邻苯二甲酸二(2-乙基)己酯诱导隐睾对SD幼鼠睾丸生殖细胞凋亡的影响

目的探讨环境内分泌干扰物邻苯二甲酸二(2-乙基)己酯D(i2-ethylhexy1)phthalate,DEHP]作用于SD孕鼠后,对哺乳期雄性幼鼠睾丸组织中生殖细胞凋亡及凋亡基因Bax和Bcl-2表达的影响。方法将30只妊娠第12.5天的SD孕鼠随机分正常对照组、玉米油对照组和DEHP诱导隐睾组,每组10只。玉米油对照组和DEHP诱导隐睾组自妊娠第12.5～19.5天分别每日灌胃玉米油(2 ml)和DEHP(500 mg/kg),正常对照组不给药。取各组出生后第20天的雄性幼鼠睾丸组织,采用Q-PCR法检测睾丸组织中Bax和Bcl-2基因的水平,流式细胞术检测睾丸生殖细胞的凋亡情况。结果 DEHP诱导隐睾组幼鼠睾丸组织中Bax基因mRNA的水平显著高于两对照组(P<0.000 1),Bcl-2基因mRNA的水平显著低于两对照组(P<0.01);DEHP诱导隐睾组幼鼠睾丸生殖细胞凋亡百分率显著高于两对照组(P<0.000 1)。结论孕期暴露环境内分泌干扰物DEHP可引起雄性子代发生隐睾,且隐睾鼠睾丸生殖细胞凋亡率增加,隐睾子代睾丸组织中凋亡基因Bax和Bcl-2的表达有改变,推测其改变可能参与了生殖细胞的凋亡过程,并可能与隐睾继发的远期不育有关。

Effect of di-2-(ethylhexy1)phthalate-induced cryptorchidism on apoptosis of germ cells in infant SD rats

Objective To analyze the apoptosis of germ cells and the expression of Bax / Bcl-2 in testes of infant male rats with cryptorchidism induced by maternal exposure to di-2(-ethylhexy1)phthalate(DEHP).Methods Thirty healthy SD rats on day 12.5 after pregnancy were randomly divided into normal control,coin oil control and DEHP-exposure groups,ten for each.The rats in corn oil and DEHP-exposure groups were treated with corn oil and DEHP by gavage,each at a dosage of 500 mg / kg,once a day on gestation days(GD)12.5 ~ 19.5,respectively,while those in normal control group were untreated.Testes of infant male rats were collected on post-natal day(PND)20 then determined for expression levels of Bax and Bcl-2 genes by Q-PCR,and for apoptosis of germ cells by flow cytometry.Results The expression level of Bax mRNA in DEHP-exposure group was significantly higher(P < 0.001),while that of Bcl-2 mRNA was significantly lower,than those in two control groups(P < 0.01).However,the apoptosis rate of germ cells in DEHPexposure group was significantly higher than those in two control groups(P < 0.000 1).Conclusion Maternal exposure to DEHP induced cryptorchidism in male offspring,which promoted the apoptosis of germ cells.Meanwhile,the expressions of Bax and Bcl-2 in testis tissue of rats with cryptorchidism,which was speculated to involve the apoptosis of germ cells and be related to secondary infecundity in future.