SENSITIZATION TO VENTRICULAR FIBRILLATION. II. SENSITIZATION BY AMARINE AND CONGENERS OF U-0882

¹ Department of Pharmacology, University of Michigan Medical School, Ann Arbor, Michigan

The actions of amarine are similar to those of Upjohn compound U-0882. Both agents prolong atrial and ventricular refractory periods and sensitize the heart to ventricular fibrillation.

Amarine differs from U-0882 in that it has more depressant action upon intracardiac conduction and it does not block vagal slowing of the heart or the depressor response to methacholine.

Of 10 congeners of U-0882 that were studied, those 3 which, like the parent compound, have a keto oxygen and an alpha methyl group share with U-0882 the property of sensitization. The 7 congeners which lack either or both of these chemical groups do not sensitize but produce death by circulatory collapse without ventricular fibrillation.

Sebsitization to ventricular fibrilation by amarine, U-0882, and the active congeners of U-0882 is distinctly different from sensitization by hydrocarbons in mechanism of action, in the nature of prefibrillatory events, and in the agents which will afford antifibrillatory protection.