改良脊髓缺血后处理对兔缺血／再灌注损伤脊髓的保护作用

Neuroprotective Effects of Modified Ischemic Postconditioning on Spinal Cord Injury Induced by Ischemia Reperfusion in Rabbits

目的建立兔改良脊髓缺血后处理模型,研究缺血后处理对脊髓缺血/再灌注(I/R)损伤的作用。方法选取48只雄性日本大耳白兔随机分为4组,每组12只,假手术对照组(S组),缺血/再灌注损伤组(C组),经典缺血后处理组(PA组),改良缺血后处理组(PB组)。分别监测缺血前、再灌注时及再灌注10 min后的平均动脉压(MBP)、心率(HR)及动脉血气pH值、动脉血氧分压(PaO2)、动脉血二氧化碳分压(PaCO2)、乳酸(Lac值);采用Tarlov法分别于术后1,3,7,28 d对兔后肢运动功能进行评分;计数脊髓前角正常神经元数;羟胺法测定脊髓组织超氧化物歧化酶(SOD)含量,硫代巴比妥酸法测定丙二醛(MDA)含量。结果各组间各个时点MAP、HR、PaO2、PaCO2、Lac变化及术中体温差异均无统计学意义(P>0.05);缺血再灌注后1,3,7,28 d,PA、PB组Tarlov评分明显高于C组(P<0.05);PA、PB组正常神经元计数明显高于C组(P<0.05);C组脊髓MDA含量明显增加,SOD含量明显降低(P<0.05)。结论改良缺血后处理模型建立成功,两种缺血后处理法均可以显著减轻缺血再灌注后脊髓的神经功能损害。

Objective To establish file animal model of modified ischemia-reperfusion postcondltioning and study on the neumprotective el- feet of modified ischemic postconditioning on the Ischemia repeffusion （ I/R ） Injury. Methods Japanese white rabbits weighing between 2.0 to 2.5 kg were divided into 4 groups：the same surgical procedure without aortic occlusion（group S）,the control group （group C）,the standard posteonditioning group （group PA ） and the modified postconditioning group （group PB ）. Twelve rabbits were assigned randomly to each group. Mean blood pressure. （MBP）, heart rate （HR） and arterial blood gas including pH, PaO2, PaCO2 and lactic acid （Lac） were mea- sured. Functional evaluation with Tarlov scoring was done for the hind limbs 1,3,7 and 28 days postoperative. Morphologically normal motor neurons were counted, and measurements of MDA and SOD levels were performed. Results There was no significant difference among all the groups in MBP, HR, PaO2, PaCO2, Lac and intraoperative body temperature （P 〉 0.05 ）. Tarlov scores of PA and PB groups were significandy higher than those of C group 1,3,7, and 28 days ＇after spinal cord isehemia-repeffusion. The number of normal neurons in PA and PB groups were markedly higher than that of C group （ P 〈 0.05 ）. MDA markedly increased whereas SOD deereased in C group （ P 〈0.05 ）. Conclusion The model of modified ischenfia-repeffusion postconditioning was successfully established; Standard and modified postcondifioning methods exerted comparable neuroproteetive effects on the spinal cord injury caused by ischemia-repeffusion.