Developmental expression of glucokinase in rat hypothalamus

Neurons in the hypothalamus sense changes in glucose concentration. Glucokinase (GK), a key enzyme for pancreatic (β)-cell glucose sensing, was found in both the embryonic and adult hypothalamus. GK activity accounted for approximately 20% of total hexokinase (HK) activity in both embryonic and adult hypothalamus with no activity measured in cortical samples, indicating that glucose sensing in the hypothalamus initiates early in development and precedes the maturation of glucose signaling in liver.