PMID: 6167800Jul 1, 1981Paper

Effects of concentration and steric configuration of propranolol on AV conduction and ventricular repolarization in the dog

Journal of Cardiovascular Pharmacology
L BrorsonR Smith

Abstract

To investigate the electrophysiological effects of propranolol in vivo over a wide range of plasma concentrations and to distinguish effects due to beta-blockade from those due to a direct membrane action, His bundle electrograms were recorded, and ventricular effective refractory periods (VERP) and monophasic action potential duration (MAP) were measured in anesthetized control dogs and in dogs given three graded infusions of d- or dl-propranolol. Dogs were excluded if the plasma concentrations attained did not fall in predefined ranges of 25--125, 125--700, and 700--3,000 ng/ml. Isoproterenol sensitivity tests were performed to determine the relative beta-blocking potency of the isomers at the three concentration ranges. The highest concentration of d-propranolol had approximately the same beta-blocking potency as the lowest concentration of dl-propranolol. Mean AH and HV intervals in the His bundle electrogram increased with the concentration of dl-propranolol, and the increase was greater than with d-propranolol (p less than 0.03) at the first and second concentration steps but not significantly different at the highest concentrations of d- and dl-propranolol. VERP and MAP increased directly with concentration of d- and dl-...Continue Reading

Citations

May 24, 2008·Autonomic Neuroscience : Basic & Clinical·Emily R NolanN B Olivier
Dec 1, 1983·Journal of the American College of Cardiology·H J DuffR L Woosley

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