皮瓣重建兔阴囊诱导精原细胞凋亡与热休克蛋白70表达

目的:探讨皮瓣重建阴囊后睾丸表面的温度变化、生精细胞凋亡及热休克蛋白70(HSP70)的表达。方法:以健康育龄期新西兰大白兔为实验动物,雄性24只、雌性12只。将雄兔随机分成实验组12只,对照组12只。采用温度计埋藏法测量实验组阴囊内睾丸表面的温度,手术切除实验组动物阴囊,建立皮瓣重建阴囊动物模型,对照组未作处理。动物模型建立后第8周末对照组随机取6只动物进行睾丸活检,实验组随机取6只动物测量睾丸表面温度后行睾丸活检。睾丸组织行HE染色、原位末端标记(TUNEL)法检测生精细胞凋亡、免疫组化法结合图象分析仪检测睾丸生精细胞HSP70的表达。模型建立后第8周末,将两组未行睾丸活检的各6只动物分别与雌兔配对喂养观察生育情况。结果:实验组模型建立前睾丸表面温度为(36.0±0.3)℃,模型建立后第8周末睾丸表面温度为(38.1±0.6)℃(P<0.05)。模型建立后第8周末实验组睾丸生精小管中生精细胞的凋亡指数(AI)为(71.85±2.69)%,对照组为(7.73±4.95)%(P<0.05)。对照组HSP70主要在圆形精子细胞中表达,实验组主要表达在精原细胞。配对喂养结果显示,实验组没有生育,对照组生育幼兔(6.0±1.3)只(P<0.05)。结论:皮瓣重建家兔阴囊后睾丸局部温度升高诱导生精细胞凋亡增加,动物丧失生育能力。HSP70参与保护皮瓣重建阴囊诱导的精原细胞凋亡。

Apoptosis of spermatogenic cells and expression of HSP70 after scrotal reconstruction with skin flap

Objective:To explore the temperature change at the testis surface,apoptosis of spermatogenous cells and the expression of the heat shock protein 70 (HSP70) after scrotal reconstruction with the skin flap. Methods:We included 36 healthy New Zealand white rabbits,24 males and 12 females,in this study,and equally randomized the males into an experimental and a control group. The scrota of the experimental rabbits were excised and reconstructed with the hypogastric flap,while the controls were left untreated. At the end of the 8th week after surgery,6 animals were randomly taken from each of the two groups for measurement of the testis surface temperature and testicular biopsy. The apoptosis of spermatogenous cells in the testis tissues was detected by HE staining,and the expression of HSP70 determined by immunohistochemistry and imaging analysis. The other 6 animals exempt from testicular biopsy in each of the experimental and control groups were mated with the female rabbits,and observed for fertility. Results:At the end of the 8th week after scrotal reconstruction,the testicular surface temperature was (38.1±0.6)℃ in the experimental group,significantly higher than (36.0±0.30)℃ before surgery (P<0.05),and the apoptosis index (AI) of the spermatogenous cells was (71.85±2.7) %,as compared with (7.73±4.95) % in the control group (P<0.05). The expression of HSP70 was found mainly in the spermatogenous cells of the experimental group and in the spermatoblasts of the control. A total of 6.0±1.3 baby rabbits were born in the control group,but none in the experimental group (P<0.05). Conclusion:The testicular surface temperature rises after scrotal reconstruction with the hypogastric flap,which increases the apoptosis of spermatogenic cells and causes infertility. HSP70 is involved in protecting spermatogenic cells from apoptosis after scrotal reconstruction.