远端肢体缺血后处理对大鼠脊髓缺血／再灌注损伤的保护作用

Neuroprotective effects of limb remote ischemic postconditioning on spinal cord injury caused by ischemia/reperfusion in rats

[目的]建立大鼠远端肢体缺血后处理模型,研究远端肢体缺血后处理对脊髓缺血/再灌注(I/R)损伤的保护作用。[方法]选取48只雄性Sprague–Dawley大鼠随机分为4组,每组12只,假手术对照组(Sham组),缺血/再灌注损伤组(Control组),经典缺血后处理组(IPO组),远端肢体缺血后处理组(RIPO组)。分别监测缺血前、再灌注时及再灌注15 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1,2,3,7 d对大鼠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MBP、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1,2,3,7 d,IPO、RIPO组Tarlov评分明显高于Control组(P<0.05);IPO、RIPO组正常神经元计数明显高于Control组(P<0.05);Control组脊髓MDA含量明显增加,SOD含量明显降低(P<0.05)。[结论]远端肢体缺血后处理模型合理,远端肢体缺血后处理对脊髓缺血/再灌注(I/R)损伤有一定的保护作用。

[ Objective] To establish an animal model of limb remote ischemic postconditioning and study its neuroprotective effect on ischemia/reperfusion （I/R） injury. [ Method ] Sprague-Dawley rats, weighing 200 - 250 g, were divided into the follow-ing 4 groups：the identical surgical procedure without aortic and arteria axillaris occlusion group （Sham group）, the control group （Control group）,the classic ischemie postconditioning group（ IP group）, and the limb remote ischemic postconditioning group （ RIP group）. Twelve rats were assigned randomly to each group. Mean blood pressure （MBP） and heart rate（HR） were meas-ured, and arterial blood gas analysis was performed, including pH, PaO2, PaCO2, and lactic acid （Lac）. Functional evaluation with Tadov scoring was performed for the hind limbs 1,2,3, and 7 days postoperatively. Morphologically normal motor neurons were counted, and malondialdehyde （MDA） and superoxide dismutase （SOD） levels were measured. [ Result ] There was no significant difference among all the groups in MBP, HR, PaO2 , PaCO2 , Lac, and intra-operative body temperature （ P 〉 0.05 ）. Tarlov scores of the IP and RIP groups were significantly higher than those of the Control group 1,2,3, and 7 days after spinal cord ischemia/reperfusion. The number of normal neurons in the IP and RIP groups was markedly higher than that in the Control group （P 〈 0.05）. MDA levels markedly increased whereas SOD levels decreased in the Control group （P 〈 0.05 ）. [ Conclu-sion]The model of limb remote ischemic postconditioning was successfully established. Remote ischemic postconditioning has neuroprotective effects on spinal cord injury caused by ischemia/reperfusion.