Involvement of glial cells in cyclosporine-increased permeability of brain endothelial cells.

1. To test whether astrocytes participate in cyclosporine-induced dysfunction of the blood-brain barrier, we examined the effects of cyclosporine on the permeability of the mouse brain endothelial (MBEC4) cells cocultured with C6 glioma cells, each cell layer placed on the top and bottom of the insert membrane, respectively. 2. The presence of C6 cells remarkably aggravated cyclosporine-increased permeability of MBEC4 cells to sodium fluorescein. 3. In light of these findings, the possibility that astroglial cells could contribute to the occurrence of cyclosporine-induced dysfunction of the blood-brain barrier triggering neurotoxicity should be considered.