in vivo 31P-NMR study of Fatigues in the Human Skeletal Muscles

Research Project

Project/Area Number	10670076
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Environmental physiology (including Physical medicine and Nutritional physiology)
Research Institution	National Institute of Neuroscience, NCNP
Principal Investigator	OGINO Takashi NCNP, Biochemistry & Cell Biology, 神経研究所・診断研究部, 室長 (50185526)
Project Period (FY)	1998 – 1999
Project Status	Completed (Fiscal Year 1999)
Budget Amount *help	¥2,600,000 (Direct Cost: ¥2,600,000) Fiscal Year 1999: ¥900,000 (Direct Cost: ¥900,000) Fiscal Year 1998: ¥1,700,000 (Direct Cost: ¥1,700,000)
Keywords	human calf muscle / 31P-NMR / fiber types / compartmentation / non-invasive / pH / fatigue / exercise / Mg^<2+> / P31 NMR / ATP / deconvolution / Mg2+
Research Abstract	Differential metabolic response in human calf muscles during exercise was demonstrated by ィイD131ィエD1P NMR spectroscopy. Splitting of the Pi peak up to three was observed in the muscles, depending on exercise intensities of repetitive planter flexions. These results were interpreted by a pattern of fiber-type recruitment and difference in metabolic capacities of fiber types. At high work load eight of nine subjects showed three Pi peaks with the average pH values of 7.07, 6.57 and 6.21, which most likely reflected type I, type IIA and type IIB fibers, respectively. Splitting patterns differed among individuals and were related to ATP depletion and PCr utilization rates during exercise, or Pi recovery rates after exercise. These results suggested that fiber-type specific metabolism and individual difference in fiber types of human muscle can non-invasively be studied by ィイD131ィエD1PNMR spectroscopy.