Endocrine Disrupting Effects Of Lindane And Beta-Endosulfan On Zebrafish

The impacts of environmental endocrine disruptors on human and ecological environment have received worldwide attention in recent years. Compared with the advanced countries in this fidld of research specially to organochlorine, although China is still at an beginning stage. This study choosed zebrafish as the experimental animals. Refer to a short term screening test of OECD, we studied the endocrine disrupting effects of lindane and beta-endosulfan on zebrafish. This results could supply base datas and valuable experience to the research working of envirmonmental endocrine disruptors in our country.The effects of lindane on body length, body weight, hepaticosomatic index (HSI), gonadosomatic index (GSI), spawning and fertilization rates of zebrafish at low concentration were studied. The results showed that:after14-day exposure, the body length and body weight of zebrafish at all treated groups almost had no change when compared with the control groups. But the HSI of male and female zebrafish at0.5μg/L of lindane significantly increased (P<0.05) and the GSI of only male zebrafish were prominently reduced (P<0.05). Lindane remarkably inhibited zebrafish reproductive behavior and reduced the amount of average quantities of spawning and fertilization rate of zebrafish at0.05μg/L and0.5μg/L(P<0.05). The concentration of vitellogenin in the male and female zebrafish at all treated groups had no change afer14-day exposure (P>0.05).The results of SDS-PAGE and Western-blotting showed that the plasma of zebrafish contained three protein bands that reacted with mouse anti zebrafish vitellogenin monoclonal antibody.150KDa and100KDa were the major bands. Theses results demonstrated that lindane has a certain impact on the growth and reproduction of zebrafish at low concentration but no estrogenic impact on zebrafish.The effects of beta-endosulfan on body length, body weight, hepaticosomatic index (HSI), gonadosomatic index (GSI), hatching rates and fertilization rates of zebrafish at concentration of0.01μg/L,0.05μg/L,0.2μg/L were studied. The results showed that:the body length and body weight of male and female zebrafish at all treated groups had no significant change compared with the control groups after21-day exposure. The HSI of male zebrafish at0.05μg/L,0.2μg/L of beta-endosulfan significantly increased (P<0.05) but the female not.The GSI of only male zebrafish were prominently reduced at0.2μg/L (P <0.05).Beta-endosulfan inhibited zebrafish reproductive behavior and the hatching rates at0.2μg/L and fertilization rates at all concentrations had decreased remarkably (P<0.05) Although the concentration of vitellogenin in male zebrafish at all treated groups had increased significantly (P<0.05), the vitellogenin in female zebrafish were not affected by dietary concentrations used in this study.Three protein bands were proved to reacted with mouse anti zebrafish vitellogenin monoclonal antibody in the plasma of female and induced male zebrafish from the results of SDS-PAGE and Western-blotting. Theses results demonstrated that beta-endosulfan has reproductive toxicity and estrogenic impact on zebrafish.These results suggest that short-term exposure to lindane and beta-endosulfan have endocrine disrupting effects on zebrafish.