The membrane stabilizing and beta 1-adrenoceptor blocking activity of (+)- and (-)-propranolol on the rat left atria.
1. The membrane stabilizing and beta 1-adrenoceptor blocking activities of (+)- and (-)-propranolol have been determined using the rat left atria. 2. (+)- And (-)-propranolol have membrane stabilizing activity. Thus a low concentration of (-)-propranolol, 10(-8) M, and a higher concentration of (+)-propranolol, 10(-6) M, inhibited the responses to electrical stimulation. A high concentration of (+)- and (-)-propranolol, 10(-5) M, also inhibited the maximal combined response to electrical stimulation and isoprenaline. 3. As competitive beta 1-adrenoceptor antagonists, (-)-propranolol was over a 100 times more potent than (+)-propranolol.
Doggrell
S A
SA
Department of Pharmacology, School of Medicine, University of Auckland, New Zealand.
D000319:Adrenergic beta-Antagonists; D000818:Animals; D004558:Electric Stimulation; D006321:Heart / Q000187:drug effects*; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D011433:Propranolol / Q000494:pharmacology*; D051381:Rats; D013237:Stereoisomerism
D000319:Adrenergic beta-Antagonists; D011433:Propranolol; D007545:Isoproterenol