Effects of dietary omega-3 polyunsaturated Fatty acids on the skeletal-muscle blood-flow response to exercise in rats

Int J Sport Nutr Exerc Metab. 2010 Dec;20(6):475-86. doi: 10.1123/ijsnem.20.6.475.

Abstract

The polyunsaturated fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) affect vascular relaxation and involve factors (e.g., nitric oxide) that contribute to exercise-induced increases in skeletal-muscle blood flow (Q). The authors investigated whether DHA and EPA supplementation augments skeletal-muscle Q and vascular conductance (VC) and attenuates renal and splanchnic Q and VC in exercising rats. Rats were fed a diet of 5% lipids by weight, of which 20% was DHA and 30% EPA (PUFA group, n = 9), or 5% safflower oil (SO group, n = 8) for 6 wk. Heart rate (HR), blood pressure (MAP), and hind-limb, renal, and splanchnic Q were measured at rest and during moderate treadmill running. MAP, HR, and renal and splanchnic Q and VC were similar between the 2 groups at rest and during exercise. In the PUFA group, Q (158 ± 27 vs. 128 ± 28 ml × min⁻¹ × 100 g⁻¹) and VC (1.16 ± 0.21 vs. 0.92 ± 0.23 ml × min⁻¹ × 100 g⁻¹ × mm Hg⁻¹) were greater in the exercising hind-limb muscle. Q and VC were also higher in 8 of 28 and 11 of 28 muscles and muscle parts, respectively. These increases were positively correlated to the percent sum of Types I and IIa fibers. Results suggest that DHA+EPA (a) enhances Q and VC in active skeletal muscle (especially Type I and IIa fibers) and that the increase in Q is due to an increase in cardiac output secondary to increases in VC and (b) has no apparent influence on vasoconstriction in renal and splanchnic tissue.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blood Flow Velocity / drug effects
  • Blood Pressure / drug effects
  • Cardiac Output / drug effects
  • Docosahexaenoic Acids / pharmacology
  • Eicosapentaenoic Acid / pharmacology
  • Fatty Acids, Omega-3 / pharmacology*
  • Heart Rate / drug effects
  • Male
  • Muscle, Skeletal / blood supply*
  • Muscle, Skeletal / drug effects
  • Muscle, Skeletal / physiology
  • Physical Conditioning, Animal / methods
  • Physical Conditioning, Animal / physiology*
  • Rats
  • Rats, Sprague-Dawley
  • Regional Blood Flow
  • Rest
  • Safflower Oil / administration & dosage
  • Vascular Resistance / drug effects*

Substances

  • Fatty Acids, Omega-3
  • Docosahexaenoic Acids
  • Safflower Oil
  • Eicosapentaenoic Acid