缺血预适应对大鼠肢体缺血/再灌注后肺损伤的影响

EFFECT OF ISCHEMIC PRECONDITIONING ON LUNG INJURY INDUCED BY ISCHEMIA/REPERFUSION IN THE HIND LIMBS OF RATS

目的:观察肢体缺血预适应对大鼠肢体缺血/再灌注(I/R)后肺损伤的影响并探讨其机制。方法:将雄性Wistar大鼠随机分为4组(n=8):对照组(C),肢体缺血/再灌注组(LI/R),缺血预适应组(IPC)和L-NAME组。各组大鼠均于肢体缺血4h再灌注4h处死,分别测定其动脉血氧分压(PaO2)和二氧化碳分压(PaCO2),血浆及肺组织丙二醛(MDA)、一氧化氮(NO)、内皮素(ET)含量,计算血浆NO/ET比值;以及肺湿干比(W/D)、肺系数(LI),肺组织髓过氧化物酶(MPO)含量。结果:大鼠LI/R后4h,PaO2明显降低;W/D、LI、血浆及肺组织的MDA、NO、ET和肺组织MPO活性均明显增加,而血浆NO/ET比值明显减小。与LI/R组比较,IPC组各项损伤指标明显减轻,NO水平升高,血浆NO/ET比值明显增大。与对照组和IPC组比较,L-NAME处理组,各项损伤指标数值明显增加,NO水平降低;血浆NO/ET比值明显减小,差异均具有显著性。各组大鼠PaCO2的变化无显著性。结论:缺血预适应对肢体缺血/再灌注后肺损伤具有保护作用,其机制可能与内源性NO合成增加有关。

Aim： To study the effect of ischemic preconditioning on lung injury following ischemia/reperfusion（I/R） in the hind limbs of rats. Methods： Wistar rats were randomly divided into four groups（ n = 8） ： control group, limbs ischemia/reperfusion（LI/R） group, ischemia preconditioning（IPC） group and L-NAME group. At the end of the experiment, blood/gas analysis and the contents of serum MDA, NO, ET and lung tissue MDA, NO, ET, MPO were measured. Meanwhile, lung index and W/D of lung were measured. Results： After the rats＇ hind limbs suffered ischemia/reperfusion, the levd of PaO2 decreased and the values of W/D, LI, MPO of the lung issure and MDA, NO,ET of plasma and lung all increased significantly in the LI/R group; but the ratio of NO/ET decreased. Compared with LI/R group, the contents of NO and ratio of NO/ET increased but other parameters decreased in the IPC group. Compared with IPC group, the contents of NO and ratio of NO/ET decreased, but other parameters increased in the L-NAME group. Conclusion： The IPC can attenuate lung injury following IR in the hind limbs of rats, which may corrdated with the increase of NO.