title: Thyroid hormone action on glucose transporter activity in astrocytes.
abstract: In astrocytes from rat brain cultured in thyroid hormone-deficient media cytochalasin B-binding was decreased 80%; addition of L-T3 increased binding to 75% of control levels. Saponin-treatment of controls increased accessibility of binding sites to 60% above untreated cells. Saponin also increased binding in deficient cells; however, the level was less than in treated controls, suggesting L-T3 deficiency decreases total glucose transporters. Addition of L-T3 appeared to convert most (90%) of the binding sites from unavailable to accessible status. Changes in binding to plasma membranes in response to L-T3 level were similar to those in intact cells. No binding to Golgi was detectable, thus no evidence for translocation of carriers was obtained. L-T3 may activate the glucose transporter by increasing its accessibility in brain cells.
authors.affiliation: Department of Pediatrics, University of Maryland, School of Medicine, Baltimore.
authors.forename: L M
authors.initials: LM
authors.lastname: Roeder
authors.forename: I B
authors.initials: IB
authors.lastname: Hopkins
authors.forename: J R
authors.initials: JR
authors.lastname: Kaiser
authors.forename: L
authors.initials: L
authors.lastname: Hanukoglu
authors.forename: J T
authors.initials: JT
authors.lastname: Tildon
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism*; D001921:Brain / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D003470:Culture Media; D003571:Cytochalasin B / Q000378:metabolism; D006056:Golgi Apparatus / Q000187:drug effects / Q000378:metabolism; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values; D014284:Triiodothyronine / Q000494:pharmacology*
chemical_list: D003470:Culture Media; D009004:Monosaccharide Transport Proteins; D014284:Triiodothyronine; D003571:Cytochalasin B