Role of protein kinase C in insulin activation of the Na-K pump in cultured skeletal muscle

S. R. Sampson, C. Brodie, S. V. Alboim

    Research output: Contribution to journalArticlepeer-review

    41 Scopus citations

    Abstract

    Administration of insulin to preparations of skeletal muscle causes an increase in Na+-K+ pump activity within 15-30 min. Although several mechanisms have been proposed, such as promotion of Na+ influx and translocation of pumps from intracellular to membrane sites, the early events involved in this effect remain unknown. We have investigated the possibility that activation of protein kinase C (PKC) may be an initial event in Na+- K+ pump activation in primary cultures of rat skeletal muscle. Insulin (80- 100 mU/ml) and tumor-promoting phorbol esters (10-100 nM) increased Na+-K+ pump activity as determined by measurements of ouabain-suppressible 86Rb uptake, electrogenic pump component of membrane potential, and specific [3H]ouabain binding. These effects were not reduced by treatment of myotubes with amiloride, which blocks Na+-H+ exchange, or with tetrodotoxin, which blocks voltage-dependent Na+ channels. Effects of insulin and phorbol esters were not additive, suggestive of a common mechanism. Effects of both phorbol esters and insulin were significantly reduced by staurosporine (50-100 nM) and by downregulation of PKC (by pretreatment of myotubes with phorbol ester for 24 h). The findings suggest that insulin may stimulate Na+-K+ pump activity in skeletal muscle by activation of PKC.

    Original languageEnglish
    Pages (from-to)C751-C758
    JournalAmerican Journal of Physiology - Cell Physiology
    Volume266
    Issue number3 35-3
    DOIs
    StatePublished - Mar 1994

    Keywords

    • amiloride
    • membrane potential
    • ouabain
    • phorbol esters

    Fingerprint

    Dive into the research topics of 'Role of protein kinase C in insulin activation of the Na-K pump in cultured skeletal muscle'. Together they form a unique fingerprint.

    Cite this