IS ENDOTHELIN-1 RELEASE AT REPERFUSION OF THE ISCHEMIC HUMAN HEART DUE TO COLD-INDUCED DISPLACEMENT OF ENDOTHELIN FROM BINDING-SITES

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