title: [The connection between the structure and activity of enkephalins in the realization of their cardiotropic effects in cats].
abstract: In experiments on anesthetized cats the ability of natural enkephalins to affect baseline heart rate, the magnitude of vagal chronotropic effect and its components, inhibitory tonic and synchronizing, was compared with activity of synthetic analogs and short fragments of enkephalins. Substitutions of met-enkephalin structure in second and fifth positions did not modify its cardiac activity. When Tyr1 was removed the peptide lost ability to affect baseline heart rate and the magnitude of synchronizing vagal component, but modulatory influence on inhibitory tonic vagal effect still persisted. The conclusion has been made that various parts of amino acid chain of met-enkephalin have different significance in realization of cardiac effects evoked by this peptide.
authors.affiliation: Kuban Medical Academy, Krasnodar, Russia.
authors.forename: O E
authors.initials: OE
authors.lastname: Osadchiĭ
authors.forename: V M
authors.initials: VM
authors.lastname: Pokrovskiĭ
authors.forename: I L
authors.initials: IL
authors.lastname: Cherednik
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002317:Cardiovascular Agents / Q000494:pharmacology*; D002415:Cats; D004562:Electrocardiography / Q000187:drug effects; D004745:Enkephalins / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects / Q000294:innervation; D006339:Heart Rate / Q000187:drug effects; D008969:Molecular Sequence Data; D010275:Parasympathetic Nervous System / Q000187:drug effects / Q000502:physiology; D010446:Peptide Fragments / Q000494:pharmacology; D013329:Structure-Activity Relationship
chemical_list: D002317:Cardiovascular Agents; D004745:Enkephalins; D010446:Peptide Fragments
vernacular_title: Sviaz' struktury i aktivnosti énkefalinov pri realizatsii ikh kardiotropnykh éffektov u koshek.