title: Action of some natural polypeptides on the longitudinal muscle of the guinea pig ileum.
abstract: The structure--activity relationship of some natural tachykinins was investigated in the longitudinal muscle of the guinea pig ileum. The order of potency was eledoisin greater than uperolein greater than substance P greater than phyllomedusin greater than physalaemin. This ratio of activity is different from that observed in other experimental conditions, and in different in vivo or in vitro preparations; it is suggested that the N-terminal part of the molecule of the tachykinins plays a role in determining the degree of potency of these compounds.
mesh_terms: D000818:Animals; D004600:Eledoisin / Q000494:pharmacology; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D007705:Kinins / Q000494:pharmacology*; D009130:Muscle, Smooth / Q000187:drug effects*; D010803:Physalaemin / Q000494:pharmacology; D013329:Structure-Activity Relationship; D013373:Substance P / Q000031:analogs & derivatives / Q000494:pharmacology*
chemical_list: D007705:Kinins; D010803:Physalaemin; D013373:Substance P; D004600:Eledoisin