title: Evidence for the presence of glucose cycling in pancreatic islets of the ob/ob mouse.
abstract: Pancreatic islets from ob/ob mice incubated with 3H2O and 5.5 mM glucose formed 3H-labeled glucose, 74 picoatoms incorporated/islet/h. Sixty-three percent of the 3H was bound to carbon 2 of the glucose. The amount of glucose-6-P dephosphorylated to glucose, determined from this incorporation, was 48 pmol/islet/h. Glucose utilization, measured by the formation of 3H2O from [5-3H]glucose, was 72 pmol/islet/h. The amount of glucose dephosphorylated was then about 40% of that phosphorylated. Thus, glucose-6-P is dephosphorylated to glucose to a significant extent by intact islets in vitro and presumably by the beta cells of the islets. The extent of this glucose cycling, i.e. glucose----glucose-6-P----glucose, may play a role in determining the extent of glucose-induced insulin secretion.
authors.affiliation: Department of Endocrinology, Karolinska Hospital, Stockholm, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Khan
authors.forename: V
authors.initials: V
authors.lastname: Chandramouli
authors.forename: C G
authors.initials: CG
authors.lastname: Ostenson
authors.forename: B
authors.initials: B
authors.lastname: Ahrén
authors.forename: W C
authors.initials: WC
authors.lastname: Schumann
authors.forename: H
authors.initials: H
authors.lastname: Löw
authors.forename: B R
authors.initials: BR
authors.lastname: Landau
authors.forename: S
authors.initials: S
authors.lastname: Efendić
mesh_terms: D000818:Animals; D001834:Body Water / Q000378:metabolism; D002250:Carbon Radioisotopes; D005947:Glucose / Q000378:metabolism*; D066298:In Vitro Techniques; D007515:Islets of Langerhans / Q000378:metabolism*; D051379:Mice; D008820:Mice, Obese; D010766:Phosphorylation; D011865:Radioisotope Dilution Technique; D014316:Tritium
chemical_list: D002250:Carbon Radioisotopes; D014316:Tritium; D005947:Glucose