Guthrie B M, Frostick S P, Goodman J, Mikulis D J, Plyley M J, Marshall K W
Human Kinetics, Champaign, IL 61825-5076, USA.
Can J Appl Physiol. 1996 Aug;21(4):251-63. doi: 10.1139/h96-022.
Resting and submaximal isometric exercise 31P magnetic resonance spectroscopy (MRS) was carried out on 7 endurance-trained males (26.0 +/- 3 yrs) and 7 sedentary males (27.0 +/- 4 yrs). Spectral analysis provided peak areas of phosphocreatine (PCr), inorganic phosphate (Pi), adenosine triphosphate (ATP), and the chemical shift of Pi relative to PCr. The ratio of PCr/Pi was moderately lower during rest (preexercise p = .13, postexercise p = .18), and significantly higher during exercise (p < .05) in the trained subjects. Intracellular pH patterns were the same for both groups; a transient alkalosis was observed at the onset of exercise with a return to resting levels after 2 min. Differences suggest improved ATP resynthesis rate in the trained subjects during exercise. Intracellular pH changes can be attributed to the utilization of hydrogen ions that accompany PCr hydrolysis during work. The findings are congruent with previous reports indicating a superior oxidative capacity in trained skeletal muscle.
对7名耐力训练男性（26.0±3岁）和7名久坐男性（27.0±4岁）进行了静息和次最大等长运动31P磁共振波谱（MRS）检查。光谱分析提供了磷酸肌酸（PCr）、无机磷酸盐（Pi）、三磷酸腺苷（ATP）的峰面积以及Pi相对于PCr的化学位移。在训练有素的受试者中，PCr/Pi比值在静息时略低（运动前p = 0.13，运动后p = 0.18），而在运动期间显著更高（p < 0.05）。两组的细胞内pH模式相同；运动开始时观察到短暂碱中毒，2分钟后恢复到静息水平。差异表明训练有素的受试者在运动期间ATP再合成速率提高。细胞内pH变化可归因于工作期间伴随PCr水解的氢离子利用。这些发现与先前报道一致，表明训练有素的骨骼肌具有更强的氧化能力。
