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

摘要

目的探讨安息香对永久性局灶性脑缺血（pMCAO）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（pMCAO）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pMCAO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 cere-bral ischemia (pMCAO)injury in rats.Methods sixty-five adult male Sprague-Dawley rats, weighing 230 ~270g were randomly divided into five groups:sham,pMCAO,pMCAO +vehicle,pMCAO +nimo-dipine,pMCAO +benzoinum groups.The rats were subjected to permanent focal cerebral ischemia.Neuro-logical 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-αwas detected by ELISA.Results Compared with pMCAO +vehicle group,benzoinum had a tendency to improve the neurological deficit,and could significantly decrease the water content of ische-mic brain tissue,brain edema rate and cerebral infarc-tion 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 pMCAO model rats. Conclusions Benzoinum can reduce the ischemic brain tissue water content,brain edema rate and cere-bral infarction rate,playing a role in cerebral protec-tion,which may be the biological basis for inducing re-suscitation.Its mechanism may be correlated with the up-regulation of VEGF and down-regulation of TNF-α.