The potential role of inducible nitric oxide synthase (iNOS) activity in the testicular dysfunction associated with varicocele: an experimental study.

Nitric oxide (NO) has been reported to be increased in the spermatic veins of men affected by varicocele. The aim of the present study was to determine whether iNOS (inducible nitric oxide synthase) has a role in testicular dysfunction associated with varicocele, immunohistochemistry analyze was used to study iNOS activity in testis of adolescent rats with experimental left varicoceles. Rats were randomly divided into three groups. The first group consisted of rats undergoing partial ligation of left renal vein (n:12). The second group consisted of rats undergoing a sham operation (n:6) and, the third group referred to as control rats (n:7). Immunohistochemistry slides were evaluated by counting the number of positive cells and expressed as percents (% iNOS activity). We found that iNOS was predominantly expressed in the cytoplasm of Leydig cells in each group and only a small amount of iNOS was expressed in Sertoli cells. There were significant differences in % iNOS activity between both testes of varicocele group and both of testes control group (p < 0.01), but no significant differences were noted between other groups (p > 0.05). Because of iNOS activity was markedly increased in the Leydig cells of varicocele bearing rats, we suggest that iNOS activity may play a role in the testicular dysfunction associated with varicocele during adolescence.