缺血后处理对糖尿病大鼠局灶性脑缺血再灌注损伤的影响

The effect of ischemic postconditioning on cerebral ischemia-reperfusion injury in diabetic rats

目的探讨缺血后处理（I-Post）对糖尿病大鼠局灶性脑缺血再灌注（I／R）损伤的影响。方法采用链脲佐菌（STZ）腹腔注射方式建立糖尿病大鼠模型，将制模成功的糖尿病大鼠随机分为4组，即空白对照组、假手术组、缺血再灌注组（I／R组）及缺血后处理组（I-Post组）。I／R组及I-Post组均通过线栓法制作大鼠大脑中动脉阻塞（MCAO）模型，并且I-Post组于大脑中动脉阻塞90min后，反复进行3次短暂再灌注干预（灌注15S后缺血15s）；假手术组手术步骤同上，但不插入线栓；空白对照组不给予任何处理。于缺血90min、再灌注6h后对所有大鼠进行神经功能评分（NDS）、脑梗死体积测定、观察脑组织神经细胞形态学变化及计数TUNEL阳性凋亡细胞数量。结果I-Post组与I／R组比较，其神经功能评分组间差异无统计学意义（P〉0．05），I-Post组大鼠脑梗死体积及凋亡细胞数量均较I／R组明显减小（P〈0．05）。结论I-Post处理能抑制糖尿病脑缺血大鼠神经细胞凋亡，减轻局灶性I／R损伤。

Objective To observe the effect of ischemic postconditioning on cerebral ischemia-reperfusion （I/R） injury in diabetic rats. Methods A rat model of diabetes was established using a single intraperitoneal injection of streptozotocin in 40 male Sprague-Dawley rats. Focal ischemia was induced by transient middle cerebral artery occlusion （MCAO） using a thread. The rats were randomly assigned to a control group, a sham-operated group, an I/R group and an I-Post group. The animals in the I/R group were subjected to MCAO for 90 min and then reperfusion. Those in the I-post group were subjected to MCAO and 3 cycles of transient ischemia-reperfusion （ 15 seconds ischemia then 15 seconds reperfusion） before persistent reperfusion. Neurological deficit scores, infarct volume, histological changes in the brain and the number of apoptotic ceils were measured 6 hours later. Results There was no significant difference in neurological deficit scores between the I/R group and the I-post group. The histological chan- ges and apoptotic ceils were significantly less in the I-post group compared with the I/R group. Conclusion Ischemic postconditioning can inhibit cell apoptosis and reduce cerebral I/R injury after focal cerebral ischemia-reperfusion in diabetic rats.