Biomaterial Database

Low permeabilities of apical membranes of barrier epithelia: what makes watertight membranes watertight? 1996

M L Zeidel

Laboratory of Epithelial Cell Biology, University of Pittsburgh Medical Center, Pennsylvania 15213, USA.

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.

UI	MeSH Term	Description	Entries
D007668	Kidney	Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.	Kidneys
D008954	Models, Biological	Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.	Biological Model,Biological Models,Model, Biological,Models, Biologic,Biologic Model,Biologic Models,Model, Biologic
D001743	Urinary Bladder	A musculomembranous sac along the URINARY TRACT. URINE flows from the KIDNEYS into the bladder via the ureters (URETER), and is held there until URINATION.	Bladder,Bladder Detrusor Muscle,Detrusor Urinae,Bladder Detrusor Muscles,Bladder, Urinary,Detrusor Muscle, Bladder,Detrusor Muscles, Bladder
D002463	Cell Membrane Permeability	A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.	Permeability, Cell Membrane
D004848	Epithelium	The layers of EPITHELIAL CELLS which cover the inner and outer surfaces of the cutaneous, mucus, and serous tissues and glands of the body.	Mesothelium,Epithelial Tissue,Mesothelial Tissue,Epithelial Tissues,Mesothelial Tissues,Tissue, Epithelial,Tissue, Mesothelial,Tissues, Epithelial,Tissues, Mesothelial
D005753	Gastric Mucosa	Lining of the STOMACH, consisting of an inner EPITHELIUM, a middle LAMINA PROPRIA, and an outer MUSCULARIS MUCOSAE. The surface cells produce MUCUS that protects the stomach from attack by digestive acid and enzymes. When the epithelium invaginates into the LAMINA PROPRIA at various region of the stomach (CARDIA; GASTRIC FUNDUS; and PYLORUS), different tubular gastric glands are formed. These glands consist of cells that secrete mucus, enzymes, HYDROCHLORIC ACID, or hormones.	Cardiac Glands,Gastric Glands,Pyloric Glands,Cardiac Gland,Gastric Gland,Gastric Mucosas,Gland, Cardiac,Gland, Gastric,Gland, Pyloric,Glands, Cardiac,Glands, Gastric,Glands, Pyloric,Mucosa, Gastric,Mucosas, Gastric,Pyloric Gland
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D014867	Water	A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Hydrogen Oxide