Guinea pig anti-Sheep RFRP-3 polyclonal antibody for IHC. FMRFamide (Phe-Met-Arg-Phe-NH2) is a neuropeptide from a broad family of FMRFamide-related peptides (FaRPs) all sharing an -RFamide sequence at their C-terminus. First identified in Hard clam Mercenaria mercenaria it is thought to play an important role in cardiac activity regulation. In Mercenaria mercenaria, FMRFamide has been isolated and demonstrated to increase both the force and frequency of the heartbeat through a biochemical pathway that is thought to involve the increase of cytoplasmic cAMP in the ventricular region.