Adhesive strength of single muscle cells to basement membrane at myotendinous junctions.
Adhesive strength of single muscle cells to basement membrane at myotendinous junctions.
复制标题
单个肌细胞对肌腱连接处基底膜的粘附强度。
DOI：
10.1152/jappl.1989.67.3.1063
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
Chan,M
中科院分区：
文献类型：
--
作者：
Tidball,JG;Chan,M
整个肌肉负荷衰竭，经常在肌腱连接处或附近衰竭。目前的研究旨在确定完整和受伤的肌腱连接处的断裂应力和失效部位，这些肌细胞从周围的平行结构中剥离出来，但仍然附着在肌腱胶原纤维上。这些测试表明，完整肌腱单位的断裂应力为2.7 x 10(5) N/m2，相对于细胞横截面积表示。破坏立即发生在细胞膜和基膜致密层之间的连接膜的外部。破坏时的位置和应力与生物相关范围内的应变和应变速率无关。膜面断裂应力，经膜折叠修正后为1.2 × 10(4) N/m2。对于这些肌节长度上的细胞，这个值并不明显大于最大等距张力下的应力。压缩损伤后，在较低的应力（1.9 X 10(5) N/m2）下，细胞在压缩部位内衰竭。这些发现表明，在这里模拟的条件下发生的肌肉劳损损伤中，肌腱连接处发生失效，除非肌肉先前遭受过压迫损伤导致肌肉内部失效。
Whole muscles loaded to failure frequently fail at or near myotendinous junctions. The present investigation was directed toward determining the breaking stress and failure site of intact and injured myotendinous junction preparations consisting of muscle cells dissected free from surrounding parallel structures but still attached to tendon collagen fibers. These tests show that the breaking stress for intact myotendinous units is 2.7 x 10(5) N/m2, expressed relative to cell cross-sectional area. Failure occurs immediately external to the junction membrane between the cell membrane and lamina densa of the basement membrane. Site and stress at failure are independent of strain and strain rate over a biologically relevant range. Breaking stress in the plane of the membrane, corrected for membrane folding, is 1.2 X 10(4) N/m2. This value is not significantly greater than stress at maximum isometric tension for these cells at these sarcomere lengths. After compression injury, cells fail within the compression site at significantly lower stress (1.9 X 10(5) N/m2). These findings suggest that, in muscle strain injuries that occur under conditions simulated here, failure occurs at myotendinous junctions unless the muscle has suffered previous compression injury leading to failure within the muscle.