Differential effects of infused nutrients on 2-deoxy-D-glucose- and 2-mercaptoacetate-induced feeding.

We examined the effects of glucose, lipid, or fructose infusion on 2-deoxy-D-glucose (2DG)- and 2-mercaptoacetate (MA)-induced feeding. Rats with chronic intra-atrial catheters were infused for 15 min with one of the above nutrients and then injected with 2DG or MA. The nutrient infusion continued for the next 2 h and food intake was simultaneously measured. For control conditions, equitonic saline was infused, and 2DG, MA, or saline was injected. We found that glucose was the only nutrient source capable of significantly reducing 2DG-induced feeding. Equicaloric infusions of lipid or fructose did not significantly reduce 2DG-induced feeding. However, feeding induced by MA was similarly and significantly reduced by glucose, lipid, and fructose. These results suggest that 2DG-induced feeding is mediated by receptor cells that are selectively responsive to glucose availability, and MA-induced feeding is mediated by receptor cells that are responsive to a wider range of metabolic fuels.