Coronary circulation and 5-hydroxytryptamine

Abstract

Coronary vasospasm or Prinzmetal’s variant angina [1] is probably caused by a variety of substances that arise from aggregating platelets, from nerve varicosities or from different cells within the wall itself. It may not however, be simply a matter of identifying some pathological constrictor substance. The vascular reactivity, defined here by the “sensitivity” of the artery to the substance (conveniently taken as the EC50) and by the “range” or magnitude (Emax) of the contraction may have changed considerably in patients with angina pectoris.