X-RAY EVIDENCE FOR RADIAL CROSS-BRIDGE MOVEMENT AND FOR SLIDING FILAMENT MODEL IN ACTIVELY CONTRACTING SKELETAL-MUSCLE
X-RAY EVIDENCE FOR RADIAL CROSS-BRIDGE MOVEMENT AND FOR SLIDING FILAMENT MODEL IN ACTIVELY CONTRACTING SKELETAL-MUSCLE
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DOI：
10.1016/0022-2836(73)90222-2
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发表时间：
1973-01-01
影响因子：
5.6
通讯作者：
HUXLEY, HE
中科院分区：
文献类型：
--
作者：
HASELGROVE, JC;HUXLEY, HE
赤道x射线衍射图研究了肌肉在静止、收缩和收缩时的衍射图。证实了两个主要赤道反射的相对强度（1,0,1,1）既取决于肌节长度，也取决于肌肉的状态；在任何一种状态下，比值i1,0 i1,1随着肌肉肌节长度的增加而增加，而在任何固定的肌节长度下，收缩肌的比值小于静止肌，而僵硬肌的比值更小。在肌节长度不变时，i1,0 i1,1随状态变化的变化被解释为由于交叉桥的径向运动：收缩时的平均运动约为刚性时的40%。在研究的整个肌节长度范围内（在1.8到2.7 μm之间），没有证据表明肌肉等距收缩时晶格间距有任何变化。研究人员研究了肌肉在承受负荷时主动收缩后产生的张力。在主动缩短过程中，晶格间距和强度比I 1,0 I 1,1都发生了变化，其变化方式完全符合滑动丝收缩理论。
Equatorial X-ray diffraction patterns have been studied from muscles at rest, during contraction and in rigor. It is confirmed that the relative intensity (I 1, 0 I 1, 1) of the two main equatorial reflections depends both on the sarcomere length and on the state of the muscle; in any one state the ratio I 1, 0 I 1, 1 increases as the sarcomere length of the muscle increases, while at any fixed sarcomere length the ratio is smaller for contracting muscle than for resting muscle and smaller still for rigor muscles. The change of I 1, 0 I 1, 1 with change of state at constant sarcomere length is interpreted as being due to radial movement of cross-bridges: the average movement during contraction being about 40% of that in rigor. Over the whole range of sarcomere length studied (between 1.8 and 2.7 μm) there was no evidence for any change in lattice spacing when a muscle contracts isometrically. Muscles were studied generating tension after they had shortened actively against a load. The lattice spacings and intensity ratio I 1, 0 I 1, 1 both changed during active shortening in a way entirely consistent with the sliding filament theory of contraction.