Question

How is paracellular ion permeability at tight junctions determined?

Answer 1

Permeability of paracellular ion:

1. The paracellular (junction or pathway around cells) pathway involves the movement of ions across intercellular spaces between epithelial cells.
2. The permeability of the paracellular ions depends on the claudin proteins (found at tight junctions).
3. The claudin proteins are transmembrane proteins that help to form the gated ion-selective paracellular pores via the paracellular diffusion barrier.
4. Tight junctions found at the apical cell-cell interactions of adjacent epithelial cells act as the gatekeeper of paracellular ions.