title: Spasmogenic activity of chemotactic N-formylated oligopeptides: identity of structure--function relationships for chemotactic and spasmogenic activities.
abstract: The chemotactic N-formylated oligopeptides are potent spasmogenic agents for guinea pig ileum. Structure-activity studies with various N-formylated peptides suggest the presence of a specific receptor that resembles in specificity the formyl peptide receptor on leukocytes. A competitive antagonist of the formyl peptide receptor on leukocytes also inhibits formyl peptide-induced ileum contraction, whereas the antihistamine diphenhydramine is without effect. The contractile response caused by the synthetic N-formylated peptides differs from those induced by acetylcholine, histamine, and substance P. In particular, a latent period after treatment with the N-formyl peptides is seen before the onset of the response, and a sustained contractile response is not maintained. In addition, tachyphylaxis does occur, but complete recovery of activity is seen after a 20- to 30-min rest period. These observations suggest broad biological roles of prokaryotic signal peptides from bacteria as acute inflammatory mediators.
mesh_terms: D000818:Animals; D002630:Chemotactic Factors / Q000494:pharmacology*; D002633:Chemotaxis; D004305:Dose-Response Relationship, Drug; D005260:Female; D006168:Guinea Pigs; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000502:physiology*; D011956:Receptors, Cell Surface / Q000502:physiology; D044042:Receptors, Formyl Peptide; D013329:Structure-Activity Relationship
chemical_list: D002630:Chemotactic Factors; D011956:Receptors, Cell Surface; D044042:Receptors, Formyl Peptide