Vasoactive Effects of Platelet Aggregates

Abstract

To the Editor: Mullane et al. have shown that 5-hydroxytryptamine and a THROMBOXANE A₂-mimetic agent potentiate the contractile effects of each other on canine coronary arteries.¹ Despite the potential clinical importance of such an interaction, direct evidence is lacking that this occurs in human blood vessels when platelets aggregate.We have studied the contractile effects, on spiral strips of 20 human digital arteries and 4 coronary arteries removed at autopsy, of the addition of aliquots of washed human platelets aggregated with thrombin to give a 1:10 dilution in a tissue bath. The arteries and platelets were prepared according . . .