Docosahexaenoic acid (DHA) injection in spinal cord transection stimulates Na⁺,K⁺-ATPase in skeletal muscle via β 1 subunit

Cell Mol Biol (Noisy-le-grand). 2014 Nov 16;60(4):22-9.

Abstract

Spinal cord injuries (SCI) induce a loss of skeletal muscle mass and functional capacity. The muscle excitability and contractility depend on the plasma membrane potential, regulated by transmembrane ion gradients, and thus necessarily on the Na⁺,K⁺-ATPase activity. The aim of this work was to evaluate the consequences of a spinal cord transection (SCT) on the skeletal muscle Na⁺,K⁺-ATPase and the impact of collateral GlyceroPhosphoLipids enriched in DocosaHexaenoic Acid (GPL-DHA) administration. The Na⁺,K⁺-ATPase activity and membrane expression of Na⁺,K⁺-ATPase α1, α2 and β1 isoforms were assessed by K⁺-stimulated paranitrophenyl phosphatase (pNPPase) measurements and Western Blotting, respectively. The results show that spinal cord transection increased significantly (p<0.05) Na⁺,K⁺-ATPase activity in muscle by 25% and decreased the amounts of α1 isoform and α2 isoform expressions by 50% (p<0.05) respectively compared to controls. The results also show that early injection of GPL-DHA after SCT decreases in membrane skeletal muscle the α1 and α2 isoforms expression but increases the membrane Na⁺,K⁺-ATPase activity. This treament partially restores the membrane expression of the β1 subunit of the Na⁺,K⁺-ATPase. These data suggest that the increase of β1 subunit expression is probably the main trigger to the membrane Na⁺,K⁺-ATPase activation following a trans-synaptic denervation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Docosahexaenoic Acids / administration & dosage
  • Docosahexaenoic Acids / pharmacology
  • Docosahexaenoic Acids / therapeutic use*
  • Enzyme Activation / drug effects*
  • Female
  • Injections
  • Muscle, Skeletal / drug effects
  • Muscle, Skeletal / enzymology*
  • Protein Isoforms / metabolism
  • Rats, Wistar
  • Sodium-Potassium-Exchanging ATPase / metabolism*
  • Spinal Cord Injuries / drug therapy
  • Spinal Cord Injuries / enzymology*

Substances

  • Protein Isoforms
  • Docosahexaenoic Acids
  • Sodium-Potassium-Exchanging ATPase