1H NMR of intact muscle at 11 T.

1H NMR spectra of intact frog, and chicken skeletal muscles, were recorded at 470 MHz with the Plateau and Guéron pulse sequence for the suppression of water [(1982) J. Am. Chem. Soc. 104, 7310]. Only a few transients were required to resolve the resonances from the protons of muscle metabolites. The previously unobserved exchangeable protons of muscles were also recorded and thereby phosphocreatine and creatine could be measured simultaneously. During aging of dissected frog muscle, changes in levels of phosphocreatine, creatine and lactic acid, and the decrease in the intracellular pH were followed by 1H NMR.