Blood-brain barrier permeability to small and large molecules

The objective of this article is to provide the reader with an update of so me of the BBB research highlights which have occurred in recent times, and to review the impact and contributions of immunogold electron microscopic s tudies on our understanding of the brain capillary endothelium. Glucose and monocarboxylic acids are two small molecules which this review will focus upon; and advances in immunogold characterization of the GLUT1 glucose tran sporter and the MCT1 and MCT2 monocarboxylic acid nutrient transporters wil l be discussed. Human serum albumin is chosen as a representative large mol ecule, and it has recently been shown that immunogold identification of thi s protein can serve as an indicator of compromised BBB function in a variet y of pathophysiological conditions. (C) 1999 Elsevier Science B.V. All righ ts reserved.