【原创论文】同侧和对侧大鼠睾丸缺血再灌注损伤的生化效应和褪黑激素对此的保护作用

睾丸扭转（TT），是一个多发于青春期男性的泌尿急症，如果不及时治疗，可致不孕不育。睾丸扭转所致缺血再灌注（I／R）损伤在睾丸损伤的病理生理过程中起一定作用。我们研究了褪黑激素在单侧睾丸扭转大鼠中同侧和对侧睾丸的氧化损伤效应：将21只青春期雄性Wistar大鼠分成三组，每组七只，处理如下：第1组（假手术组）：行左睾丸和双边睾丸假切除术；第2组（I/R组）：通过以下方式诱发缺血再灌注损伤（顺时针720°旋转左侧睾丸2小时，2小时后复位）：第3组（I／R＋MEL组）：大鼠经诱导缺血再灌注损伤和一次性褪黑激素注射（50mgkg-1，i．p）。处理后离体分离各组大鼠双侧睾丸，用于检测睾丸组织中抗氧化过氧化氢酶、超氧化物歧化酶和谷胱甘肽过氧化物酶的活性，丙二醛、蛋白质羰基和一氧化氮的组织水平。较对照组，褪黑激素注射组同侧睾丸的脂质过氧化水平，相关酶活性降低，具有显著性（P〈0．05），而在对侧的睾丸中相关酶活性变化无统计学意义（P〉0．05）。在对侧睾丸中，丙二醛水平改变具有明显统计学意义（P=0．009）。应用褪黑素能减轻老鼠同侧睾丸扭转所致缺血再灌注损伤的不利影响，而对于对侧睾丸，睾丸扭转影响不大。

The biochemical effects of ischemia-reperfusion injury in the ipsilateral and contralateral testes of rats and the protective role of melatonin

Testicular torsion （TT） is a serious urologic emergency that is observed in adolescent males and that can lead to infertility if left untreated. The ischemia-reperfusion （I/R） injury due to TT has been implicated in the pathogenesis of testicular damage. We investigated the effects of melatonin on oxidative damage in the ipsUateral and contralateral testes of rats induced by unilateral TT. A total of 21 prepubertal male Wistar albino rats were divided into three groups, each consisting of seven rats, In Group 1 （SHAM group）： a sham operation to the left testis and bilateral orchiectomy were performed. In Group 2 （I/R group）： I/R injury was created by rotating the left testis 720° in a clockwise direction for 2 h and detorsing the testis after 2 h. Group 3 （I/R ＋ MEL group）： rats were subjected to I/R injury and one-shot melatonin injection （50mgkg-1, intraperitoneal （i.p.））. The testes of the rats were excised bilaterally in all groups. The testicular tissue activities of antioxidant catalase （CAT）, superoxide dismutase （SOD） and glutathione peroxidase enzymes （GSH-Px）, and the tissue levels of malondialdehyde （MDA）, protein carbonyl （PC） and nitric oxide （NO） were determined. Administration of melatonin caused a significant decrease in lipid peroxidation and enzyme activities in the ipsilateral testis when compared with the control group （P 〈 0.05）. All of the changes in the enzyme activities of the contralateral testis were insignificant （P 〉 0.05）. MDA levels were significantly altered in the contralateral testis （P = 0.009）, Melatonin administration decreased the deleterious effects of I/R injury in the ipsilateral torted testes of the rats. The contralateral testes were slightly affected by unilateral TT.