目的探讨肢体后适应(limb remote ischemic postconditioning,LRIP)对急性高糖状态下大鼠脑缺血/再灌注损伤(ischemia-reperfusion injury,IRI)的保护作用,并初步阐明其机制。方法大鼠腹腔注射50%葡萄糖(6 m L·kg^-1)造成急性高血糖模型,采用线栓法复制大脑中动脉栓塞(middle cerebral artery occlusion,MCAO)模型,将大脑中动脉栓塞1.5 h后再灌注,且同时刻给LRIP组大鼠LRIP操作,将大鼠左后肢股动脉夹闭5 min/再通5 min(此为1个循环),连续3个循环。再灌注2 h后,检测各组大鼠行为学指标,摘眼球取血,测定血清中一氧化氮(nitric oxide,NO)浓度及超氧化物歧化酶(superoxide dismutase,SOD)活力;取全脑切片后氯化三苯基四氮唑(2,3,5-triphenyhetrazolium chloride,TTC)染色检测脑梗死面积。结果 LRIP能改善急性高血糖状态下脑IRI大鼠的行为学评分,升高血清中NO浓度及SOD活力,能减小脑梗死面积,以上指标LRIP组与IRI模型组比较差异均具有显著性(P〈0.05)。结论 LRIP对急性高血糖状态大鼠的脑IRI有保护作用,该作用部分通过升高血清SOD活力及NO水平实现。
Aim To study the protective effects of limb remote ischemic postconditioning ( LRIP ) on is-chemic stroke rats under hyperglycemia and explore the mechanisms. Methods Rats were given 50% glucose (6 mL·kg^-1 ) by intraperitoneal injection to get acute hyperglycemia model. Then middle cerebral artery oc-clusion ( MCAO) models were created. After blocking middle artery for 1. 5 h and reperfusion for 2 h, behav-ioral testing, infarct size of brain, NO concentration and SOD activity in the serum of those rats were detec- ted. Results LRIP could improve behavioral score, decrease the area of cerebral infarction, increase the concentration of NO and the SOD activity in serum of MCAO rats. Conclusion LRIP can relieve cerebral ischemia-reperfusion injury of MCAO rats under acute hyperglycemia.