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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
5
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pubmed:dateCreated |
1982-5-27
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pubmed:abstractText |
The carotid injection technique, used previously to quantitate the kinetics of blood-brain barrier transport of metabolic substrates, may be modified to analyze the rate of cerebral glucose utilization. A 0.2-ml solution of [14C]glucose (GF) and [3H]methylglucose (M), an internal reference, is rapidly injected into the carotid artery, followed by microwave fixation of brain at various times up to 4 min after injection. The brain radioactivity is separated into a fraction containing neutral hexoses (GF and M) and a fraction containing metabolites of glucose. The GF/M ratio is related to the rate constant (k3) of brain glucose utilization by the simple, linear equation: 1n(GF/M) = ln(GF0/0)--k3t, where GF0/M0 = the brain uptake index of glucose, relative to methylglucose, at 5--15 s after injection, and t = the time after carotid injection, e.g., 1--4 min. It is assumed that (a) the rate of influx due to recirculation of label is minimal during the 4-min circulation period; and (b) the rate constants of glucose efflux (k2) and methylglucose efflux (k2*) are identical. Independent estimates of k2 and k2* showed these parameters to be identical: k2 = 0.14 +/- 0.08 min-1; k2* = 0.14 +/- 0.02 min-1. A logarithmic plot of GF/M ratios versus time was linear (r = 0.99), and was described by the slope k3 = 0.21 +/- 0.02 min-1. Assuming glucose is uniformly distributed in brain, then the glycolytic rate = k3 x brain glucose = (0.21 min-1) (2.6 mumol g-1) = 0.55 mumol min-1 g-1 for the cortex of the barbiturate-anesthetized rat. These studies provide the basis for a simple method of measurement of regional brain glycolysis that does not require either the use of correction factors, e.g., the lumped constant, or the use of differentially labeled glucose.
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pubmed:grant | |
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 |
May
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pubmed:issn |
0022-3042
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
38
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
1413-8
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:7062059-3-O-Methylglucose,
pubmed-meshheading:7062059-Animals,
pubmed-meshheading:7062059-Blood-Brain Barrier,
pubmed-meshheading:7062059-Brain,
pubmed-meshheading:7062059-Carotid Arteries,
pubmed-meshheading:7062059-Glucose,
pubmed-meshheading:7062059-Injections, Intra-Arterial,
pubmed-meshheading:7062059-Male,
pubmed-meshheading:7062059-Mathematics,
pubmed-meshheading:7062059-Methylglucosides,
pubmed-meshheading:7062059-Rats,
pubmed-meshheading:7062059-Rats, Inbred Strains
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pubmed:year |
1982
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pubmed:articleTitle |
Measurement of cerebral glucose utilization using washout after carotid injection in the rat.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, U.S. Gov't, Non-P.H.S.,
Research Support, Non-U.S. Gov't
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