Evidence for a channel for the electrogenic transport of chloride ion in the rat hepatocyte

Journal Article · Wed May 01 04:00:00 EDT 1985 · Hepatol.; (United States)

DOI:https://doi.org/10.1002/hep.1840050307· OSTI ID:6380293

Bear, C E; Petrunka, C N; Strasberg, S M

Chloride is the major inorganic anion in bile but its mechanism of passage from blood to bile is uncertain. Specific membrane channels account for most net inorganic anion flux in other cell types such as the proximal tubular cell and red blood cell; disulfonic stilbenes inhibit anion movement through these channels. Therefore, we have sought the presence of similar channels in the hepatocyte. Net inorganic anion flux or conductance was initiated in isolated rat hepatocytes by valinomycin in the presence of an outward potassium gradient. Potassium concentration in the extracellular medium increased from 2.75 +/- 0.02 in control cell suspensions to 3.15 +/- 0.04 in valinomycin-treated cell suspensions. Membrane potential difference (Em) (mV), determined as the distribution of (/sup 14/C)tetraphenyl phosphonium ion was -28 mV in control cells and -42 mV in valinomycin-treated cells. Intracellular chloride concentration (/sup 36/Cl-) (mEq per liter of cell water) decreased significantly from 38.6 in control cells to 32.0 in valinomycin-treated cells. The observed intracellular concentrations (/sup 36/Cl-) in both control and valinomycin-treated cell suspensions closely approximates values predicted on the basis of the Nernst equation: 41 and 29 (mEq per liter of cell water), respectively, suggesting that the chloride ion is passively distributed on the basis of the membrane potential difference. Furthermore, net rate-limited cell water loss of approximately 15% of control values was associated with the above valinomycin-stimulated changes in ion distribution, as assessed using three methods of cell water volume determination.

• OSTI ID: 6380293
• Journal Information: Hepatol.; (United States), Journal Name: Hepatol.; (United States) Vol. 3; ISSN HPTLD
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
551001 -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALI METALS
ANIMAL CELLS
ANIMALS
ANTI-INFECTIVE AGENTS
ANTIBIOTICS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBON 14 COMPOUNDS
CELL CONSTITUENTS
CELL MEMBRANES
CHLORIDES
CHLORINE 36
CHLORINE COMPOUNDS
CHLORINE ISOTOPES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
ELECTROPHYSIOLOGY
ELEMENTS
HALIDES
HALOGEN COMPOUNDS
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
LIVER CELLS
MAMMALS
MEMBRANE TRANSPORT
MEMBRANES
METALS
NUCLEI
ODD-ODD NUCLEI
PHYSIOLOGY
POTASSIUM
RADIOISOTOPES
RATS
RODENTS
SOMATIC CELLS
TRACER TECHNIQUES
VALINOMYCIN
VERTEBRATES
YEARS LIVING RADIOISOTOPES