为了进一步研究纳米与微米尺度SiO2对雄性大鼠的生殖毒性作用,选择不同剂量的纳米SiO2(20~40nm)与微米SiO2(1~10μm),采用气管滴注方式对雄性Wistar大鼠分组染毒.于染毒5周后处死大鼠,应用流式细胞技术对睾丸生精细胞进行分析.结果表明:1)高、低剂量纳米SiO2组及高剂量微米SiO2组细胞凋亡率均显著高于对照组;2)与对照组相比,高、低剂量纳米SiO2组及高剂量微米SiO2组1C细胞显著减少,4C细胞显著增加;3)与对照组相比,高剂量纳米SiO2组和高剂量微米SiO2组G0/G1期细胞比例显著降低,高剂量纳米SiO2组G2/M期细胞比例显著增加.结果提示纳米SiO2能够阻滞细胞周期进程,诱导生精细胞凋亡;与微米SiO2相比,纳米SiO2对大鼠睾丸生精细胞的损伤有更严重的趋势.
In order to study the toxic effects of micro-nano-scale SiO2 on male rat spermatogenic cells, male Wistar rats were exposed to nanometer SiO2(20~40nm) and micro-meter SiO2(1~10μm)by intratracheal injection once two days. The rats were killed after 5 weeks exposure. Flow cytometry(FCM) was applied to analyze the spermatogenic cells. The results showed that the percentage of apoptotic cells in nm-SiO2 and high dose μm-SiO2 groups were higher than that in the control group. In nm-SiO2 and high dose μm-SiO2 groups the percentage of 1C cells was lower and 4C cells was higher than that in the control group, respectively. The percentages of cells in G0/G1-phase in high dose nm-SiO2 and high dose μm-SiO2 groups were lower and G2/M-phase in high dose nm-SiO2 group was higher than that in the control group. It can be concluded that nm-SiO2 could block the proceeding of cell cycle and induce spermatogenic cell apoptosis; nm-SiO2 showed the tendency of higher toxicity than μm-SiO2, and the detailed mechanism needs further discussion.