BIOLOGICAL EVALUATION OF 2 ANOMERIC GLUCOSE ANALOGS IODINATED IN POSITION-6

Two anomeric analogues of glucose labelled with 123 iodine in position 6, proposed as tracers of glucose transport in vivo, have been synthe sized: alpha- and beta-methyl-6-deoxy-6-iodo-D-glucopyranoside (alpha MDIG and beta MDIG). The aim of this study was to determine whether th ese molecules interact with the glucose transporter and whether they c ould be used as tracers of glucose transport in vivo. The biodistribut ion of alpha MDIG and beta MDIG was studied in the mouse in vivo. To d etermine if these two anomers enter the cell via the glucose transport er, their uptake was measured in isolated perfused rat hearts, in huma n erythrocytes in suspension, and in cardiomyocytes of neonatal rat in culture. Both alpha MDIG and beta MDIG had similar repartitions in th e mouse: myocardial uptake averaged 7% of the injected dose/g of organ at 2 min postinjection and alpha MDIG competed with D-glucose to ente r the cells. Insulin produced a 123% increase of its uptake in isolate d perfused rat hearts and a 100% increase in cardiomyocytes of neonata l rat in culture, alpha MDIG uptake was lowered in the presence of glu cose transport inhibitors in each experimental model. An interaction b etween beta MDIG and glucose transporters was observed only in human e rythrocytes in suspension. Only alpha MDIG interacts with the glucose transporter, and thus could be used to estimate glucose transport in v ivo. (C) 1997 Elsevier Science Inc.