Figure 6. Schematic representation of the proposed mechanism by which arcuate nucleus glucokinase regulates glucose intake.
(A) Representation when only one diet is available. When mixed food is ingested, glucose is released and enters the arcuate nucleus. Metabolism of the glucose by glucokinase results in closure of the KATP channel and increased NPY release. The increase in NPY stimulates further food intake. The normal satiety process would terminate the feeding response. (B) Representation when a rich source of glucose is available in addition to normal diet. If pure glucose or a food high in glucose is available, the positive feedback loop will be more active. This will result in a preferential intake of the food with a high glucose concentration and reduced intake of the mixed diet.