Leptin expression in the testicular tissue of fertile and infertile men

There have been several studies about the presence of leptin in serum and testicular tissue, and none of them compares the leptin expression in the testicular tissue of fertile and infertile men. We assessed the presence of leptin expression in the testicular tissue of fertile and infertile men. 20 azoospermic infertile men were included in the study. All patients underwent testicular sperm extraction (TESE) for ICSI. For the detection of leptin, the immunohistochemistry was carried out. Intensity of immunohistochemical staining was subjectively estimated and expressed as negative (-), weak positive (+), intermediate positive (++) and strong positive (+++). Testicular tissues of 5 fertile patients, aged 50-60 years, was stained with leptin for control group. Mann-Whitney U test was used as the statistical method. There was no statistically significant difference in leptin staining between infertile patients and control group (p < 0.05). Leptin staining in tubuli seminiferi and Leydig cells were generally equal or Leydig cells were stained (+) much. This difference was not statistically significant. We found that there is leptin staining in Leydig cells and tubuli seminiferi. There is no difference in normal and infertile men for leptin staining properties in testicular tissue. This condition suggests that the effect of leptin on reproductive functions originates from a systemic effect related to central neuroendocrine system, androgen levels or spermatogenic existence rather than its direct effect on testicular tissue.