雷公藤内酯醇对雄性大鼠生殖毒性的机制研究(Ⅱ)

Mechanism research on reproductive toxicity of triptolide in male rats(Ⅱ)

目的:考察雷公藤内酯醇对大鼠睾丸细胞相关凋亡基因mRNA表达的影响,研究雷公藤内酯醇生殖毒性的分子机制。方法:以低(0.025 mg·kg^(-1))、中(0.05 mg·kg^(-1))、高(0.1 mg·kg^(-1))剂量的雷公藤内酯醇对健康雄性Wistar大鼠连续灌胃染毒30 d,每天一次,于末次染毒24 h后处死大鼠,取睾丸组织进行病理学检查,并通过实时荧光定量PCR测定Bcl-2、Bax、Fas、FasL、CREM和Caspase-3基因mRNA的表达情况。结果:与阴性对照组相比,雷公藤内酯醇染毒组睾丸组织生精细胞明显减少,精索内几乎无精子;高剂量组Bcl-2、CREM mRNA表达降低;而Bax mRNA表达水平在中、高剂量组时呈显著地高表达;Fas和FasL mRNA表达水平在高剂量组显著上升;Caspase-3 mRNA表达水平呈现依赖剂量的高表达,中、高剂量时呈现显著性差异。结论:提示在本实验染毒剂量范围内,特别是高剂量的雷公藤内酯醇能够使生殖细胞相关凋亡基因Bcl-2、Bax、Fas、FasL、CREM和Caspase-3不同程度的表达异常,这很可能是雷公藤内酯醇诱导大鼠生殖细胞凋亡的重要原因,为进一步深入阐述雷公藤内酯醇雄性生殖毒性的分子机制提供了依据。

OBJECTIVE To investigate the molecular mechanism of Triptolide’s reproductive toxicity by investigating the effects of triptolide on the expression of apoptosis gene mRNA in rats.METHODS Male Wistar rats were treated with low(0.025 mg·kg-1),medium(0.05 mg·kg-1)and high(0.1 mg·kg-1)doses of triptolide by gavage for 30 days,The rats were excuted 24 h after the last exposure.Testis tissues were collected for pathological examination.The expression of Bcl-2,Bax,Fas,FasL,CREM and caspase-3 mRNA was determined by real-time PCR.RESULTS Compared with the negative control group,the spermatogenic cells in the testes of the triptolide-exposed group were significantly reduced,with almost no sperm in the spermatic cord.The expression of Bcl-2 and CREM mRNA was decreased in the high-dose group;the expression level of Bax mRNA was significantly higher in the medium-and high-dose groups;the expression level of Fas and FasL mRNA was significantly increased in the high-dose group;the expression level of caspase-3 mRNA was high in a dose-dependent manner,with significant differences in the mid-and high-dose groups.CONCLUSION The results indicated that in the range of exposure dose,especially at a high dose,triptolide could cause the abnormal expression of Bcl-2,Bax,Fas,FasL,CREM and Caspase-3 in different degrees Maybe this was the important cause of the apoptosis induced by triptolide in rat germ cells,and provided the basis for the further explanation of the molecular mechanism of triptolide male reproductive toxicity.