Biomaterial Database

Hydrogen peroxide inhibits cAMP-induced Cl- secretion across colonic epithelial cells. 1998

M D DuVall, and Y Guo, and S Matalon

Department of Anesthesiology, University of Alabama, Birmingham, Alabama 34294, USA.

We examined the effects of H2O2 on Cl- secretion across human colonic T84 cells grown on permeable supports and mounted in modified Ussing chambers. Forskolin-induced short-circuit current, a measure of Cl- secretion, was inhibited in a concentration-dependent fashion when monolayers were pretreated with H2O2 for 30 min (30-100% inhibition between 500 microM and 5 mM). Moreover, H2O2 inhibited 76% of the Cl- current across monolayers when the basolateral membranes were permeabilized with nystatin (200 micrograms/ml). When the apical membrane was permeabilized with amphotericin B, H2O2 inhibited the Na+ current (a measure of Na+-K+-ATPase activity) by 68% but increased the K+ current more than threefold. In addition to its effects on ion transport pathways, H2O2 also decreased intracellular ATP levels by 43%. We conclude that the principal effect of H2O2 on colonic Cl- secretion is inhibitory. This may be due to a decrease in ATP levels following H2O2 treatment, which subsequently results in an inhibition of the apical membrane Cl- conductance and basolateral membrane Na+-K+-ATPase activity. Alternatively, H2O2 may alter Cl- secretion by direct action on the transporters or alterations in signal transduction pathways.

UI	MeSH Term	Description	Entries
D007413	Intestinal Mucosa	Lining of the INTESTINES, consisting of an inner EPITHELIUM, a middle LAMINA PROPRIA, and an outer MUSCULARIS MUCOSAE. In the SMALL INTESTINE, the mucosa is characterized by a series of folds and abundance of absorptive cells (ENTEROCYTES) with MICROVILLI.	Intestinal Epithelium,Intestinal Glands,Epithelium, Intestinal,Gland, Intestinal,Glands, Intestinal,Intestinal Gland,Mucosa, Intestinal
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D007770	L-Lactate Dehydrogenase	A tetrameric enzyme that, along with the coenzyme NAD+, catalyzes the interconversion of LACTATE and PYRUVATE. In vertebrates, genes for three different subunits (LDH-A, LDH-B and LDH-C) exist.	Lactate Dehydrogenase,Dehydrogenase, L-Lactate,Dehydrogenase, Lactate,L Lactate Dehydrogenase
D008564	Membrane Potentials	The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).	Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D009761	Nystatin	Macrolide antifungal antibiotic complex produced by Streptomyces noursei, S. aureus, and other Streptomyces species. The biologically active components of the complex are nystatin A1, A2, and A3.	Fungicidin,Mycostatin,Nilstat,Nystatin A1,Nystatin A2,Nystatin A3,Nystatin G,Stamicin,Stamycin
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
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
D002712	Chlorides	Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.	Chloride,Chloride Ion Level,Ion Level, Chloride,Level, Chloride Ion
D003106	Colon	The segment of LARGE INTESTINE between the CECUM and the RECTUM. It includes the ASCENDING COLON; the TRANSVERSE COLON; the DESCENDING COLON; and the SIGMOID COLON.	Appendix Epiploica,Taenia Coli,Omental Appendices,Omental Appendix,Appendices, Omental,Appendix, Omental