title: Changes in the natural abundance 13C NMR spectra of intact frog muscle upon storage and caffeine contracture.
abstract: The carbons of phospholipids have limited mobility in fresh, resting, gastrocnemius frog muscle, but a population of phospholipids gains considerable mobility upon storage in the muscle or in contracture induced by caffeine. In parallel with the appearance of sharp phospholipid resonances, lactic acid also appears in the 13C NMR spectra. There is a correlation between the mobility of phospholipids and the depletion of phosphocreatine and ATP in muscle.
mesh_terms: D000818:Animals; D002110:Caffeine / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy; D009119:Muscle Contraction / Q000187:drug effects*; D009132:Muscles / Q000187:drug effects / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism*; D011894:Rana pipiens
chemical_list: D010743:Phospholipids; D002110:Caffeine