Abstract
Gated 31P-nuclear magnetic resonance followed the metabolic fluctuation in rat gastrocnemius muscle during a contraction cycle. Within 16 ms after stimulation, the phosphocreatine (PCr) level drops 11.3% from its reference state. The PCr minimum corresponds closely to the time of maximum force contraction. P(i) increases stoichiometrically, while ATP remains constant. During a twitch, PCr hydrolysis produces 3.1 μmol ATP/g tissue, which is substantially higher than the reported 0.3 μmol ATP·twitch-·g tissue-1 derived from steady-state experiments. The results reveal that a substantial energy fluctuation accompanies a muscle twitch.
Original language | English (US) |
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Journal | American Journal of Physiology - Cell Physiology |
Volume | 274 |
Issue number | 3 43-3 |
State | Published - Mar 1998 |
Keywords
- Energetics
- Metabolism
- Nuclear magnetic resonance
- Twitch
ASJC Scopus subject areas
- Clinical Biochemistry
- Cell Biology
- Physiology
- Physiology (medical)