Experimental study on myocardial cellular membrane injury after retrograde coronary sinus perfusion

Objective To study the mechanism of myocardial cells membrane damage following retrograde sinus coronary perfusion.Methods Twenty-four isolated rabbits were randomly divided into three groups.Group A received antegrade perfusion.Group B were maitainted heart beating by retrograde perfusion with normothermic oxygenated blood.Group C received retrograde coronary sinus perfusion with warm blood cardioplegia.After 60min retrograde perfusion,the hearts were switched on Langendorff-Neely antegrade perfused working heart model for another 60min.Intramyocyte free calcium,myocardial membrane MDA, ATPase and fluidity were measured.Results After retrograde coronary sinus perfusion,activity of ATPase and fluidity of the myocardial cells membrane in group B was superior to those of group C.The content of myocardial cells membrane MDA and the intramyocyte calcium followed retrograde perfusion was much lower in group B than those of group C.Conclusion Retrograde perfused beating heart was superior to those perfused with warm blood cardioplegia in reducing free radical production,ameliating intramyocyte paradoxical calcium accumulation,and maintaining activity of ATPase and fluidity of the myocardial cells membrane.