DOI

Sustained sarcolemma depolarization due to loss of the Na,K-ATPase function is char-acteristic for skeletal muscle motor dysfunction. Ouabain, a specific ligand of the Na,K-ATPase, has a circulating endogenous analogue. We hypothesized that the Na,K-ATPase targeted by the elevated level of circulating ouabain modulates skeletal muscle electrogenesis and prevents its dis-use-induced disturbances. Isolated soleus muscles from rats intraperitoneally injected with oua-bain alone or subsequently exposed to muscle disuse by 6-h hindlimb suspension (HS) were stud-ied. Conventional electrophysiology, Western blotting, and confocal microscopy with cytochemis-try were used. Acutely applied 10 nM ouabain hyperpolarized the membrane. However, a single injection of ouabain (1 µg/kg) prior HS was unable to prevent the HS-induced membrane depo-larization. Chronic administration of ouabain for four days did not change the α1 and α2 Na,K-ATPase protein content, however it partially prevented the HS-induced loss of the Na,K-ATPase electrogenic activity and sarcolemma depolarization. These changes were associated with increased phosphorylation levels of AMP-activated protein kinase (AMPK), its substrate ac-etyl-CoA carboxylase and p70 protein, accompanied with increased mRNA expression of inter-leikin-6 (IL-6) and IL-6 receptor. Considering the role of AMPK in regulation of the Na,K-ATPase, we suggest an IL-6/AMPK contribution to prevent the effects of chronic ouabain under skeletal muscle disuse.

Original languageEnglish
Article number3920
Number of pages18
JournalInternational Journal of Molecular Sciences
Volume22
Issue number8
DOIs
StatePublished - 10 Apr 2021

    Research areas

  • AMP-activated protein kinase, Hindlimb suspension, Na,K-ATPase isozymes, Ouabain, Resting membrane potential, Skeletal muscle, ouabain, Na, K-ATPase isozymes, resting membrane potential, hindlimb suspension, skeletal muscle

    Scopus subject areas

  • Molecular Biology
  • Spectroscopy
  • Catalysis
  • Inorganic Chemistry
  • Computer Science Applications
  • Physical and Theoretical Chemistry
  • Organic Chemistry

ID: 77796425