Kouyoumdjian J A
Disciplina de Neurologia da Faculdade de Medicina, São José do Rio Preto.
Arq Neuropsiquiatr. 1993 Sep;51(3):299-306. doi: 10.1590/s0004-282x1993000300001.
Cachexia, ageing and disuse and their effects on the human and animals neuromuscular system are reviewed. Disuse induces reduction of muscle fibers (mainly II) diameter with peripheral myofibrils lost; there is no core-targetoid or even reduction on myophosphorilase activity, both typical of denervation; the acetylcholine spontaneous release and trophic factors on myoneural junction are maintained; muscle fibers could change to angular shape. Ageing affects nerve and muscle by a continuous and progressive process of denervation and reinnervation; the number of motor units diminishes in sixties without any denervation electric activity; there is also reduction on the amount of ACh release on terminal neurons and mitochondrial oxidative capacity leading to compensatory type I muscle fiber number increase. Cachexia also induces reduction on muscle fibers diameter first on legs and then on arms and trunk; there is type II atrophy with occasional angular fibers, RNA/proteic synthesis reduction and normal DNA.
本文综述了恶病质、衰老和废用及其对人和动物神经肌肉系统的影响。废用会导致肌纤维（主要是II型）直径减小，外周肌原纤维丢失；不存在典型的去神经支配所具有的核心靶样结构，甚至肌磷酸化酶活性也无降低；神经肌肉接头处的乙酰胆碱自发释放和营养因子得以维持；肌纤维可能会变成角状。衰老通过持续且渐进的去神经支配和再支配过程影响神经和肌肉；在六十多岁时运动单位数量减少，但无任何去神经支配电活动；终末神经元上乙酰胆碱释放量以及线粒体氧化能力也会降低，从而导致I型肌纤维数量代偿性增加。恶病质也会首先导致腿部肌纤维直径减小，随后是手臂和躯干；出现II型萎缩，偶尔有角状纤维，RNA/蛋白质合成减少，而DNA正常。
