Does ET-A receptor blockade with FR-139317 attenuate coronary vasoconstriction induced by low concentrations of exogenous ET-1?
Coronary vasoconstriction induced by pathophysiological concentrations of ET-1 is predominantly mediated by the ET-A receptor.
The present study demonstrates that low concentrations of exogenous ET-1, which may mimic pathophysiological concentrations, result in coronary vasoconstriction mediated predominantly via the ET-A receptor because such vasoconstriction is significantly attenuated by blockade with FR-139317. The ET-B receptor may have a dual vasoconstrictive and vasodilatory effect.
Cannan et al. (Fri,) studied this question.