Potential of calcitonin gene-related peptide in coronary heart disease

A subpopulation of capsaicin-sensitive cardiac C-fibre afferents co-store calcitonin gene-related peptide (CGRP), substance P and neurokinin A. CGRP exerts positive inotropic and chronotropic effects and is one of the most potent endogenous vasodilators yet discovered. A number of endogenous agents and conditions cause activation of cardiac C-fibre afferents with subsequent local release of CGRP. In myocardial ischaemia with its clinical manifestations angina pectoris and infarction, C-fibre afferents not only convey the sensation of pain, but there is also a local 'efferent' release of CGRP in the heart. After being released, CGRP causes coronary vasodilatation and attenuates the development of myocardial infarction. CGRP may thus represent an endogenous local myocardial protective substance with interesting clinical implications.