Potency and selectivity in vitro of compounds related to isoprenaline and orciprenaline on beta-adrenoceptors in the guinea-pig.
1 Amines related in structure to either isoprenaline (catechol series) or orciprenaline (resorcinol series) were examined for activity on isolated trachea (relaxation), atria (chronotropic action) and perfused hind-limb (vasodilatation) of the guinea-pig.2 Compounds with a resorcinol nucleus were less potent on all three preparations but more selective for trachea than were compounds with a catechol nucleus.3 In both catechol and resorcinol compounds potency on trachea was enhanced by and selectivity for trachea was favoured by substitution of a p-OH phenyl group in the N-iso propyl, or by replacement of the N-iso propyl with an N-t-butyl, with or without a p-OH phenyl group.4 Most of the compounds, particularly the resorcinols, had much lower potencies, relative to isoprenaline, on hind-limb than on trachea.5 Some of the problems associated with the quantitative measurement of selectivity and with sub-classification of beta-adrenoceptors are discussed.
D000818:Animals; D005260:Female; D005263:Femoral Artery / Q000187:drug effects; D006168:Guinea Pigs; D006325:Heart Atria / Q000187:drug effects; D006614:Hindlimb / Q000098:blood supply; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000031:analogs & derivatives / Q000494:pharmacology*; D009921:Metaproterenol / Q000031:analogs & derivatives / Q000494:pharmacology*; D011941:Receptors, Adrenergic; D012039:Regional Blood Flow / Q000187:drug effects; D014132:Trachea / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
D011941:Receptors, Adrenergic; D014665:Vasodilator Agents; D009921:Metaproterenol; D007545:Isoproterenol