Coronary Thrombolysis and Endothelin-1 Release

Abstract

The relation between intracoronary thrombus and endothelin-1 (ET-1) was studied. In a canine model, acute myocardial infarction (MI) was induced by coronary occlusive thrombus produced at a mock atheromatous plaque. Blood samples were collected from the aorta (A) and coronary vein (V). Twenty-eight open-chest dogs divided into three groups were studied. Group I (n=15): acute MI was induced by coronary occlusive thrombus, and thrombolysis was ob tained by urokinase two hours after MI. Group II (n=8): nonocclusive throm bus was produced without inducing MI. Group III (n = 5) : coronary artery was ligated for two hours and reperfused by release of ligation.

In Group I, ET-1 was significantly increased after MI in A and V, and ET-1 in V was significantly more elevated than in A during thrombolysis, suggesting ET-1 production in the coronary vessels by thrombolysis. In Group II, ET-1 increased slightly during thrombus formation, but there was no difference in A and V. In Group III, ET-1 was elevated significantly after MI without A and V difference.

These results indicate that there is no detectable ET-1 production with coro nary thrombus formation, whereas coronary ET-1 production is detected dur ing thrombolysis, most probably because resolved thrombus releases a more potent stimulus to ET-1 production.