Skeletal muscle oxygen availability during respiratory acid-base disturbances in cats.

Published

Journal Article

Respiratory acid-base disorders elicit physiological responses that alter O2 delivery to various tissues. We have used a near infrared (NIR) optical technique to monitor cytochrome a,a3 oxidation state, tissue O2 store (relative hemoglobin plus myoglobin oxygenation), and regional blood volume in intact resting skeletal muscle during respiratory acid-base disturbances in anesthetized cats. Hypercapnic acidosis and hypocapnic alkalosis were produced in separate groups of animals by ventilation with increasing concentrations of CO2 (n = 13) or hyperventilation (n = 8). Respiratory acidosis decreased oxygen availability to hindlimb muscle while respiratory alkalosis did not change tissue oxygenation. Inspired CO2 progressively decreased muscle blood volume, cytochrome a,a3 oxidation level, and muscle oxygen store. These optical responses were greatly attenuated both by pre-treatment with bretylium and by hemorrhagic hypotension, suggesting mediation through sympathetic vasoconstriction. Metabolic acidosis, produced by intravenous HCl infusion (n = 8), did not reproduce the hindlimb optical responses mediated by CO2. These experiments demonstrate that hypercapnic acidosis significantly decreases oxygen supply to resting skeletal muscle in the anesthetized cat, probably via neuroregulatory responses to CO2 which do not depend on changes in arterial [H+] in the tested pH range.

Full Text

Duke Authors

Cited Authors

  • Hampson, NB; Jöbsis-VanderVliet, FF; Piantadosi, CA

Published Date

  • November 1987

Published In

Volume / Issue

  • 70 / 2

Start / End Page

  • 143 - 158

PubMed ID

  • 2823360

Pubmed Central ID

  • 2823360

International Standard Serial Number (ISSN)

  • 0034-5687

Language

  • eng

Conference Location

  • Netherlands