Nonaka I, Takagi A, Sugita H
Muscle Nerve. 1981 Jul-Aug;4(4):326-33. doi: 10.1002/mus.880040409.
Undifferentiated type 2C fibers, which are dark on ATPase staining with both alkaline and acid preincubation, comprised on average 16.1% of the muscle fibers in 12 patients with Duchenne muscular dystrophy (DMD). Many of type 2C fibers had characteristics of regenerating fibers: basophilic cytoplasm, vesicular nuclei with occasional prominent nucleoli, high alkaline phosphatase and nonspecific esterase activity, and also high oxidative enzyme activity at the periphery of the fiber. A localized high acetylcholinesterase activity suggested the presence of a neuromuscular junction in some of the type 2C fibers. In serial sections, histochemical reactions characteristic of the type 2C fiber were present in segments of a single fiber, which in other parts was either a type 1 or a type 2 fiber. Since most of the opaque (hyaline, dark) fibers, which previously have been thought to be precursors of necrotic fibers, behaved as differentiated type 1 or type 2 fibers, the presence of type 2C fibers in DMD may not reflect "dedifferentiation" of fiber type, but rather indicate an active regenerating process. It remains unknown whether the type 2C fiber segments in DMD develop into fully differentiated functional fibers or remain as incompletely regenerated fibers.
未分化的2C型纤维在碱性和酸性预孵育后的ATP酶染色中呈深色，在12例杜氏肌营养不良症（DMD）患者的肌纤维中平均占16.1%。许多2C型纤维具有再生纤维的特征：嗜碱性细胞质、有偶尔突出核仁的泡状核、高碱性磷酸酶和非特异性酯酶活性，并且在纤维周边也有高氧化酶活性。局部高乙酰胆碱酯酶活性表明部分2C型纤维存在神经肌肉接头。在连续切片中，2C型纤维的组织化学反应特征存在于单根纤维的节段中，该纤维在其他部分要么是1型纤维要么是2型纤维。由于大多数以前被认为是坏死纤维前体的不透明（透明、深色）纤维表现为分化的1型或2型纤维，DMD中2C型纤维的存在可能并不反映纤维类型的“去分化”，而是表明存在活跃的再生过程。DMD中的2C型纤维节段是否会发育成完全分化的功能性纤维或仍为不完全再生的纤维尚不清楚。
