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Fluxes catalyzed by soluble creatine kinase (MM) in equilibrium in vitro and by the creatine kinase system in perfused rat hearts were studied by 31P-NMR saturation transfer method. It was found that in vitro both forward and reverse fluxes through creatine kinase at equilibrium were almost equal and very stable to changes in phosphocreatine/creatine ratio (from 0.2 to 3.0) as well as to changes in pH (from 7.4 to 6.5 or 8.1), free Mg2+ concentration and 2-fold decrease of total adenine nucleotides and creatine pools (from 8.0 to 4.0 mM and from 30 to 14 mM, respectively). In the rat hearts perfused by the Langendorff method the creatine kinase-catalyzed flux from phosphocreatine to ATP was increased by 50% when oxygen consumption grew from 8 to 55 mumol/min per g of dry wt. due to transition from rest to high workload. These changes could not be exclusively explained on the basis of the equilibrium model by activation of heart creatine kinase due to some decrease in [phosphocreatine]/[creatine] ratio (from 1.8 to 0.8) observed during transition from rest to high workload. Analysis of our data showed that an increase in the flux via creatine kinase is correlated with an increase in the rate of ATP synthesis with a linearity coefficient higher than 1.0. These data are more consistent with the concept of energy channeling by phosphocreatine shuttle than with that of the creatine kinase equilibrium in the heart.
V V Kupriyanov, and
A Ya Steinschneider, and
E K Ruuge, and
V I Kapel'ko, and
M Yu Zueva, and
V L Lakomkin, and
V N Smirnov, and
V A Saks
October 1998,
The American journal of physiology,
V V Kupriyanov, and
A Ya Steinschneider, and
E K Ruuge, and
V I Kapel'ko, and
M Yu Zueva, and
V L Lakomkin, and
V N Smirnov, and
V A Saks
May 2002,
The Journal of biological chemistry,
V V Kupriyanov, and
A Ya Steinschneider, and
E K Ruuge, and
V I Kapel'ko, and
M Yu Zueva, and
V L Lakomkin, and
V N Smirnov, and
V A Saks
April 1996,
Journal of muscle research and cell motility,
V V Kupriyanov, and
A Ya Steinschneider, and
E K Ruuge, and
V I Kapel'ko, and
M Yu Zueva, and
V L Lakomkin, and
V N Smirnov, and
V A Saks
November 1983,
The Journal of surgical research,
V V Kupriyanov, and
A Ya Steinschneider, and
E K Ruuge, and
V I Kapel'ko, and
M Yu Zueva, and
V L Lakomkin, and
V N Smirnov, and
V A Saks
July 1989,
Magnetic resonance in medicine,
V V Kupriyanov, and
A Ya Steinschneider, and
E K Ruuge, and
V I Kapel'ko, and
M Yu Zueva, and
V L Lakomkin, and
V N Smirnov, and
V A Saks
November 1982,
Biochimica et biophysica acta,
V V Kupriyanov, and
A Ya Steinschneider, and
E K Ruuge, and
V I Kapel'ko, and
M Yu Zueva, and
V L Lakomkin, and
V N Smirnov, and
V A Saks
March 1985,
The Journal of biological chemistry,
V V Kupriyanov, and
A Ya Steinschneider, and
E K Ruuge, and
V I Kapel'ko, and
M Yu Zueva, and
V L Lakomkin, and
V N Smirnov, and
V A Saks
September 1992,
The American journal of physiology,
V V Kupriyanov, and
A Ya Steinschneider, and
E K Ruuge, and
V I Kapel'ko, and
M Yu Zueva, and
V L Lakomkin, and
V N Smirnov, and
V A Saks
January 1992,
Biochimica et biophysica acta,
V V Kupriyanov, and
A Ya Steinschneider, and
E K Ruuge, and
V I Kapel'ko, and
M Yu Zueva, and
V L Lakomkin, and
V N Smirnov, and
V A Saks
July 1999,
The American journal of physiology,
