Plasma concentrations of endothelin-1 and endothelin-3 are altered differently in various pathophysiological conditions in humans.

Several studies have indicated that endothelin-1 (ET-1) and endothelin-3 (ET-3) are produced by different cells. Although ET-1 is produced by vascular endothelial cells, these cells do not produce ET-3. In the present study, we measured plasma concentrations of both ET-1 and ET-3 by sandwich-enzyme immunoassays which we developed recently in patients on chronic hemodialysis, age-matched normal subjects, patients with acute myocardial infarction, patients undergoing surgery, and healthy subjects before and after strenuous endurance exercise. Plasma levels of ET-1 and ET-3 were demonstrated to be altered differently in the above conditions in humans. Although the exact origin of circulating endothelins has yet to be elucidated, the different alterations of plasma levels suggest that both ET-1 and ET-3 may play different roles in physiological and/or pathophysiological responses to various conditions in humans.