大剂量甲基强的松龙对大鼠脑I／R损伤的保护作用及其机制探讨

目的观察大剂量甲基强的松龙（MP）对大鼠脑缺血／再灌注（I／R）损伤的保护作用，并探讨其机制。方法将48只SD大鼠随机分为A、B组各24只，均制备大鼠局灶性脑I／R模型，A、B组大鼠经尾静脉分别一次性注入MP10μl（90mg／kg）、生理盐水10μl。采用开阔法观察大鼠行为学变化，采用TUNEL法和免疫组织化学方法检测大鼠脑缺血区神经细胞的凋亡和热休克蛋白（HSP27）、细胞色素C-3（Cyt-3）、Caspase-9蛋白。结果与B组相比，MP组SD大鼠探索活动显著增加，脑缺血区凋亡细胞数明显减少，HSP27表达增加，Cyt．3、Caspase-9蛋白表达降低，P均〈0．01。结论大剂量甲基强的松龙对脑I／R损伤有保护作用，可能与其调控HSP27／DISC信号复合体的表达有关。

Protective effect and mechanism of high dose of methylprednisolone for focal cerebral ischamic/reperfusion damage in rats

Objective To observe the protective effect of high dose of methylprednisolone （MP） for focal cerebral isehamie/reperfusion damage in rats and explore its meehanism. Methods 48 SD rats were operated to establish focal cerebral I/R model and were divided into A,B groups randomly. 101.d MP（90 mg/kg） and NS were injected in to tail fo rats in A and B group respectively. Open field test was used to examine the behavioral changes ,TUNEL and Immunohistochemistry were used to observe opopsis of neuronal cells at the central and around the focal cerebral isehemia and to detect the expression of protein HSP27,Cyt-3 ,Caspase-9. Results The behavioral mark and the number of apoptosis neurons at the central and around the focal cerebral isehemia were much less in MP group than that in I/R group, and the expression of Hsp27 was increased,while Cyt-3 ,Caspase-9 was decreased （ all above P 〈 0.01 ）. Conclusions High dose of MP can significantly protect neurons against cerebral isehemia,moding the expression of HSP27/DISC may be one of the protective mechanism.