Document Detail


Cat brain cytochrome-c oxidase redox changes induced by hypoxia after blood-fluorocarbon exchange transfusion.
MedLine Citation:
PMID:  7653605     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
We used rapid-scanning near-infrared (NIR) spectroscopy (730-960 nm) to study the effects of graded or acute hypoxia on cerebral cytochrome-c oxidase (cyt aa3) redox state in blood-perfluoro-carbon-exchanged cats with somatosensory evoked potential (SEP) monitoring. In graded hypoxia [10 min each at fractional inspiratory O2 concentration (FIO2) 0.9, 0.8, 0.7, 0.6, and 0.5], cyt aa3 reduction occurred at FIO2 0.6 when cerebral O2 delivery was < 3.5 ml.100 g-1.min-1. In acute hypoxia (FIO2 0.6 for 10 min), significant cyt aa3 reduction occurred from 5 to 10 min (cerebral O2 delivery 3.1 +/- 0.3 ml.100 g-1.min-1) and recovered with reoxygenation (FIO2 1.0). Cyt aa3 redox changes preceded or coincided with SEP alterations in both hypoxia protocols. These results demonstrate that cerebral cyt aa3 reduction occurs with severe reduction of cerebral O2 delivery, but no significant change in cerebral cyt aa3 redox state occurs with small reductions of cerebral O2 delivery. We conclude that substantial changes in cerebral cyt aa3 do not occur at physiological levels of O2 delivery and that current NIR clinical instruments would detect oxygen-dependent cerebral cyt aa3 redox changes only when O2 delivery is extremely compromised.
Authors:
M Ferrari; M A Williams; D A Wilson; N V Thakor; R J Traystman; D F Hanley
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The American journal of physiology     Volume:  269     ISSN:  0002-9513     ISO Abbreviation:  Am. J. Physiol.     Publication Date:  1995 Aug 
Date Detail:
Created Date:  1995-09-22     Completed Date:  1995-09-22     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0370511     Medline TA:  Am J Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  H417-24     Citation Subset:  IM    
Affiliation:
Department of Anesthesiology/Critical Care Medicine, Johns Hopkins Medical Institutions, Baltimore, Maryland 21287, USA.
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MeSH Terms
Descriptor/Qualifier:
Animals
Anoxia / metabolism*,  physiopathology
Brain / enzymology*,  physiopathology
Cats
Cerebrovascular Circulation
Electron Transport Complex IV / metabolism*
Evoked Potentials, Somatosensory
Exchange Transfusion, Whole Blood*
Feasibility Studies
Female
Fluorocarbons*
Oxidation-Reduction
Spectrophotometry, Infrared
Grant Support
ID/Acronym/Agency:
2-R01-NS-24282-03A2/NS/NINDS NIH HHS; 5-P01-NS-20020/NS/NINDS NIH HHS; R43-NS-27795-01/NS/NINDS NIH HHS
Chemical
Reg. No./Substance:
0/Fluorocarbons; EC 1.9.3.1/Electron Transport Complex IV

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


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