Bicarbonate sulfate exchange in canalicular rat liver plasma membrane vesicles

Journal Article · Thu Oct 01 00:00:00 EDT 1987 · American Journal of Physiology; (USA)

OSTI ID:7266828

Meier, P J; Valantinas, J; Hugentobler, G; Rahm, I ^[1]

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1. University Hospital, Zurich (Switzerland)

The mechanism(s) and driving forces for biliary excretion of sulfate were investigated in canalicular rat liver plasma membrane vesicles (cLPM). Incubation of cLPM vesicles in the presence of an inside-to-outside (in, out) bicarbonate gradient but not pH or out-to-in sodium gradients, stimulated sulfate uptake 10-fold compared with the absence of bicarbonate and approximately 2-fold above sulfate equilibrium (overshoot). Initial rates of this bicarbonate gradient-driven ({sup 35}S)-sulfate uptake were saturable with increasing concentrations of sulfate and could be inhibited by probenecid, N-(4-azido-2-nitrophenyl)-2-aminoethylsulfonate, acetazolamide, furosemide, 4-acetamideo-4{prime}-isothiocyanostilbene-2,2{prime}-disulfonic acid, and 4,4{prime}-diisothiocyanostilbene-2,2{prime}-disulfonic acid (IC{sub 50}, {approximately}40 {mu}M). Cisinhibition of initial bicarbonate gradient-stimulated sulfate uptake and transstimulation of sulfate uptake in the absence of bicarbonate were observed with sulfate, thiosulfate, and oxalate but not with chloride, nitrate, phosphate, acetate, lactate, glutamate, aspartate, cholate, taurocholate, dehydrocholate, taurodehydrocholate, and reduced or oxidized glutathione. These findings indicate the presence of a sulfate (oxalate)-bicarbonate anion exchange system in canalicular rat liver plasma membranes. These findings support the concept that bicarbonate-sensitive transport system might play an important role in bile acid-independent canalicular bile formation.

• OSTI ID: 7266828
• Journal Information: American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 253:4; ISSN 0002-9513; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ACID CARBONATES
ANIMALS
ANIONS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BILE
BIOLOGICAL MATERIALS
BIOSYNTHESIS
BODY
BODY FLUIDS
CARBOXYLIC ACID SALTS
CELL CONSTITUENTS
CELL MEMBRANES
CHARGED PARTICLES
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
EVEN-ODD NUCLEI
GLANDS
IONS
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
LIVER
MAMMALS
MATERIALS
MEMBRANE TRANSPORT
MEMBRANES
NUCLEI
ORGANS
OXALATES
OXYGEN COMPOUNDS
PH VALUE
RADIOISOTOPES
RATS
RODENTS
SULFATES
SULFUR 35
SULFUR COMPOUNDS
SULFUR ISOTOPES
SYNTHESIS
TRACER TECHNIQUES
VERTEBRATES