Mechanisms of glucose transport at the blood-brain barrier: an in vitro study

Brain Res. 2001 Jun 15;904(1):20-30. doi: 10.1016/s0006-8993(01)02418-0.


How the brain meets its continuous high metabolic demand in light of varying plasma glucose levels and a functional blood-brain barrier (BBB) is poorly understood. GLUT-1, found in high density at the BBB appears to maintain the continuous shuttling of glucose across the blood-brain barrier irrespective of the plasma concentration. We examined the process of glucose transport across a quasi-physiological in vitro blood-brain barrier model. Radiolabeled tracer permeability studies revealed a concentration ratio of abluminal to luminal glucose in this blood-brain barrier model of approximately 0.85. Under conditions where [glucose](lumen) was higher than [glucose](ablumen), influx of radiolabeled 2-deoxyglucose from lumen to the abluminal compartment was approximately 35% higher than efflux from the abluminal side to the lumen. However, when compartmental [glucose] were maintained equal, a reversal of this trend was seen (approximately 19% higher efflux towards the lumen), favoring establishment of a luminal to abluminal concentration gradient. Immunocytochemical experiments revealed that in addition to segregation of GLUT-1 (luminal>abluminal), the intracellular enzyme hexokinase was also asymmetrically distributed (abluminal>luminal). We conclude that glucose transport at the CNS/blood interface appears to be dependent on and regulated by a serial chain of membrane-bound and intracellular transporters and enzymes.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Astrocytes / cytology
  • Astrocytes / metabolism
  • Blood-Brain Barrier / drug effects
  • Blood-Brain Barrier / physiology*
  • Carbon Radioisotopes / pharmacokinetics
  • Cattle
  • Cell Compartmentation / drug effects
  • Cell Compartmentation / physiology
  • Cell Differentiation / physiology
  • Cell Membrane / drug effects
  • Cell Membrane / metabolism
  • Cell Membrane Permeability / physiology
  • Cells, Cultured
  • Coculture Techniques
  • Deoxyglucose / pharmacokinetics
  • Endothelium, Vascular / cytology
  • Endothelium, Vascular / metabolism
  • Fetus
  • Glucose / metabolism*
  • Glucose Transporter Type 1
  • Hexokinase / metabolism
  • Immunohistochemistry
  • Membranes, Artificial
  • Monosaccharide Transport Proteins / drug effects
  • Monosaccharide Transport Proteins / metabolism*
  • Phenotype
  • Rats


  • Carbon Radioisotopes
  • Glucose Transporter Type 1
  • Membranes, Artificial
  • Monosaccharide Transport Proteins
  • Slc2a1 protein, rat
  • Deoxyglucose
  • Hexokinase
  • Glucose