Atenolol, bufuralol and prizidilol are dual antagonists of the responses of the electrically driven rat right ventricle strip to isoprenaline.
1. Procaine, a membrane stabilizer, depresses the maximal responses of the electrically driven rat right ventricle to isoprenaline. 2. Esmomol is a competitive beta-adrenoceptor antagonist as it causes parallel rightward shifts of isoprenaline response curves. 3. Atenolol, bufuralol and prizidilol were dual antagonists of the responses to isoprenaline. 4. The competitive component of the dual antagonism (parallel rightward shift of response curve) is due to beta-adrenoceptor antagonism whereas the noncompetitive component (depression of isoprenaline maximal response) is probably due to membrane stabilization. 5. This membrane stabilizing activity of beta-adrenoceptor antagonists may be clinically relevant.
Doggrell
S A
SA
Department of Pharmacology, School of Medicine, University of Auckland, New Zealand.
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D001262:Atenolol / Q000494:pharmacology; D004558:Electric Stimulation; D004983:Ethanolamines / Q000494:pharmacology; D006321:Heart / Q000187:drug effects / Q000502:physiology*; D006352:Heart Ventricles / Q000187:drug effects; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology*; D008297:Male; D011343:Procaine / Q000494:pharmacology; D011724:Pyridazines / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D016276:Ventricular Function
D000319:Adrenergic beta-Antagonists; D004983:Ethanolamines; D011724:Pyridazines; D011343:Procaine; D001262:Atenolol; C010831:bufuralol; C024293:prizidilol; D007545:Isoproterenol