ALTERATIONS IN TRANSENDOTHELIAL ELECTRICAL-RESISTANCE BY VASOACTIVE AGONISTS AND CYCLIC-AMP IN A BLOOD-BRAIN-BARRIER MODEL SYSTEM

We have previously reported that the co-culture of endothelial and gli oma cell lines provides an in vitro model for investigating properties of the blood-brain barrier (BBB). To characterise the model system fu rther we have investigated the effects of vasoactive substances implic ated in increases in BBB permeability. Additionally, we have also exam ined whether activation of cyclic AMP signalling pathways, which eleva te cerebral endothelial cell barrier function, similarly modulate our model system. ATP, histamine, bradykinin, and serotonin significantly decreased model BBB transendothelial electrical resistance and manipul ations which elevate cyclic AMP enhanced culture resistance. These dat a indicate that our model BBB system responds in a manner characterist ic of cerebral microvascular endothelial cells and the BBB in vivo. Th ese data further emphasize the usefulness of our model system.