缺锌对大鼠睾丸细胞凋亡影响机制的研究

Mechanism of effect of zinc deficiency on apoptosis of rat testis cells

目的 探讨缺锌对睾丸细胞凋亡影响的可能机制 ,研究其对睾丸一氧化氮合酶 (NOS)活性和血清睾丸酮水平的影响。方法 选用 2月龄Wistar雄性大鼠 16只 ,均分为实验组和对照组 ,实验组和对照组分别喂养缺锌和常锌饲料 ,喂养 4周后 ,采用原子吸收分光光度法测定血清锌含量 ;采用放射免疫分析法测定血清睾丸酮含量 ;采用NADPH -d组织化学显示睾丸细胞NOS活性 ;采用原位缺口平移法计数睾丸细胞凋亡数目的变化。结果 缺锌大鼠血清锌较对照组明显降低 (P <0 0 5 ) ;血清睾丸酮较对照组明显降低 (P <0 0 1) ;睾丸间质细胞NOS阳性细胞数目 (378 44± 5 1 78No . 10个曲细精管 )较对照组 (192 5 7± 2 6 30No . 10个曲细精管 )明显增多 (P <0 0 1) ,NOS活性反应强度明显增高 ;睾丸曲细精管生精细胞凋亡的数目 (2 1 41± 3 82No . 10个曲细精管 )较对照组 (6 94± 12 44No . 10个曲细精管 )明显增多。结论 锌是睾丸发育必需的营养素 ,缺锌可诱导睾丸生精细胞凋亡 ;缺锌大鼠睾丸酮水平降低 ,睾丸细胞NOS活性明显增强 ,这种变化可能是缺锌诱导睾丸细胞凋亡的重要机制。

Objective To study the changes in serum testosterone level and testis nitric oxide synthase (NOS) activity in zinc deficient male rats,thereby promoting the understanding of the molecular mechanism of effect of zinc deficiency on apoptosis of testis cells.Methods Sixteen Wistar male rats were divided into 2 groups of 8 each:zinc deficient rats and control rats.After 4 weeks,the serum zinc and testosterone contents were measured by atomic absorption spectro photometry and radioimmunoassay,the testicular NOS activity was assayed by NADPH-d histochemistry and the apoptosis of testis cells was studied by in situ nick translation technique. Results In the zinc deficient rats,the serum zinc and testostronc contents obviously decreased (P<0 05 or P<0 01).NOS positive cells in testis significantly increased (P<0 01),NOS activity significantly elevated,and the apoptotic spermatogenic cells significantly increased in number (P<0 01). Conclusions Adequate amouunt of zinc is essential to the development of testis,whereas zinc deficiency can induce apoptosis of testis cells.Decrease in serum testostrone and increase in number and activity of NOS positive cells might be one of the importent mechanisum of zinc deficiency induced apoptosis of testis cells.