Chaussain M, Camus F, Defoligny C, Eymard B, Fardeau M
Laboratoire d'Explorations Fonctionnelles Respiratoires, Hôpital Saint-Vincent-de-Paul, Paris, France.
Eur J Med. 1992 Dec;1(8):457-63.
To assess respiratory and metabolic adaptations in patients with phosphorylase deficiency and mitochondrial myopathies using maximal exercise tests.
Five patients with McArdle's disease and five patients with mitochondrial myopathies performed the same incremental maximal exercise test. Their respiratory gas exchanges and the variation of the venous blood metabolites--lactate (LACT), pyruvate (PYR), alanine (ALA), ammonia (NH3)--were studied in comparison with the results of fourteen control subjects who performed the same test.
Compared with controls, the two groups of patients displayed a similar significant decrease of their maximal VO2. In McArdle's patients the limitation of the maximal oxygen consumption was associated with a low respiratory exchange ratio (RER), a high VE/VO2, and characteristic metabolic data: no rise of LACT and PYR, a decrease of ALA and an important rise of NH3. In mitochondrial myopathies low VO2 max were due to a leftwards shift, i.e. towards low powers of exercise, of LACT, PYR, NH3 and ALA values. However the pattern of increase of LACT, PYR and NH3, exponential, and of ALA, linear, as well as respiratory exchange ratios were similar to control values. In this case, the limitation of oxygen consumption was due to a lack of the usual substrate, pyruvate. Low respiratory exchange ratio demonstrated that the muscle metabolism had a tendency to shift to lipid oxidation.
These results suggest that patients with McArdle's disease may improve their muscle energy production by endurance training which enhances lipid metabolism, whereas in mitochondrial myopathies, the energy production by oxidation of pyruvate or lipids may be improved only by enzymatic substitution.
通过最大运动试验评估磷酸化酶缺乏症和线粒体肌病患者的呼吸和代谢适应性。
5例麦克尔迪氏病患者和5例线粒体肌病患者进行了相同的递增式最大运动试验。研究了他们的呼吸气体交换以及静脉血代谢物——乳酸（LACT）、丙酮酸（PYR）、丙氨酸（ALA）、氨（NH3）的变化，并与14例进行相同试验的对照受试者的结果进行比较。
与对照组相比，两组患者的最大摄氧量均显著下降。在麦克尔迪氏病患者中，最大耗氧量的限制与低呼吸交换率（RER）、高VE/VO2以及特征性代谢数据相关：LACT和PYR无升高，ALA降低，NH3显著升高。在线粒体肌病中，最大摄氧量低是由于LACT、PYR、NH3和ALA值向左移动，即向低运动功率方向移动。然而，LACT、PYR和NH3的增加模式呈指数型，ALA呈线性，以及呼吸交换率与对照值相似。在这种情况下，耗氧量的限制是由于缺乏通常的底物丙酮酸。低呼吸交换率表明肌肉代谢有向脂质氧化转变的趋势。
这些结果表明，麦克尔迪氏病患者可通过增强脂质代谢的耐力训练来改善肌肉能量产生，而在线粒体肌病中，只有通过酶替代才能改善丙酮酸或脂质氧化产生的能量。
