Study on P-CNB Induced SOD and CAT Activities in Brocarded Carp Liver

The acute toxicity of p-CNB (p-Chloronitrobenzene) to Brocarded Carp and 2 kinds of antioxidant activities in liver of fish were investigated. The acute toxicity test showed that 24 h, 48 h, 72 h, 96 h value of median lethal concentration (LC₅₀) at 20-22degC were 30.98, 24.89, 23.9 and 19.93 mg/L, respectively. Fish was exposed to different concentrations (1/6LC₅₀, 1/4LC₅₀, 1/3LC₅₀, 1/2LC₅₀) and killed at 3, 7, 14, 21 and 28 day after exposure. The activities of Superoxide dismutase (SOD) and Catalase (CAT) in liver tissue were analyzed. The results indicated the activities of SOD and CAT were induced from the third day in all treatment groups at post-exposures, they were higher than those of the control group (p < 0.05). The SOD activities of the control group were stable during 28-days, but the CAT activity of the control group changed slightly. The results demonstrated that the SOD and CAT activities of liver in Brocarded Carp might be the promising biomarker of p-CNB exposure. Therefore it was suggested that SOD and CAT could be used as biomarker of nitroaromatics compounds, when their pollutions affected living beings in aquatic environment. But, the order of the sensibility and stability for 2 kinds of antioxidant enzymes was SOD > CAT.