左旋卡尼汀对大鼠睾丸缺血再灌注损伤的防护作用

目的 探讨左旋卡尼汀对大鼠睾丸缺血再灌注后生精功能的影响.方法 30只成年健康雄性SD大鼠随机分为对照组、扭转组和治疗组,每组10只,建立右侧睾丸扭转复位动物模型(720°,2 h).扭转组和治疗组于复位前30 min分别腹腔注射生理盐水和左旋卡尼汀(500 mg/kg).复位后4 +h,每组各处死5只取扭转侧睾丸,分别检测组织丙二醛(MDA)含量和超氧化物歧化酶(SOD)、过氧化氖酶(CAT)、谷胱甘肽过氧化物酶(GPx)活性以及热休克蛋白70(HSP70)的含量.复位后24 h,取每组剩余大鼠的扭转侧睾丸,检测生精细胞凋亡指数(AI)和组织病理学参数.结果 治疗组平均生精细胞AJ和MDA水平明显低于扭转组AJ(6.87 4±2.47)比(17.13 4±3.56),MDA(160±15)比(199 ±15)nmoL/g],抗氧化酶活性和HSP70含量显著高于扭转组SOD(1638±153)比(1078 4±158)U/g,CAT(317±28)比(188 ±33)U/g,GPx(667 ±94)比(311±65)U/g,HSP70(0.87±0.13)比(0.25 ±0.04)],组织病理学损害较扭转组轻,差异均有统计学意义(均P<0.05).结论 左旋卡尼汀对睾丸缺血再灌注后的生精能力具有保护作用,其机制可能是通过诱导热休克蛋白表达而实现.

Protective effects of L-carnitine upon testicular ischemia-reperfusion damage in rats

Objective To investigate the protective effects of L-carnitine upon testicular ischemiareperfusion injury in rats. Methods Sprague-Dawley rats were divided into 3 groups (n = 10). In those animals undergoing unilateral testicular torsion, right testes were rotated 720° for 2 h. Sham operated group served as a control group. Torsion group underwent 2 h torsion and saline was injected intraperitoneally at 30min pre-detorsion. Treatment group underwent similar torsion but L-carnitine (500 mg/kg) was infused intraoperatively. The right testes of 5 animals in each group were excised after 4 h reperfusion for measuring the levels of malondialdehyde (MDA) and heat shock protein 70 (HSPT0), evaluation of activities of antioxidant enzyme including superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). Histopathoiogical changes and germ cell apoptosis indices (AI) were determined at 24 h postdetorsion in right testes of the remaining 5 animals in each group. Results The mean number of apoptotic nuclei per tubule cross section and the malondialdchyde level were significantly lower in treatment group as compared with torsion groupAI (6.87 ± 2.47) vs (17.13 ± 3.56), MDA (160 ± 15) vs (199 ± 15) nmol/g].Activities of antioxidant enzyme and the level of HSP70 were significantly higher in treatment group than those in torsion groupSOD(1638 ± 153) vs (1 078 ± 158) U/g, CAT(317 ± 28) vs (188 ± 33) U/g, GPx (667±94) vs (311±65) U/g,HSP70(0. 87 s0. 13) vs (0.25 ±0.04)]. The pathological damage of testes in the treatment group was lighter than that in the torsion group (all P < 0.05). Conclusions The administration of L-carnitine exerts a beneficial effect upon testicular ischemia-reperfusion injury. This effect may be achieved through an induced expression of HSP70.