大剂量甲基强的松龙对缺血再灌注大鼠脑组织兴奋性氨基酸的影响

THE EFFECT OF LARGE DOSE METHYLPREDNISOLONE ON THE EXCITATORY AMINO ACIDS OF CEREBRAL TISSUES OF THE WISTAR RATS AFTER GLOBAL CEREBRAL ISCHEMIA AND REPERFUSION

目的 :探讨大剂量甲基强的松龙 (MP)对缺血再灌注大鼠脑保护作用的机制。方法 :采用大鼠全脑缺血再灌注模型 ,观察缺血前后应用大剂量 MP对脑组织兴奋性氨基酸含量的影响 ,同时做脑组织病理学观察。结果 :MP治疗组脑组织谷氨酸 (GL U)、天门冬氨酸 (ASP)、甘氨酸 (GLY)以及 γ-氨基丁酸(γ- GABA)的含量较对照组 (盐水组 )明显降低 (P<0 .0 1) ;而 MP治疗组四种氨基酸的水平与假手术组比较无明显差别 (P>0 .0 5)。脑组织超微结构观察发现 MP可抑制再灌注中脑组织巨噬细胞浸润。结论 :MP的脑保护作用与抑制兴奋性氨基酸的产生以及抑制巨噬细胞浸润有关。

Objective:To explore the mechanism of protective effect of large dose methylprednisolone(MP) on cerebral tissues of rats after ischemic reperfusion.Methods:Using wistar rat model of global cerebral ischemia and reperfusion, we observed the effect of MP before and after ischemia on the levels of cerebral excitatory amino acids and the histopathology of cerebral ischemic regions.Results:Compared with the control groups(saline treatment groups),the levels of four kinds of amino acids(GLU、ASP、GLY、γ GABA)were markedly decreased in the MP treatment groups(P<0.01);there were no differences about the levels of four kinds of amino acids between the MP treatment group and the sham operated group.In the meantime,we discovered that MP could inhibit cerebral macrophage infiltration from the cerebral histopathology.Conclusion:Large dose MP might have protective effects,the mechanism related to decreasing the levels of excitatory amino acids and inhibiting the macrophage infiltration in the rat brain tissues.