Influence of tributyltin on the plasma steroid levels, hepatic enzyme activity and microstructure of organs in rabbitfish Siganus oramin
三丁基锡对蓝子鱼的激素和酶指标及组织显微结构的影响

Toxic effects of tributyltin chloride (TBTCl) on the rabbitifish Siganus oramin were tested via a static exposure experiment. After fish were exposed to TBTCl at doses of 40, 400 or 4000 ng·L-1 for 10 or 20 days, the hepatosomatic indexes (HSI) were increased, and histopathological changes were observed in liver, spleen, gill, heart and skin. These toxic symptoms increased with exposure dose and/or duration. Compared with the control group, after TBTCl exposure for 10 days, the plasma level of testosterone in the 40 ng·L-1 group and that of cortisol in the 400 ng·L-1 group were significantly increased, whereas the plasma cortisol level was significantly decreased and hepatic glutathione-s-transferase (GST) activity was remarkably increased in the 4000 ng·L-1 group. After 20 days, no obvious difference in plasma testosterone or cortisol level was observed between the control and TBTCl exposed groups; however, the hepatic GST activity in the 40 or 400 ng·L-1 group was significantly increased. The results suggest that HSI, histopathological changes of organs, hepatic GST activity and plasma cortisol level may be used as biological indexes for evaluating the toxic effects of environmental pollutants such as tributyltin.