Sodium 22+ washout from cultured rat cells

Journal Article · Wed Oct 01 00:00:00 EDT 1986 · J. Cell. Physiol.; (United States)

DOI:https://doi.org/10.1002/jcp.1041290102· OSTI ID:6933874

Kino, M; Nakamura, A; Hopp, L; Kuriyama, S; Aviv, A

The washout of Na/sup +/ isotopes from tissues and cells is quite complex and not well defined. To further gain insight into this process, we have studied /sup 22/Na/sup +/ washout from cultured Wistar rat skin fibroblasts and vascular smooth muscle cells (VSMCs). In these preparations, /sup 22/Na/sup +/ washout is described by a general three-exponential function. The exponential factor of the fastest component (k1) and the initial exchange rate constant (kie) of cultured fibroblasts decrease in magnitude in response to incubation in K+-deficient medium or in the presence of ouabain and increase in magnitude when the cells are incubated in a Ca++-deficient medium. As the magnitude of the kie declines (in the presence of ouabain) to the level of the exponential factor of the middle component (k2), /sup 22/Na/sup +/ washout is adequately described by a two-exponential function. When the kie is further diminished (in the presence of both ouabain and phloretin) to the range of the exponential factor of the slowest component (k3), the washout of /sup 22/Na/sup +/ is apparently monoexponential. Calculations of the cellular Na/sup +/ concentrations, based on the /sup 22/Na/sup +/ activity in the cells at the initiation of the washout experiments, and the medium specific activity agree with atomic absorption spectrometry measurements of the cellular concentration of this ion. Thus, all three components of /sup 22/Na/sup +/ washout from cultured rat cells are of cellular origin. Using the exponential parameters, compartmental analyses of two models (in parallel and in series) with three cellular Na/sup +/ pools were performed. The results indicate that, independent of the model chosen, the relative size of the largest Na+ pool is 92-93% in fibroblasts and approximately 96% in VSMCs. This pool is most likely to represent the cytosol.

• Research Organization: Univ. of Medicine and Dentistry of New Jersey, Newark
• OSTI ID: 6933874
• Journal Information: J. Cell. Physiol.; (United States), Vol. 1
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
RADIONUCLIDE KINETICS
SODIUM 22
MEMBRANE TRANSPORT
CALCIUM
DIFFUSION
FIBROBLASTS
IN VITRO
MUSCLES
OUABAIN
RATS
SKIN
ALKALI METAL ISOTOPES
ALKALINE EARTH METALS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BODY
CARBOHYDRATES
CARDIAC GLYCOSIDES
CARDIOTONICS
CARDIOVASCULAR AGENTS
CONNECTIVE TISSUE CELLS
DRUGS
ELEMENTS
GLYCOSIDES
ISOTOPES
LIGHT NUCLEI
MAMMALS
METALS
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANS
RADIOISOTOPES
RODENTS
SODIUM ISOTOPES
SOMATIC CELLS
STROPHANTHINS
VERTEBRATES
YEARS LIVING RADIOISOTOPES
560162* - Radionuclide Effects
Kinetics
& Toxicology- Animals
Plants
Microorganisms
& Cells