目的:研究切除精索神经对睾丸组织及生殖细胞凋亡的影响,探讨精索神经在精子发生过程中的调控作用。方法:健康成年雄性SD大鼠54只,随机分为假手术(SO)组、精索上神经切除(SSN)组、精索下神经切除(ISN)组、精索上神经切除+精索下神经切除(SSN+ISN)组,其中每个手术组分为术后1个月、术后2个月2个亚组,每个亚组6只大鼠,剩余18只大鼠纳入假手术组,各亚组均分配3只作为对照。解剖显微镜下建立睾丸去神经支配大鼠模型,分别于术后1、2个月采用苏木精-伊红染色、透射电镜、脱氧核糖核酸末端转移酶介导的dUTP的缺口末端标记技术(TUNEL)观察睾丸组织病理学变化与生殖细胞凋亡。结果:术后2个月各手术组大鼠睾丸出现明显的组织病理学改变:生精小管内大部分生殖细胞消失,仅残留支持细胞和少量精原细胞,精索上神经切除组、精索下神经切除组及精索上神经+精索下神经切除组大鼠睾丸组织中各有(13.25±2.03)%、(11.01±4.36)%、(34.17±3.78)%的生精小管发生类似的病理改变。透射电镜显示术后1个月各手术组大鼠生殖细胞发生染色质浓缩、断裂等超微结构的改变,TUNEL法进一步显示睾丸组织中大量精原细胞和Leydig细胞发生凋亡,精索上神经+精索下神经切除组凋亡细胞数显著高于精索上神经切除组和精索下神经切除组。结论:精索神经对精子发生具有重要的调控作用。
Objective : To evaluate the role of spermatic nerves in the regulation of spermatogenesis. Methods : Fifty-four mature SD male rats (350-375 g) were randomized into a sham operation group (SO) and three experiment groups, and the latter underwent bilateral surgical removal of the superior spermatic nerve ( SSN ) or/and the inferior spermatic nerve ( ISN ). The animals were killed 1 month and 2 months after the operation. HE stain was used to observe spermatogenesis. Transmission electron microscopy and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) were employed to detect apoptosis. Results: Impaired spermatogenesis was observed 2 months after the operation, with only Sertoli cells and a few spermatogonia remaining in the regressed tubules in all the treatment groups. The abnormal tubules in the SSN, ISN and SSN + ISN denervated testes accounted for ( 13.25 ± 2.03 ) %, ( 11.0 ± 4.36) % and ( 34.17 ± 3.78 ) % respectively. Chromosome condensation and fragmentation in the germ cells were observed under the electron transmission microscope in all the denervated testes. TUNEL showed the spermatogonia and Leydig cells to be apoptotic in all the denervated testes and the incidence of the apoptotic cells in the SSN + ISN denervated testes was significantly higher than in the SSN or ISN denervated ones. Conclusion : Spermatic nerves play an important role in spermatogenesis.