Argov Z, Bank W J
Department of Neurology, Hadassah University Hospital, Jerusalem, Israel.
Ann Neurol. 1991 Jul;30(1):90-7. doi: 10.1002/ana.410300116.
Phosphorus magnetic resonance spectroscopy monitors muscle energy metabolism by recording the ratio of phosphocreatine to inorganic phosphate at rest, during exercise, and during recovery from exercise. In mitochondrial diseases, abnormalities may appear during some or all these phases. Low phosphocreatine-inorganic phosphate ratios at rest are not disease-specific, but can be increased by drug therapy in several myopathies. Phosphorus magnetic resonance spectroscopy can also record intracellular pH and thus identify disorders of glycogen metabolism in which the production of lactic acid is blocked during ischemic exercise. The measurements of accumulated sugar phosphate intermediates further delineate glycolytic muscle defects. Myophosphorylase deficiency responds to intravenous glucose administration with improved exercise bioenergetics, but no such response is seen in phosphofructokinase deficiency. The muscular dystrophies show no specific bioenergetic abnormality; however, elevation of phospholipids metabolites and phosphodiesters was detected in some cases. While phosphorus magnetic resonance spectroscopy remains primarily a research tool in metabolic myopathies, it will be clinically useful in identifying new therapies and monitoring their effects in a variety of neuromuscular disorders.
磷磁共振波谱通过记录静息状态、运动期间以及运动恢复期间磷酸肌酸与无机磷酸盐的比率来监测肌肉能量代谢。在线粒体疾病中，在这些阶段中的某些或全部阶段可能会出现异常。静息时低磷酸肌酸 - 无机磷酸盐比率并非疾病特异性的，但在几种肌病中可通过药物治疗使其升高。磷磁共振波谱还可以记录细胞内pH值，从而识别糖原代谢紊乱，其中在缺血性运动期间乳酸生成受阻。对积累的磷酸糖中间体的测量进一步明确了糖酵解性肌肉缺陷。肌磷酸化酶缺乏症对静脉注射葡萄糖有反应，运动生物能量学得到改善，但在磷酸果糖激酶缺乏症中未见此类反应。肌肉营养不良症未显示出特定的生物能量异常；然而，在某些情况下检测到磷脂代谢物和磷酸二酯升高。虽然磷磁共振波谱在代谢性肌病中主要仍是一种研究工具，但它在识别新疗法并监测其在各种神经肌肉疾病中的效果方面将具有临床实用性。
