左卡尼汀对肾缺血／再灌注损伤的保护作用

目的探讨左卡尼汀在肾缺血／再灌注损伤中的保护作用及其可能机制。方法建立大鼠肾急性缺血／再灌注模型，随机分为对照组（n=24）和左卡尼汀治疗组（n=24），组内再分为假手术组及再灌注1、6、12h组。检测大鼠血清尿素氮（BUN）、肌酐（Scr）水平和肾组织超氧化物歧化酶（SOD）活性、丙二醛（MDA）含量，并观察肾组织形态学变化。结果对照组的BUN、Scr再灌注6h后开始与假手术组出现统计学差异（P〈0．05和P〈0．01）；治疗组再灌注12h的BUN和再灌注6、12h的Scr也显著高于假手术组（P〈0．05，P〈0．05和P〈0．01），但低于同时点对照组（均P〈0．01），治疗组再灌注12h后SOD活力显著高于（P〈0．01），而MDA含量低于对照组（P〈0．01），且病理损伤较同期对照组明显减轻。结论左卡尼汀对肾缺血／再灌注损伤具有保护作用，其机制与增强SOD活性，降低肾脏过氧化程度从而抗氧自由基损伤有关。

Protection of L-carnitine on Renal Ischemic Reperfusion Injury in Rats

Objective To investigate possible mechanisms involoved in the protection of L-camitine against renal ischemic reperfusion injury in rat models. Methods Models of renal ischemia-reperfusion were established, and rats were divided into control and L-carnitine treated groups（ each with n = 24）. Within each group, rats were further divided into four subgroups, Sham, lh, 6h and 12h IR treatment. The levels of blood serum urea nitrogen（Bun） and creatinine（Scr）, the activities of superoxide dismutase（SOD） and the content of malonaldehyde（MDA） in nephridial tissue were measureed. Histopathological damages were monitored accordingly. Results In the control group, Scr and Bun levels of the IR6h group and those of the sham operation group showed difference of statistical significance（P 〈0.05 and P 〈0. 01 respectively）. Furthermore, in the L-carnitine treatment group, the levels of Bun 12h after reperfusion and those of Scr 6 hours after reperfusion were markedly higher than those of the sham group（ P 〈 0.05, P 〈 0.05, and P 〈 0.01 respectively）, though lower than those of the control group（ each P 〈 0. 01） at the same reperfusion time points. In L-earnitine treatment group, the activity of SOD was apparently higher and the content of MDA was lower than those in control group（ each P 〈 0. 01）. In addition, renal histological injuries were attenuated after L-carnitine administration. Conclusion L-carnitine protects kidney against isehemia after acute renal ischemia reperfusion injury through increasing SOD activity while inhibiting peroxidation in kidney, which may in turn be protective against renal damages by free radicals.