities of CAT and SOD from the hepatopancreas were determined.The results showed that within the experimental dose range,the activity of CAT was enhanced in the presence of 0.5 or 2.0 mg/L of Cd2+ and was inhibited by 6.0 mg/L of Cd2+ and that the activity of SOD was enhanced in the presence of 0.5 mg/L of Cd2+ and was inhibited by 2.0 or 6.0 mg/L of Cd2+.The dose-effect relationship of CAT and SOD activity with Cd2+ could be described with a parabola curve,whose vertex indicated the toxication threshold of the hepatopancreas of C.auratus and,therefore,could be used as an indirect indicator of environmental pollution.SOD appeared more sensitive to Cd2+ pollution than CAT and is thus recommended for environmental Cd2+ pollution monitoring.