染锰大鼠生精细胞Caspaes-3和Ki-67表达

目的 研究氯化锰对大鼠生精细胞半胱天冬酶(Caspase-3)和抗霍奇金淋巴瘤细胞核抗体(Ki-67)表达的影响及意义.方法 48只雄性SD大鼠随机分为6组:空白对照组,15和30 mg/kg MnCl2组,锰与生理盐水均为腹腔注射,1次/d,5 d/周,分别染锰4和6周.用免疫组化法检测睾丸生精细胞Caspase-3与Ki-67表达.结果 与空白对照组比较,各染锰组Caspase-3阳性细胞率均显著升高(P<0.01);染锰剂量相同,染锰6周组与4周组比较,Caspase-3阳性细胞率均显著升高(P<0.01);染锰时间相同,30 mg/kg MnCl2与15 mg/kg MnCl2组比较,Caspase-3阳性细胞率均显著升高(P<0.01).与空白对照组比较,染锰15 mg/kg MnCl24周组Ki-67阳性细胞率降低(P<0.05);染锰30 mg/kg MnCl2 4周组,15 mh/kg MnCl2 6周组,30 mg/kg MnCl2 6周组Ki-67阳性细胞率均显著降低(P<0.01);染锰时间相同,30 mg/kg MnCl2组与15 mg/kg MnCl2组比较,Ki-67阳性细胞率显著降低(P<0.01).各组大鼠生精细胞Caspase-3阳性细胞率与Ki-67阳性细胞率呈明显负相关(r=-0.798,P<0.01),结论染锰15 mg/kg 4周即可促进大鼠生精细胞Caspase-3表达和抑制大鼠生精细胞Ki-67表达,且存在一定的剂量-效应和时间-效应关系,锰的这种双重作用可能是导致大鼠生精障碍的主要机制.

Effects and significance of manganese on expression of Caspase-3 and KI-67 In spermatogenic cells of rats

Objective To study the effects and significance of manganese on the expression of Caspase-3 and Ki-67 in spermatogenic cells of male rats. Methods Forty-eight male rats were randomly divided into 6 groups (2 blank control groups,2,15 mg/kg MnCI2, and 30mg/kg MnCI2 groups) and were exposed to manganese ( MnCI2 H2O) by I. P. for 4 and 6 weeks,respectively and blank control group was injected with NS. All rats were injected once everyday, five times per week. In the 4th and 6th weekend,their testis were collected for examination. The expression of Caspase-3 and Ki-67 in testis were determined by immunohistochemical methods (SABC). Results Compared with blank control group, the Caspase-3-posi-five-cell rate in all exposure groups were increased significantly (P < 0. 01). Among manganese exposure groups of same dose,the Caspase-3-positive-cell rate of 6wks exposure groups was increased significantly than those in 4wks exposure groups (P < 0. 01). Among exposure groups of same time,the Caspase-3-positive-celi rate of 30mg/kg MnCI2 group was in-creased significantly than those of 15mg/kg MnC12 group(P < 0. 01). Compared with blank control group, the Ki-67-posi-tire-cell rate in 15mg/kg MnCI2 4wks group was decreased (P < 0. 05), those of 15mg/kg MnCI2 6wks group, 30mg/kg MnCI2 4wks group and 30mg/kg MnC12 6wks group were much lower (P <0. 01). Among exposure groups of same dose, the Ki-67-positive-cell rate of 15mg/kg MnCi2 6wks group was decreased significantly compared with that of 15mg/kg MnCI2 4wks group(P < 0. 01). Among exposure groups of same time, the Ki-67-positive-cell rate of cells in 30mg/kg MnCI2 group was decreased significantly than that of 15mg/kg MnCI2 group(P <0. 01), There existed a negative correlation between Caspase-3-positive-cell rate and Ki-67-positive rate (r=-0. 798, P < 0. 01). Conclusion 15mg/kg MnCI2 expo-sure for 4wks could promote the expression of Caspase-3 and inhibit the expression of Ki-67 in rat spermatogenic cells with dose-effect and time-effect relationship. It may be an important mechanism of spermatogenic dysfuction