缺血再灌注期经皮氧分压与MDA、MPO的变化

The changes of percutaneous oxygen pressure and MDA、MPO during ischemia-reperfusion in rat

目的 旨在为临床预计缺血再灌注损伤的程度提供参考。方法 采用夹闭大白鼠右髂总动脉制成右后肢缺血模型。实验分对照组 (Ⅰ组 )、缺血 2小时组 (Ⅱ组 )、缺血 2小时再灌注组(Ⅲ组 )、缺血 6小时组 (Ⅳ组 )、缺血 6小时再灌注组 (Ⅴ组 )。经皮氧监测动脉氧分压及局部相对血流量。对不同条件缺血的骨骼肌丙二醛 (MDA)的含量和髓过氧化物酶 (MPO)的活性进行测定。结果 与Ⅰ组比 ,4个实验组的MDA含量、MPO活性均显著增加 (P <0 0 5或P <0 0 1) ;与Ⅳ组比 ,Ⅱ组MDA含量、MPO活性低 (P <0 0 5或P <0 0 1) ,Ⅴ组MDA含量、MPO活性均有增加 (P <0 0 5 ) ;Ⅲ组比Ⅱ组MDA含量、MPO活性显著增加 (P <0 0 1) ;Ⅱ组与Ⅳ组比 ,氧分压和相对血流量的变化 :阻断中PO2 :0～ 1mmHg ,W :4 5～ 6mW ;阻断 2小时后再灌注的最初 2分钟PO2 :35mmHg ,W :349mW ,随后PO2 :18～ 2 0mmHg ,W :76～ 99mW ;阻断 6小时再灌注的PO2 :0mmHg ,W :1 0mW ,此时被阻断的肢体无痛觉反应。结论 随缺血时间的延长 ,组织中脂质过氧化产物增加 ,MPO活性增加 ,相对血流减少直至停止 ,反映缺血区域组织除强氧化剂次氯酸和超氧阴离子造成组织细胞损伤外 ,尚有不可忽视的血管中有大量白细胞积聚以至血管腔狭窄 ,甚至梗阻 。

Objective To evaluate the ischemia reperfusion injury.Methods An ischemia model was made by clamping the right common iliac artery of the rat.The animals were randomly divided into five groups:group Ⅰ,the control;group Ⅱ,ischemia for 2h;group Ⅲ,the reperfusion followed 2h ischemia;group Ⅳ,ischemia for 6h and group Ⅴ,reperfusion followed 6h ischemia.The oxygen partial pressure of the artery and local blood flow were monitored with percutanneous oxygen monitor.The malondialdehyde(MDA) content and myeloperoxidase(MPO) activity in skeletal muscles of the different ischemia conditions were measured.Results The MDA contents and MPO activities in all experiment groups were increased as compared with the control.Which were higher in group Ⅲ and Ⅳ than those in group Ⅱ.In group Ⅴ they were highest in all groups.The changes of oxygen partial pressure and relative blood flow were PO 2 0 1mmHg,W 4 5 6mW in blood blocking;in the first tow min followed reperfusion after 2 hour ischemia PO 2 35mmHg,W 349mW;then PO 218 20mmHg,W 76 99mW as the time prolonged.In group Ⅴ PO 2 was 0mmHg and W 1 0mW,at this time the hindlimb of blood blocking was no response to painful stimulation.Conclusion As the ischemia time prolonged the metabolic products of the lipid peroxidation and MPO activities increased,and the blood flow decreased and at last stopped.In the area reactive to ischemia strong oxidant hypochlorous and puperoxide resulted in the tissue injury,except for this much more leukocytes accumulated to result in the blood vessel stenosis,even obstructed.This produces a vicious circle and at the end the tissue cells death. [