染锰大鼠生精细胞半胱氨酸蛋白酶3的表达及锌的保护作用

目的:研究氯化锰对生精细胞半胱氨酸蛋白酶3(caspase-3)表达的影响,探讨锰诱发大鼠生精细胞caspase-3表达的机制及锌的拮抗作用.方法:雄性SD大鼠随机分为空白对照组,ZnCl_2对照组,15mg/kg和30mg/kg MnCl_2组;15mg/kg和30mg/kg MnCl_2+ZnCl_2组.免疫组织化学法检测睾丸caspase-3表达.结果:各染锰组,染锰补锌组及染锰剂量相同的6周组,染锰时间相同的30mg/kg MnCl_2组caspase-3阳性细胞率均显著升高,染锰补锌组显著降低.结论:染锰15mg/kg 4周可诱发大鼠生精细胞caspase-3表达,且随染锰时间和剂量的增加而增加,两者存在一定时间-效应和剂量-效应关系;摄入含锌100mg/kg的食物可拮抗锰诱发的生精细胞caspase-3表达.

Effects of manganese on the expression of caspase-3 in spermatogenic cells of rat and protection of zinc

Objective: To study the effects of manganese on the expression of caspase-3 in spermatogenic cells of male rat, and to discuss its mechanism and the antagonize effects of zinc. Methods: Eighty healthy male rats were randomly divided into blank control, ZnCl_2 control, 15mg/kg MnCl_2, 30mg/kg MnCl_2 and 15mg/kg MnCl_2+ZnCl_2, and 30mg/kg MnCl_2+ZnCl_2 groups. In the 4~(th) and 6~(th) weekend, their testis were collected and the expression of caspase-3 in testis was investigated by immunohistochemical methods (SABC). Results: The caspase-3-positive-cell rate was increased in every manganese and Mn+Zn groups, and was decreased in Mn+Zn groups compared with MnCl_2 groups. It increased more in 6 weeks group than that in 4 weeks group, and more in 30mg/kg than that in 15mg/kg groups. Conclusion: Lintraperitoneal injection of 15mg/kg MnCl_2 for 4 weeks could induce the expression of caspase-3 in rat spermatogenic cells that exhibited in dose and time dependent. Oral administration of 100mg/kg zinc suppresses the over expression of caspase-3 in rat spermatogenic cells induced by manganese.