Anomeric dissociation between glucokinase activity and glycolysis in pancreatic islets
Sener, A.; Giroix, M.H.; Leclercq-Meyer, V.; Marchand, J.; Malaisse, W.J.
Biochemistry International 11(1): 77-84
1985
ISSN/ISBN: 0158-5231 PMID: 3899118 Document Number: 244786
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.