IMMUNOLOGICAL ANALYSIS OF GLUCOSE TRANSPORTERS EXPRESSED IN DIFFERENT REGIONS OF THE RAT-BRAIN AND CENTRAL-NERVOUS-SYSTEM

Glucose is the major energy source for brain tissue. It is now well established that glucose crosses the blood-brain barrier by facilitated diffusion mediated by the erythrocyte-type (GLUT 1) glucose transporter. Northern blot analysis has indicated that brain tissue expresses two different glucose transporters, the erythrocyte-type transporter and the brain-type transporter (GLUT 3). Here we use a panel of antibodies specific for four glucose transporters to examine the distribution of these transporters in various regions of rat brain and central nervous system. We show that GLUT 1 and GLUT 3 are expressed in virtually all regions of the brain examined, but that the relative levels of the proteins differ. We also demonstrate that GLUT 2 appears to be widely expressed in all brain regions, but at apparently low levels. In addition, GLUT 4 is expressed in the pituitary, the hypothalamus and the medulla. These results are discussed in the light of potential glucose-regulated processes in the brain. © 1993 Academic Press, Inc.