安息香对永久性大脑中动脉栓塞大鼠模型的保护作用及其机制研究

Study of protective effects and mechanism of benzoinum against permanent focal cerebral ischemia injury in rats

目的探讨安息香对永久性局灶性脑缺血(p MCAO)大鼠模型的脑保护作用及其机制。方法健康成年♂SD大鼠65只,随机分为5组:假手术组、模型对照组、溶剂组、尼莫地平组、安息香组。通过线栓法建立永久性局灶性脑缺血(p MCAO)大鼠模型,参照Longa评分法对大鼠神经功能损伤进行评分,计算缺血侧脑组织含水量及脑水肿率,TTC染色法测定脑梗死率,ELISA法检测血清中VEGF和TNF-α含量。结果与溶剂组相比,安息香有降低模型大鼠神经功能评分的趋势,但差异无显著性;安息香能明显地降低模型大鼠缺血侧脑组织含水量、脑水肿率及脑梗死率(P<0.01);升高模型大鼠血清中VEGF的含量(P<0.01),降低TNF-α的含量(P<0.05)。结论安息香降低p MCAO大鼠脑含水量和脑水肿率,减小脑梗死范围发挥脑保护作用,可能是其呈现开窍醒神效应的生物学基础,机制可能与上调VEGF含量和下调TNF-α的含量有关。

Aim To discuss protective effects and the mechanism of benzoinum against permanent focal cerebral ischemia（ p MCAO） injury in rats. Methods sixty-five adult male Sprague-Dawley rats, weighing230 - 270 g were randomly divided into five groups：sham,p MCAO,p MCAO ＋ vehicle,p MCAO ＋ nimodipine,p MCAO ＋ benzoinum groups. The rats were subjected to permanent focal cerebral ischemia. Neurological deficit testing was performed with Longa ＇s Scale,and ischemic brain tissue water content as well as brain edema rate was calculated. Cerebral infarction rate was tested by TTC-staining. Serum content of VEGF and TNF-α was detected by ELISA. Results Compared with p MCAO ＋ vehicle group,benzoinum had a tendency to improve the neurological deficit,and could significantly decrease the water content of ischemic brain tissue,brain edema rate and cerebral infarction rate（ P〈0.01）. Benzoinum also could increase serum levels of VEGF（ P〈0.01） and decrease serum levels of TNF-α（ P〈0.05） in p MCAO model rats.Conclusions Benzoinum can reduce the ischemic brain tissue water content,brain edema rate and cerebral infarction rate,playing a role in cerebral protection,which may be the biological basis for inducing resuscitation. Its mechanism may be correlated with the up-regulation of VEGF and down-regulation of TNF-α.