艾灸预处理对大脑皮质caspase蛋白表达的影响

［摘要］目的　观察艾灸预处理对大脑皮质caspase-3蛋白表达的影响，阐明艾灸预处理减轻脑缺血再灌注损伤的作用机制。方法　雄性SD大鼠21只，分为假手术组(6只)、模型组(8只)和艾灸预处理组(7只)。采用线栓法闭塞大脑中动脉2h后进行再灌注，制备局灶性脑缺血再灌注损伤大鼠模型。采用TTC染色检查脑组织梗死情况；HE染色检查大脑皮质的形态结构；电子显微镜观察大脑皮质神经细胞的超微结构；荧光免疫组织化学技术检测大脑皮质caspase-3蛋白的表达。结果　艾灸预处理组大鼠患侧脑组织梗死百分数［(24.9±4.7)%］低于模型组［(45.8±4.6)%］；大脑皮质神经细胞形态结构变化较模型组轻；caspase-3阳性细胞数(39.17±7.28)低于模型组(58.17±16.53)。结论　艾灸预处理具有减轻大鼠脑缺血再灌注损伤的作用，降低大脑皮质caspase-3蛋白的表达可能是其作用机理之一。

［关键词］艾灸预处理；脑缺血再灌注损伤；超微结构；caspase-3

Effects of moxibustion pretreatment on the expression of caspase-3 protein in cortex of rats with cerebral ischemia-reperfusion injury

［Abstract］Objective To observe the effect of moxibustion pretreatment on the caspase-3 expression in cortex of rats with cerebral ischemia-reperfusion injury.Methods Twentyone male SD rats were randomly divided into three groups，sham group(n=6)，model group(n=8)and moxibustion group(n=7).Focal cerebral ischemia-reperfusion injury rat model was induced for 2h by middle cerebral artery occlusion(MCAO)followed by reperfusion.Brain infarct was examined by TTC staining，brain morphology was by HE staining，the ultrastructure of cell was observed with electron microscope，and the expression of caspase-3 protein in cor-tex was examined by immunofluorescent histochemistry.Results Percentage of infarct volume was significantly smaller［(24.9±4.7)%］in moxibustion pretreatment group than that in model group［(45.8 ±4.6)%］，brain cells experienced less morphological and structural changes in moxibustion pretreatment group than those in model group，and caspase-3 positive cells(39.17±7.28)were less in moxibustion pretreatment group than those in model group(58.17±16.53).Conclusion Moxibustion pretreatment could attenuate cerebral ischemia-reperfusion injury，which might be through decreasing caspase-3 expression.(www.xing528.com)

［Key words］cerebral ischemia-reperfusion injury； moxibustion pretreatment； infarct volume； ultrastructure； caspase-3

脑血管疾病是危害人类生命和健康的主要疾病之一，缺血性脑血管病约占全部脑血管病的80%左右［1］，其中大多由大脑中动脉阻塞引起。目前国际上通常采用溶栓疗法［2］以恢复脑组织血流供应，但再灌注本身有时也可加重组织的功能障碍和结构损伤，即引起脑缺血再灌注损伤。因此，脑缺血再灌注损伤是缺血性脑血管病的重要病理过程。有研究认为，细胞凋亡参与了脑缺血再灌注损伤的发病过程［3］，而caspase-3在细胞凋亡中起重要调控作用，其激活后可引起细胞形态结构改变和DNA片段化［4］。研究发现，脑缺血再灌注后caspase-3的表达明显增加［5］。本课题前期预实验发现，艾灸预处理“大椎”穴能缩小大脑中动脉缺血再灌注损伤模型大鼠的脑梗死面积，减轻脑缺血再灌注损伤。然而艾灸预处理是否通过调节大脑皮质caspase-3蛋白的表达而达到减轻大鼠脑缺血再灌注损伤的作用机制还不十分清楚。为此，本研究采用雄性SD大鼠，建立大脑中动脉栓塞(middle cerebral artery occlusion，MCAO)缺血再灌注损伤模型，采用荧光免疫组织化学技术观察艾灸预处理对大鼠大脑皮质caspase-3蛋白表达的影响，以阐明艾灸预处理减轻脑缺血再灌注损伤的机制，旨在为艾灸治未病提供理论和实验依据。