高压氧对精索静脉曲张大鼠生精细胞凋亡及其基因缺氧诱导因子-α、bcl-2及bax表达的影响

目的 观察高压氧(HBO)对精索静脉曲张(VC)SD大鼠生精细胞凋亡的影响,探讨精索静脉曲张导致男性不育的机制.方法 50只青春期雄性SD大鼠,随机抽出10只作为假手术对照组(A).A组只游离左肾静脉不予结扎,其余40只部分结扎左肾静脉建立VC模型,8周后,将建立了VC模型的40只随机分为VC模型组(B)和HBO干预的VC模型组(C),C组用HBO对VC模型进行干预.实验结束后各组大鼠切取双侧睾丸,采用原位末端标记法(TUNEL)检测大鼠睾丸生精细胞凋亡,免疫组织化学检测低氧诱导因子(HIF)-α、bcl-2及bax的基因表达.结果 B组较A组生精细胞凋亡数明显增多,HIF-α、bax表达增强(P＜0.01),bcl-2表达减弱(P＜0.01),bcl-2/bax比值降低;C组大鼠较B组生精细胞凋亡数减少(P＜0.01),HIF-α表达减弱(P＜0.01)、bcl-2/bax比值上升,而与A组比较差异无统计学意义.结论 VC大鼠生精细胞凋亡率增加,HIF-α表达增强、bcl-2和bax基因表达失调为其凋亡机制之一;高压氧可能通过HIF-α、bcl-2和bax基因调控途径调节生精细胞凋亡,从而改善VC所致的生精功能障碍.

Effects of hyperbaric oxygenation on experimental varicocele on the apoptosis of spermatogenic cell and the expression of hypoxia inducible factor-1α, bax, bcl-2 in adolescent rats

Objective To study the effects of hyperbaric oxygenation (HBO) on experimental varicocele on the apoptosis of spermatogenic cell and the expression of hypoxia-inducible factor-1 α( HIF-1α),bax,bcl-2 in adolescent rats. Methods Experimental varicocele models were created by partial ligation of left renal vein in adolescent Sprague-Dawley (SD) male rats. A total of 50 rats were randomly divided into 3 groups, namely sham operation group ( A, n = 10 ) , varicocele group ( B, n = 20 ), and HBO administered after being induced varicocele model ( C, n = 20 ). All the animals were killed 8w after operation. The left testis was collected and the expression of HIF-1α, bcl-2 and bax was detected by immunohistochemical method. The apoptosis of spermatogenic cells was detected by in situ terminal deoxylnucleotidyl transferase mediated-dUTP nick end labeling (TUNEL) technique. Results The expression of HIF-1α and bax in left testis of varicocele group was significantly higher than that of A and C group ( P ＜ 0. 01 ) and positive correlation was found between them ( r = 0. 6751, P ＜ 0. 05 ). The expression of bcl-2 in left testis of varicocele group was significantly lower than that of A and C group ( P ＜ 0.05 ). The incidence of apoptosis was decreased significantly in C group than that in B group (P ＜ 0. 01 ), and the apoptosis number of spermatogenic cells of bilateral testes was decreased. Conclusion HBO can change the expression of HIF-1α, bcl-2and apoptosis associated gene bax in germ cells of experimental varicocele adolescent rats. The apoptosis of spermatogenic cells of bilateral testes caused by left varicocele may be one of the mechanisms of male sterility caused by varicocele.