ATP-ADP-dependent phosphorylations of glycolysis metabolites, creatine and glycerol: Their compartition and thermodynamic relationship in gastrocnemius muscle cell of exercised guinea pigs

AbstractThe concentrations of following metabolites were determined in freeze-clamped gastrocnemius muscle samples : glucose 1-phosphate, glucose 6-phosphate, glucose, fructose 1,6-diphosphate, fructose 6-phosphate, D-glycerdldehyde 3-phosphate. dihydroxyacetone phosphate, phosphoenolpyruvate, pyruvate, glycerol 3-phosphate, glycerol, creatine phosphate, creatine, glycerate 3-phosphate, glycerate 2-phosphate, adenosine monophosphate, adenosine diphosphate, adenosine triphosphate, inorganic phosphate.The results showed that within the limits of experimental error, concentration homeostasis for this metabolites is founded at least in some cases on equilibria between enzymic transformations. Discrepancies between constant mass ratios measured in this study and equilibrium constants allow the free energy variation AG to keep creatine phosphate at high concentration to be calculated. For the phosphogly-cerate mutase system, the equilibrium constant in controls and trained animals is unchanged and corresponds t...