A STUDY OF IN-VITRO BLOOD-BRAIN-BARRIER MODEL BY ENDOTHELIAL-CELLS AND ASTROCYTES CULTURE

We have examined the effects of astrocytes on the permeability of endothelial cell monolayer in the in vitro Blood-Brain Barrier (BBB) models, using bovine aortic endothelial cells (BAEC) and bovine brain endothelial cells (BBEC) cocultured with astrocytes. In the system 1 where astrocyts were apart from endothelial cells, the permeability of BBEC monolayer for L-glucose which passes through the intercellular space between endothelial cells, was reduced by a cocultivation with astrocytes. In contrast, in the system 2 where astrocytes and endothelial cells layered on and across a membrane, respective up-side and bottom side of the membrane, the permeability of BAEC as well as BBEC monolayers was reduced by a cocultivation with astrocytes. These results suggest that the primary cultured BBEC which had been already primed by astrocytes in vivo, retains a higher sensitivity to an astrocytic soluble factor(s) to exhibit BBB phenotypes, but BAEC from extra-neural tissues was primed only by astrocytes very closely neighboring in vitro, and then may acquire BBB phenotypes.