From blood to brain and vice versa: transport processes in choroid plexus can be studied in vitro.

The choroid plexus represents the second barrier between blood and brain besides the blood brain barrier. The barrier function is set up by plexus epithelial cells, which are equipped with a variety of active transport systems. However in contrast to the epithelial organs location and extent of expression of these transporters may be different. Studying the choroid plexus (CP) epithelium in living animals is difficult due to its complex morphology, anatomical location and small size. Therefore, an in vitro monolayer model of choroid plexus was established from porcine brain in order to study the functional contribution of transport proteins to drug transport across CP tissue with special focus on ABC-proteins.