Bank W, Chance B
Department of Neurology, University of Pennsylvania, Philadelphia 19104.
Ann Neurol. 1994 Dec;36(6):830-7. doi: 10.1002/ana.410360606.
Metabolic myopathies due to a variety of enzymatic deficiencies are well recognized. The dynamics of oxygen delivery and utilization during exercise have not been observed previously in these disorders. We used a noninvasive optical technique to measure oxygen consumption in the exercising limb in normal subjects and patients with metabolic myopathies. We measured near-infrared spectra of hemoglobin in the gastrocnemius muscle during treadmill exercise in 10 normal subjects, 1 patient with cytochrome c oxidase deficiency, 2 patients with myophosphorylase deficiency, 3 patients with phosphofructokinase deficiency, and 2 patients with carnitine palmityl transferase deficiency. All normal subjects demonstrated a sustained deoxygenation during exercise, indicating an efficient utilization of delivered oxygen. The patient with cytochrome c oxidase deficiency demonstrated consistent oxygenation during exercise, indicating an underutilization of delivered oxygen. In the patients with myophosphorylase or phosphofructokinase deficiency, abnormal oxygenation during exercise indicated an oxidative defect due to a lack of pyruvate production. In the patients with myophosphorylase deficiency, changes in oxidation coincident with glucose utilization and "the second wind phenomenon" were observed. Patients with carnitine palmityl transferase deficiency demonstrated a normal deoxygenation during exercise. Noninvasive tissue oximetry during exercise demonstrates specific abnormalities in a variety of metabolic myopathies, indicating abnormal oxygen utilization, and will be a useful addition to the clinical investigation of exercise intolerance.
因多种酶缺乏所致的代谢性肌病已广为人知。此前在这些疾病中尚未观察到运动期间氧输送和利用的动态变化。我们使用一种非侵入性光学技术来测量正常受试者和代谢性肌病患者运动肢体的氧消耗。我们在10名正常受试者、1名细胞色素c氧化酶缺乏患者、2名肌磷酸化酶缺乏患者、3名磷酸果糖激酶缺乏患者和2名肉碱棕榈酰转移酶缺乏患者进行跑步机运动期间，测量了腓肠肌血红蛋白的近红外光谱。所有正常受试者在运动期间均表现出持续的脱氧，表明所输送的氧得到有效利用。细胞色素c氧化酶缺乏患者在运动期间表现出持续的氧合，表明所输送的氧未得到充分利用。在肌磷酸化酶或磷酸果糖激酶缺乏的患者中，运动期间的异常氧合表明由于丙酮酸生成不足而存在氧化缺陷。在肌磷酸化酶缺乏的患者中，观察到氧化变化与葡萄糖利用以及“第二次呼吸现象”一致。肉碱棕榈酰转移酶缺乏患者在运动期间表现出正常的脱氧。运动期间的非侵入性组织血氧饱和度测定显示了多种代谢性肌病中的特定异常，表明氧利用异常，这将成为运动不耐受临床研究的有益补充。
