title: Potentiation of bradykinin with synthetic peptides on guinea pig ileum.
abstract: Potentiation of the activity of bradykinin on the isolated guinea pig ileum was studied using a designed test system with the synthetic peptides Leu-Val-Glu-Ser-Ser-Lys, Thr-Pro-Val-Ser-Glu-Lys, derivatives of the former coupled to the N- and C-terminals of bradykinin and two peptides with phenylalanine substituted with its isomer L-3-amino-3-phenylpropanoic acid in the 5- and 5,8-positions in bradykinin respectively. On average, two times potentiation effects were obtained at 10-6 to 10-8 M concentrations of the peptides. After elimination of the basic lysine no potentiation occurred with synthetic Leu-Val-Glu-Ser-Ser. With the [beta Phe5,8]-bradykinin a mixed sensitizing/potentiating effect was observed, suggesting that a separation of the two effects may be difficult with an intact receptor structure of this kind. This peptide was not hydrolyzed by carboxypeptidase B or chymotrypsin.
mesh_terms: D000818:Animals; D001920:Bradykinin / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D006168:Guinea Pigs; D007082:Ileum / Q000502:physiology; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000502:physiology*; D009842:Oligopeptides / Q000138:chemical synthesis / Q000494:pharmacology*; D013329:Structure-Activity Relationship
chemical_list: D009842:Oligopeptides; D001920:Bradykinin