Protective Effects of Melatonin on Testicular Torsion and Detorsion Damage in Sprague-Dawley Rats

In this study, we evaluated the ultrastructural findings of testis with systemic administration of different doses of melatonin during ischemic period in a rat model of testicular torsion/detorsion (T/D). Testis ischemia-reperfusion (I/R) injury was induced by torsion of the left testis, with a 720 degrees twisting of the spermatic cord so as to produce a total occlusion of testis for 2.5 hours. Subsequently, the same testis was then detorsioned. According to surgical procedure in each group, unilateral orchiectomies were performed for histopathologic examination. The groups were labelled as control group, torsion group (T), torsion and detorsion group (T/D), torsion-detorsion and melatonin group (T/D+20,50 and 100 mg/kg melatonin). For the histological examination, testicular tissues were fixed in 2.5% glutheraldehyde and postfixation 1% osmic acid solutions. They were examined under transmission electron microscopy after application of contrast stained. In torsion group testis cross-sections, cytoplasm residues of mature sperms and large vacuole-like structures were noticeable. In detorsion group testis cross-sections, dissociations in spermatocide nuclei, many vacuoles and residual particles resulting from organelle degeneration, local voids in cytoplasms of spermatogonia, dilatation in granulated endoplasmic reticulum, large lipid droplets, chromatid particles, along with mitochondrial crystalisis were determined. In the testis cross-sections of the group of T/D+50 mg/kg melatonin administration, sertoli and spermatogonia cells that showed membrane-like structures and cytoplasmic voids were observed. Testis cross-sections of rats that were administered with T/D+50 mg/kg melatonin showed small mitochondrions and vacuole-like structures placed on the edge. Testis cross-sections of rats that were administered with T/D+100 mg/kg melatonin resulted in views similar to those of controls in the microstructural level. As a result, the most effective dose of melatonin, which was used in different doses, for prevention of ischemia/reperfusion damage was found to be 100 mg/kg.