Photoinactivation of sodium-potassium-chloride cotransport in LLC-PK1/Cl 4 cells by bumetanide
Rb+ uptake into LLC-PK1/Cl 4 cells can be subdivided into three components: 1) ouabain-sensitive uptake, 2) bumetanide-sensitive uptake, and 3) ouabain- and bumetanide-insensitive uptake. Exposure of cells to near-UV light in the presence of low concentrations of bumetanide produces a specific, irreversible inhibition of the bumetanide-sensitive uptake component, while not affecting the other two uptake components. Irreversible inhibition of bumetanide-sensitive transport is observed when measuring either cellular uptake or efflux and also when measuring /sup 86/Rb+ uptake into membrane vesicles. The irreversible inhibition is both concentration and time dependent and is blocked under conditions where the interaction of bumetanide with the Na+-K+-Cl- cotransporter is disturbed. We conclude that bumetanide, at low concentrations, can specifically and irreversibly inhibit the Na+-K+-Cl- cotransporter of LLC-PK1/Cl 4 cells. We suggest that this irreversible inhibition is the result of the photoactivation of an ether linkage in the bumetanide molecule, leading to a covalent binding of bumetanide to the Na+-K+-Cl- cotransporter.
- Research Organization:
- Max-Planck-Institut fuer Systemphysiologie, Dortmund, Germany, F.R.
- OSTI ID:
- 5654165
- Journal Information:
- Am. J. Physiol.; (United States), Journal Name: Am. J. Physiol.; (United States); ISSN AJPHA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
ALKALI METAL COMPOUNDS
ALKALI METAL ISOTOPES
ANIMAL TISSUES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BODY
CARBOHYDRATES
CARDIAC GLYCOSIDES
CARDIOTONICS
CARDIOVASCULAR AGENTS
CHEMISTRY
CHLORINE COMPOUNDS
COVALENCE
DAYS LIVING RADIOISOTOPES
DIURETICS
DOMESTIC ANIMALS
DRUGS
EPITHELIUM
GLYCOSIDES
HALOGEN COMPOUNDS
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MAMMALS
MEMBRANE TRANSPORT
MINUTES LIVING RADIOISOTOPES
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
OUABAIN
PHOTOCHEMISTRY
POTASSIUM COMPOUNDS
RADIOISOTOPES
REACTION KINETICS
RUBIDIUM 86
RUBIDIUM ISOTOPES
SODIUM COMPOUNDS
STROPHANTHINS
SWINE
TISSUES
TRACER TECHNIQUES
UPTAKE
VERTEBRATES