Effects of captopril postconditioning on mRNA expression of angiotensinconvertion enzyme in lung ischemia-reperfusion injury in rats
WU Huo-zhi1,ZHANG Hao1,YUAN Mao-xi2,et al(1.Department of Cardiothoracic Surgery,The Fifth Affiliated Hospital of Zunyi Medical College,Zhuhai,Guangdong 519100,China; 2.Department of Cardiothoracic Surgery,Yishui Central Hospital,Linyi,Shandong 276400,China)
Objective To investigate the effects of captopril postconditioning on mRNA expression of angiotensin-convertion enzyme(ACE) in pulmonary vascular endothelium during lung ischemia-reperfusion injury in rats and to analyze its possible mechanisms.Methods Twenty-four rats were randomly assigned into three groups:a Sham operation group(Sham group,n=8),an ischemia-reperfusion group(I/R group,n=8) and a captopril postconditioning group(CAP group,n=8).As for Sham group,left thoracotomy,explosion and reperfusion of the left lung was conducted for 2 hours.As for I/R group,Blood perfusion and ventilation of the left lung were occluded for 1 hour followed by reperfusion for 1 hour.As for CAP group,captopril was injected into the abdominal of rats between the end of ischemia and the beginning of reperfusion;the other procedures were identical to I/R group.Small pieces of lung tissue were cut after 1 hour reperfusion.The concentrations of myeloperoxidase(MPO),malondialdehyde(MDA),superoxide dismutase(SOD),expression of ACE mRNA in lung homogenate and endothelin-1(ET-1)in serum were determined.The wet to dry weight ratio(W/D)of lung was also measured at the end of reperfusion.The lung tissue was prepared for light microscopic morphological observation at the end of experiment.Results The expression of ACE mRNA was obviously decreased in CAP group than that in I/R group(P0.05).The levels of MPO and MDA in lung tissue became significantly lower in CAP group than that in I/R group(P0.05).The W/D ratio was significantly lower in CAP group than that in I/R group(P0.05).The level of ET-1 in serum became significantly lower in CAP group compared with I/R group(P0.05).The level of SOD in serum became significantly higher in CAP group than that in I/R group.The lung histological examination showed that lung injury in I/R group was significantly more severe than that in CAP group.Conclusions Captopril postconditioning can significantly reduce lung ischemia-reperfusion injury.The possible mechanism is that captopril postconditioning may inhibit the expression of ACE mRNA in the lung tissue.
【CateGory Index】： R965
【CateGory Index】： R965