吸入二氧化硅纳米颗粒和微米颗粒对雄性大鼠精子及其功能的影响

Comparative study of nanosized and microsized silicon dioxide on spermatogenesis function of male rats

目的比较雄性大鼠吸入纳米二氧化硅(nm-SiO2)与微米二氧化硅(μm-SiO2)对其生精功能的影响并探讨作用机理。方法45只雄性Wistar大鼠按体重随机分为5组,分别为nm-SiO2100mg/m3和300mg/m3组,μm-SiO2100mg/m3和300mg/m3组和对照组。动物隔天在装有风扇扬尘的静式染毒柜中吸入染毒2h,对照组不扬尘,只吸入空气。65天后,用HE染色法观察大鼠睾丸组织的病理改变;显微镜下观察精子数量、活动度和畸形率;用试剂盒检测大鼠睾丸组织中乳酸脱氢酶同工酶-C4(LDH-C4)、琥珀酸脱氢酶(SDH)、超氧化物歧化酶(SOD)的活性、丙二醛(MDA)含量和血清中MDA、SOD;ELISA法测定血清8-羟基脱氧鸟苷(8-OHdG)水平。结果nm-SiO2可引起大鼠睾丸组织病理改变,病变程度明显重于同剂量水平的μm-SiO2;nm-SiO2致大鼠精子数量、LDH-C4活力下降和MDA生成量增加程度显著高于同剂量μm-SiO2(P<0·05);nm-SiO2可引起大鼠精子活动度、睾丸组织SDH活力和血清8-OHdG水平下降,精子畸形率升高(P<0·05),但与同剂量μm-SiO2比较差异无显著性(P>0·05);各实验组血清中MDA含量和SOD活力与对照值比较,差异均无显著性(P>0·05);各同剂量水平纳米和微米组之间差异无显著性(P>0·05)。结论nm-SiO2和μm-SiO2对雄性大鼠生精功能影响存在差异,nm-SiO2致生殖损伤能力强于同剂量水平的μm-SiO2。

Objective To compare the effects of nanosized and microsized silicon dioxide on spermatogenesis function of male rats exposed by inhalation, Methods 45 male rats were randomly divided into control group and four experimental groups which were exposed by 100mg/m^3 or 300mg/m^3 nanosized and microsized silicon dioxide in inhalation chambers 2 hours every other day. Age-matched rats were exposed to room air with the same condition and served as controls. 65 days later, the testicular and epididymal viscera coefficients, the quantity and quality of sperm were examined and the histopathological assessment was done. The changes in biochemical parameters in serum and testes were also measured. Results Nanosized silicon dioxide could induce histopathological changes of testes in rats, and the effect was higher than that of microsized particles at the same concentration. Nanosized silicon dioxide could reduce the sperm counts of rats and the testicular LDH-C4 activities, increase MDA levels in the testes and the effect was higher than that of microsized particles at the same concentration. Nanosized silicon dioxide could lead to the reduction of sperm motility, testicular LDH-C4 activities and 8-hydroxydeoxyguanosine（8-OHdG）concentration in serum elevation in particles-exposed rats compared with the control animals, but there are no significant difference compared with that of microsized particles at the same concentration. Conclusion The present findings suggest a different effect of impairment of sperm production and maturation induced by inhalation of nanosized and microsized silicon dioxide, and nanosized silicon dioxide exerted more severe reaction.