Effect of lorcainide, a new antiarrhythmic compound, on the changes in heart rhythm induced by intravenous injection of adenosine-5'-diphosphate in rats.
In rats, the intravenous injection of 1 mg/kg A.D.P. (adenosine-5'-diphosphate) results in transient thrombocytopenia, bradycardia and arrhythmias. Pre-treatment of the animals with the antiarrhythmic compounds lorcainide, aprindine, procaine (1.25, 2.5, 5 mg/kg i.v.) and xylocaine (5, 10, 20 mg/kg i.v.) before A.D.P. injection results in a reduction of bradycardia and a faster normalization of heart rate. All 4 compounds were equipotent in this respect, but the higher dose of xylocaine used should be stressed. The duration of irregular heart rhythm after A.D.P. injection was significantly shortened by all 4 compounds. Peak thrombocytopenia after A.D.P. administration is reduced only by lorcainide and the highest dose of aprindine, with two dose levels of xylocaine, but is not reduced by procaine. Suloctidyl (50 mg/kg orally) had no effect on any of the parameters registered. From this study we conclude that the normalization by the compounds of cardiac rate and rhythm disturbances after A.D.P. is due to their direct antiarrhythmic effect rather than to inhibition of platelet aggregation.
D000081:Acetamides / Q000494:pharmacology; D000244:Adenosine Diphosphate / Q000494:pharmacology*; D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D001073:Aprindine / Q000494:pharmacology; D001145:Arrhythmias, Cardiac / Q000139:chemically induced / Q000503:physiopathology*; D044482:Benzeneacetamides; D004347:Drug Interactions; D006339:Heart Rate / Q000187:drug effects; D008012:Lidocaine / Q000494:pharmacology; D008297:Male; D010880:Piperidines / Q000494:pharmacology*; D011343:Procaine / Q000494:pharmacology; D011412:Propanolamines / Q000494:pharmacology; D051381:Rats; D013921:Thrombocytopenia / Q000139:chemically induced; D013997:Time Factors
D000081:Acetamides; D000889:Anti-Arrhythmia Agents; D044482:Benzeneacetamides; D010880:Piperidines; D011412:Propanolamines; D011343:Procaine; D001073:Aprindine; D000244:Adenosine Diphosphate; D008012:Lidocaine; C015970:lorcainide