【摘要】 此试验研究了阿维菌素对雄性鲤鱼(Cyprinus carpio)的急性毒性以及在不同暴露质量分数和不同作用时间下低剂量阿维菌素对雄性鲤鱼血清雌二醇含量的影响。结果表明:阿维菌素对鲤鱼的24、48、72和96h半致死质量分数(LC50)分别为134.12、60.55、45.31和33.50μg/L,安全质量分数为3.35μg/L;长期(第20天)暴露时,在低质量分数(3.2~5.6μg/L)范围内阿维菌素对雄性鲤鱼血清雌二醇的合成产生了抑制作用,当质量分数为5.6μg/L时,抑制作用最强,与对照组相比血清雌二醇含量降低了28.8%;在高质量分数组10.0和18.0μg/L,鲤鱼血清雌二醇质量分数水平与空白对照组相比均没有显著差异(P>0.05)。在5.6μg/L质量分数下,各处理组时间的血清雌二醇含量均低于对照组,其中第20天时雌二醇含量最低,与对照组相比质量分数降低了28.8%(P<0.01)。在染毒鲤鱼血清雌二醇含量和阿维菌素作用时间或暴露质量分数之间不存在明显的时间-效应或剂量-效应关系。血液中雌激素含量的变化直接影响到鱼体的生殖功能及性征变化。更多还原

【Abstract】 Avermectins is considered one of the most commonly used pesticides in China and probably the world. Studies on avermectins acute toxicity toCyprinus carpio and effects of low level avermectins on serum estradiol contents in maleCyprinus carpio at different effecting time and exposure concentrations were done. Results of toxicity test showed that 24 h, 48 h, 72 h and 96 hLC 50 values were 134.12 μg/L, 60.55 μg/L, 45.31 μg/L and 33.50 μg/L respectively. The safety concentration of avermectin toCyprinus carpio was 3.35 μg/L; therefore it was virulent toxic to fish. Under effecting time of 20 days, the synthesis of serum estradiol in male C. carpio was inhibited by avermectin at the lower concentrations ranging from 3.2 to 5.6 μg/L. The strongest inhibiting effect happened when the avermectin concentration was 5.6 μg/L, and the content of serum estradiol reduced by 28.8% compared to the control group. However, the synthesis of serum estradiol had no obvious difference at higher concentrations of 10.0 μg/Land 18.0 μg/L. The contents of serum estradiol in maleC. carpio were lower than the control group at all effecting time at the concentration of 5.6 μg/L, and on the 20thday the serum estradiol content showed the lowest value by induced 28.8% compared to the control one. And there was no significant time-response or dose-response relationship between serum estradiol contents in male C. carpio and the effecting time or exposure concentrations of averectin. It is suggested that low level avermectins could induce depressions of serum estradiol in fish,thus threatening reproduction of fish.更多还原