This study was undertaken to examine the effects of leptin on testicular histology in mice. Animals were divided into two groups. Group I served as controls. Mice in Group II were injected daily with leptin for five days. All animals were killed by decapitation at the end of the experiment. The testes were removed and weighed out. Some of the testicular tissue specimens were used for light and electron microscopic examination. The remaining samples were processed for semiquantitative evaluation of immunohistochemical testosterone staining. Intensity of immunostaining was determined on a scale between 0 (no staining) and 5 (heavy staining). For morphometric comparison, diameters of seminiferous tubules from each group were measured. In leptin injected group, testicular weights and diameters of seminiferous tubules were significantly increased compared to control group. In light microscopic examination, an increase in secretory granules in the cytoplasm of Leydig cells was observed after leptin treatment. The amount of mitochondria, lysosomes and cytoplasmic secretory granules were increased in the leptin-treated mice. Furthermore, an increase in extensiveness of rough endoplasmic reticulum was noticed in this group. Immunohistochemical testosterone staining of the cytoplasm of Leydig cells was mild (2+) in control mice. Whereas heavy (5+) staining was seen in mice that were treated with leptin. Additionally, heavy immunostaining of testosterone in interstitial space was observed after injection of leptin. The results of our study suggest that leptin stimulates testicular functions and synthesis of testosterone in mice.
22 - 24 Mar 2004
British Endocrine Societies