Human RFamide-related peptide-1 diminishes cellular and integrated cardiac contractile performance

▶ Human RFRP-1 peptide (hRFRP-1) dramatically decreases contractility in isolated cardiac myocytes. ▶ The structurally-related peptide 26RFa does not affect contractility in isolated cardiac myocytes. ▶ Pertussis toxin did not affect the influence of hRFRP-1 on cardiac function in isolated cardiac myocytes suggesting the peptide activates PKC to impact contractility. ▶ Human RFRP-1 decreases cardiac function in whole animal as well as in the isolated cardiac myocyte.