Antiaccelerator and decelerator activity of eleven phenothiazine derivatives.
Eleven N-substituted phenothiazine derivatives were studied for their antiaccelerator and decelerator activities on the dog heart. The antiaccelerator activity was determined in heart-lung preparation in dogs. Taking into consideration the percentage inhibition of cardio-acceleration produced by continuous infusion of 3 mug/min of adrenaline, all the drugs except chlorpromazine and 10-butyl-phenothiazine in two experiments caused more than 50 percent inhibition. 10-Propylphenothiazine induced maximum inhibitory effect, i.e. 90.1 percent in a total dose of 20 mg. Two types of effects were observed upon impulse generation in the sinus node. Acceleration was produced by chlorpromazine, 10-cyclopentyl-phenothiazine, prothipendyl, and thiazinamium, which was very short-lived, whereas other drugs produced deceleration. The correlation between antiaccelerator and decelerator properties is rather a close one.
D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D001145:Arrhythmias, Cardiac / Q000188:drug therapy; D001158:Arteries; D001283:Atrioventricular Node / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D003864:Depression, Chemical; D004285:Dogs; D004562:Electrocardiography; D004837:Epinephrine / Q000037:antagonists & inhibitors; D005260:Female; D006329:Heart Conduction System / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects*; D008297:Male; D010640:Phenothiazines / Q000494:pharmacology*; D012849:Sinoatrial Node / Q000187:drug effects; D014690:Venous Pressure / Q000187:drug effects
D000889:Anti-Arrhythmia Agents; D010640:Phenothiazines; D004837:Epinephrine