Microinfusion of 5-thioglucose into either the lateral or fourth cerebral ventricle caused increased feeding and hyperglycemia in rats when the cerebral aqueduct was unobstructed. If the aqueduct was obstructed and 5-thioglucose was infused into the fourth ventricle, increased feeding and hyperglycemia persisted, whereas feeding and hyperglycemia in response to lateral ventricle infusion were abolished. Drinking in response to infusion of angiotensin II into the lateral ventricle was not diminished by aqueduct obstruction. These results indicate that glucoreceptors that mediate feeding and hyperglycemia in response to cerebral glucoprivation are located in the caudal hindbrain and not in the hypothalamus where they have previously been sought.
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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.