Structural and physiological features of blood-brain barrier

Masaki Ueno

Department of Pathology and Host Defense, Faculty of Medicine, Kagawa University

The blood-brain barrier is built up by a monolayer of endothelial cells lining brain capillaries that restricts the movement of macromolecules between the blood and the brain interstitial fluid. Several kinds of transporters located at the capillaries play roles in influx transport of essential nutrients to the brain and efflux transport of toxic substances from the brain. In this way, physiological environment in the brain are maintained under fixed conditions. In addition, it is supposed that enzymatic degradation, cellular uptake, and perivascular lymphatic drainage pathway contributes to efflux transport of interstitial fluids or molecules from the brain. Clarifying mechanisms of clearance of interstitial fluids including toxic substances from the brain may be necessary for development of fundamental therapy of several kinds of brain diseases as well as elucidation of the pathogenesis of them.

Address correspondence to Dr. Masaki Ueno, Department of Pathology and Host Defense, Faculty of Medicine, Kagawa University(1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan)