title: The action of AD6 on experimental arrhythmias and on action potentials of cardiac fibers.
abstract: AD6 is a coumarinic derivative which increases both coronary blood flow and prostacyclin production, while it decreases platelet responsiveness. We tested its action on experimental cardiac arrhythmias. AD6 (2.5-10 mg/kg) was able to antagonize the arrhythmogenic action of aconitine in rats and of adrenaline in cats. AD6 action was also tested in vitro. The drug (20-50 microM) prolonged the functional refractory period of guinea-pig atrial and ventricular muscle and lengthened the refractory period shortened by hypoxia. Intracellular electrophysiological experiments showed that AD6 prolongs action potential duration (APD) of guinea-pig atrial myocardium, sino-atrial node and cat Purkinje fibers. The results obtained in vitro may explain the effect on experimental arrhythmias, therefore suggesting a protective action on cardiac rhythm disturbances.
mesh_terms: D000157:Aconitine; D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001145:Arrhythmias, Cardiac / Q000139:chemically induced / Q000188:drug therapy / Q000503:physiopathology*; D002415:Cats; D002866:Chromonar / Q000031:analogs & derivatives / Q000494:pharmacology*; D003374:Coumarins / Q000494:pharmacology*; D004837:Epinephrine; D006168:Guinea Pigs; D006325:Heart Atria / Q000187:drug effects / Q000503:physiopathology; D066298:In Vitro Techniques; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D012849:Sinoatrial Node / Q000187:drug effects / Q000503:physiopathology
chemical_list: D003374:Coumarins; C025945:cloricromen; D002866:Chromonar; D000157:Aconitine; D004837:Epinephrine