中文摘要：

目的：研究低氧对大鼠睾丸生殖细胞凋亡和Bax、Bcl-2表达的影响。方法：雄性成年Wistar大鼠随机分为4组：常氧对照组、低氧5d组、低氧15d组和低氧30d组（各组n=6）。常氧对照组在平原喂养；低氧5d组、15d组和30d组分别在低压舱内模拟5000m高原喂养5、15、30d。采用流式细胞术和TUNEL法检测低氧对睾丸生殖细胞凋亡的影响。运用Western印迹技术检测低氧对大鼠睾丸内凋亡相关蛋白Bax、Bcl-2表达的影响。结果：低氧5d组、15d组和30d组睾丸内发生生殖细胞凋亡的生精小管数量[每100个生精小管中，含有凋亡生殖细胞的生精小管数分别为（20．50±5．07）、（21．25±7．85）、（14．00±2．45）个]均非常显著地高于常氧对照组[（6．00±2．16）个，P〈0．01]。凋亡的生殖细胞以精原和精母细胞为主。低氧15d组睾丸组织亚单倍体细胞百分率[（2．18±0．82）％]显著高于常氧对照组[（1．30±0．33）％，P〈0．05]，低氧30d组[（3．08±0．93）％]极显著高于常氧对照组（P〈0．01）。低氧30d组睾丸组织Bax表达显著高于常氧对照组（P〈0．05），其灰度值分别为17．34±4．54和10．50±2．82。低氧30d组睾丸组织Bax／Bcl-2比值显著高于常氧对照组（P〈0．01），比值分别为0．40±0．10和0．27±0．04。结论：低氧诱导大鼠睾丸生殖细胞凋亡增多，慢性低氧引起的睾丸生殖细胞凋亡增多与Bax表达增加有关。

英文摘要：

Objective ： To explore the effects of hypobaric hypoxia on the apoptosis of germ cells in male rats. Methods ： Adult male Wistar rats were randomly divided into four groups： a control group raised at sea level; a 5 d, a 15 d and a 30 d hypoxic group raised in a hypobaric chamber simulating 5 000 m altitude for 5 days, 15 days and 30 days respectively. Flow cytometry and TUNEL were used to evaluate the apoptosis of germ cells in the testis. Bax and Bcl-2 in the testis were measured by Western blot. Results ： Seminiferous tubules with apoptotic germ cells were significantly more in the hypoxic groups than in the control （ P 〈 0.01 ）. Most apoptotic germ cells were spermatogonia and spermatocytes. Compared with the control group, apoptotic germ cells detected by PI flow cytometry were significantly increased in the hypoxic 15 d and 30 d groups（ P 〈 0.05 ） ; Bax was significantly higher（ P 〈 0.05 ）, and so was the ratio of Bax to Bcl-2 in the hypoxic 30 d group （ P 〈 0.01 ）. Conclusion ： Hypoxia promotes apoptosis of testicular germ cells in male rats. Chronic hypoxia increases Bax expression in the rat testis.