Dephosphorylation of 2-deoxyglucose 6-phosphate and 2-deoxyglucose export from cultured astrocytes.
Neurochem Int
; 28(3): 243-50, 1996 Mar.
Article
in En
| MEDLINE
| ID: mdl-8813241
ABSTRACT
Neurotransmitter-stimulated mobilization of astrocyte glycogen has been proposed as a basis for local energy homeostasis in brain. However, uncertainty remains over the fate of astrocyte glycogen. Upon transfer of cultured astrocytes pre-loaded with [2-3H]2-deoxyglucose 6-phosphate at non-tracer concentrations to a glucose-free, 2-deoxyglucose-free medium, rapid dephosphorylation of a proportion of the intracellular 2-deoxyglucose 6-phosphate pool and export of 2-deoxyglucose to the extracellular fluid occurs. Astrocytes show very low, basal rates of gluconeogenesis from pyruvate (approx. 1 nmol mg protein-1 h-1). Astrocytes in vivo may be capable of physiologically significant glucose export from glucose-6-phosphate. The low gluconeogenic activity in astrocytes suggests that the most likely source of glucose-6-phosphate may be glycogen. These findings support the hypothesis that export, as glucose, to adjacent neurons may be one of the possible fate(s) of astrocytic glycogen. Such export of glycogen as glucose occurring in response to increases in neuronal activity could contribute to energy homeostasis on a paracrine scale within brain.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Astrocytes
/
Glucose-6-Phosphate
/
Deoxyglucose
/
Antimetabolites
Limits:
Animals
Language:
En
Journal:
Neurochem Int
Year:
1996
Document type:
Article
Affiliation country:
United kingdom