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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
3
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pubmed:dateCreated |
1985-12-18
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pubmed:abstractText |
Previous studies have shown that severe neonatal asphyxia and hypoxia lead to a redistribution of cerebral blood flow (CBF) with a preferential perfusion of the brain stem. The present study shows that this mechanism is operative also in moderately hypoxic newborn lambs (oxygen saturation 32.7-65.2) with a threshold of about 25% reduction in oxygen saturation. In hypoxia, the mean increase in total CBF, brain stem and telencephalic blood flow was 44%, 68% and 43%, respectively (five lambs). We found that naloxone reverses this redistribution, and that the effects of naloxone on telencephalic perfusion and cerebral metabolic rate of oxygen (CMRO2) were proportional. In hypoxia + naloxone (1 mg/kg), a further increase in total CBF, brain stem, and telencephalic blood flow of 30%, 7% and 31% was noted. We therefore suggest that the redistribution of CBF is an important opioid-mediated homeostatic mechanism, which diminishes the metabolic requirements of the newer part of the brain in hypoxia and allows a preferential perfusion of the vital structures of the brain stem.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Sep
|
pubmed:issn |
0340-6199
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pubmed:author | |
pubmed:issnType |
Print
|
pubmed:volume |
144
|
pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
|
pubmed:pagination |
225-7
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:2996903-Animals,
pubmed-meshheading:2996903-Animals, Newborn,
pubmed-meshheading:2996903-Asphyxia Neonatorum,
pubmed-meshheading:2996903-Brain Stem,
pubmed-meshheading:2996903-Cerebrovascular Circulation,
pubmed-meshheading:2996903-Endorphins,
pubmed-meshheading:2996903-Homeostasis,
pubmed-meshheading:2996903-Hypoxia, Brain,
pubmed-meshheading:2996903-Naloxone,
pubmed-meshheading:2996903-Receptors, Opioid,
pubmed-meshheading:2996903-Sheep
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pubmed:year |
1985
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pubmed:articleTitle |
Preferential blood flow increase to the brain stem in moderate neonatal hypoxia: reversal by naloxone.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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