GLUCOSE EXPORT FROM THE BRAIN IN MAN - EVIDENCE FOR A ROLE FOR ASTROCYTIC GLYCOGEN AS A RESERVOIR OF GLUCOSE FOR NEURAL METABOLISM

We report transients of net export of glucose from brain with jugular venous glucose content exceeding arterial by up to 5.3 mmol.l(-1) in 1 9 children undergoing cardiopulmonary bypass surgery. The magnitude of the release implies the presence of a glucose reservoir in brain, the most likely candidate being astrocytic glycogen. These data provide e vidence that astrocytic glycogen can be exported as glucose, permittin g spatial and temporal modulation of glucose delivery to neurons.