[Apoptosis in male germ cells induced by testicular denervation]

To evaluate the role of spermatic nerves in the regulation of spermatogenesis.

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.

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.

Spermatic nerves play an important role in spermatogenesis.