Insulin-mimetic effects of vanadate in isolated rat adipocytes

Journal Article · Tue Jun 10 04:00:00 EDT 1980 · J. Biol. Chem.; (United States)

OSTI ID:5024385

Dubyak, G R; Kleinzeller, A

The effects of vanadate on hexose transport and (Na/sup +/-K/sup +/)ATPase function in isolated rat adipocytes were characterized. Incubation of these cells with vanadate elicited an insulin-like stimulation of the rate of glucose oxidation and 2-deoxyglucose transport, the magnitude of which was dependent on both the extracellular vanadate concentration and the duration of the incubation. The maximal 6- to 12-fold stimulation of transport observed in vanadate-treated adipocytes was equivalent to that produced by a maximally activating concentration of insulin. Vanadate produced no additional activation of sugar transport in adipocytes pretreated with a maximally activating concentration of insulin. Incubation of adipocytes with concentrations of vanadate which significantly stimulated sugar transport produced no inhibition of (Na/sup +/-K/sup +/)ATPase function measured as the rate of /sup 86/Rb/sup +/ uptake. The uptake of (/sup 48/V)-vanadate by adipocytes was linear for at least 3 h and exceeded the calculated equilibrium space. Progressive stimulation of the 2-deoxyglucose transport rate was correlated with the apparent vanadate content of the cells during prolonged incubation with (/sup 48/V) vanadate. The effects of vanadate on sugar transport were reversed by washing the cells in vanadate-free medium; the degree of reversibility was dependent on the duration of the cells' exposure to vanadate. These findings suggest that adipocytes convert accumulated vanadate to a form (perhaps vanadyl) incapable of inhibiting the (Na/sup +/-K/sup +/)ATPase; in the course of this intracellular conversion, however, the insulin-sensitive hexose transport system is activated.

• Research Organization: Univ. of Pennsylvania School of Medicine, Philadelphia
• OSTI ID: 5024385
• Journal Information: J. Biol. Chem.; (United States), Journal Name: J. Biol. Chem.; (United States) Vol. 255:11; ISSN JBCHA
• Country of Publication: United States
• Language: English

Related Subjects

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59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALDEHYDES
ALKALI METAL ISOTOPES
ANIMAL CELLS
ANIMALS
ATP-ASE
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL EFFECTS
CARBOHYDRATES
CONNECTIVE TISSUE CELLS
DAYS LIVING RADIOISOTOPES
ENZYMES
ESTERASES
FAT CELLS
GLUCOSE
HEXOSES
HORMONES
HYDROLASES
INSULIN
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
KINETICS
MAMMALS
METABOLISM
MINUTES LIVING RADIOISOTOPES
MONOSACCHARIDES
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PEPTIDE HORMONES
PHOSPHATASES
RADIOISOTOPES
RADIONUCLIDE KINETICS
RATS
REACTION KINETICS
RESPONSE MODIFYING FACTORS
RODENTS
RUBIDIUM 86
RUBIDIUM ISOTOPES
SACCHARIDES
SOMATIC CELLS
TRANSITION ELEMENT COMPOUNDS
VANADIUM 48
VANADIUM COMPOUNDS
VANADIUM ISOTOPES
VERTEBRATES