[Hypoxia promotes apoptosis of germ cells in rat testes].

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 5000 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.