伊维菌素对雄性鲫的生殖毒性评价

Evaluation of ivermectin's reproductive toxicity to male Carassius auratus

伊维菌素作为一种广谱、高效的新型抗寄生虫类药物,在我国农、牧、渔业均有广泛应用.为了评价伊维菌素对雄性鲫的生殖毒性效应,本文研究了口灌不同剂量伊维菌素对雄性鲫生殖腺指数、血清及精巢中性激素(睾酮和雌二醇)、血清及脑组织中的γ-氨基丁酸含量、精子超微结构及性腺组织的影响.分别以0、1、3、5倍治疗剂量,即0、0.3、0.9和1.5mg·kg-1剂量对鲫进行口灌给药,分别标记为A、B、C、D组,每天1次,连续3 d,停药8 d后对供试鲫各组织进行检测观察.结果表明:随着给药剂量的增加,供试鲫生殖腺指数逐渐降低,且C和D组显著低于A组;血清及精巢中的睾酮及雌二醇、血清和脑中γ-氨基丁酸含量均表现为先升高再降低趋势,均在B组达到峰值;精子寿命逐渐降低,Ⅱ、Ⅲ和Ⅳ级精子运动时间逐渐减少,C、D组表现尤为明显;精子超微结构和精巢组织未见明显异常.表明正常治疗剂量伊维菌素对生产期雄性鲫未产生明显生殖毒性效应,但高剂量给药可对鲫造成严重的潜在生殖毒性.

As a new type of antiparasitic drugs,ivermectin（ IVM） has been widely applied in agriculture,stock raising and aquaculture in China because of its broad spectrum and high efficiency.In order to evaluate the IVM ＇s reproductive toxicity to male Crucian carp（ Carassius auratus）,IVM was orally given to the experimental fish with different dosages and the gonadosomatic index（ GSI）,sexual hormone contents（ including testosterone and estradiol） in serum and testis,γ-aminobutyric acid content in serum and brain tissues,ultra-structure of spermatozoa and gonadal tissue in fish were determined in this study. The experimental fish were classified into A,B,C and D groups corresponding to the different dosages of IVM（ 0,0. 3,0. 9 and 1. 5 mg·kg- 1,respectively once a day for 3 days continuously）. Several indices in fish were detected after 8 days self-purification. The results indicated that GSI gradually decreased with the increase of drug dosage,and GSI in groups C and D was significantly lower than that in group A. The contents of testosterone,estra-diol and γ-aminobutyric acid exhibited a trend of first increasing and then decreasing and reached the peak at group B. Sperm longevity gradually decreased and the motion time also decreased in Ⅱ,Ⅲ and Ⅳ level sperms with the increasing dosage of IVM,which appeared to be especially obvious in group C and D. No obvious differences were found in the ultra-structure of spermatozoa and gonadal tissues. In conclusion,this study suggested that IVM had no obvious reproductive toxicity to male Crucian carp at the normal therapeutic dosage but could cause serious potential reproductive toxicity to fish at a high concentration.