氧化乐果和毒死蜱混剂对大鼠雄性生殖功能的联合毒性

为探讨有机磷农药混合物对生物生殖毒性的影响，以模式动物Sprague- Dawley (SD)大鼠为实验材料，采用亚慢性染毒动物实验，利用3×3析因实验设计方法研究了常见有机磷农药——氧化乐果和毒死蜱的联合雄性生殖毒性效应及机理。结果表明：氧化乐果和毒死蜱联合染毒60 d后，附睾系数增加，精子数量和精子活力降低，联合作用呈现协同效应(p<0.05)；混配农药能降低睾丸标志酶乳酸脱氢酶(LDH)、酸性磷酸酶(ACP)、碱性磷酸酶(AKP)、γ-谷氨酰转移酶(γ-GT)的活力，对LDH、ACP、γ-GT的联合作用表现为协同作用(p<0.05)；混配农药能增加睾丸中促卵泡生成激素(FSH)含量，降低睾酮(T)含量，联合作用表现为协同作用(p<0.05)。通过组织病理学观察，氧化乐果和毒死蜱混合物能引起曲细精管的萎缩、畸形精子增多、生精细胞坏死、胞浆溶解和线粒体空泡化；支持细胞数量减少，出现坏死，精子从支持细胞上脱落，基底膜脱落等损伤。氧化乐果和毒死蜱对大鼠的联合生殖毒性为协同效应，混合后有明显的增毒作用；对睾丸标志酶(LDH、ACP、γ-GT)活力及睾丸性激素水平(FSH、T)的协同影响，是产生联合生殖毒性的机理之一。以上结果提示，对氧化乐果和毒死蜱进行环境健康风险评价时应考虑这种协同作用。

Combined Reproductive Toxicity Effects of Omethote and Chlopyrifos on Male Rats

To study the the combined reproductive toxicity of omethoate and chlopyfifos on biological reproductive toxicity, the combined reproductive toxicity and mechanism of omethoate and chlopyfifos to Sprague- Dawley rats were investigated using the chronic infected animal experiments and 3×3 factorial experimental design. After 60 days' exposure to the mixture of omethoate and chlopyfifos, the epididymal viscera coefficients increased (p<0.05), while sperm number and rate of sperm mobility (p<0.05) reduced. There was synergism between omethoate and chlopyfifos on the reproductive organs. According to the results of histomorphological examination, the exposure of omethoate and chlorpyrifos mixtures can cause atrophy of the seminiferous tubules, sperm deformation, germ cell necrosis, cytoplasmic dissolution, and mitochondrial vacuolization; the number of sertoli cells was reduced, the percentage of necrosis of sertoli cells was increased, and sperm was shed from the supporting cells, and cause basement membrane loss. All the evidences adequately indicated that the combined omethoate and chlopyfifos showed synergism effects on the reproductive toxicity of SD rats, and there was obvious toxic potentiation. The synergism of the mixture on marker enzyme and sex hormone of testicular was the one of mechanism of synergism reproductive male toxicity. Therefore, the combined effect of these pollutants should be considered in the process of environmental health risk assessmet.