Boesch C, Décombaz J, Slotboom J, Kreis R
Department of Clinical Research, MR Spectroscopy and Methodology, University of Bern, Switzerland.
Proc Nutr Soc. 1999 Nov;58(4):841-50. doi: 10.1017/s0029665199001147.
Magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) are being increasingly used for investigations of human muscle physiology. While MRI reveals the morphology of muscles in great detail (e.g. for the determination of muscle volumes), MRS provides information on the chemical composition of the tissue. Depending on the observed nucleus, MRS allows the monitoring of high-energy phosphates (31P MRS), glycogen (13C MRS), or intramyocellular lipids (1H MRS), to give only a few examples. The observation of intramyocellular lipids (IMCL) by means of 1H MRS is non-invasive and, therefore, can be repeated many times and with a high temporal resolution. MRS has the potential to replace the biopsy for the monitoring of IMCL levels; however, the biopsy still has the advantage that other methods such as those used in molecular biology can be applied to the sample. The present study describes variations in the IMCL levels (expressed in mmol/kg wet weight and ml/100 ml) in three different muscles before and after (0, 1, 2, and 5 d) marathon runs for a well-trained individual who followed two different recovery protocols varying mainly in the diet. It was shown that the repletion of IMCL levels is strongly dependent on the diet post exercise. The monitoring of IMCL levels by means of 1H MRS is extremely promising, but several methodological limitations and pitfalls need to be considered, and these are addressed in the present review.
磁共振成像（MRI）和磁共振波谱（MRS）越来越多地用于人体肌肉生理学研究。MRI能非常详细地显示肌肉形态（例如用于确定肌肉体积），而MRS则提供有关组织化学成分的信息。根据所观察的原子核，MRS可监测高能磷酸盐（31P MRS）、糖原（13C MRS）或肌内脂质（1H MRS），仅举几个例子。通过1H MRS观察肌内脂质（IMCL）是非侵入性的，因此可以多次重复且具有高时间分辨率。MRS有潜力取代活检来监测IMCL水平；然而，活检仍具有优势，即可以对样本应用分子生物学等其他方法。本研究描述了一名训练有素的个体在进行马拉松跑步前后（0、1、2和5天），按照两种主要在饮食方面有所不同的不同恢复方案，三块不同肌肉中IMCL水平（以mmol/kg湿重和ml/100 ml表示）的变化。结果表明，IMCL水平的补充强烈依赖于运动后的饮食。通过1H MRS监测IMCL水平极具前景，但需要考虑一些方法学上的局限性和陷阱，本综述将对此进行探讨。
