Effects of acute waterborne cadmium exposure on activities of antioxidant enzyme and acetycholinesterase in the fish crimson red snapper (Lutjanus erythropterus)

Fish are widely used as biological monitors of variations in environmental levels of pollutants. To understand how the fish antioxidant, neural systems respond to the oxidative stress under acute Cd2+ exposures (0.005mg/L, 0.025mg/L, 0.05mg/L, 0.25mg/L), the superoxide dismutase (SOD) activities and lip peroxidation (MDA ) contents in the liver and gill, and acetycholinesterase (AChE) activities in the brain of Lutijanus erythropterus were measured respectively. The results showed that the hepatic SOD activities were induced significantly (p<0.01) on 24 and 48 hours of cadmium exposure, but inhibited on 168 hours (p<0.01), and impaired after 96 hours exposure from the content of MDA except the group of 0.005mg/L Cd2+. While the SOD activities of branchial tissues were earlier than that of the hepatic in response to the cadmium exposure (about 6 and 12 hours), but the oxidative damage to the gills was less than the liver on 168 hours exposure. In addition, the activities of AChE in brain tissues were disturbed during 96 hours exposure, and inhibited on 168 hours exposure, which may have relations with the oxidative stress resulted from the cadmium exposure.