Kauhanen S, Leivo I, Pettilä M, Michelsson J E
University of Helsinki, IV Department of Surgery, Surgical Hospital, Finland.
APMIS. 1996 Nov;104(11):797-804. doi: 10.1111/j.1699-0463.1996.tb04945.x.
The histopathology of the deep portion of the vastus intermedius (VIP) muscle from 13 rabbit hindlimbs immobilized in shortened position for 2-2.5 (n = 4), 3 (n = 3), 14 (n = 3) and 28 (n = 3) days and VIP muscles from 13 rabbit hindlimbs immobilized for the same time periods and subsequently remobilized for 4 weeks were compared. After 3 days of immobilization the VIP muscles displayed a 15% (p < 0.004) decline in muscle fibre diameter. By 2 weeks of immobilization fatty change was prominent and muscle fibre diameters had decreased to 56% (p < 0.0001) of control values. By 4 weeks of immobilization severe fibrotic damage of myofibres was observed and fibre diameters had decreased to 47% (p < 0.0001) of control values. Three days of immobilization followed by 4 weeks of remobilization led to marked fatty change as well as an increase in connective tissue in the affected VIP muscles. The muscle fibre diameter in these muscles was 71% (p < 0.0001) compared to the VIP immobilized for 3 days and 61% (p < 0.0001) compared to the control muscles. By 2-4 weeks of immobilization the subsequent remobilization did not aggravate the initial damage. We conclude that the morphology of VIP muscle immobilized for 3 days suffers more during a subsequent remobilization period than those immobilized for 14-28 days. These findings focus attention on the mechanisms operating at the onset of disuse muscle atrophy.
对13只后肢处于缩短位置固定2 - 2.5天（n = 4）、3天（n = 3）、14天（n = 3）和28天（n = 3）的兔股中间肌（VIP）深部的组织病理学变化，与13只在相同固定时间段后再活动4周的兔后肢的VIP肌进行了比较。固定3天后，VIP肌的肌纤维直径下降了15%（p < 0.004）。固定2周时，脂肪变化明显，肌纤维直径降至对照值的56%（p < 0.0001）。固定4周时，观察到肌纤维出现严重的纤维化损伤，纤维直径降至对照值的47%（p < 0.0001）。固定3天后再活动4周导致受影响的VIP肌出现明显的脂肪变化以及结缔组织增加。这些肌肉的肌纤维直径与固定3天的VIP肌相比为71%（p < 0.0001），与对照肌相比为61%（p < 0.0001）。在固定2 - 4周后再活动，并未加重初始损伤。我们得出结论，固定3天的VIP肌在随后的再活动期间比固定14 - 28天的肌肉遭受的损伤更大。这些发现聚焦于废用性肌肉萎缩起始阶段的作用机制。
