Glycolysis-induced discordance between glucose metabolic rates measured with radiolabeled fluorodeoxyglucose and glucose

Journal Article · Fri Dec 01 00:00:00 EST 1989 · Journal of Cerebral Blood Flow and Metabolism; (USA)

DOI:https://doi.org/10.1038/jcbfm.1989.111· OSTI ID:5084192

Ackermann, R F; Lear, J L ^[1]

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1. UCLA School of Medicine (USA)

We have developed an autoradiographic method for estimating the oxidative and glycolytic components of local CMRglc (LCMRglc), using sequentially administered ({sup 18}F)fluorodeoxyglucose (FDG) and ({sup 14}C)-6-glucose (GLC). FDG-6-phosphate accumulation is proportional to the rate of glucose phosphorylation, which occurs before the divergence of glycolytic (GMg) and oxidative (GMo) glucose metabolism and is therefore related to total cerebral glucose metabolism GMt: GMg + GMo = GMt. With oxidative metabolism, the {sup 14}C label of GLC is temporarily retained in Krebs cycle-related substrate pools. We hypothesize that with glycolytic metabolism, however, a significant fraction of the {sup 14}C label is lost from the brain via lactate production and efflux from the brain. Thus, cerebral GLC metabolite concentration may be more closely related to GMo than to GMt. If true, the glycolytic metabolic rate will be related to the difference between FDG- and GLC-derived LCMRglc. Thus far, we have studied normal awake rats, rats with limbic activation induced by kainic acid (KA), and rats visually stimulated with 16-Hz flashes. In KA-treated rats, significant discordance between FDG and GLC accumulation, which we attribute to glycolysis, occurred only in activated limbic structures. In visually stimulated rats, significant discordance occurred only in the optic tectum.

• OSTI ID: 5084192
• Journal Information: Journal of Cerebral Blood Flow and Metabolism; (USA), Vol. 9:6; ISSN 0271-678X
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
GLUCOSE
METABOLISM
AUTORADIOGRAPHY
CARBON 14 COMPOUNDS
CEREBRAL CORTEX
FLUORINE 18
MATHEMATICAL MODELS
PHOSPHORYLATION
RATS
ALDEHYDES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BODY
BRAIN
CARBOHYDRATES
CENTRAL NERVOUS SYSTEM
CEREBRUM
CHEMICAL REACTIONS
FLUORINE ISOTOPES
HEXOSES
HOURS LIVING RADIOISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
MAMMALS
MONOSACCHARIDES
NERVOUS SYSTEM
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANS
RADIOISOTOPES
RODENTS
SACCHARIDES
VERTEBRATES
550501* - Metabolism- Tracer Techniques