Insulin regulation of Na/K pump activity in rat hepatoma cells

Journal Article · Tue May 01 04:00:00 EDT 1984 · Diabetes; (United States)

DOI:https://doi.org/10.2337/diabetes.33.5.428· OSTI ID:6540200

Gelehrter, T D; Shreve, P D; Dilworth, V M

Insulin rapidly increases Na/K pump activity in HTC rat hepatoma cells in tissue culture, as measured by the ouabain-sensitive influx of the potassium analogue 86Rb+. Increased influx is observed within minutes and is maximal (70% above control) within 1-2 h. The effect appears to be mediated by the insulin receptors, as: the concentration dependence on insulin is identical to that for insulin induction of tyrosine aminotransferase and stimulation of 2-aminoisobutyric acid transport, proinsulin is 6% as potent as insulin, and the effect is blocked by anti-receptor antibodies. The early stimulation of potassium influx is not blocked by cycloheximide and is not associated with an increased number of pump sites as measured by /sup 3/H-ouabain binding. The insulin effect is blocked by amiloride, which blocks sodium influx, and is mimicked by the sodium ionophore monensin, which increases sodium influx and intracellular accumulation. Insulin also rapidly increases the initial rate of /sup 22/Na+ influx, suggesting that insulin may enhance Na/K pump activity, in part, by increasing intracellular sodium concentration. Incubation of HTC cells with insulin for 24 h causes complete unresponsiveness to the insulin induction of transaminase and stimulation of amino acid transport, a phenomenon mediated by postbinding mechanisms. In contrast, similar incubation with insulin does not cause unresponsiveness to the insulin stimulation of Na/K pump activity. Therefore, the site of regulation of responsiveness to insulin must be distal to, or separate from, those events causing stimulation of ion fluxes.

• Research Organization: Univ. of Michigan, Ann Arbor
• OSTI ID: 6540200
• Journal Information: Diabetes; (United States), Journal Name: Diabetes; (United States) Vol. 33:5; ISSN DIAEA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALI METAL COMPOUNDS
ALKALI METAL ISOTOPES
AMINO ACIDS
AMINOTRANSFERASES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL EFFECTS
CARBOXYLIC ACIDS
CATIONS
CELL CULTURES
CHARGED PARTICLES
DAYS LIVING RADIOISOTOPES
DISEASES
ENZYME ACTIVITY
ENZYMES
EXPERIMENTAL NEOPLASMS
HEPATOMAS
HORMONES
INSULIN
INTERMEDIATE MASS NUCLEI
IONS
ISOMERIC TRANSITION ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LABELLED COMPOUNDS
LIGHT NUCLEI
MEMBRANE TRANSPORT
MINUTES LIVING RADIOISOTOPES
NEOPLASMS
NITROGEN TRANSFERASES
NUCLEI
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
PEPTIDE HORMONES
POTASSIUM COMPOUNDS
RADIOISOTOPES
REACTION KINETICS
RECEPTORS
RUBIDIUM 86
RUBIDIUM COMPOUNDS
RUBIDIUM ISOTOPES
SODIUM 22
SODIUM COMPOUNDS
SODIUM ISOTOPES
TRACER TECHNIQUES
TRANSFERASES
TRITIUM COMPOUNDS
YEARS LIVING RADIOISOTOPES