Evidence for a K/sup +/-H/sup +/ exchanger in rabbit renal cortical brush-border membrane vesicles

Journal Article · Wed Dec 31 23:00:00 EST 1986 · Ga. J. Sci.; (United States)

OSTI ID:5409542

Miyamoto, Y; Tiruppathi, C; Ganapathy, V; Leibach, F H

An outward-directed H/sup +/ gradient stimulated /sup 86/Rb/sup +/ uptake in brush-border membrane vesicles isolated from rabbit renal cortex. This H/sup +/ gradient-stimulated /sup 86/Rb/sup +/ uptake was inhibited by unlabeled K/sup +/ (IC/sub 50/ = 7.5 mM). The carrier system responsible for this uptake is different from the Na/sup +/-H/sup +/ exchanger, because inhibitors of the Na/sup +/-H/sup +/ exchanger did not affect or affected minimally the /sup 86/Rb/sup +/ uptake whereas these compounds caused 60-85% inhibition of the /sup 22/Na/sup +/ uptake. Moreover, /sup 86/Rb/sup +/ uptake was preferentially inhibited by unlabeled K/sup +/ and Rb/sup +/ whereas /sup 22/Na/sup +/ uptake was preferentially inhibited by Na/sup +/ and Li/sup +/. Furosemide, an inhibitor of the Na/sup +/-K/sup +/-2Cl/sup -/ cotransporter and Ca/sup 2 +/ and Ba/sup 2 +/, modulators of the K/sup +/-channel did not affect /sup 86/Rb uptake in the renal brush-border membrane vesicles, indicating that these transport mechanisms were also not responsible for the observed /sup 86/Rb/sup +/ uptake. These results provide evidence for the presence of a distinct K/sup +/-H/sup +/ exchanger in renal cortical brush-border membrane vesicles.

• Research Organization: Medical College of Georgia, Augusta (USA)
• OSTI ID: 5409542
• Journal Information: Ga. J. Sci.; (United States), Journal Name: Ga. J. Sci.; (United States) Vol. 45:2; ISSN GJSCD
• Country of Publication: United States
• Language: English

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550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALI METAL COMPOUNDS
ALKALI METAL ISOTOPES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BODY
CATIONS
CELL CONSTITUENTS
CELL MEMBRANES
CHARGED PARTICLES
DAYS LIVING RADIOISOTOPES
HYDROGEN IONS
INHIBITION
INTERMEDIATE MASS NUCLEI
IONS
ISOMERIC TRANSITION ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KIDNEYS
LIGHT NUCLEI
MAMMALS
MEMBRANE TRANSPORT
MEMBRANES
MINUTES LIVING RADIOISOTOPES
NUCLEI
ODD-ODD NUCLEI
ORGANS
POTASSIUM COMPOUNDS
RABBITS
RADIOISOTOPES
RUBIDIUM 86
RUBIDIUM COMPOUNDS
RUBIDIUM ISOTOPES
SODIUM 22
SODIUM COMPOUNDS
SODIUM ISOTOPES
TRACER TECHNIQUES
VERTEBRATES
YEARS LIVING RADIOISOTOPES