Nonaka I, Sugita H
Acta Neuropathol. 1981;55(3):173-81. doi: 10.1007/BF00691315.
An electron-microscopic study on dystrophic chicken white muscle, posterior latissimus dorsi (PLD), was performed with histochemical identification of three fiber types of beta R (red), alpha R and alpha W (white) fibers to evaluate the pathophysiology in fiber necrosis. As seen in histochemically stained sections, vacuolar formation in the cytoplasm, an outstanding pathologic feature in chicken dystrophy, was recognized in the alpha W fibers by electron microscopy. The vacuole was membrane-bound and thought to originate from coalescence or dilatation of extensively proliferated sarcotubular system. There was evidence of a delay in fiber type transformation from alpha R to alpha W in dystrophic white muscle, while the initial pathologic event of sarcotubular system proliferation might be expressed only after muscle fibers had attained histochemical characteristics of alpha W fibers. Localized myofibrillar degeneration was encountered in the vicinity of the vacuole with focal membrane defect. An influx of extracellular fluid through the vacuolated sarcotubular system into the sarcoplasm may activate certain proteases, such as calcium-dependent protease because the extracellular fluid contains high concentration of calcium ion. The activated protease then degrades structural protein, especially Z-line protein, followed by fiber necrosis with phagocytosis.
对患营养障碍的鸡背阔肌后肌（PLD）进行了电子显微镜研究，并对βR（红色）、αR和αW（白色）三种纤维类型进行了组织化学鉴定，以评估纤维坏死中的病理生理学。如在组织化学染色切片中所见，通过电子显微镜在αW纤维中识别出细胞质中的空泡形成，这是鸡营养障碍的一个突出病理特征。空泡有膜包被，被认为起源于广泛增殖的肌管系统的融合或扩张。有证据表明，患营养障碍的白色肌肉中从αR到αW的纤维类型转变存在延迟，而肌管系统增殖的初始病理事件可能仅在肌肉纤维达到αW纤维的组织化学特征后才表现出来。在空泡附近遇到局部肌原纤维变性，伴有局灶性膜缺陷。细胞外液通过空泡化的肌管系统流入肌浆可能会激活某些蛋白酶，如钙依赖性蛋白酶，因为细胞外液含有高浓度的钙离子。激活的蛋白酶随后降解结构蛋白，尤其是Z线蛋白，随后是伴有吞噬作用的纤维坏死。
