Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom.
PLoS One. 2012;7(6):e37237. doi: 10.1371/journal.pone.0037237. Epub 2012 Jun 11.
Magnetic resonance spectroscopy (MRS) provides an exceptional opportunity for the study of in vivo metabolism. MRS is widely used to measure phosphorus metabolites in trained muscle, although there are no published data regarding its reproducibility in this specialized cohort. Thus, the aim of this study was to assess the reproducibility of (31)P-MRS in trained skeletal muscle.
We recruited fifteen trained men (VO(2)peak = 4.7±0.8 L min(-1)/58±8 mL kg(-1) min(-1)) and performed duplicate MR experiments during plantar flexion exercise, three weeks apart.
Measures of resting phosphorus metabolites were reproducible, with 1.7 mM the smallest detectable difference in phosphocreatine (PCr). Measures of metabolites during exercise were less reliable: exercising PCr had a coefficient of variation (CV) of 27% during exercise, compared with 8% at rest. Estimates of mitochondrial function were variable, but experimentally useful. The CV of PCr(1/2t) was 40%, yet much of this variance was inter-subject such that differences of <20% were detectable with n = 15, given a significance threshold of p<0.05.
31-phosphorus MRS provides reproducible and experimentally useful measures of phosphorus metabolites and mitochondrial function in trained human skeletal muscle.
磁共振波谱（MRS）为活体代谢研究提供了极好的机会。MRS 广泛用于测量训练有素的肌肉中的磷代谢物，尽管在这个专门的队列中，关于其可重复性的研究尚无发表数据。因此，本研究旨在评估（31）P-MRS 在训练有素的骨骼肌中的可重复性。
我们招募了 15 名训练有素的男性（峰值 VO（2）= 4.7±0.8 L min（-1）/58±8 mL kg（-1）min（-1）），并在相隔三周的时间内进行了两次跖屈运动的磁共振实验。
静息磷代谢物的测量具有可重复性，磷酸肌酸（PCr）的最小可检测差异为 1.7 mM。运动时代谢物的测量结果则不太可靠：运动时 PCr 的变异系数（CV）为 27%，而在休息时为 8%。线粒体功能的估计值存在差异，但具有实验价值。PCr（1/2t）的 CV 为 40%，但大部分差异是个体间的，因此，在 n=15 的情况下，即使存在 20%的差异，也可以通过统计学检验发现，且显著性阈值为 p<0.05。
31 磷 MRS 可提供重复性高且具有实验价值的训练有素的人体骨骼肌磷代谢物和线粒体功能的测量值。
