5-Thio-D-glucose causes increased feeding and hyperglycemia in the rat

5-Thio-D-glucose (5TG) is a novel antimetabolic glucose analogue in which sulfur is substituted for the pyranose ring oxygen. Intracardiac infusion of 5TG caused dose-dependent increases in feeding and blood glucose concentrations. Increased food intake was reliably elicited by molar doses of 5TG that were one-third those necessary to reliably elicit feeding using 2-deoxy-D-glucose (2DG). 5TG also caused marked dose-related hyperglycemia. Plasma glucose concentrations after 5TG rose to levels 3 to 4.6 times as high as those measured after equimolar 2DG. 5TG-induced hyperglycemia was reduced by only 40% after adrenalectomy. These results, taken together with known differences in the biochemical modes of action for 2DG and 5TG, suggest that feeding elicited by 5TG may result from interference with metabolic events different from or additional to those affected by 2DG. 5TG should be a useful new tool for investigation of the physiology of feeding behavior.