title: An approach to the self regulatory mechanism of substance P actions: II. Biological activity of new synthetic peptide analogs related both to enkephalin and substance P.
abstract: Analogs of substance P in which the N-terminal part of native peptide was replaced by an enkephalin active fragment have been synthesized. We found this peptide to be as active as substance P on the GPI test. The analogs were completely inactive on GPI opiate test; the opiate activity was observed on MVD and RVD tests. Surprisingly, we found that SP-activity was reduced by naloxone.
mesh_terms: D000818:Animals; D001681:Biological Assay; D004745:Enkephalins; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D008297:Male; D051379:Mice; D009119:Muscle Contraction / Q000187:drug effects; D051381:Rats; D013329:Structure-Activity Relationship; D013373:Substance P / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000494:pharmacology*; D014649:Vas Deferens / Q000187:drug effects
chemical_list: D004745:Enkephalins; D013373:Substance P