Effects of nitrate supplementation via beetroot juice on contracting rat skeletal muscle microvascular oxygen pressure dynamics.


Journal Article

NO3(-) supplementation via beetroot juice (BR) augments exercising skeletal muscle blood flow subsequent to its reduction to NO2(-) then NO. We tested the hypothesis that enhanced vascular control following BR would elevate the skeletal muscle O2 delivery/O2 utilization ratio (microvascular PO2, PmvO2) and raise the PmvO2 during the rest-contractions transition. Rats were administered BR (~0.8 mmol/kg/day, n=10) or water (control, n=10) for 5 days. PmvO2 was measured during 180 s of electrically induced (1 Hz) twitch spinotrapezius muscle contractions. There were no changes in resting or contracting steady-state PmvO2. However, BR slowed the PmvO2 fall following contractions onset such that time to reach 63% of the initial PmvO2 fall increased (MRT1; control: 16.8±1.9, BR: 24.4±2.7 s, p<0.05) and there was a slower relative rate of PmvO2 fall (Δ1PmvO2/τ1; control: 1.9±0.3, BR: 1.2±0.2 mmHg/s, p<0.05). Despite no significant changes in contracting steady state PmvO2, BR supplementation elevated the O2 driving pressure during the crucial rest-contractions transients thereby providing a potential mechanism by which BR supplementation may improve metabolic control.

Full Text

Cited Authors

  • Ferguson, SK; Hirai, DM; Copp, SW; Holdsworth, CT; Allen, JD; Jones, AM; Musch, TI; Poole, DC

Published Date

  • July 2013

Published In

Volume / Issue

  • 187 / 3

Start / End Page

  • 250 - 255

PubMed ID

  • 23584049

Pubmed Central ID

  • 23584049

Electronic International Standard Serial Number (EISSN)

  • 1878-1519

International Standard Serial Number (ISSN)

  • 1569-9048

Digital Object Identifier (DOI)

  • 10.1016/j.resp.2013.04.001


  • eng