Handel S E, Stickland N C
J Comp Pathol. 1986 Jul;96(4):447-57. doi: 10.1016/0021-9975(86)90040-x.
Observations made during a growth and development study of the semitendinosus and trapezius muscles of 49 purebred Large White pigs between birth and 128 days of age revealed the presence of giant fibres. The occurrence, histochemical and ultrastructural properties of these giant fibres were investigated. A high proportion of the pigs (85 per cent) contained giant fibres in their muscles but these giant fibres usually represented less than 1 per cent of the total myofibre population. Giant fibres possessed enhanced adenosine triphosphatase activity and a high capacity for oxidative metabolism (indicated by succinate dehydrogenase activity) which was reflected ultrastructurally by the greatly heightened electron density of myofibrils and by an abnormally high percentage of mitochondria and lipid droplets. These deviations from normal muscle fibre composition, together with the reduced percentage volume of sarcoplasmic reticulum, were consistent with changes seen in functionally over-loaded muscle. It appears that giant fibre anomalies occur through increased activity stimulated in occasional muscle fibres, perhaps by a structural defect, such as an inadequate amount of sarcoplasmic reticulum, which causes hyper-contractile activity within the fibres and associated compensatory adaptations. Giant fibres did not appear to represent fibres undergoing degenerative changes.
在一项针对49头纯种大白猪从出生到128日龄的半腱肌和斜方肌生长发育研究中进行的观察发现了巨大纤维的存在。对这些巨大纤维的发生情况、组织化学和超微结构特性进行了研究。高比例的猪（85%）肌肉中含有巨大纤维，但这些巨大纤维通常占总肌纤维群体的比例不到1%。巨大纤维具有增强的三磷酸腺苷酶活性和较高的氧化代谢能力（由琥珀酸脱氢酶活性表明），这在超微结构上表现为肌原纤维的电子密度大大提高，以及线粒体和脂滴的比例异常高。这些与正常肌纤维组成的偏差，连同肌浆网体积百分比的降低，与功能过载肌肉中所见的变化一致。似乎巨大纤维异常是通过偶尔的肌纤维中受刺激的活动增加而发生的，可能是由一种结构缺陷引起的，比如肌浆网数量不足，这会导致纤维内的过度收缩活动以及相关的代偿性适应。巨大纤维似乎并不代表正在经历退行性变化的纤维。
