The role of nitric oxide on spermatogenesis in infertile men with azoospermia

Abstract

Objectives: The underlying pathophysiological mechanisms of azoospermia is still unclear. The aim of the study was to evaluate nitric oxide synthase (NOS) isoforms and free radical release in testicular sperm extraction (TESE) in infertile men with azoospermia. Materials and methods: The study included 40 men (mean age: 37.2±2 years; range 25 to 55 years) with azoospermia which were divided into two groups: spermatozoa-present (n=20) and spermatozoa-absent (n=20). Testicular samples were examined morphologically, immunohistochemically, and biochemically. The TESE samples were examined according to number of mast cells stained with toluidine blue; immunohistochemically with three types of NOS isoforms, and free radicals were measured with chemiluminescence method, respectively. Results: Endothelial NOS (eNOS) reaction in spermatozoa-present group was considerably higher than spermatozoa-absent group (p<0.001). Compared to the spermatozoa-present group, inducible NOS (iNOS) reaction was higher than the spermatozoa-absent group (p<0.05). Neuronal NOS (nNOS) reaction was only prominent in Leydig cells in both groups. Mast cells increased (p<0.05) in the interstitial area surrounding seminiferous tubules in spermatozoa-absent samples. Superoxide radical generation in spermatozoa-present samples was significantly lower (p=0.0003). The peroxynitrite ratio in spermatozoa-absent samples was significantly higher (p=0.0038). Conclusion: These results suggest that eNOS, iNOS, and mast cells play an important role in spermatogenesis process in azoospermic men.