Effect of chronic electrostimulation of rabbit skeletal muscle on calmodulin level and protein kinase activity

Int J Biochem Cell Biol. 1999 Feb;31(2):303-10. doi: 10.1016/s1357-2725(98)00112-5.

Abstract

(a) Chronic electrostimulation of fast-twitch skeletal muscles makes them resemble slow-twitch muscles. The involvement of second-messenger cascades in this muscle reprogramming is not well understood. The goal of this study was to examine protein kinase activities and calmodulin levels as a function of the duration of electrostimulation. (b) Fast-twitch rabbit muscle was subjected to continuous low-frequency electrostimulation for 2 weeks. The extensor digitorum longus was taken and examined for calmodulin concentration and cAMP-dependent (PKA). Ca(2+)-phospholipid-dependent (PKC) and Ca(2+)-calmodulin-dependent (CaM kinase or PKB) protein kinase activities. (c) Electrostimulation for 14 days led to a significant increase in total calmodulin level and PKB activity, both rising in the cytosolic fraction. Protein kinase C translocated to the membrane fraction, although total activity did not change. (d) These changes could be related with electrostimulation-induced changes in excitation-contraction coupling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calmodulin / metabolism*
  • Cyclic AMP-Dependent Protein Kinases / metabolism
  • Electric Stimulation*
  • Female
  • Muscle Fibers, Fast-Twitch / physiology
  • Muscle Fibers, Slow-Twitch / physiology
  • Muscle, Skeletal / physiology*
  • Protein Kinase C / metabolism
  • Protein Kinases / metabolism*
  • Protein-Serine-Threonine Kinases*
  • Proto-Oncogene Proteins / metabolism
  • Proto-Oncogene Proteins c-akt
  • Rabbits

Substances

  • Calmodulin
  • Proto-Oncogene Proteins
  • Protein Kinases
  • Protein-Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt
  • Cyclic AMP-Dependent Protein Kinases
  • Protein Kinase C