兽药阿苯达唑的蚯蚓繁殖毒性研究

阿苯达唑是目前应用广泛的高效抗寄生虫兽药,其残留对蚯蚓等土壤动物的繁殖毒性鲜见报道.本研究选择了阿苯达唑的5个染毒剂量(1、3、6、9和12 mg·kg-1),检测染毒56 d阿苯达唑对蚯蚓产茧、孵化及其幼蚓产生的影响,以及染毒14 d蚯蚓精子畸形率和精子细胞超微结构的变化.结果表明,染毒28 d时,卵茧数量比其他繁殖参数(卵茧重和孵化率)对低剂量阿苯达唑敏感,随着染毒剂量(3~12 mg·kg-1)增加,卵茧数量显著降低(p0.01),呈现明显的剂量-效应关系;染毒56 d时,幼蚓重量比其他繁殖参数(幼蚓数量和孵化率)敏感,产生有毒作用的最低染毒剂量为3 mg·kg-1(p0.01).短期染毒14 d时,精子细胞的超微结构在染毒剂量为3~12 mg·kg-1时发生明显变化,尤其是线粒体,而精子畸形率发生明显变化的最低剂量为6 mg·kg-1,可见,短期染毒时精子细胞的超微结构比光镜下的精子畸形率敏感.该研究结果可为阿苯达唑残留的土壤生态毒理及早期监测提供依据.

Reproductive toxicity of earthworms exposed to veterinary pharmaceutical albendazole

Albendazole is a veterinary medicine with a high efficiency against helminths which has been used widely in livestock. However, few studies have been published on reproductive toxicity of albendazole residues on soil organisms including earthworms. In this study, earthworms were exposed to five levels of albendazole (1, 3, 6, 9, and 12 mg · kg^-1) for 56 days to investigate cocoon production, hatching success and juvenile production and for 14 days to assess sperm deformity and ultrastructure of germ cells. After 28 days, cocoon number of earthworms was more sensitive to low concentrations of albendazole than other reproductive parameters (cocoon weight and hatching success), and a significant dose-related decrease was found in cocoon number over the range of concentrations from 3 to 12 mg · kg^-1(p <0.01). After 56 days, juvenile weight was more sensitive to low concentrations of albendazole. Significant decrease in juvenile weight was observed at 3 mg · kg^-1 and above(p <0.01). In short-time exposure of 14 days, ultrastructural alteration of germ cells, particularly morphology of mitochondria,was observed at 3 mg · kg^-1 and above, whereas increase of sperm deformity was observed at 6 mg · kg^-1 and above, suggesting the higher sensitivity of germ cell ultrastructure to low concentrations than sperm deformity in short-time exposure. The results provides important information on ecotoxicology of albendazole residues in soil and their early pollution prediction.