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

采用静态暴露方式研究三丁基锡氯化物(TBTCl)对黄斑蓝子鱼(Siganus oramin)的毒性效应.当蓝子鱼暴露于40～4000 ng·L-1 TBTCl中10d或20d后,雌鱼和雄鱼的肝体指数显著升高,鳃、肝脏、脾脏、心脏、皮肤等组织的显微结构发生明显的病理变化;上述病变随毒物暴露剂量或暴露时间的增加而加剧.与对照组相比,暴露10d后,40 ng·L-1组的血浆睾酮水平和400 ng·L-1组的血浆皮质醇水平显著升高,4000ng·L-1组的血浆皮质醇水平显著降低、肝脏谷胱甘肽-S-转移酶(GST)活性极显著升高;暴露20d后,各处理组的血浆睾酮和皮质醇水平无显著变化,但40、400 ng·L-1组的肝脏GST活性显著升高.结果提示,肝体指数、肝脏代谢酶活性、血浆皮质醇水平,以及有关组织的病理变化可以作为评估三丁基锡等环境污染物毒性效应的生物指标.

Influence of tributyltin on the plasma steroid levels, hepatic enzyme activity and microstructure of organs in rabbitfish Siganus oramin

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.