Document Detail


Coupling between the blood lactate-to-pyruvate ratio and MCA Vmean at the onset of exercise in humans.
MedLine Citation:
PMID:  19779155     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
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 V(mean) 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.
Authors:
Peter Rasmussen; Camilla A Madsen; Henning B Nielsen; Morten Zaar; Albert Gjedde; Niels H Secher; Bj??rn Quistorff
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2009-09-24
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  107     ISSN:  1522-1601     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  2009 Dec 
Date Detail:
Created Date:  2009-12-02     Completed Date:  2010-02-02     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1799-805     Citation Subset:  IM    
Affiliation:
1Department of Anesthesia, Copenhagen Muscle Research Center, Rigshospitalet, Copenhagen, Denmark. peter@prec.dk
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MeSH Terms
Descriptor/Qualifier:
Adolescent
Adult
Blood Flow Velocity / physiology*
Blood Pressure / physiology
Catheters, Indwelling
Cerebrovascular Circulation / physiology
Exercise / physiology*
Heart Rate / physiology
Humans
Lactic Acid / blood*
Male
Middle Cerebral Artery / physiology*,  ultrasonography
Models, Biological
Oxygen Consumption / physiology
Pyruvic Acid / blood*
Signal Processing, Computer-Assisted
Time Factors
Ultrasonography, Doppler, Transcranial
Chemical
Reg. No./Substance:
127-17-3/Pyruvic Acid; 50-21-5/Lactic Acid

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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