Phosphate metabolites in muscular contraction caused by magnetic stimulation.
The metabolism of high energy phosphates during muscular contraction due to direct electrical stimulation, indirect stimulation via nerve excitation, and magnetic stimulation was studied in isolated muscles (frog sartorius muscles) by (31)P nuclear magnetic resonance ((31)P-NMR). Twitch amplitudes elicited by each stimulus were measured alternatively at 3 mm displacement loading and 5 g weight. Both the creatine/inorganic phosphate (PCr/Pi) and pH changes were more marked in direct electrical stimulation than in magnetic stimulation. The muscular contraction caused by magnetic stimulation showed less fatigue than that caused by direct electrical muscular stimulation.
Chiba
Atsushi
A
Department of Physiology, Kinki University School of Medicine, Osaka-Sayama, Japan. kchiba@med.kindai.ac.jp
Inase
Masahiko
M
D000818:Animals; D004307:Dose-Response Relationship, Radiation; D004558:Electric Stimulation / Q000379:methods*; D004574:Electromagnetic Fields; D005260:Female; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D009119:Muscle Contraction / Q000502:physiology* / Q000528:radiation effects*; D018482:Muscle, Skeletal / Q000737:chemistry / Q000294:innervation / Q000502:physiology* / Q000528:radiation effects*; D010710:Phosphates / Q000032:analysis / Q000378:metabolism*; D010725:Phosphocreatine / Q000378:metabolism; D011829:Radiation Dosage; D011892:Rana catesbeiana; D012584:Sciatic Nerve / Q000502:physiology / Q000528:radiation effects
D010710:Phosphates; D010725:Phosphocreatine