TJ or zonula occludens (ZO) are the first and the least permeable membrane for
paracellular transport of proteins formed by several transmembrane proteins, and they connect intercellularly to one another between cells in the extracellular space.
The
paracellular transport relies on intestinal permeability.
diffusional
paracellular transport directly through cell-cell junctions (Hill and Shachar-Hill, 2006; Murakami et al.
11: Effect of extracellular calcium concentration on the
paracellular transport of drugs of different lipophilicities across monolayers of intestinal epithelial (Caco-2) cells.
TJs seal the intercellular spaces between cells and regulate
paracellular transport of water, ions, and solutes (Proksch et al.
As claudin-1 has two extra cellular loops that display variability in the distribution and number of charged residues, it is the major determinant of ionic selectivity in
paracellular transport processes (Gonzalez et al.
Therefore the enhancement of
paracellular transport path is most likely to be responsible for increased passive transport of calcium in the intestine of rats fed high calcium diet.
The
paracellular transport of lactulose was significantly reduced in cases (median: 0.
Recently these structures that give rise to
paracellular transport have been shown to contain a relatively large amount of protein.
Alessio Fasano, zonulin appears to be involved in many disease states in which leakage occurs via
paracellular transport across epithelial and endothelial tight junctions (tj), and thus may play an important potential role in the treatment of autoimmune diseases.
The adjacent cells adhere through tight junctions formed at the apical side of the monolayer, which can discriminate the transcellular and
paracellular transport of drugs across the epithelial layer (Yamashita et al.
However, up to now it has not been fully revealed whether the increased macromolecular passage is mainly due to transcellular or
paracellular transport.
