Glucose cycling is markedly enhanced in pancreatic islets of obese hyperglycemic mice.
Pancreatic islets from fed 7-month old lean and obese hyperglycemic mice (ob/ob) were incubated with 3H2O and 5.5 mM or 16.7 mM glucose. Incorporation of 3H into the medium glucose was taken as the measure of glucose-6-P hydrolysis to glucose. Glucose utilization was measured from the yield of 3H2O from [5-3H]glucose. Only 3-4% of the glucose phosphorylated was dephosphorylated by the lean mouse islets irrespective of the glucose concentration. In contrast, the ob/ob mouse islets at 5.5 mM glucose dephosphorylated 18% of the glucose phosphorylated and 30% at 16.7 mM. Thus, the islets of hyperglycemic mice demonstrate increased glucose cycling as compared to the islets of normoglycemic lean mice.
Khan
A
A
Department of Endocrinology, Karolinska Hospital, Stockholm, Sweden.
Chandramouli
V
V
Ostenson
C G
CG
Berggren
P O
PO
Löw
H
H
Landau
B R
BR
Efendic
S
S
D000818:Animals; D005947:Glucose / Q000378:metabolism*; D019298:Glucose-6-Phosphate; D005958:Glucosephosphates / Q000378:metabolism; D006868:Hydrolysis; D007515:Islets of Langerhans / Q000378:metabolism*; D007700:Kinetics; D051379:Mice; D008820:Mice, Obese; D010766:Phosphorylation; D014316:Tritium
D005958:Glucosephosphates; D014316:Tritium; D019298:Glucose-6-Phosphate; D005947:Glucose