Cardiovascular action of calcitonin gene-related peptide in humans

Abstract
Summary Calcitonin gene-related peptide (CGRP) has been localized in cardiac nerve fibers and blood vessels from which it may be released as neurotransmitter or neuromodulator. Acute cardiovascular effects of i.v. administered CGRP have been studied in human subjects. CGRP (25.3 nmol) caused a mean maximal increase of the heart rate of 41 beats per min (PPPPPP<0.01), presumably acting as positive inotropic agent. Labetalol, blocking adrenergic receptors, obliterated these inotropic effects, whereas the positve chronotropic and hypotensive actions of CGRP remained unchanged.