The effects of dietary fish oil on exercising skeletal muscle vascular and metabolic control in chronic heart failure rats

Clark T. Holdsworth, Steven W. Copp, Daniel M. Hirai, Scott K. Ferguson, Gabrielle E. Sims, Karen S. Hageman, Charles L Stebbins, David C. Poole, Timothy I. Musch

Research output: Contribution to journalArticle

4 Scopus citations

Abstract

Impaired vasomotor control in chronic heart failure (CHF) is due partly to decrements in nitric oxide synthase (NOS) mediated vasodilation. Exercising muscle blood flow (BF) is augmented with polyunsaturated fatty acid (PUFA) supplementation via fish oil (FO) in healthy rats. We hypothesized that FO would augment exercising muscle BF in CHF rats via increased NO-bioavailability. Myocardial infarction (coronary artery ligation) induced CHF in Sprague-Dawley rats which were subsequently randomized to dietary FO (20% docosahexaenoic acid, 30% eicosapentaenoic acid, n = 15) or safflower oil (SO, 5%, n = 10) for 6-8 weeks. Mean arterial pressure (MAP), blood [lactate], and hindlimb muscles BF (radiolabeled microspheres) were determined at rest, during treadmill exercise (20 m·min-1, 5% incline) and exercise + NG-nitro-L-arginine-methyl-ester (L-NAME) (a nonspecific NOS inhibitor). FO did not change left ventricular end-diastolic pressure (SO: 14 ± 2; FO: 11 ± 1 mmHg, p > 0.05). During exercise, MAP (SO: 128 ± 3; FO: 132±3mmHg) andblood [lactate] (SO: 3.8 ± 0.4; FO: 4.6 ± 0.5 mmol·L-1) were not different (p > 0.05). Exercising hindlimb muscle BF was lower in FO than SO (SO: 120 ± 11; FO: 93 ± 4 mL·min-1·100 g-1, p < 0.05) but was not differentially affected by L-NAME. Specifically, 17 of 28 individual muscle BF's were lower (p < 0.05) in FO demonstrating that PUFA supplementation with FO in CHF rats does not augment muscle BF during exercise but may lower metabolic cost.

Original languageEnglish (US)
Pages (from-to)299-307
Number of pages9
JournalApplied Physiology, Nutrition and Metabolism
Volume39
Issue number3
DOIs
StatePublished - 2014

Keywords

  • Endothelium
  • Hyperemia

ASJC Scopus subject areas

  • Physiology
  • Endocrinology, Diabetes and Metabolism
  • Nutrition and Dietetics
  • Physiology (medical)

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    Holdsworth, C. T., Copp, S. W., Hirai, D. M., Ferguson, S. K., Sims, G. E., Hageman, K. S., Stebbins, C. L., Poole, D. C., & Musch, T. I. (2014). The effects of dietary fish oil on exercising skeletal muscle vascular and metabolic control in chronic heart failure rats. Applied Physiology, Nutrition and Metabolism, 39(3), 299-307. https://doi.org/10.1139/apnm-2013-0301