Relationship between mast cell and iNOS expression in testicular tissue associated with infertility

The objective of this study was to investigate mast cells and iNOS expression in testis tissue, and to correlate these results with spermatogenic disorders. A total of 136 testicular biopsies were obtained from the testes of 80 patients with infertility. Their age ranged from 21 to 45 years. The biopsy specimens were immunohistochemically stained with antihuman tryptase for mast cells. In each section, all interstitial fields were evaluated for the total number of mast cells as well as the total number of Leydig cells. The number of mast cells per Leydig cell was calculated and recorded as mast cell index. Immunohistochemical iNOS staining was evaluated semiquantitatively according to intensity and the proportion of the stained cells. There was a significant increase of the mast cell index in all groups with testicular disorder compared with normal spermatogenesis group (p < 0.05). Increase of the index was in the order of hypospermatogenesis, maturation arrest and SCO, and index of SCO group was especially higher, i.e, more than twice than other groups. iNOS score was significantly higher in the SCO group than in the men with normal spermatogenesis, hypospermatogenesis, and maturation arrest (p < 0.05). Finally, a significantly statistical correlation was found between the iNOS score and mast cells index (r = 0.758, p = 0.001). Increase of mast cell index was observed in the groups of infertile testis, and high expression of iNOS in Leydig cells was associated with the highest mast cell index in SCO, the lesion with the most severe damage of the germ cell.