Linked Life Data

3343291

Source:http://linkedlifedata.com/resource/pubmed/id/3343291

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1988-4-6
pubmed:abstractText
Oxygen-dependent changes in brain cytochrome redox state and cerebrocortical energy metabolism were evaluated in fluorocarbon-circulated rats at hematocrits of less than 1%. Redox levels of three respiratory chain cytochrome complexes, b, c, and a,a3 (cytochrome c oxidase), were continuously measured directly through the intact skulls of animals using reflectance spectrophotometry. The in vivo redox status of cytochromes at different FiO2 was directly compared with in vitro measured changes in cortical metabolites known to reflect energy production, i.e., glucose, pyruvate, lactate, phosphocreatine (PCr), ADP, and ATP. Lowering the FiO2 to less than 1.0 caused the cytochromes to become increasingly more reduced. This was associated with increased tissue accumulation of pyruvate and lactate and a concomitant increase in the lactate/pyruvate (L/P) ratio. At FiO2 = 0.6, cytochromes b, c, and a,a3 were 57, 53, and 46% reduced, respectively. There was no apparent cerebral energy deficit since changes in cortical PCr, ADP, and ATP concentrations were not statistically significant. Bloodless animals did not survive below FiO2 = 0.5. At this FiO2, the inability of the animals to sustain arterial pressure correlated (r = 0.87) with depletion of PCr and further increases in the L/P ratio (r = 0.66). Yet, the cortical ATP content was reduced by only 9% of control value. These data provide direct evidence that fluorocarbon emulsion (FC-43) sustains brain oxygenation and energy metabolism at high partial pressures of molecular O2. At lower FiO2, however, mitochondrial O2 uptake becomes limited as a function of decreasing perfusion pressure.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0271-678X
pubmed:author
pubmed:issnType
Print
pubmed:volume
8
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
163-72
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
O2 dependence of in vivo brain cytochrome redox responses and energy metabolism in bloodless rats.
pubmed:affiliation
Department of Physiology, Duke University Medical Center, Durham, North Carolina 27710.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.