Document Detail

Near-infrared optical responses in feline brain and skeletal muscle tissues during respiratory acid-base imbalance.
MedLine Citation:
PMID:  2118821     Owner:  NLM     Status:  MEDLINE    
The effects of hyper- and hypocapnia on oxidative metabolism were evaluated by near-infrared (NIR) multiwavelength spectroscopy in intact brain and skeletal muscle tissues of the anesthetized cat. A 3-wavelength NIR algorithm was used to monitor cytochrome a,a3 oxidation state, regional blood volume, and tissue oxyhemoglobin and O2 stores simultaneously in brain and muscle in ventilated animals. Incremental hypercapnia was produced in 10 cats by raising arterial pCO2 from 27.0 +/- 1.3 to 95.1 +/- 1.9 mmHg with inspired CO2. Hypercapnia produced progressive increases in cerebral HbO2, blood volume, and cytochrome a,a3 oxidation state (P less than 0.01). In contrast, CO2 simultaneously decreased all 3 NIR parameters in intact hindlimb muscles (P less than 0.01). Blood volume changes during hypercapnia correlated with changes in blood flow measured qualitatively by intravascular injections of indocyanine green dye. Hypocapnia produced by hyperventilation in 8 cats lowered paCO2 from 28.5 +/- 0.4 to 13.5 +/- 0.5 mmHg. Hypocapnia decreased cerebral HbO2, blood volume, and cytochrome a,a3 redox level (P less than 0.05), but NIR changes were not seen in skeletal muscle. These experiments demonstrate preferential distribution of oxygen to brain during hypercapnia and the ability of NIR spectroscopy to assess regional oxygenation in multiple tissues non-invasively.
N B Hampson; C A Piantadosi
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Brain research     Volume:  519     ISSN:  0006-8993     ISO Abbreviation:  Brain Res.     Publication Date:  1990 Jun 
Date Detail:
Created Date:  1990-10-16     Completed Date:  1990-10-16     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0045503     Medline TA:  Brain Res     Country:  NETHERLANDS    
Other Details:
Languages:  eng     Pagination:  249-54     Citation Subset:  IM    
Department of Medicine, Virginia Mason Medical Center, Seattle, WA 98111.
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MeSH Terms
Acid-Base Imbalance / physiopathology*
Acidosis, Respiratory / physiopathology
Alkalosis, Respiratory / physiopathology
Blood Pressure
Brain / physiopathology*
Carbon Dioxide / blood
Hydrogen-Ion Concentration
Hypercapnia / physiopathology
Muscles / physiopathology*
Oxygen / blood
Partial Pressure
Spectrophotometry, Infrared / methods
Grant Support
Reg. No./Substance:
124-38-9/Carbon Dioxide; 7782-44-7/Oxygen

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

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