缺血预处理对肢体缺血／再灌注肾损伤保护作用的机制初探

目的：探讨缺血预处理对肢体缺血／再灌注时肾损伤的保护作用。方法：复制家兔肢体缺血／再灌注（I／R）损伤模型,观察肢体缺血4h再灌注4h后以及应用缺血预处理干预对肾损伤的影响。分别从右颈外静脉、肾动脉和肾静脉取血,代表外周血以及入、出肾血,观察外周血超氧化物歧化酶（SOD）、丙二醛（MDA）及尿素氮（BUN）;同时测定入肾血和出肾血NO、SOD、MDA和肾组织SOD、MDA、诱导型一氧化氮合酶（iNOS）以及缺血预处理对上述指标的影响。结果：与对照组比较,缺血再灌组松夹后4h外周血、入、出肾血及肾组织SOD活性明显降低,MDA含量增高（P〈0．01）;外周血BUN以及入、出肾血NO和肾组织iNOS含量升高（P〈0．01）;在缺血前给予缺血预处理组．SOD活性升高,而MDA、BUN、NO、iNOS含量降低（P〈0．01）。相关分析显示MDA与SOD间存在明显负相关（P〈0．01）．而MDA与NO、BUN间呈显著正相关（P〈0．01）。结论：肢体缺血／再灌注时伴有肾脏氧自由基代谢紊乱,缺血预处理可以增强肾组织的抗氧化能力,对肢体缺血再灌注肾损伤具有保护作用。

The protective effects of ischemic preconditioning on the kidney injury following with ischemia/reperfusion of limbs and the possible mechanisms

Aim： To explore the protective effects of iscliemic preconditioning on the kidney injury following with ischemia/reperfusion（I/R） of limbs. Methods： The models of I/R injury of limbs were constructed in rabbits. The blood from fight external jugular vein, renal artery and renal vein represent the peripheral blood, into and out-flowing kidney blood（IKB, OKB） respectively. Superoxide dismutase（SOD）, malondialdehyde（MDA）, blood uria nitrogen（BUN） in peripheral blood and SOD, MDA, nitric oxide（NO） in IKB and OKB were measured, as well as SOD, MDA, induced nitric oxide synthase（iNOS） in kidney were detected in different groups. The effects of ischemic preconditioning（IPC） on the kidney injury were observed. Results： Compared with control group, the activity of SOD in peripheral blood, IKB, OKB and kidney decreased, and the content of MDA increased after 4 h ischemia followed by 4 h reperfusion. The content of BUN in peripheral blood, NO in IKB, OKB and iNOS in kidney increased remarkably as well. SOD increased and MDA, NO, BUN, iNOS decreased significantly by ischemie preconditioning（IPC） before ischemia/reperfnsion. The correlation analysis indicated that MDA was negatively correlated with SOD and positively correlated with NO, BUN. Conclusion： Oxygen free radicals metabolic confusion of kidney occurred in the course of I/R of limbs, could strengthen the resistance of peroxidation in kidney and had protective effects on the kidney injury following with ischemia/reperfusion（ I/ R） of limbs