刚地弓形虫感染对小鼠生精细胞凋亡的影响

Effect of Toxoplasma gondii infection on apoptosis of spermatogenic cells in mice

目的 探讨刚地弓形虫感染对小鼠生精细胞（单倍体、二倍体、四倍体）凋亡的影响程度，进一步阐明弓形虫致雄性不育的机制。方法 选用9～10周龄雄性BALB／c小鼠60只，随机分为：PBS正常对照组、刚地弓形虫纯化速殖子感染组（2．5×10^3、5×10^3、1×10^4、2×10^4）及环磷酰胺阳性对照组。采用腹腔注射法建立刚地弓形虫感染致小鼠睾丸损伤的模型，病理切片观察，流式细胞仪检测各组小鼠睾丸各倍体生精细胞的凋亡情况，免疫组化测定睾丸凋亡蛋白bel-2、bax的变化，进行图像分析。结果 正常对照组未出现明显的凋亡峰，实验组小鼠睾丸的单倍体、二倍体细胞均出现明显凋亡，尤以二倍体明显，同时四倍体细胞明显减少；睾丸细胞bel-2的表达无明显改变，但bax的表达量随攻虫剂量增加而增加。结论 弓形虫可致小鼠睾丸各级生精细胞凋亡，对二倍体细胞的影响尤为明显。

Objective To explore the effect of Toxoplasma gondii on apoptosis of spermatogenic （ haploid,diploid,tetraploid） cells in mice. Methods Sixty BALB/c mice （9 - 10 weeks） were randomly divided into six groups： normal control group, tachyzoites infected groups （2.5 × 10^3 ,5 × 10^3 ,1 ×10^4 , and 2 × 10^4 tachyzoites injected individually） and cyclophosphamide positive control group. Experimental model was created by intraperitoneal injection of tachyzoites of Toxoplasma. The apoptosis number of spermatogenic cells was determined by flow cytometry; bcl-2 and bax were measured by immunohistochemistry. Results No marked apoptosis peak was observed in the control group, but it was observed in haploid, especially in diploid cells. Tetraploid cells were decreased. There was no obvious change in bcl-2 expression in testes, but bax expressed higher than that in normal control group （ P 〈 0.05 ）. Conclusion Toxoplasma could induce apopotosis of spermatogenic, especially in diploid cells.