Editorial Focus ICAM-1: role in inflammation and in the regulation of vascular permeability

exchange between blood and peripheral tissues. The regulation of vascular permeability is an essential and critical function that is effectively carried out by the endothelium (12). This function is important since endothelial cells will regulate or prevent the specific infiltration of molecules and cells into organs such as the brain. Vascular permeability has been shown to be affected in a number of disease states such as cancer and atherosclerosis as well as in infections. Molecules can be transported via two major pathways across the endo-thelium. They can be transferred from the lumen of blood vessels via a pathway termed transcytosis. This pathway allows the transfer of molecules across endothelial cells and has been shown to be regulated by caveolae (4, 15). In addition, trans-port across the endothelium can occur via a paracellular path-way that involves the transport of molecules between endothe