title: (n-3) Long chain PUFA dose-dependently increase oxygen utilization efficiency and inhibit arrhythmias after saturated fat feeding in rats.
abstract: Fish oil (FO) modifies cardiac membrane phospholipid fatty acid composition to confer increased efficiency of oxygen utilization and antiarrhythmic effects. We tested the capacity of low-dose increments of FO, rich in (n-3) PUFA, to reverse the detrimental pro-arrhythmic and inefficient oxygen usage effects of dietary saturated fat (SAT) [including high ratio of (n-6) PUFA:(n-3) PUFA] during ischemia and reperfusion. Wistar rats were fed an SAT-enriched diet (15.3% fat, including 12% SAT, added by weight) for 6 wk and were then divided into 4 groups (n = 10/group) fed that diet or a 12% fat diet containing 3, 6, or 12% FO in place of SAT for 6 wk. Paced (300/min), erythrocyte-perfused isolated working hearts were subjected to low coronary flow ischemia (15 min) and were then reperfused. At normoxic baseline, external work capacity increased marginally at 6 and 12% FO; however, marked dose-related reductions in oxygen consumption were evident due to FO-dependent reduction in oxygen-energy utilization efficiency and associated reductions in coronary flow and oxygen extraction. Postischemic recovery resulted in lower oxygen consumption, greater oxygen-energy utilization efficiency, reduced coronary release of creatine kinase, and reduced incidence of arrhythmias in all FO groups compared with the SAT group. FO at a dose as low as 3% of total fat dietary supplement effectively reversed the high oxygen requirements and pro-arrhythmic effects of a SAT-rich diet even with continued consumption of SAT (9%) in this ex vivo animal model.
authors.affiliation: Department of Surgery, Monash University, Australia. salvatore.pepe@med.monash.edu.au
authors.forename: Salvatore
authors.initials: S
authors.lastname: Pepe
authors.forename: Peter L
authors.initials: PL
authors.lastname: McLennan
mesh_terms: D000818:Animals; D001145:Arrhythmias, Cardiac / Q000517:prevention & control*; D004041:Dietary Fats / Q000494:pharmacology*; D004195:Disease Models, Animal; D015525:Fatty Acids, Omega-3 / Q000494:pharmacology*; D008297:Male; D010101:Oxygen Consumption / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D004041:Dietary Fats; D015525:Fatty Acids, Omega-3