Effect of the tumor promoter 12-0-tetradecanoylphorbol-13-acetate on. cap alpha. -aminoisobutyrate uptake in friend erythroleukemic cells

Journal Article · Sun Nov 01 04:00:00 EST 1981 · Cancer Res.; (United States)

OSTI ID:5474228

Becker, J H ^[1]; Cook, J S

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1. Oak Ridge National Lab., TN

In Friend erythroleukemic cells, the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) increases the rate of influx as well as the steady-state accumulation of the amino acid transport probe ..cap alpha..-aminoisobutyric acid (AIB). This non-metabolizable analog is concentrated in these cells by utilizing the energy of the Na/sup +/ electrochemical gradient. The effect of TPA is to increase the ouabain-sensitive component of uptake of AIB (and of the K/sup +/ analog /sup 86/Rb/sup +/). Transport changes are not observed until 30 min after application of the promoter and reach a maximum in about 6 hr. The effects are blocked by cycloheximide. The flux results are consistent with a model in which the membrane potential is increased and, with it, the driving force on the coupled Na/sup +/-AIB movement. The effect is possible mediated by a change in electrogenicity of the Na:K pump. TPA raises the steady-state accumulation levels of AIB. By altering external K/sup +/ in the presence of valinomycin, the membrane potential may be adjusted and, with it, the accumulation of AIB. Over a wide range of membrane potentials, TPA-treated cells accumulate more AIB than do controls, suggesting a possible change in the internal Na/sup +/ activity.

• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5474228
• Journal Information: Cancer Res.; (United States), Journal Name: Cancer Res.; (United States) Vol. 41; ISSN CNREA
• Country of Publication: United States
• Language: English

Related Subjects

560301* -- Chemicals Metabolism & Toxicology-- Cells-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALKALI METALS
AMINO ACIDS
ANIMAL CELLS
ANIMALS
BIOLOGICAL EFFECTS
CARBOXYLIC ACIDS
CATIONS
CELL CONSTITUENTS
CELL DIFFERENTIATION
CELL FLOW SYSTEMS
CELL MEMBRANES
CHARGED PARTICLES
ELEMENTS
IONS
MAMMALS
MEMBRANES
METALS
MICE
ORGANIC ACIDS
ORGANIC COMPOUNDS
POTASSIUM
PROMOTERS
RODENTS
SODIUM
TUMOR PROMOTERS
UPTAKE
VERTEBRATES