低温卡托普利局部灌注对缺血再灌注后脊髓组织自由基和MPO的影响

目的观察低温卡托普利局部灌注对兔脊髓缺血再灌注后脊髓组织氧自由基、髓过氧化物酶（MPO）的影响。方法80只成年新西兰白兔随机分成4组，A组：假手术组（n=8）；B组：缺血对照组（n=24）；C组（n=24）：低温生理盐水局部灌注；D组（n=24）：低温生理盐水和卡托普利（4mg／kg）局部灌注。建立兔脊髓缺血损伤模型，经主动脉阻断段灌注保护液；采用化学比色法测定再灌注后8h、24h及72h脊髓组织MDA含量，黄嘌呤氧化酶法测定SOD活力，检测MPO活力。结果脊髓缺血再灌注后组织MDA含量升高，SOD活力下降，MPO活性增强；C组、D组与B组比较，MDA含量在各时相点均下降（P〈0．01），MPO活力明显降低（P〈0．01），脊髓组织MDA与动物后肢神经功能评分之间呈负相关。结论低温溶液可减少脊髓缺血再灌注后氧自由基的生成，减轻中性粒细胞浸润，联合卡托普利局部灌注，具有协同保护脊髓的作用。

The effects of regional infusion of hypothermic captopril on the free radicals and MPO in rabbit spinal cord tissue of ischemia-reperfusion

Objective To investigate the effects of regional infusion of hypothermic normal saline contained captopril on free radicals level and myeloperoxidase(MPO) activity in rabbits during spinal cord ischemia-reperfusion(I/R).Methods The 80 rabbits were randomly divided into four equal groups,group A(sham operated,no I-R injury,n=8),group B(control,only I/R,n=24),group C(I/R + intraaortic hypothermic normal saline,n=24),and group D(I/R + N.S plus 4mg/kg captopril,n=24).The model of spinal cord ischemia in the rabbit was induced with the aorta clamped.Hypothermic solution was infused into the isolated aortic segments.The content of spinal cord MDA and the activities of superoxide dismutase(SOD),MPO were measured at 8h,24h and 72 h after the reperfusion respectively.Results The level of spinal cord MDA increased,the activity of SOD decreased and the activity of MPO increased markedly after the reperfusion.Compared with group B,the MDA content decreased significantly at the three observation time points and the MPO activity decreased significantly in groups C and D(all P<0.01).There was a negative correlation between the neurologic function scores and the content of MDA.Conclusion Regional infusion of hypothermic normal saline solution can reduce the production of free radicals and inhibit the infiltration of neutrophil.Infusion of hypothermic solution combined with captopril may have a synergistic effect on spinal cord protection against ischemia.