British Journal of Nutrition

Metabolism and Metabolic Studies

Dietary fish oil preserves cardiac function in the hypertrophied rat heart

Peter L. McLennana1 c1, Mahinda Y. Abeywardenaa2, Julie A. Dallimorea2 and Daniel Raederstorffa3

a1 Cardiovascular Research Laboratory, Graduate School of Medicine, University of Wollongong, Wollongong, NSW 2522, Australia

a2 CSIRO Human Nutrition, Adelaide, Australia

a3 DSM Nutritional Products, Basel, Switzerland

Abstract

Regular fish or fish oil intake is associated with a low incidence of heart failure clinically, and fish oil-induced reduction in cardiac remodelling seen in hypertrophy models may contribute. We investigated whether improved cardiac energy efficiency in non-hypertrophied hearts translates into attenuation of cardiac dysfunction in hypertrophied hearts. Male Wistar rats (n 33) at 8 weeks of age were sham-operated or subjected to abdominal aortic stenosis to produce pressure-overload cardiac hypertrophy. Starting 3 weeks post-operatively to follow initiation of hypertrophy, rats were fed a diet containing 10 % olive oil (control) or 5 % fish oil (ROPUFA® 30 (17 % EPA, 10 % DHA))+5 % olive oil (FO diet). At 15 weeks post-operatively, ventricular haemodynamics and oxygen consumption were evaluated in the blood-perfused, isolated working heart. Resting and maximally stimulated cardiac output and external work were >60 % depressed in hypertrophied control hearts but this was prevented by FO feeding, without attenuating hypertrophy. Cardiac energy efficiency was lower in hypertrophy, but greater in FO hearts for any given cardiac mass. Coronary blood flow, restricted in hypertrophied control hearts, increased with increasing work in hypertrophied FO hearts, revealing a significant coronary vasodilator reserve. Pronounced cardiac dysfunction in hypertrophied hearts across low and high workloads, indicative of heart failure, was attenuated by FO feeding in association with membrane incorporation of n-3 PUFA, principally DHA. Dietary fish oil may offer a new approach to balancing the high oxygen demand and haemodynamic requirements of the failing hypertrophied heart independently of attenuating hypertrophy.

(Received June 13 2011)

(Revised September 18 2011)

(Accepted September 30 2011)

(Online publication November 09 2011)

Correspondence:

c1 Corresponding author: Professor P. L. McLennan, fax +61 2 4221 4341, email petermcl@uow.edu.au

Footnotes

Abbreviations: CO, cardiac output; FO, fish oil; FOH, rats with cardiac hypertrophy fed with a fish oil diet; MVO2, myocardial oxygen consumption; OO, olive oil; OOH, rats with cardiac hypertrophy fed with an olive oil diet; SV, stroke volume

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