Structural evaluation of glucose analogues on feeding elicitation in rat

The effects of 12-mumol doses of the glucose analogues glucosamine, 2-fluoroglucose, 2-chloroglucose, 2-deoxyglucose (which were modified at carbon 2 of the glucopyranose ring), 1-aminoglucose and 1-deoxyglucose (modified at carbon 1), on feeding behavior and plasma glucose, insulin, and glycerol were examined after infusion into the rat third cerebroventricle. Plasma glucose and glycerol levels were elevated by glucosamine or 1-aminoglucose. Plasma insulin levels were unchanged by these analogues. Feeding was induced in 62% to 87% of the rats tested after infusion of glucosamine, 2-fluoroglucose, 2-chloroglucose, 2-deoxyglucose, 1-aminoglucose, or 1-deoxyglucose (mean meal size in responding rats, 43.9, 25.8, 22.7, 16.0, 42.3, and 3.8 pellets, respectively). The order of potency to induce feeding was amino, halogen, and hydrogen groups. These data reinforced the concept that the potency of glucose analogues to induce feeding depends on substituents at carbon 1 and carbon 2 of the glucopyranose ring.