Paracellular Pores in Endothelial Barriers
Luca Manzi and Gianfranco Bazzoni
The endothelium is an efficient barrier located at the boundary between vascular and
perivascular compartments. However, it is also regarded to as a permeable filter that
contains aqueous pores and allows selective passage of solutes between these compartments. Two distinct routes of permeability have been identified, namely the transcellular pathway (which crosses the apical and basolateral membranes of individual cells) and the paracellular pathway (which passes through the intercellular tight junctions between contacting cells). Here, we focus on the molecular architecture of the tight junctions, as an initial attempt to outline the molecular determinants of paracellular permeability.