镍染毒大鼠睾丸生精细胞凋亡及其对Bcl-2和Bax表达的影响

目的探讨硫酸镍诱导大鼠睾丸生精细胞凋亡的类型及其对生精细胞Bcl-2、Bax蛋白表达和雌二醇水平的影响。方法健康性成熟Wistar雄性大鼠32只,随机分为4组,正常对照组,硫酸镍1.25、2.5、5.0 mg/kg 3个剂量组。腹腔注射染毒,1次/d,连续30 d。采用原位缺口末端标记法(TUNEL)检测睾丸生精细胞凋亡;免疫组化SABC法检测生精细胞Bcl-2和Bax蛋白表达;放射免疫法检测血清雌二醇(E2)水平。结果与对照组比较,各剂量组大鼠睾丸生精细胞凋亡增多(P<0.05),且凋亡细胞主要是生精早期和晚期阶段的精原细胞和精母细胞。各剂量组大鼠生精细胞Bcl-2阳性表达减少而Bax阳性表达增多,且血清E2水平降低(P<0.05)。结论硫酸镍可诱导大鼠睾丸精原细胞和精母细胞凋亡,其机制可能与生精细胞内Bcl-2蛋白表达下调,Bax蛋白表达上调以及雌二醇水平降低有关。

Spermatogenic cell apoptosis and the effects on the expression of Bcl-2 and Bax induced by nickel sulfate in rats

Objective To explore the effects and the type on the apoptosis of rat spermatogenic cells and the expression of Bcl-2 and Bax induced by nickel sulfate(NiSO_4).Method 32 male wistar rats,adult and healthy,were divided into 4 groups randomly including normal saline,NiSO_4 1.25,2.50,5.00 mg/kg.The 4 groups rats were exposed to NiSO_4 by intraperitoneal injection at dose of 1.25,2.50,5.00 mg/kg for 30 days.After exposure,the terminal deoxynucleotidyl transferase(TdT)-mediated dUTP nick end-labeling(TUNEL) technique were used to detect the apoptosis of spermatogenic cells.The expression of Bcl-2 and Bax in rat spermatogenic cells were measured by immunohistochemical method and the estradiol levels of serum were measured by estradiol radioimmunoassay assay.Results The number of apoptotic cells in NiSO_4 exposure groups were significantly higher than that of control group(P<0.05),and the apoptotic cells were mostly spermagonia and spermatocytes at the early stage and later stage of spermatogenesis.Compared with the control group,Bcl-2 expression was significantly decreased while Bax expression was increased in NiSO_4 exposure groups(P<0.05).Meanwhile,the estradiol levels of serum were lower than that of control group(P<0.05).Conclusion NiSO_4 could induce apoptosis of the spermatogonium and spermatocyte in rats through the downloads expression of Bcl-2,the upwards expression of Bax and the decreased levels of serum estradiol.