COMPARATIVE EFFICACY OF N-3 AND N-6 POLYUNSATURATED FATTY-ACIDS IN MODULATING VENTRICULAR-FIBRILLATION THRESHOLD IN MARMOSET MONKEYS

Programmed electrical stimulation in anesthetized marmoset monkeys was used to examine relative antiarrhythmic efficacies of dietary n-3 and n-6 polyunsaturated fatty acids (PUFAs) from fish and plant oils. Die ts contained 31% of energy (en%) as fat, comprising 15 en% saturated f at and 7 en% PUFAs, obtained by blending sheep fat with sunflower seed (SF/SSO) or fish oil (SF/FO) and a base diet. After 16-wk feeding, ve ntricular fibrillation (VF) was inducible in 6 of 10 animals on each d iet under control conditions. The VF threshold (VFT) was significantly elevated in the SF/FO group (33.3 +/- 3.1 mA; n = 6) compared with th e SF/SSO group (14.3 +/- 4.9 mA; n = 6). VFT, reduced during acute myo cardial ischemia with 10 of 10 animals inducible per diet, remained si gnificantly higher with SF/FO feeding. The SF/FO diet contained 3.8 en % as n-3 PUFAs, which was incorporated as 31% of myocardial membrane f atty acids. Dietary n-3 PUFA reduced vulnerability of normal or ischem ic myocardium to arrhythmias in a nonhuman primate.