Vascular endothelial growth factor: a novel endocrine defensive response to hypoglycemia.

Glucose, the most important fuel for the brain, is supplied by the actions of counterregulatory hormones and the sympathetic nervous system. Yet to obtain access to the brain, glucose must pass the blood-brain barrier. Here we show that vascular endothelial growth factor (VEGF), a potent regulator of blood vessel function, is a candidate hormone for facilitating glucose passage across the blood-brain barrier under critical conditions.