Journal of North Khorasan

Background & objectives: The aim of the present study was to characterize the localization of endothelial nitric oxide synthase (eNOS) in" normal" human testis and in testis with azoospermia and their possible relationship with testicular tissue. Materials & Methods: In this case-control study, testicular biopsies were obtained from 10 men with obstructive azoospermia (Group1= OA) and 10 men with non-obstructive azoospermia (Group2=NO) and 7 men with normospermia(Group 3=control) who were attended to infertility center for diagnosis or infertility treatment. Immunohitochemistry was used to localize of the isoform of eNOS. In addition, the histopathological evaluation was examined in these three groups. Results: Histopathological examination of the testis revealed no difference between normal and obstructive groups. Different histopathological appearances were observed in non-obstructive azoospermic group. The eNOS protein was localized in the cytoplasm of sertoli and leydig cells in three groups. Except from normal germ cells, the rest of germ cells including (immature spermatids, abnormal germ cells and germ cells with picknotic neuclei) showed positive immunosatining . The expression of eNOS in non-obstructive group was significantly higher than others (P ˂ 0.001). In contrast, immature spermatids and abnormal germ cells in three groups were the same. Conclusion: various expression of eNOS in several types of testicular tissue suggest that elevated eNOS localization could play important role in abnormal spermatogenesis and germ cell apoptosis.