Abstract
Effect of endothelin on platelets was studied. Affinity labeling of bovine platelet membrane with 125I-endothelin-1 by a cross-linking reagent followed by SDS-polyacrylamide gel electrophoresis and autoradiography revealed the existence of a speciffic binding site with apparent molecular mass of 37kDa on platelet membrane. When added to human platelet-rich plasma, endothelin showed a potentiating effect on the second wave of ADP-induced platelet aggregation, though it alone had no effect. This effect on ADP-induced aggregation was abolished by the treatment of platelets with aspirin, suggesting the involvement of arachidonic acid metabolism in the signal transduction elicited by endothelin.
