内分泌干扰物莠去津对鲫鱼血清激素的影响

为了研究低剂量条件下,内分泌干扰物莠去津对鲫鱼血清激素的影响,探讨其作用机理和剂量-效应关系,同时筛选出敏感的生物标志物,实验以除草剂莠去津对鲫鱼进行低剂量染毒(染毒浓度0～3mg·L-1),采用放射免疫法测定莠去津长期暴露下(60d)幼年雄性鲫鱼血清中性激素(17β-雌二醇(E2)、睾酮(T))及甲状腺激素(促甲状腺激素(TSH)、三碘甲状腺原氨酸(T3))的浓度,并将测定结果与空白对照及溶剂对照进行比较.结果发现:1)莠去津长期暴露下,各处理组鲫鱼血清E2浓度普遍升高,0.023、0.094、1.500、3.000mg·L-1组与空白对照相比,升高显著(p<0.05);2)各处理组鲫鱼血清T浓度与空白对照相比均无显著性差异(p>0.05);3)莠去津长期暴露下,低浓度莠去津组(0.006、0.023mg·L-1组)鲫鱼血清TSH浓度与空白对照相比差异不显著(p>0.05),而高浓度莠去津组(0.094、1.500、3.000mg·L-1组)则显著降低(p<0.05);4)类似地,莠去津长期暴露下,低浓度莠去津组(0.006、0.023、0.094、0.375、1.500mg·L-1组)鲫鱼血清T3浓度与空白对照相比差异不显著(p>0.05),只有高浓度莠去津组(3.000mg·L-1组)显著升高(p<0.05).实验结果表明,低剂量长期暴露下,莠去津对鲫鱼体内性激素及甲状腺激素具有一定的干扰作用,尤其是对17β-雌二醇影响更为显著,因此,17β-雌二醇可作为评价农药内分泌干扰效应的生物标志物.

Effects of Atrazine on Serum Sex Steroids, TSH and T3 in Juvenile Male Carassius auratus

Endocrine disruption of low-dose atrazine exposure to Carassius auratus was studied. In this study, effects on serum sex steroids(17β-estradiol(E2)、testosterone(T))、thyroid-stimulating hormone(TSH)and triiodothyronine(T3)were measured, with the purpose to explore the mechanism, dose-effect relationship and biomarker. Juvenile male Carassius auratus were exposed to low-dose(0~3mg·L-1)atrazine for 60 days, concentrations of serum E2, T, TSH, T3 were determined by RIA, respectively. Compared with the controls, the results indicated that:1)Levels of serum E2 significantly (p<0.05) increased in the treatments(0.023、0.094、1.500、3.000mg·L-1); 2)No obvious effects on the concentrations of serum T in all treatments were observed; 3)TSH was significantly(p<0.05)decreased when fish were exposed to high doses (0.094、1.500、3.000mg·L-1) and no significant difference in low-dose treatments(0.006?0.023mg·L-1); 4)Similarly, T3 increased significantly (p<0.05) in the highest dose treatment(3.000mg·L-1), but showed no significant differences in low-dose treatments(0.006、0.023、0.094、0.375、1.500mg·L-1). These results suggested that atrazine had effects on the level of serum sex steroids, TSH and T3 in juvenile male Carassius auratus, and it had significant effect on E2. So E2 can be used as a biomarker of evaluation of endocrine disruption.