Response of Antioxidant Parameters to 3,3’-dimethyl-benzidine in Goldfish (carassius Auratus) Liver

Adaptive responses of the livers of goldfish (Carassius auratus) exposed to five concentrations of 3,3’-dimethyl-benzidine (DMBz) (0.9-9.0 mg/L) for 3, 7 or 14days (d) relative to unexposed goldfish were investigated. A suite of antioxidant parameters including glutathione (GSH) concentration and activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione-s-transferase (GST) were evaluated. DMBz caused measurable oxidative parameters changed in goldfish liver with the following adaptive responses: (1) activities of SOD were significantly less in livers of goldfish exposed to 0.9 mg DMBz/L, but significantly greater when exposed to 4.5, 9.0 mg DMBz/L; (2) activities of GST and GSH were well-correlated with DMBz exposure concentrations; (3) SOD was the primary antioxidant while CAT and GPx activities were not related to concentrations of DMBz, to which the fish were exposed. DMBz caused oxidative parameters changed in livers of goldfish, possibly due to the presence of redox-active metabolites. The concentration of GSH and activities of SOD and GST responded to the effects of DMBz and can be useful functional measures of exposure of goldfish to compounds, such as DMBz, that cause oxidative stress.