铝暴露对大鼠精子线粒体细胞色素氧化酶亚基I、II、III mRNA表达的影响

目的 研究铝暴露对大鼠精子质量及线粒体细胞色素氧化酶（COX）亚基I、II、III mRNA表达的影响。方法 取健康雄性Wistar大鼠48只，根据饮水中AlCl3的半数致死量设立:对照组和低、中、高剂量组［剂量分别为0.00、64.18 、128.36、256.72 mg/ (kg·d)］，每组随机分配 12只，连续作用 110 d。造模完成后称量生殖脏器重量并计算脏器系数，利用CASA检测精子质量参数， RT-PCR法测定COX I、COX II、COX III mRNA表达。结果 与对照组相比，低、中、高剂量组大鼠体重及睾丸重量均明显下降（P＜0.05）；中、高剂量组大鼠附睾重量、睾丸及附睾脏器系数均低于对照组（P＜0.05）；低、中、高剂量组大鼠前向运动精子百分比均显著低于对照组（P＜0.05），死精子百分比均显著高于对照组（P＜0.05）；低、中、高剂量组大鼠COX I、COX II、COX III mRNA相对表达量较对照组均有不同程度的下降（P＜0.05）。结论 铝暴露可致大鼠精子线粒体COX I、COX II、COX III mRNA表达降低，从而影响雄性生殖系统，降低精子质量。

Effects of aluminum exposure on mRNA expression of sperm mitochondrial cytochrome oxidase subunits I,II and III in male rats

To study the effects of aluminum exposure on sperm quality and mRNA expression of mitochondrialcytochrome oxidase (COX) subunits I, II and III in male rats. Methods According to the median lethal dose of AlCl3·6H2O indrinking water, 48 healthy male Wistar rats were divided into four groups randomly and averagely with AlCl3 aqueousdrinking water: control group, low dose, medium dose and high dose groups 0, 64.18, 128.36, 256.72 mg/(kg·d), respectively], alltreated for 110 days. Then reproductive organs were weighed and viscera coefficients were calculated; sperm qualityparameters were detected by Computer-aided sperm analysis; COX I, COX II, COX Ⅲ mRNA expression were determined byRT-PCR. Results Compared with the control group, the body weight and testicular weight of rats in low -, medium - andhigh-dose groups were decreased significantly (P<0.05). The testicular viscera coefficient, epididymal weight and its visceracoefficient of medium- and high-dose group were lower than that of control group (P<0.05). The percentage of progressivelymotile sperm was significantly decreased in low-, medium- and high-dose groups as compared with that in the control group(P<0.05), while the percentage of dead sperm was remarkably higher than that in the control group (P<0.05). The relative mRNAexpression of COX I, COX Ⅱ, COX Ⅲ was decreased in varying degrees in low-, medium- and high-dose groups comparedwith that in the control group (P<0.05). Conclusion Exposure to aluminum can reduce the mRNA expression of mitochondrialCOX Ⅰ, COX Ⅱ, COX Ⅲ in rats’ sperm, consequently affect the male reproductive system and impair sperm quality