[The specificity of action of penbutolol and propranolol and their optical isomers].
Several specific and unspecific effects of penbutolol and propranolol and their optical isomers were tested in the following test models: -- The beta-sympatholytic activity in the heart of the anaesthetized dog (measurement of the contractility), -- the sympathomimetic intrinsic activity in the reserpinized rat, -- the antiarrhythmic activity in the digoxin poisoned guinea pig, the digitoxin/aconitine poisoned isolated guinea pig heart, and the cooled cat, -- the beta-sympatholytic activity together with electrophysiological effects in the isolated guinea pig papillary muscle. The antiarrhythmic effects of l-penbutolol are mainly due to its beta-sympatholytic activity. d-Penbutolol reveals only a local anaesthetic action and is otherwise nearly without pharmacological effects. In beta-sympatholysis it is 50 times less active than l-penbutolol. It has no intrinsic sympathomimetic activity. It does not prolong the refractory period in the heart muscle. For this reason only l-penbutolol is proposed to be used as a beta-sympatholytic drug.
D000200:Action Potentials / Q000187:drug effects; D000319:Adrenergic beta-Antagonists; D000818:Animals; D000889:Anti-Arrhythmia Agents; D002415:Cats; D004077:Digoxin / Q000037:antagonists & inhibitors; D004285:Dogs; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects; D066298:In Vitro Techniques; D010210:Papillary Muscles / Q000187:drug effects; D010394:Penbutolol / Q000494:pharmacology*; D011412:Propanolamines / Q000494:pharmacology*; D011433:Propranolol / Q000494:pharmacology*; D051381:Rats; D013237:Stereoisomerism; D013566:Sympathomimetics
D000319:Adrenergic beta-Antagonists; D000889:Anti-Arrhythmia Agents; D011412:Propanolamines; D013566:Sympathomimetics; D004077:Digoxin; D010394:Penbutolol; D011433:Propranolol
Untersuchungen zur Spezifität der Wirkungen von Penbutolol und Propranolol unter Berücksichtigung der optischen Isomeren.