Antagonistic effect of selenium on oxidative damage of liver in swordtail (Xiphophorus helleri Heckel) initiated by mercury
FANG Zhan-qiang, WANG Chun-feng(College of Life Science, South China Normal University, Guangzhou 510631, China)
The present article aims to present the authors' research on the effect of mercury on the superoxide dismutase(SOD) and glutathione peroxidase(GSH-Px) activities and the concentration of melonedialdehyde (MDA) in liver tissue of swordtail(Xiphophorus helleri Heckel). Our research results indicate that the activities of SOD and GSH-Px were induced by mercury at low concentrations during early stage, and the induction reached to a significant level on the third day in contrast to the control group. However, the high concentration Hg can remarkably decrease the activities of SOD and GSH-Px to 68% and 38.2% of the control group. Nevertheless, the concentration of MDA was able to maintain significant increase all through the exposure period. Another result shows that Se could remarkably prevent the decrease of SOD and GSH-Px in the liver, as well as make the concentration of MDA decrease, particularly compared with the contrast Hg group. However, it is beyond expectation that the Ⅳ group ((0.105Hg +0.064Se) mg/L) reveals little protections, therefore, it is suggested that the dose of Se used for protection from the poisoning of Hg should be considered. In addition, the activity of GSH-Px is also recommended as a biomarker for indicating the oxidative damage to the liver of swordtail fish.