甲基强的松龙与钙蛋白酶抑制剂对大鼠缺血再灌注损伤脊髓保护作用比较

Comparison of methylprednisolone and calpain inhibitor for the protection of ischemia-reperfusion spinal cord injury in rats

[目的]观察脊髓缺血再灌注损伤后应用甲基强的松龙和钙蛋白酶抑制剂E-64-D,脊髓组织钙蛋白酶表达和活性的变化及对动物后肢功能的影响。[方法]纯种雄性成年SD大鼠,夹闭右肾动脉分支下腹主动脉30 min,造成动物脊髓缺血再灌注损伤(B组),再灌注后静脉应用钙蛋白酶特异性抑制剂E-64-D(C组)或甲基强的松龙(D组),观察3、24、72 h和7 d后脊髓损伤节段的钙蛋白酶的表达,及钙蛋白酶特异性底物68-KD NFP的降解和动物后肢功能情况。[结果]脊髓再灌注损伤后3 h,开始出现的钙蛋白酶阳性细胞,于再灌注后72 h最明显。68-KDNFP的降解产物也在再灌注损伤后3 h出现,并在72 h后达到高峰。应用E-64-D和甲基强的松龙后,钙蛋白酶的表达和68-KD NFP的降解得到抑制,而且E-64-D的抑制作用明显强于甲基强的松龙,结果具有显著性差异(P<0.01)。[结论]脊髓缺血再灌注损伤后两种治疗方法均可不同程度地保护脊髓组织和动物后肢的运动功能。

[ Objective ] To compare the protection effectiveness of methylprednisolone or ealpain inhibitor（ E - 64 - D） on the protection of ischemia-reperlusion spinal cord injury in rats. [ Method] The abdomial aorta of male Sprague-Dawley （SD） rats were elipped lor 30 minutes （ B group） and treated with intravenous of E-64-D（ C group） or methylprednisolone （ D group）. Aiier reperfusiun for 3,24,72 and 7 days, the expression of ealpain- I in the attached segments of the spinal cord was indicated with im- munohistoehemistry stain. Western Blot analysis of 68-KD NFP was used to indicate the activity of ealpain. The motor function score of＂ hind-limb at 72 hours of reperlusion was observed. [ Result] The immunohistochemistry stain of ealpain- I was found and 68-K1） NFP was degradated in the spinal cord sections at 3 hours of reperfusion and peaked at 72 hours. In the E-64-D and meth- ylprednisolone treated groups,the expression of calpain- Ⅰ and degradation of E-64-D was inhibited. Statistically analysis showed significant differenees between the isehemia-reperfusion group and the treated groups. Furthermore,the inhibition effect to the eal- pain- 1 was higher in group C than that in group D（ P 〈 0.01 ）. At 72 hours of repertusiun, the motor tunetion of hind-limp in both treated groups have a highter function score than in the ischemia-reperfusion group. [ Conclusion] Post-injury cntravenous methyl- prednisohme in rat spinal cord after isehemia-reperfusion can inhibite early increased ealpain- Ⅰ expression and activity. Bul the inhibition effeetiveness of E-64-D is stronger than methylprednisolone. We advaneed a hypothesis eombination trearment with eal- pain-speeifie inhibitor E-64-D and methylprednisolone,it can provide more effectiveness in the second spinal cord injury.