Sub-compartmentation of the 'cytosolic' glucose 6-phosphate pool in cultured rat hepatocytes.
[14C]Glucose release either from endogenous 14C-prelabelled glycogen or from added 14C-labelled glucose 6-phosphate was measured in filipin-treated, permeabilized hepatocytes in 48 h culture. [14C]Glucose output from prelabelled glycogen was not altered by the addition of 5 mM glucose 6-phosphate to the incubation medium. Conversely, [14C]glucose release from 5 mM labelled glucose 6-phosphate was not influenced by different glycogen concentrations in the cells. Moreover, in the permeabilized cells the anion transport inhibitor DIDS (4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid) inhibited only the liberation of [14C]glucose from labelled glucose 6-phosphate but not from glycogen. It is therefore concluded that there exist at least 2 separate, mutually non-accessible glucose 6-phosphate pools in cultured rat hepatocytes, one linked to glycogenolysis and the other to gluconeogenesis.
D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002463:Cell Membrane Permeability; D002478:Cells, Cultured; D003600:Cytosol / Q000032:analysis; D005943:Gluconeogenesis; D005947:Glucose / Q000378:metabolism; D019298:Glucose-6-Phosphate; D005958:Glucosephosphates / Q000032:analysis*; D006003:Glycogen / Q000378:metabolism; D008099:Liver / Q000032:analysis*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
D005958:Glucosephosphates; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; D019298:Glucose-6-Phosphate; D006003:Glycogen; D005947:Glucose; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D002118:Calcium