Premium
Effects of (±)‐propranolol, (±)‐, (+)‐, and (–)‐alprenolol on unanaesthetized dogs with ventricular arrhythmias resulting from coronary artery ligation
Author(s) -
DUCE B. R.,
GARBERG L.,
SMITH E. R.
Publication year - 1970
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1970.tb09907.x
Subject(s) - alprenolol , propranolol , heart rate , medicine , anesthesia , cardiology , artery , blood pressure
Summary1 The effects of (±)‐propranolol, (±)‐, (+)‐ and (–)‐alprenolol were studied in unanaesthetized dogs with ventricular arrhythmias produced by ligation of the left coronary artery. The responses were compared with those of similar control dogs which were given only isotonic saline. 2 The ventricular arrhythmias were abolished by cumulative doses of 3·5 mg/kg of (±)‐alprenolol, 7·5 mg/kg of (–)‐alprenolol and (±)‐propranolol and by 15·5 mg/kg of (+)‐alprenolol. 3 At the time of maximum antiarrhythmic activity none of the drugs produced significant alterations in mean arterial pressure or atrial rate. 4 Cumulative doses of 7·5 mg/kg and 15·5 mg/kg of the four drugs resulted in some instances of lip licking, emesis and/or head tremors while 31·5 mg/kg was invariably lethal. 5 Since the β‐adrenoceptor blocking activity of (–)‐alprenolol is 100 times greater than that of (+)‐alprenolol, suppression of these ventricular arrhythmias was apparently unrelated to antagonism of sympathetic influences. 6 Alprenolol and propranolol have myocardial depressant properties apart from their effects on β‐adrenoceptors which could account for the antiarrhythmic activity observed.