Use of Cocultures to Measure the Blood-Brain Barrier Permeability of Oxytocin.

Primary monkey brain capillary endothelial cell cultures, with rat pericytes and astrocytes, provide an assay system for predicting the ability of oxytocin (OT) to cross the blood-brain barrier (BBB), using a commercially available in vitro BBB kit. The integrity of the in vitro "BBB," which has a high transendothelial electrical resistance (TEER), can be established approximately 4 days after preparations for experiments. Dominant endothelial transport of OT is from the upper (luminal blood side) to lower (abluminal brain side) chambers, dose-dependently. OT is transported by the receptor for advanced glycation end-products (RAGE) in endothelial cells, which is evidenced using the RAGE knockdown system with short hairpin RNA (shRNA) treatment. This in vitro assay system is useful for further assessment of OT transport across the BBB.