Astrocytes enhance radical defence in capillary endothelial cells constituting the blood-brain barrier

Astrocytes (AC) induce blood-brain barrier (BBB) properties in brain endoth elial cells (EC), As antioxidative activity (AOA) is assumed to be a BBB ch aracteristic, we tested whether AC improve AOA of EC, Monocultivated AC sho wed higher AOA [manganese superoxide dismutase (SOD), catalase (Cat), gluta thione peroxidase (GPx)] than EC, Cocultivation elevated AOA in EC (MnSOD, CuZnSOD, Cat, GPx), and AC (MnSOD, CuZnSOD, GPx), Hypoxia increased radical -induced membrane lipid peroxidation in monocultivated, but not in cocultiv ated EC, Thus, EC/AC cocultivation intensifies AOA in both cell types, prot ects the EC, and therefore, the BBB against oxidative stress. The high AOA is regarded as an essential property of the BBB, which is induced by AC, (C ) 1999 Federation of European Biochemical Societies.