| Abstract: | The effects of cadmium (Cd) on metal accumulation, microelements contents, and antioxidant responses in Hexagram- mos otakii were studied. The fish were exposed to 0.2, 2.5, or 10 μg L?1 Cd for 12 or 24 days. Then, the concentration of Cd and mi- croelements (Ca, Fe, Zn, and Se) were determined in the liver and kidney. Moreover, the activities of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), and glutathione-S-transferase (GST), and the content of malondialdehyde (MDA) in the liver and kidney were also measured. A continuous accumulation of Cd was observed throughout the experimental period. Cd accumulation was higher in liver than that in the kidney, while Ca and Fe contents were lower in liver than those in the kidney. Cd exposure resulted in a decrease of Ca and Fe concentrations in the kidney, while there was no effect on the liver. Zn and Se remained unaffected with exposure to Cd. Cd exposure induced severe oxidative stress in H. otakii, as indicated by significant induction of the activities of SOD, CAT, and GST, and a simultaneous increase of MDA content. These data show that antioxidant enzymes and mi-croelements contents can be used as potential biomarkers to monitor environmental health in fish. |
