单?多循环缺血预处理对缺血性肾损伤保护作用的研究

目的:探讨单、多循环两种缺血预处理方案对大鼠肾脏急性缺血再灌注损伤的保护作用.方法:加只雄性SD大鼠经切除右肾、分离出左肾动脉后随机均分为4组:①缺血再灌注(I/R)组:直接夹闭左肾动脉45 min恢复血供24 h;②单循环缺血预处理(SCP)组:夹闭左肾动脉10 min,开放血流10 min,仅一个循环,余同I/R组;③多循环缺血预处理(MCP)组:夹闭左肾动脉2 min,开放血流5 min,反复三个循环,余同I/R组;④假手术(Sham)组:暴露术野60 min后,直接缝合.24 h后取材行生化、病理检查及肾小管损伤评分.结果:sham组未见明显改变;I/R、SCP、MCP组血肌酐(Ser)水平及肾小管损伤评分明显高于sham组(P<0.01),MCP组低于L/R组,差异显著(P<0.01);SCP组低于I/R组,差异显著(P<0.05);MCP组低于SCP组,差异显著(P<0.01).结论:缺血预处理可从功能和组织学上减轻肾脏的急性缺血再灌注损伤,多循环预处理方案的保护作用在24 h内强于单循环的方案.

Protection of single-cycle and multi-cycles ischemic preconditioning on renal ischemia injury in rat models

Objective:To evaluate renal protection between schedules of single-cycle and multi-cycles ischemic precondition(IP) in rats. Methods:Forty male Sprague-Dawley rats were divided randomly into 4 groups after right kidney nephrectomy:Group 1 was for ischemia-reperfusion(I/R):the rats were treated with 45-minutes ischemia in left artery and then reperfused. Group 2 was for single-cycle ischemic precondition(SCP):the left artery of rat were blocked for 10 minutes,reperfused for 10 minutes,and then treated with 45 minutes ischemia prior to reperfusion. Group 3 was for multi-cycles ischemic precondition(MCP):the left artery of rats were blocked for 2 minutes,reperfused for 5 minutes,repeated for 3 cycles,and then treated with 45 minutes ischemia prior to reperfusion. Group 4 was sham-operated controls. Results:Serum creatinine(Scr)level in all groups increased markedly compared with sham group(P < 0. 01). Scr concentration,tubular ischemic injury index decreased significantly after IP in SCP and MCP groups compared with I/R group(P < 0.01). Furthermore,they were showed in a lower level in MCP group than that in SCP group(P < 0.01). Conclusion:Ischemic preconditioning can protect kidney from ischemia injury on histological and biochemical level. The renal ischemic preconditioning which induced by 2 minutes occlusion,5 minutes reperfusion and repeated for 3 cycles,followed by 45 minutes re-ischemia showed better protection than the single-cycle ischemic precondition.