咪唑安定对脑缺血/再灌注大鼠顶叶碱性成纤维细胞生长因子表达的调节作用

目的观察咪唑安定对大鼠脑局灶性缺血/再灌注脑组织碱性成纤维细胞生长因子(bFGF)表达水平的影响,从而探讨咪唑安定对脑缺血的作用机制。方法采用可逆性大脑中动脉缺血再灌注模型,再灌注同时腹腔注射咪唑安定50 mg.kg-1,再灌注6 h、24 h后断头取脑。观察大鼠梗死体积的变化,用免疫组织化学方法及W estern-b lot方法观察缺血区bFGF的表达,并进行显微图像分析。结果顶叶缺血区周围组织可见bFGF阳性表达产物,正常大鼠未见bFGF阳性表达产物,咪唑安定组与生理盐水组(NS)相比梗死灶体积缩小,免疫组化结果显示咪唑安定组脑缺血灶周围bFGF的平均光密度值高于NS组(P<0.05),阳性细胞主要以神经元、神经胶质细胞为主。W estern-b lot结果表明咪唑安定组整合光密度值与β-actin比值显著高于NS组(P<0.05)。结论咪唑安定对脑缺血性损伤的恢复作用可能与提高缺血周围区bFGF的表达有关。

Effect of Midazolam on the Expression of bFGF in Parietal lobe of Cerebral Ischemia Rats

Objective To investigate the effect of midazolam on the expression of basic fibroblast growth factor(bFGF) following focal cerebral ischemia/reperfusion in a rat model of reversible middle cerebral artery occlusion(MCAO).Methods Rats were scheduled to undergo 2 h MCAO by intraluminal suture.Midazolam(50 mg·kg~(-1)) was given intraperitoneally at the beginning of reperfusion.The animals were decapitated 6 h or 24 h after reperfusion.Infarct volume was measured,and the expression of bFGF was measured by immunohistochemistry and Western-blot techniques and analyzed by micro-image analysis system.Results The positive product of bFGF was found in surrounding area of the ischemic region of the parietal lobe,but not found in normal rat.Midazolam reduced significantly infarct volume,and increased the mean optical density value of bFGF positive product in the surrounding area of the cerebral ischemic foci in parietal lobe(P<0.05) by immunohistochemistry analysis compared with saline group,and the positive cells were primarily neurons and gliocytes.Western-blot showed that the ratio of integrated density value(IDV) of bFGF positive product to IDV of β-actin in midazolam group was higher than that in saline group(P<0.05).Conclusion The neuroprotective effects of midazolam may be related to its up-regulation of bFGF in the surrounding area of ischemia.