Phosphorylation of d- Glucosamine by Brain Extracts

DURING an investigation into the relationship between acetylcholine synthesis and carbohydrate metabolism in the central nervous system, it became important for us to study the inhibitory action of glucose and fructose on the rate of acetyl-choline formation by extracts of acetone-dried brain powder. Acetylcholine synthesis in such extracts and in homogenates proceeds rapidly under anaerobic conditions provided adenosinetriphosphate is present 1 2. Feldberg and Mann1 also reported an inhibitory action of hexoses on this process. They made the suggestion that the sugars exercised their effects by being phos-phorylated at the expense of adenosinetriphosphate, the quantity of the latter thus being diminished and the rate of acetylcholine synthesis being correspondingly decreased.