Apical membrane sodium (Na sup + ) channels are inhibited by peroxynitrite (ONOO-), but not by oxygen radicals

Conference · Mon Mar 11 04:00:00 EST 1991 · FASEB Journal (Federation of American Societies for Experimental Biology); (United States)

OSTI ID:5863234

Bauer, M L; Bridges, R J; Beckman, J S; Matalon, S ^[1]

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1. Childrens Hospital, Birmingham, AL (United States) Univ. of Alabama, Birmingham (United States)

More than 80% of Na{sup +} uptake into rat colon epithelial cell membrane vesicles from dexamethasone-treated rats occurs through 1{mu}M amiloride sensitive sodium channels. The authors compared the effects of hydrogen peroxide (H{sub 2}O{sub 2}), xanthine (X) plus xanthine oxidase (XO), and ONOO- on Na{sup +} uptake into these vesicles. K{sub 2}SO{sub 4} filled membrane vesicles were prepared by homogenization and centrifugation of freshly isolated rat colonic epithelial cells. Vesicles were incubated with H{sub 2}O{sub 2}, X plus XO, or ONOO-. Carrier free {sup 22}Na{sup +} uptake into vesicles was measured in the presence of an inside negative membrane potential, produced by the addition of potassium (K+) ionophore valinomycin (10{mu}M) after removal of all external K+ by cation exchange chromatography. The amiloride-sensitive fraction of Na{sup +} uptake was inhibited 27{plus minus}7% and 65{plus minus}2% by 100{mu}M and 1mM ONOO- respectively. Neither inactivated ONOO-, H{sub 2}O{sub 2}, nor X plus XO inhibited Na{sup +} uptake. These data suggest that ONOO- is a potent injurious agent that can compromise Na{sup +} uptake across epithelial cells, possibly by damaging sodium channels.

• OSTI ID: 5863234
• Report Number(s): CONF-9104107--
• Conference Information: Journal Name: FASEB Journal (Federation of American Societies for Experimental Biology); (United States) Journal Volume: 5:4
• Country of Publication: United States
• Language: English

Related Subjects

560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALKALI METAL COMPOUNDS
ALKALI METAL ISOTOPES
ANIMAL TISSUES
ANIMALS
AROMATICS
AZAARENES
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
BODY
CELL CONSTITUENTS
CELL MEMBRANES
COMPARATIVE EVALUATIONS
DIGESTIVE SYSTEM
ELEMENTS
ENZYMES
EPITHELIUM
EVALUATION
GASTROINTESTINAL TRACT
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
HYDROGEN PEROXIDE
INTESTINES
ISOMERIC TRANSITION ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LARGE INTESTINE
LIGHT NUCLEI
MAMMALS
MEMBRANE TRANSPORT
MEMBRANES
NANOSEC LIVING RADIOISOTOPES
NONMETALS
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANS
OXIDOREDUCTASES
OXYGEN
OXYGEN COMPOUNDS
PEROXIDES
PROTEINS
PURINES
RADICALS
RADIOISOTOPES
RATS
RODENTS
SODIUM 22
SODIUM COMPOUNDS
SODIUM ISOTOPES
TISSUES
TRACER TECHNIQUES
VERTEBRATES
XANTHINES
YEARS LIVING RADIOISOTOPES