Anomeric dissociation between glucokinase activity and glycolysis in pancreatic islets.
In pancreatic islet homogenates incubated in the presence of a high glucose concentration (40 mM), the beta-anomer of D-glucose is phosphorylated at a higher rate than the alpha-anomer, whether in the absence or presence of exogenous glucose 6-phosphate. However, in intact islets also exposed to 40 mM D-glucose, the production of 3H2O from D-[5-3H] glucose, the oxidation of D-[U-14C] glucose and the glucose-induced increment in either lactate production or 45Ca net uptake, as well as the release of insulin from isolated perfused pancreases, are not higher with beta- than alpha-D-glucose. It is concluded that the rate of glucose utilization by islet cells is not regulated solely by the activity of hexokinase and/or glucokinase.
D000818:Animals; D005941:Glucokinase / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D006019:Glycolysis; D066298:In Vitro Techniques; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000378:metabolism*; D010766:Phosphorylation; D051381:Rats; D013237:Stereoisomerism
D007328:Insulin; D005941:Glucokinase; D005947:Glucose