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Effect of anaerobic metabolic changes on the creatine kinase reaction in frog muscle studied by 31 P saturation transfer NMR
Author(s) -
Yoshizaki Kazuo,
Nishikawa Hiroyasu,
Naruse Shoji
Publication year - 1991
Publication title -
nmr in biomedicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.278
H-Index - 114
eISSN - 1099-1492
pISSN - 0952-3480
DOI - 10.1002/nbm.1940040105
Subject(s) - phosphocreatine , chemistry , creatine kinase , anaerobic exercise , creatine , bullfrog , time constant , reaction rate constant , spin–lattice relaxation , nuclear magnetic resonance , biophysics , kinetics , biochemistry , endocrinology , biology , energy metabolism , physiology , physics , engineering , electrical engineering , quantum mechanics , nuclear quadrupole resonance
The effect of anaerobic metabolic changes on the flux of the creatine kinase reaction in bullfrog skeletal muscle was evaluated by 31 P saturation transfer NMR. During an anaerobic time course the reduction ratio ( M + / M 0 ) of the phosphocreatine signal and the spin‐lattice relaxation time measured in the presence of saturating irradiation at the ATP γ‐phosphate resonance were decreased; however, the intrinsic spin‐lattice relaxation time of phosphocreatine was constant (4 s). The pseudo‐first‐order rate constant for the forward reaction of creatine kinase (i.e., phosphocreatine to ATP) was increased during the time course, accompanied by a decrease in phosphocreatine concentration and an intracellular acidification. However, the flux was constant (4 mmol . kg −1 wet wt . s −1 ) over the anaerobic time course. The fluxes analysed in several locations along the fibers, which were simultaneously measured by means of the one‐dimensional chemical shift imaging technique, were almost the same along the entire length of the fibers. These results indicate that the creatine kinase reaction is at equilibrium along the entire length of the frog muscle fibers.