Format

Send to

Choose Destination
Brain Res. 2001 Jun 15;904(1):20-30.

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

Author information

1
Department of Neurological Surgery, Cerebrovascular Research Center, Cleveland Clinic Foundation/NB20, 9500 Euclid Avenue, Cleveland, OH 44195, USA.

Abstract

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.

PMID:
11516408
DOI:
10.1016/s0006-8993(01)02418-0
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center