腹股沟区皮下埋藏睾丸对兔精子发生的影响

目的探讨采用腹股沟区皮下埋藏睾丸的方式修复阴囊皮肤缺损对睾丸精子发生的影响。方法普通级健康6～8月龄新西兰大白兔60只，雄性36只，雌性24只，体重2．5～2．7kg。将雄兔随机分为实验组及对照组，每组各18只。实验组动物将双侧睾丸分别移位埋藏至双侧腹股沟区皮下，以制备睾丸埋藏修复阴囊皮肤缺损模型；对照组未作处理。两组于造模后8周末时采集精液进行常规分析，每组随机取6只兔测量睾丸表面温度，另随机每组取6只兔的睾丸进行活检，应用TUNEL法检测生精细胞凋亡情况。同时将两组未采集活检的雄兔分别与雌兔一一配对喂养，观察生育情况。结果对照组精液密度为（237．3±39．7）×10^9／L，精子活动率为76．9％±3．8％；实验组精液密度为（4．7±2．7）×10^9／L，精子活动率为0；两组比较差异有统计学意义（P〈0．05）。对照组的睾丸表面温度为（36．15±0．64）℃，实验组为（38．02±0．36）℃，两组比较差异有统计学意义（P〈0．05）。TUNEL检测示：实验组生精上皮变薄，仅存的精原细胞和初级精母见明显凋亡，凋亡指数（apoptotic index，AI）为89．69％±3．76％；对照组可见散在精母细胞和精子细胞凋亡，AI为7．73％±4．95％；两组比较差异有统计学意义（P〈0．05）。实验组配对后对应的母兔均未受孕生崽；对照组配对后对应母兔均受孕生崽，平均生崽数为6只；两组比较差异有统计学意义（P〈0．05）。结论与皮瓣重建阴囊一样，腹股沟区埋藏睾丸修复阴囊皮肤缺损将导致兔生殖功能障碍，主要因睾丸局部环境温度升高诱导生精细胞过度凋亡所致。

INFLUENCE OF BURYING TESTIS IN INGUINAL REGION ON SPERMATOGENESIS IN RABBIT TO REPAIR SCROTUM DEFECT

OBJECTIVE: To explore the effect of burying testis in inguinal pocket on spermatogenesis. METHODS: Sixty New Zealand rabbits of 6-8 months old included 36 males and 24 females, weighing 2.5-2.7 kg. The male rabbits were randomly divided into the experimental group (n=18) and the control group (n=18). The model of repairing skin defect of scrotum were established by burying testes in inguinal region subcutaneously in the experimental group. The rabbits were not treated in the control group. The sperms were collected and the surface temperature of testis was measured in both groups after 8 weeks. Testes biopsies were harvested from 6 rabbits of 2 groups randomly respectively. The apoptosis of spermatogenic cells was detected with TUNEL. The other 12 male rabbits in two groups were fed respectively with female rabbits to observe the fertility. RESULTS: The semen density and the spermid activity ratio were (237.3 +/- 39.7) x 10(9)/L and 76.9% +/- 3.8% in the control group, and were (4.7 +/- 2.7) x 10(9)/L and 0 in the experimental group respectively; showing statistically significant difference between two groups (P< 0.05). The average superficial temperature of testes was (38.02 +/- 0.36) degrees C in the experimental group and (36.15 +/- 0.64) degrees C in the control group (P < 0.05). TUNEL results showed: The spermatogenic epithelium became thin and obvious apoptotic spermatogenic cells were found in experimental group; the spermatogenic epithelium was normal and few apoptotic spermatogenic cells were found in the control group. The apoptotic index (A1) was 89.69% +/- 3.76% in the experimental group and 7.73% +/- 4.95% in the control group (P < 0.05). The Pairing results showed that the female rabbits pairing with male rabbits of the experimental group were all not pregnant, and those of the control group were all pregnant (P < 0.05). CONCLUSION: As the same as the scrotum was reconstructed with skin flaps, it will induce the rabbit infertility that the testes were buried in inguinal region subcutaneously to repair defect of scrotum skin. The main reason is the excessive apoptosis of spermatogenic cell by the high testes environmental temperature.