[Effects of melatonin on oxidative stress and apoptosis-related gene signaling pathways following testicular torsion in rats].

Objective: To investigate the effects of melatonin on the oxidative stress and signaling pathways of apoptosis-related genes following testicular torsion/detorsion in male rats.

Methods: Twenty-four healthy male Sprague-Dawley rats were randomly divided into a control, a torsion and a melatonin group of equal number. The torsion model was made in the animals of the latter two groups by 720° torsion of the left testis for 2 hours. The rats of the torsion and melatonin groups received intraperitoneal injection of isotonic saline and melatonin (17 mg/kg) respectively at 15 minutes prior to detorsion. At 24 hours after modeling, testis tissues were collected from the rats for detection of the apoptosis of the germ cells by flow cytometry (FCM), analysis of the expressions of Fas, Fas ligand (FasL) and Bax mRNA by quantitative real-time PCR (qRT-PCR), measurement of the cytochrome C content released from the mitochondrion by Western blot, and determination of the total antioxidant capacity (T-AOC) and the levels of myeloperoxidase (MPO) and malodialdehyde (MDA) by spectrophotometry.

Results: Compared with the torsion group, the rats treated with melatonin showed significantly increased normal testicular cells (［77.81 ± 6.52］% vs ［88.61 ± 7.93］%, P < 0.05), decreased early apoptotic germ cells (［16.74 ± 3.16］% vs ［6.97 ± 1.65］%, P < 0.05), down-regulated expressions of Fas (［4.52 ± 0.29］ vs ［2.66 ± 0.37］, P < 0.01), FasL (［2.82 ± 0.30］ vs ［1.73 ± 0.18］, P < 0.01) and Bax mRNA (［2.39 ± 0.18］ vs ［1.50 ± 0.14］, P < 0.01), reduced levels of cytochrome C (［1.40 ± 0.38］ vs ［0.67 ± 0.30］, P < 0.01), MPO (［0.52 ± 0.15］ vs ［0.19 ± 0.10］ U/g prot, P < 0.01) and MDA ［6.37 ± 1.73］ vs ［3.98 ± 0.90］ nmol/mg prot, P < 0.01) and elevated T-AOC (［0.76 ± 0.25］ vs ［1.55 ± 0.32］ U/mg prot, P < 0.01).

Conclusions: Melatonin has a significant protective effect on spermatogenesis after testicular torsion by regulating the expressions of apoptosis-related genes and increasing T-AOC in the testis tissue.