The effect of spermatic vessel ligation on testicular nitric oxide levels and germ cell-specific apoptosis in rat testis. 
Management of high testis may vary but the most popular method in surgical treatment is the Fowler-Stephens maneuver.  The aim of the present study was to investigate the effects of spermatic vessel ligation on testicular nitric oxide (NO) levels, expression of inducible nitric oxide synthase (iNOS), and endothelial nitric oxide synthase (eNOS) and germ cell-specific apoptosis in both ipsilateral and contralateral testes in rats.  Twenty-eight animals were randomly allocated into four groups (n=7 each).  The spermatic vessels were ligated as a simulation of the Fowler-Stephens maneuver.  The groups of animals were sacrificed at 2 h (group 1), 4 h (group 2) and 24 h (group 3) after ligation, respectively.  Sham-operated animals served as controls (group 4).  Biochemical assessment of testicular NO levels was performed by the Griess method.  iNOS and eNOS expression and apoptosis were studied in ipsilateral and contralateral testes.  Testicular NO levels at 24 h after the simulated Fowler-Stephens maneuver were found to be significantly increased in both ipsilateral and contralateral testes when compared with the sham-operated group.  eNOS expression was clearly increased in ipsilateral testes, whereas moderate expression was detected in the contralateral seminiferous tubules at 24 h after ligation.  Mild focal iNOS immunostaining was also observed in seminiferous tubules of the ipsilateral testis at 24 h after the simulated Fowler-Stephens maneuver.  Apoptosis was dramatically increased in ipsilateral testes; however, it was only detected in single cells in the contralateral side at 24 h after ligation.  In conclusion, the simulated Fowler-Stephens maneuver induces testicular nitric oxide synthesis and germ cell-specific apoptosis in the ipsilateral testis.  These results suggest that high levels of NO induce apoptosis and may impair spermatogenesis thus explaining the unsuccessful outcome of the Fowler-Stephens maneuver.