FMRFamide enhances acetylcholine-induced contractions of guinea pig ileum.
Isolated guinea pig ilea were contracted with acetylcholine (ACh) in the absence and presence of the neuropeptide FMRFamide (Phe-Met-Arg-Phe-NH2). FMRFamide (0.17-17 microM) enhanced ACh-induced contractions (observed as a leftward shift of the dose-response curve and increase in Emax) with maximal effect at 1.7 microM. FMRFamide had no effect when administered alone. These results extend the demonstration of a FMRFamide/ACh interaction to mammalian tissue and support the concept that FMRFamide, or mammalian equivalents, could play a modulatory role in mammals.
Department of Biological Research, Janssen Research Foundation, Spring House, PA 19477-0776.
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Raffa
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Jacoby
D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D004357:Drug Synergism; D019835:FMRFamide; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology*; D009479:Neuropeptides / Q000494:pharmacology*
D009479:Neuropeptides; D019835:FMRFamide; D000109:Acetylcholine