Sullivan M J, Saltin B, Negro-Vilar R, Duscha B D, Charles H C
Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710.
J Appl Physiol (1985). 1994 Nov;77(5):2194-200. doi: 10.1152/jappl.1994.77.5.2194.
The present study was designed to compare evaluation of skeletal muscle metabolism (vastus lateralis) evaluated by 31P-magnetic resonance spectroscopy (MRS) and biochemical analysis. During identical isometric knee extensor exercise protocols to fatigue in eight men, biopsy samples were taken at rest, peak exercise, and 32 s postexercise and 31P-MRS data were collected continuously for phosphocreatine (PCr), pH, ATP, and P(i) at 8- or 32-s intervals. There was no difference in ATP or pH measurements between the two techniques at rest, during peak exercise, or in recovery. Corresponding measurements of pH by the two techniques were closely related (r = 0.88, P < 0.01), and pH measured by 31P-MRS was closely related to muscle lactate accumulation (r = -0.84, P < 0.001). The level of PCr at peak exercise, expressed as a percentage of the baseline value, was not different between the two techniques (42 +/- 15 vs. 46 +/- 15%). The results indicate that, in skeletal muscle in normal subjects, 1) measurements of pH and PCr at rest and during exercise do not differ between the 31P-MRS and biopsy techniques and 2) muscle pH measured by 31P-MRS is closely related to lactate accumulation in men. Our data suggest that direct comparison of results of studies of exercise metabolism using these two techniques is warranted.
本研究旨在比较通过31P磁共振波谱法（MRS）和生化分析评估的骨骼肌代谢（股外侧肌）。在8名男性进行相同的等长伸膝运动直至疲劳的过程中，在静息、运动峰值和运动后32秒采集活检样本，并以8秒或32秒的间隔连续收集31P-MRS数据，用于测量磷酸肌酸（PCr）、pH值、三磷酸腺苷（ATP）和无机磷（P(i)）。在静息、运动峰值或恢复阶段，两种技术在ATP或pH测量方面没有差异。两种技术对pH值的相应测量结果密切相关（r = 0.88，P < 0.01），并且通过31P-MRS测量的pH值与肌肉乳酸积累密切相关（r = -0.84，P < 0.001）。运动峰值时的PCr水平，以基线值的百分比表示，两种技术之间没有差异（42±15%对46±15%）。结果表明，在正常受试者的骨骼肌中，1）31P-MRS和活检技术在静息和运动期间对pH值和PCr的测量没有差异，2）通过31P-MRS测量的肌肉pH值与男性的乳酸积累密切相关。我们的数据表明，有必要对使用这两种技术的运动代谢研究结果进行直接比较。
