title: Effects of tiprenolol, practolol and propranolol on experimental ventricular tachyarrhythmias.
abstract: 1 Low doses of tiprenolol (0.01-0.02 mg/kg) and propranolol (0.05 mg/kg) abolished the ventricular arrhythmias produced by the intravenous injection of adrenaline in anaesthetized dogs respired with halothane.2 Larger doses of tiprenolol (2.0-4.0 mg/kg) restored sinus rhythm in four of five dogs with ventricular tachycardia produced by toxic doses of ouabain. Propranolol (2.0-4.0 mg/kg) had the same effect in each of four dogs.3 Both tiprenolol (4.0-8.0 mg/kg) and propranolol (4.0 mg/kg) increased the frequency of sinus beats and reduced the ventricular rate in dogs with ventricular tachycardia 20-44 h after ligation of a coronary artery.4 Practolol (0.5-16.0 mg/kg) did not reduce the ventricular rate or increase the frequency of sinus beats in dogs with ventricular tachycardia after ligation of a coronary artery.5 In dogs with ouabain-induced ventricular tachycardia mean arterial pressure was reduced after the administration of tiprenolol (0.5-8.0 mg/kg) or propranolol (4.0-8.0 mg/kg). Depression of sinus and atrioventricular nodal function, and of intraventricular conduction developed in some of the dogs given tiprenolol (4-8 mg/kg) or propranolol (8.0 mg/kg).6 The administration of tiprenolol (1.0-8.0 mg/kg) or propranolol (4.0-8.0 mg/kg) depressed the arterial pressure and caused the deaths of some dogs in which a coronary artery had been ligated. Such deaths did not occur in the group which had been given toxic doses of ouabain.
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000818:Animals; D001145:Arrhythmias, Cardiac / Q000139:chemically induced / Q000188:drug therapy*; D003331:Coronary Vessels / Q000502:physiology; D003864:Depression, Chemical; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004837:Epinephrine; D005260:Female; D006221:Halothane; D006329:Heart Conduction System / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006352:Heart Ventricles / Q000187:drug effects*; D008026:Ligation; D008297:Male; D010042:Ouabain; D011217:Practolol / Q000627:therapeutic use*; D011412:Propanolamines / Q000627:therapeutic use*; D011433:Propranolol / Q000627:therapeutic use*; D011437:Propylamines / Q000627:therapeutic use; D013440:Sulfides / Q000627:therapeutic use; D013997:Time Factors
chemical_list: D000319:Adrenergic beta-Antagonists; D011412:Propanolamines; D011437:Propylamines; D013440:Sulfides; D010042:Ouabain; D011433:Propranolol; C021339:tiprenolol; D011217:Practolol; D006221:Halothane; D004837:Epinephrine