title: Low permeabilities of apical membranes of barrier epithelia: what makes watertight membranes watertight?
abstract: Several epithelia, including those of collecting duct (in the absence of antidiuretic hormone), thick ascending limb of Henle, and mammalian bladder exhibit extremely low permeabilities for water, small nonelectrolytes like urea, and protons. This brief review describes how apical membrane structure might account for these low permeabilities by incorporating recent biophysical and molecular modeling results.
authors.affiliation: Laboratory of Epithelial Cell Biology, University of Pittsburgh Medical Center, Pennsylvania 15213, USA.
authors.forename: M L
authors.initials: ML
authors.lastname: Zeidel
mesh_terms: D000818:Animals; D002463:Cell Membrane Permeability; D004848:Epithelium / Q000378:metabolism; D005753:Gastric Mucosa / Q000378:metabolism; D006801:Humans; D007668:Kidney / Q000378:metabolism; D008954:Models, Biological; D001743:Urinary Bladder / Q000378:metabolism; D014867:Water / Q000378:metabolism*
chemical_list: D014867:Water