FMRFamide: an endogenous peptide with marked inhibitory effects on opioid-induced feeding behavior.
The peptide FMRFamide (Phe-Met-Arg-Phe-NH2), which displays a broad phylogenetic distribution, is considered to have important regulatory influences on basic functions in invertebrates. Extensive FMRFamide-like immunoreactive neuropeptides have also been demonstrated in the mammalian central nervous system, suggesting a possible physiological role for these peptides in mammals. There is evidence that FMRFamide, and/or related neuropeptides, may modulate opioid-mediated responses. Intracerebroventricular (ICV) administrations of FMRFamide inhibit in a dose-dependent manner (0.01-10 micrograms) mu- (morphine) and kappa- (U-50,488H) opiate-induced feeding in the laboratory mouse. In deer mice, FMRFamide inhibits the display of exogenous opiate-induced components of natural feeding behavior, such as food hoarding and food ingestion. In addition, ICV administrations of FMRFamide also antagonize endogenous opioid-mediated, stress-induced feeding in mice. These observations suggest that FMRFamide, or FMRFamide-like peptides present in the mammalian brain, may have important roles in the control of opioid-mediated feeding.
D000818:Animals; D004723:Endorphins / Q000037:antagonists & inhibitors / Q000502:physiology*; D019835:FMRFamide; D005247:Feeding Behavior / Q000187:drug effects / Q000502:physiology*; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists; D009419:Nerve Tissue Proteins / Q000494:pharmacology / Q000502:physiology*
D004723:Endorphins; D009292:Narcotic Antagonists; D009419:Nerve Tissue Proteins; D009270:Naloxone; D019835:FMRFamide