异氟醚预处理对大脑中动脉闭塞大鼠胶质细胞中Toll样受体4表达的影响

Eeffects of isoflurane preconditioning on the expression of toll-like receptor 4 in glial cells in rats with middle cerebral artery occlusion

目的观察异氟醚预处理对大脑中动脉闭塞(MCAO)模型大鼠胶质细胞中Toll样受体4(TLR4)表达的影响。方法雄性SD大鼠48只,体重250～300g,随机均分为三组:假手术组(S组)、MCAO模型组(M组)、异氟醚预处理组(I组)。2h后进行再灌注,再灌注24h后进行神经功能评分,检测脑梗死容积,分别测定每个视野内TLR4与星形胶质细胞标记物(GFAP)共存阳性细胞数和TLR4与小胶质细胞标记物(OX42)共存阳性细胞数。结果与M组相比,I组神经功能评分降低,脑梗死容积减少,GFAP和OX42阳性细胞数均减少(P<0.05)。结论异氟醚预处理具有脑保护作用,抑制TLR4的表达及胶质细胞的活化可能是其作用机制之一。

Objective To observe the effects of isoflurane preconditioning on the expression of toll-like receptor 4 （TLR4） in glial cell in rats with middle cerebral artery occlusion （MCAO）. Methods Forty-eight male SD rats weighing 250-300 g were randomly divided into three groups： sham operated group （group S）, MCAO model group （group M） and isoflurane preconditioning group （group I）. Scores of neurologic impairment, cerebral infarct volume and positive cell numbers of GFAP and 0）（42 were measured after ischemia for 2 hours and reperfusion for 24 hours. Results Compared with group M, the neurologic impairment score, the cerebral infarct volume, and the positive cell numbers of GFAP and 0X42 decreased in group 1 24 h after reperfusion （P〈0.05）. Conclusion Isoflurane preconditioning protects the brain, which may be mediated by the downregulation of TLR4 and the inhibition of the activation of glial cell.