Abstract
Abstract: :
Purpose:Facilitative glucose transporters (GLUTs) of the blood-retinal barrier (BRB) are important in the function and pathology of the retina. GLUT8 is a newly discovered facilitative glucose transporter in human and animals. GLUT8 is modulated in brain-ganglion cells in diabetic rats but has never been reported in the BRB where GLUT1 is believed to be the exclusive GLUT. Methods:GLUT8 expression was determined by confocal microscopy, Northern, western, plasma membrane and cytosolic fractions and by in situ analysis of BRB. Results:GLUT8 (like GLUT1) was present in the inner and outer BRB and the ganglion layer in retina. Approximately 25% of GLUT8 is present in the plasma membrane of the BRB and the remainder in microsomal (perinuclear Golgi) fractions. Conclusion:GLUT8 is expressed at high levels in the BRB and distributed in both the plasma membrane and Golgi. GLUT1 is not the exclusive GLUT of the BRB. Possible regulation of expression of GLUT8 by glucose, cytokines and growth factors may contribute to the disruption of BRB in diabetes.
Keywords: 342 cell membrane/membrane specializations • 331 blood supply • 388 diabetic retinopathy