Ethanol inhibits G-protein-mediated glucose uptake by C6 glioma cells

THE mechanism of ethanol inhibition of glucose uptake was investigated usin g C6 glioma cells. Basal [H-3]2-deoxy-D-glucose (2DG) uptake by C6 cells wa s inhibited by ethanol in a concentration-dependent manner. Fifty, 75 and 1 00 mM ethanol significantly inhibited basal 2DG uptake by 12, 20 and 23%, r espectively (p < 0.05). Carbachol (an agonist acting via G protein-coupled receptors) stimulated the uptake by 26% (p < 0.05). In the presence of 100 mM ethanol, the ability of carbachol to stimulate 2DG uptake was abolished. In contrast, ethanol did not inhibit the ability of insulin to stimulate 2 DG uptake. These results suggest that ethanol inhibits 2DG uptake by select ively interfering with G protein-mediated signal transduction pathway. (C) 1999 Lippincott Williams & Wilkins.