亚甲蓝对家兔肠缺血再灌注后肺损伤的保护作用

目的 观察肠缺血再灌注(I／R)后对肺脏的影响,探讨亚甲蓝(MB)的抗自由基(ROS)损伤作用及机制。方法 选择健康家兔32只,开腹分离肠系膜前动脉,随机分为正常对照组、缺血再灌注组(L／R)、低、高剂量亚甲蓝(MB)治疗组,后3组夹闭肠系膜前动脉建立肠缺血再灌注模型。低、高剂量MB组分别静脉给MB 5mg／kg和15mg／kg治疗。实验结束时取肺组织测酶学变化及MDA含量。 结果 与正常对照组比较I／R组肺组织中超氧阴离子(O2-)、丙二醛(MDA)含量显著增高(P<0.05),而低剂量与高剂量MB组二者均无显著改变(P>0.05)。各组肺组织的超氧化物岐化酶(SOD)和黄嘌呤氧化酶(XOD)I／R前后均无显著变化。肠L／R组再灌注后动脉血压(MAP)明显下降(P<0.05),而两个MB治疗组MAP始终无明显改变(P>0.05)。 结论 亚甲蓝可减轻家兔肠缺血再灌注后肺损伤,其机制可能与抑制氧自由基的生成有关。

The protective role of Methylene blue by reperfusion in the damage to the lung of rabbit

Objective To investigate the effect of pulmonary injury after intestinal ischemia reperfusion(I-R), and the mechanism of methylene blue(MB)to radical oxygen species(ROS) . Methods Thirty two healthy rabbits were randomly divided into four groups. After opening abdomen the fore mesenteric artery was divided carefully.The model of intestinal I-R was developed by occluding the mesenteric artery.Last three groups were occluded the fore mesenteric artery for 60 min.and reperfused for 120 min.The lower MB group was 5mg/kg iv.and the higher MB group was 15mg/kg iv.The level of MDA and the activities of SOD,XOD,CAT and O2 in lung tissue were determined at the end of the experiment. Results The level of O2 - and MDA in the lung tissue were markedly increased than the control group(P < 0.05) ,and the level of this two components were not significantly changed in the lower and higher dose groups ( P > 0.05 ) . The activities of SOD, XOD in lung tissue were not significantly changed in all groups. The mean artary pressure (MAP) was lower in the I-R group after intestinal I-R( P < 0.05) ,but MAP was not changed in two MB group ( P > 0.05) . Conclusions MB can reduce lung injury after intestinal I-R. The mechanisms might be associated with the inhibition of the generation of ROS.