Webster C, Silberstein L, Hays A P, Blau H M
Department of Pharmacology, Stanford University School of Medicine, California 94305.
Cell. 1988 Feb 26;52(4):503-13. doi: 10.1016/0092-8674(88)90463-1.
We show that Duchenne muscular dystrophy (DMD) selectively affects a subset of skeletal muscle fibers specialized for fast contraction. Muscle fiber types were characterized immunohistochemically with monoclonal antibodies that distinguish isoforms of fetal and adult-fast or adult-slow myosin heavy chain present in the same fiber. Fetal myosin expression increased with patient age and was not due to arrested development but rather to de novo synthesis, which served as a sensitive indicator of muscle regeneration. A subset of fast fibers were the first to degenerate (type IIb). Extensive fast fiber regeneration occurred before slow fibers were affected. These results suggest that the DMD gene product has a specific function in a subpopulation of muscle fibers specialized to respond to the highest frequency of neuronal stimulation with maximal rates of contraction.
我们发现，杜兴氏肌营养不良症（DMD）选择性地影响了专门用于快速收缩的一部分骨骼肌纤维。通过单克隆抗体对肌纤维类型进行免疫组织化学表征，这些抗体可区分存在于同一纤维中的胎儿型和成人快速型或成人慢速型肌球蛋白重链的亚型。胎儿肌球蛋白的表达随患者年龄增加而增加，这并非由于发育停滞，而是由于从头合成，这是肌肉再生的一个敏感指标。一部分快速纤维是最先退化的（IIb型）。在慢速纤维受到影响之前，广泛的快速纤维再生就已发生。这些结果表明，DMD基因产物在专门用于以最大收缩速率响应最高频率神经元刺激的一部分肌纤维中具有特定功能。
