【作者】 孙晓四；

【导师】 谭敦勇； 颜亮；

【作者基本信息】 暨南大学 ， 病理学与病理生理学， 2004， 硕士

【摘要】 目的：观察肾脏缺血预处理(ischemic preconditioning，IPC)对缺血／再灌注(ischemia／reperfusion，I／R)损伤的第二窗保护(second window of protection，SWOP)作用，探讨诱导型一氧化氮合酶(inducible nitric oxide synthase，iNOS)的作用机制。 方法：对大鼠肾动脉进行四个循环的5分钟夹闭／5分钟放开造成IPC，24小时后进行45分钟夹闭／24小时放开造成I／R损伤模型。检测IPC后I／R的大鼠血清肌酐、尿素氮改变观察肾功能变化情况，Paller法评分观察肾组织损伤情况；酶法检测IPC后血清一氧化氮水平及肾组织iNOS活性的变化；以逆转录-聚合酶链反应法(reverse transcriptase-polymerase chain reaction，RT-PCR)测定肾组织iNOS的mRNA表达以及用蛋白印迹法(Western blot)测定肾组织iNOS的蛋白表达水平。 结果：1．IPC能显著降低I／R损伤时血清肌酐、尿素氮水平，减轻肾组织损伤的程度；2．诱导型一氧化氮合酶抑制剂氨基胍能阻断IPC的SWOP作用；3．IPC后24小时肾组织iNOS活性和血清一氧化氮(nitric oxide，NO)水平升高；4．RT-PCR显示IPC后24小时IPC组肾组织iNOS的mRNA表达明显较假手术组高；5．Western blot显示，IPC组的iNOS蛋白表达明显高于假手术组的水平；6．氨基胍抑制了IPC引起的iNOS mRNA和蛋白的升高，在假手术组没有观察到mRNA和iNOS蛋白的变化。 结论：1．IPC能显著降低I／R损伤时血清肌酐、尿素氮水平，减轻肾组织损伤程度，发挥SWOP作用；2．氨基胍能阻断IPC的SWOP作用；3．IPC引起肾组织iNOS的mRNA和蛋白水平升高，iNOS／NO系统激活，NO生成量增加，对受到FR影响的肾组织具有重要的保护作用。更多还原

【Abstract】 OBJECTIVE: To investigate the role of inducible nitric oxide synthase/nitric oxide (iNOS-NO) in the second window of protection (SWOP) of renal ischemic reconditioning(IPC) against ischemia/reperfusion (I/R) injury in rats. METHODS: Rats were preconditioned with 4 cycles of 5-min renal artery occlusion/5-min reperfusion and 24 h later underwent 45-min renal artery occlusion followed by 24 h reperfusion. Blood urea nitrogen and creatinine were examined to demonstrate the renal function and Paller’s count to assess the changes in renal pathological morphology. Serum nitric oxide was assayed by Greiss reaction. Renal iNOS activity, mRNA and protein were assayed by enzymatic method, reverse transcriptase-polymerase chain reaction and western blot, respectively. RESULTS: 1. IPC significantly decreased the levels of blood urea nitrogen, creatinine and Paller’s count compared with those in I/R group. 2. Aminoguanidin, an inducible nitric oxide synthase inhibitor, abolished the second window of protection of IPC against I/R injury. 3. Renal iNOS activity and serum nitric oxide level were significantly increased 24 h after IPC. 4. RT-PCR showed that iNOS mRNA expression in IPC group was higher than that in Sham group. 5. Western blot demonstrated that iNOS protein increased moderately in IPC group compared with that in Sham group. 6. Aminoguanidin suppressed iNOS mRNA and protein expression caused by IPC. Sham operation didn’t influence iNOS mRNA and proteinexpression.CONCLUSIONS: 1. IPC alleviated I/R injury in rat kidneys. 2. The second window of protection was greatly attenuated by the co-administration of aminoguanidin, an iNOS inhibitor. 3. IPC moderately upregulated the expression of iNOS mRNA and protein. iNOS-NO system was activated by IPC and iNOS-NO pathway may be of great importance in the mechanism of SWOP.更多还原