Increased tissue endothelin immunoreactivity in atherosclerotic lesions associated with acute coronary syndromes.

Abstract

Acute coronary syndromes are accompanied by exaggerated vasoconstriction. Since thrombin induces production of the potent vasoconstrictor endothelin-1, we used immunohistochemistry on coronary atherosclerotic specimens from 30 consecutive patients. Endothelin-1-like immunoreactivity was present in 5 of 9 (55%) lesions from patients with stable angina, in 6 of 7 (86%) from crescendo angina, and in all 14 from angina at rest. Endothelin-1 immunoreactivity was most common in areas with a positive Prussian-blue reaction indicative of previous intraplaque haemorrhage. Tissue endothelin-1-like immunoreactivity might contribute to the exaggerated coronary vasoconstriction.