α1-Acid glycoprotein induced effects in rat brain microvessel endothelial cells

► AGP decreased 20% paracellular permeability across RBMEC monolayers. ► RBMECs showed a biphasic response in occludin expression following AGP treatment. ► AGP changed ZO-1 expression of RBMECs in a dose- and time-dependent manner. ► AGP significantly changed transcription factor AP-1 DNA‐binding activity.