龙蛭汤对大鼠脑缺血再灌注损伤后Bcl-2和Caspase-3蛋白表达的影响

Effects of Longzhi decoction on the expression of Bcl-2 and Caspase-3in cerebral ischemia/reperfusion injury rats

目的:研究龙蛭汤对大鼠脑缺血再灌注损伤后Bcl-2和Caspase-3蛋白表达的影响。方法:将48只大鼠随机分为4组,假手术组、模型组、尼莫地平组(0.01g/kg·d^(-1))及龙蛭汤组(13.60g/kg·d^(-1)),每组12只。用药6d后采用改良Longa线栓法建立右侧脑缺血再灌注损伤大鼠模型。术后24h对各组大鼠进行神经功能缺损评分,苏木精—伊红(HE)染色观察皮层缺血半暗带区脑组织病理形态变化,2,3,5-氯化三苯四氮唑(TTC)染色法测定脑梗死体积,免疫组织化学染色法检测Bcl-2和Caspase-3蛋白表达情况。结果:模型组神经功能缺损评分明显高于假手术组(P<0.01)。龙蛭汤组及尼莫地平组脑梗死区域体积百分比较模型组减小(P<0.05)。光学显微镜下可见,模型组脑组织缺血半暗带区皮层神经细胞出现明显缺血性坏死,龙蛭汤组、尼莫地平组半暗带区细胞形态明显改善。与模型组比较,龙蛭汤组和尼莫地平组脑组织中Bcl-2蛋白阳性细胞率均明显升高,Caspase-3蛋白阳性细胞率明显降低(P<0.01)。结论:龙蛭汤能减轻脑缺血再灌注大鼠神经元损伤,保护缺血脑组织,其机制可能与调控Bcl-2和Caspase-3的表达有关。

Objective: To investigate the effects of Longzhi decoction on the expression of Bcl-2 and Caspase-3 in cerebral ischemia/reperfusion injury rats. Methods: A total of 48 SD rats were divided into four groups (n=12):sham-operated group,model group,nimodipine group (0.01 g/kg·d^-1) and Longzhi decoction group (13.60 g/kg·d^-1).After 6 days of administration,the rat model of right cerebral ischemia/reperfusion injury was established by the modified Longa thread occlusion method.After 24 h of operation,the neurologic deficit score was evaluated.Hematoxylin-eosin (HE) staining was used to observe the pathological changes of ischemic penumbra in brain tissue. 2,3,5-triphenyltetrazolium chloride (TTC) staining was used to compare the infarct volume of each group.Immunohistochemistry was used to detect the expression of Bcl-2 and Caspase-3 in neurons of ischemic brain tissue. Results: The neurologic deficit score of the model group was significantly higher than that of the sham-operated group(P<0.01).The volume of cerebral infarction was reduced in nimodipine group and Longzhi decoction group compared with the model group(P<0.05).The neuronal damage was severe in the model group,and the cell morphology of penumbra in Longzhi decoction group and nimodipine group was significantly improved.The positive rate of Bc1-2 protein was remarkably higher in Longzhi decoction group and nimodipine group than that of the model group,while the Caspase-3 positive rate was lower (P<0.05). Conclusion: Longzhi decoction could improve the symptoms of neurological deficits in rats with ischemic brain injury,reduce the volume of cerebral infarction and the damage of neurons.The mechanism might be related to the regulation of Bcl-2 and Caspase-3 expressions.