Recovery of free ADP, Pi, and free energy of ATP hydrolysis in human skeletal muscle

J Appl Physiol (1985). 1998 Dec;85(6):2140-5. doi: 10.1152/jappl.1998.85.6.2140.

Abstract

We measured significant undershoots of the concentrations of free ADP ([ADP]) and Pi ([Pi]) and the free energy of ATP hydrolysis (DeltaGATP) below initial resting levels during recovery from severe ischemic exercise with 31P-nuclear magnetic resonance spectroscopy in 11 healthy sports students. Undershoots of the rate of oxidative phosphorylation would be predicted if the rate of oxidative phosphorylation would depend solely on free [ADP], [Pi], or DeltaGATP. However, undershoots of the rate of oxidative phosphorylation have not been reported in the literature. Furthermore, undershoots of the rate of oxidative phosphorylation are unlikely because there is evidence that a balance between ATP production and consumption cannot be achieved if an undershoot of the rate of oxidative phosphorylation actually occurs. Therefore, oxidative phosphorylation seems to depend not only on free [ADP], [Pi], or DeltaGATP. An explanation is that acidosis-related or other factors control oxidative phosphorylation additionally, at least under some conditions.

MeSH terms

  • Adenosine Diphosphate / metabolism*
  • Adenosine Triphosphate / metabolism*
  • Adult
  • Energy Metabolism
  • Exercise / physiology
  • Female
  • Humans
  • Hydrogen-Ion Concentration
  • Hydrolysis
  • Ischemia / physiopathology
  • Isometric Contraction / physiology
  • Magnetic Resonance Spectroscopy
  • Male
  • Muscle, Skeletal / metabolism*
  • Oxidative Phosphorylation
  • Phosphates / metabolism*
  • Phosphocreatine / metabolism
  • Thermodynamics

Substances

  • Phosphates
  • Phosphocreatine
  • Adenosine Diphosphate
  • Adenosine Triphosphate