Sodium-proton exchanger in isolated hepatocytes exhibits a set point

Journal Article · Thu Sep 01 04:00:00 EDT 1988 · American Journal of Physiology; (USA)

OSTI ID:7005289

Stewart, D J ^[1]

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1. Univ. of Toronto, Ontario (Canada)

Na{sup +}-H{sup +} exchange activity was examined in hepatocytes isolated from rat liver. Activity was measured as amiloride-sensitive fluorescence changes utilizing the pH-sensitive chromophore, bis(carboxyethyl)-carboxyfluorescein. Hepatocytes, after being acidified by an NH{sub 4}Cl prepulse, exhibit amiloride-sensitive and sodium-dependent alkalinization. The rate of cellular pH recovery after acidification varied with the intracellular pH. The rate was highest at approximately pH 6.4 and declined as the pH rose, ceasing measurable activity at approximately pH 7.3. The phorbol ester, 12-O-tetradecanoylphorbol-13-acetate, at a concentration of 10{sup {minus}6} M, shifted the set point for the exchanger to a more alkaline pH by 0.2-0.3 pH units. The above observations indicate that the Na{sup +}-H{sup +} exchanger plays an active role in regulating intracellular pH in liver cells and that hormones acting through protein kinase C may modulate that function.

• OSTI ID: 7005289
• Journal Information: American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 255:3; ISSN 0002-9513; ISSN AJPHA
• 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.
ACIDIFICATION
ALKALI METAL COMPOUNDS
AMMONIUM CHLORIDES
AMMONIUM COMPOUNDS
AMMONIUM HALIDES
ANIMAL CELLS
ANIMALS
BARYONS
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL EFFECTS
CARCINOGENS
CHLORIDES
CHLORINE COMPOUNDS
DIURETICS
DRUGS
ELEMENTARY PARTICLES
ENZYME ACTIVITY
ENZYMES
ESTERS
FERMIONS
FLUORESCENCE
HADRONS
HALIDES
HALOGEN COMPOUNDS
KINETICS
LIVER CELLS
LUMINESCENCE
MAMMALS
MEMBRANE PROTEINS
MEMBRANE TRANSPORT
MOLECULAR STRUCTURE
NUCLEONS
ORGANIC COMPOUNDS
PH VALUE
PHORBOL ESTERS
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHOTRANSFERASES
PROTEINS
PROTONS
RATS
REACTION KINETICS
RODENTS
SODIUM COMPOUNDS
SOMATIC CELLS
TRANSFERASES
VERTEBRATES