Coupling between the blood lactate-to-pyruvate ratio and MCA V mean at the onset of exercise in humans

Peter Rasmussen, Camilla A. Madsen, Henning B. Nielsen, Morten Zaar, Albert Gjedde, Niels H. Secher, Bjørn Quistorff

Research output: Contribution to journalArticle

Abstract

Activation-induced increase in cerebral blood flow is coupled to enhanced metabolic activity, maybe with brain tissue redox state and oxygen tension as key modulators. To evaluate this hypothesis at the onset of exercise in humans, blood was sampled at 0.1 to 0.2 Hz from the radial artery and right internal jugular vein, while middle cerebral artery mean flow velocity (MCA V mean) was recorded. Both the arterial and venous lactate-to-pyruvate ratio increased after 10 s (P < 0.05), and the arterial ratio remained slightly higher than the venous (P < 0.05). The calculated average cerebral capillary oxygen tension decreased by 2.7 mmHg after 5 s (P < 0.05), while MCA Vmean increased only after 30 s. Furthermore, there was an unaccounted cerebral carbohydrate uptake relative to the uptake of oxygen that became significant 50 s after the onset of exercise. These findings support brain tissue redox state and oxygenation as potential modulators of an increase in cerebral blood flow at the onset of exercise.

Original languageEnglish (US)
Pages (from-to)1799-1805
Number of pages7
JournalJournal of applied physiology
Volume107
Issue number6
DOIs
StatePublished - Dec 1 2009

Keywords

  • Cerebral blood flow
  • Lactate
  • Lactate-to-pyruvate ratio
  • Mitochondrial oxygen tension
  • NADH

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

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    Rasmussen, P., Madsen, C. A., Nielsen, H. B., Zaar, M., Gjedde, A., Secher, N. H., & Quistorff, B. (2009). Coupling between the blood lactate-to-pyruvate ratio and MCA V mean at the onset of exercise in humans. Journal of applied physiology, 107(6), 1799-1805. https://doi.org/10.1152/japplphysiol.00468.2009