[PDF][PDF] Route of passive ion permeation in epithelia

E Fromter, J Diamond - Nat New Biol, 1972 - jareddiamond.org
EPITHELIA are uninterrupted sheets of cells surrounding cavities and held together at the
luminal surface by junctional complexes “3 (Fig. 1). The question of whether permeating
substances traverse epithelia through the cells themselves or through the junctions has long
been a problem. While proteins and large colloidal tracers are generally stopped at. the
zonula occludens or “tight junction”, junctions could still be leaky to small molecules such as
water, inorganic ions, and small non-electrolytes. Recent physiological evidence “" 11 …