Expression of Na, K-ATPase at the Blood-Brain Interface

A closed regulation of ionic composition in the brain is a prerequisite for normal neuronal functions and for the maintenance of physiological brain volume and intracranial pressure. The blood-brain barrier (BBB) and choroid plexus play the chief roles in preserving relatively constant K+ and Na+ concentrations in extracellular fluid (ECF) and cerebrospinal fluid (CSF) of the brain despite variations in plasma levels of these ions (1). Na, K-ATPase is a key enzyme that catalyzes active transport of K+ and Na+ between blood, ECF and CSF.