Is endothelin-1 release at reperfusion of the ischaemic human heart due to cold-induced displacement of endothelin from binding sites?

Abstract

Following reperfusion of ischaemic human hearts subjected to cold (4° C) cardioplegia during coronary bypass surgery, there was an increase in cardiac outflow of endothelin-1 but not the pro-peptide big endothelin-1. Furthermore, specific endothelin-1 binding in human lung membrane preparations was displaced by incubation in buffer medium at 4° C. The present results thus indicate that cold-induced displacement of endothelin-1 binding, rather than increased synthesis, may explain the cardiac release of endothelium-1 following ischaemia during heart surgery in which cold cardioplegia has been used.