δ阿片受体在大鼠脑缺血耐受中的作用

Effect of δ-opioid receptor on brain ischemic tolerance of rat ,

目的探讨δ阿片受体（DOR）在脑缺血耐受中的作用。方法采用二次线栓法建立局灶性SD大鼠脑缺血耐受的动物模型。24只SD雄性大鼠随机分为：假手术组；缺血组；假手术＋缺血组；预缺血＋缺血组。大鼠脑梗死后7d处死，运用荧光定量聚合酶链反应（PCR）方法测定DOR、Bax、Bel—2的mRNA表达水平。结果大鼠脑梗死后7d，假手术组、缺血组、假手术组＋缺血组及预缺血组＋缺血组Zea-Longa评分分别为（O．0±0．0）分、（2．6±0．5）分、（2．8±0．6）分和（1．5±0．6）分（F=51．936，P〈0．01），缺血组、假手术组＋缺血组两组与预缺血组＋缺血组间比较差异均有统计学意义（P〈0．01），而缺血组和假手术组＋缺血组间比较差异无统计学意义（P〉0．05）。DOR、Bcl-2mRNA的表达水平高于缺血组和假手术组＋缺血组，而BaxtuRNA的表达水平低于缺血组和假手术组＋缺血组。缺血组、假手术组＋缺血组两组和预缺血组＋缺血组比较差异均差异有统计学意义（P〈0．01）。结论缺血预处理可促进大鼠DOR、Bel-2的mRNA水平上调，BaxmRNA的表达水平降低，并能改善其神经功能缺损症状。

Objective To explore the effect of δ-opioid receptor （DOR）on ischemic tolerance of rat brain. Methods The focal isehemic tolerance models of Sprague Dawley rats were established using the twice suture method with the middle cerebral artery occlusion （MCAO）. A total of 24 male Sprague Dawley rats were randomly divided into sham group, isehemia （MCAO） group, sham ＋ ischemia （sham＋MCAO） group and ischemic preconditioning ＋ ischemia （IP＋MCAO） group （n= 6, each）. The neurological status was assessed using Zea-Longa neurological deficit scores at 7 days after cerebral infarction. The mRNA expressions of DOR, Bax, Bcl-2 in hippocampus in ischemic rat brain were detected by RT-PCR method. Results The Zea-Longa neurological deficit scores were 0.0±0.0, 2.6±0.5, 2.8±0.6 and 1.5±0.6 in Sham group, MCAO group, Sham＋MCAO group and IP-＋- MCAO group, respectively at 7 days after cerebral infarction. The scores had significant differences among MCAO group, Sham＋MCAO group and IP＋MCAO group （both P〈0.01）, but no difference between MCAO group and Shamff-MCAO group（P〈0.05）. The mRNA expressions of DOR and Bcl-2 were higher and Bax mRNA expression was lower in IP＋MCAO group than in MCAO and Sham＋MCAO groups （all P〈0.01）. Conclusions Ischemic preconditioning may increase the mRNA expressions of DOR and Bcl-2, reduce Bax mRNA expression, and improve the neurological status in rats.