Transporter Localization in the Blood-Brain Barrier Brain Interstitial Space Basolateral --------------------- OCTN1 ----- OCTN2 ----- OAT3 ----------------------- | | | | | | \_/ \_/ \_/ | | | | Brain capillary endothelial cells | | | | _ _ | | / \ / \ | | | | | --- OATP1A2 -- OATP2B1 -- MDR1 -- BCRP -- MRP1 -- MRP2 -- MRP4 -- MRP5 --- Blood | | | | | | Apical/luminal \_/ \_/ \_/ \_/ \_/ \_/ arrows denote primary direction of transport
The image shows a simplified cell outline with marked basolateral side facing the brain interstitial space and apical/luminal side facing the blood. OCTN1, OCTN2, and OAT3 are placed as influx transporters on the basolateral side. OATP1A2 and OATP2B1 are apical influx transporters; while MDR1, BCRP, MRP1, MRP2, MRP4, and MRP5 are apical efflux transporters.