Uptake of 2-deoxy-D-glucose by cortical synaptosomes from the Long-Evans rat.

Uptake of 2-deoxy-D-glucose (2-DG) has been studied in synaptosomes from the Long-Evans rat. Although there are some differences, the results are generally similar to those reported for Sprague--Dawley rats. Both D-glucose and 2-DG are taken up by the same carrier, since D-glucose was found to inhibit uptake of 2-DG. Uptake is highly dependent on a source of metabolic energy, since incubation at 0 degrees C completely eliminated uptake, while 10(-3) M 2,4-dinitrophenol (DNP) inhibited uptake by 76.5%. Uptake has also been measured as a function of both 2-DG and sodium concentration and the data fitted to a model. Sodium is found to inhibit uptake. A model assuming noncompetitive inhibition by sodium gives best fit to the data. Thus both Kt and apparent Vm are dependent on the sodium concentration. Although these effects are small, Kt increases with [Na], while apparent Vm declines.