Dissociated effects of 2-deoxy-D-glucose on D-[2-3H]glucose and D-[5-3H]glucose conversion into 3HOH in rat erythrocytes.
When rat erythrocytes were preincubated with 2-deoxy-D-glucose, the generation of both 3H-labelled acidic metabolites and 3HOH from D-[5-3H]glucose, the total production of L-lactate, and the generation of 14CO2, 14C-labelled acidic metabolites and 14C-labelled lactate from D-[1-14C]glucose or D-[U-14C]glucose were all lower than in erythrocytes preincubated in the absence of a hexose or in the presence of 3-O-methyl-D-glucose. However, preincubation with 2-deoxy-D-glucose failed to decrease the generation of 3H-labelled acidic metabolites and L-[3-3H]lactate from D-[2-3H]glucose, while decreasing the production of 3HOH more severely from D-[2-3H]glucose than from D-[5-3H]glucose. This may be attributable not solely to inhibition of D-glucose phosphorylation by 2-deoxy-D-glucose and 2-deoxy-D-glucose 6-phosphate, but also to inhibition by 2-deoxy-D-glucose 6-phosphate of hexose 6-phosphate interconversion in the reaction catalysed by phosphoglucoisomerase, as also observed with the purified enzyme. The generation of 3HOH from D-[2-3H]glucose should therefore be considered as a tool to assess the efficiency of interconversion of hexose 6-phosphates in the reaction catalysed by phosphoglucoisomerase, rather than to estimate D-glucose phosphorylation rate.
Manuel y Keenoy
B
B
Laboratoire de Médecine Expérimentale, Faculté de Médecine Erasme, Université Libre de Bruxelles, Belgium.
Zähner
D
D
Malaisse
W J
WJ
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism*; D003847:Deoxyglucose / Q000494:pharmacology*; D004912:Erythrocytes / Q000378:metabolism*; D005956:Glucose-6-Phosphate Isomerase / Q000097:blood; D005958:Glucosephosphates / Q000097:blood*; D066298:In Vitro Techniques; D007536:Isomerism; D007700:Kinetics; D007773:Lactates / Q000097:blood; D010766:Phosphorylation; D051381:Rats; D014867:Water / Q000378:metabolism
D001786:Blood Glucose; D005958:Glucosephosphates; D007773:Lactates; D014867:Water; D003847:Deoxyglucose; D005956:Glucose-6-Phosphate Isomerase