Chi M M, Hintz C S, McKee D, Felder S, Grant N, Kaiser K K, Lowry O H
Metabolism. 1987 Aug;36(8):761-7. doi: 10.1016/0026-0495(87)90113-2.
Individual muscle fibers from patients with Duchenne muscular dystrophy at an early stage in their disease, and from apparently normal boys of similar age, were analyzed for 13 enzymes of energy metabolism. This approach avoided the serious problems with muscle homogenate assays from increases in nonparenchymal components and permitted assessment of disease changes in different fiber types. Some enzymes of glycogenolysis (phosphorylase, phosphoglucomutase, and pyruvate kinase) were decreased in dystrophic fibers of all types. Phosphofructokinase was decreased in presumptive type II fibers. Lactate dehydrogenase was increased in type I fibers and essentially unchanged in type II. Phosphoglucoisomerase was near normal. Two enzymes of glucose metabolism not involved in glycogenolysis, hexokinase and glycogen synthase, were near normal, but a third, fructose bisphosphatase, was sharply reduced. Two enzymes of oxidative metabolism, citrate synthase, and beta-hydroxyacyl CoA dehydrogenase, were unchanged or increased. Two enzymes of high energy phosphate transfer, creatine kinase and adenylokinase, were only marginally affected. The net result is to leave the type II fibers, which normally exert the greatest force, with a severe deficit in the glycogenolytic enzyme machinery to maintain that force.
对早期杜兴氏肌营养不良症患者以及年龄相仿的表面正常男孩的单个肌纤维进行了能量代谢的13种酶的分析。这种方法避免了因非实质成分增加而导致的肌肉匀浆检测的严重问题，并允许评估不同纤维类型中的疾病变化。所有类型的营养不良纤维中，一些糖原分解酶（磷酸化酶、磷酸葡萄糖变位酶和丙酮酸激酶）减少。推定的II型纤维中磷酸果糖激酶减少。乳酸脱氢酶在I型纤维中增加，在II型纤维中基本不变。磷酸葡萄糖异构酶接近正常。两种不参与糖原分解的葡萄糖代谢酶，己糖激酶和糖原合酶，接近正常，但第三种，果糖二磷酸酶，急剧减少。两种氧化代谢酶，柠檬酸合酶和β-羟酰基辅酶A脱氢酶，不变或增加。两种高能磷酸转移酶，肌酸激酶和腺苷激酶，仅受到轻微影响。最终结果是，通常产生最大力量的II型纤维在维持该力量的糖原分解酶机制方面严重不足。
