Relationship between force and stiffness in muscle fibers after stretch.
Relationship between force and stiffness in muscle fibers after stretch.
复制标题
拉伸后肌纤维的力和刚度之间的关系。
DOI：
10.1152/japplphysiol.00010.2005
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发表时间：
2005
影响因子：
3.3
通讯作者：
W. Herzog
中科院分区：
文献类型：
--
作者：
D. Rassier;W. Herzog
本研究的目的是评估激活纤维拉伸后的力和刚度之间的关系，同时通过干扰跨桥动力学和肌肉激活来改变收缩性。从青蛙的蚓状肌解剖的单纤维被放置在比力-长度关系的平台长20%的长度处，激活，并拉伸纤维长度的5%和10%（速度：40%纤维长度/s）。在林格溶液中进行最大和次大刺激实验，并向溶液中加入2和5 mM肌球蛋白抑制剂2，3-丁二酮单肟（BDM）。在所有研究条件下，活化纤维拉伸后的稳态力均高于相应长度处产生的等距力。降低刺激频率可降低等长收缩时的力和刚度，但不改变牵张后的力增强和刚度增强。注射BDM可降低等长收缩时的力和刚度，但增加牵张后的力增强和刚度增强。力增强和刚度之间的关系表明，拉伸后力的增加可能是由于连接到肌动蛋白的横桥的比例增加。由于BDM的地方跨桥在弱约束，预powerstroke状态，我们的研究结果进一步表明，力的增强部分与招聘弱约束跨桥到一个强约束状态。
The purpose of this study was to evaluate the relationship between force and stiffness after stretch of activated fibers, while simultaneously changing contractility by interfering with the cross-bridge kinetics and muscle activation. Single fibers dissected from lumbrical muscles of frogs were placed at a length 20% longer than the plateau of the force-length relationship, activated, and stretched by 5 and 10% of fiber length (speed: 40% fiber length/s). Experiments were conducted with maximal and submaximal stimulation in Ringer solution and with the addition of 2 and 5 mM of the myosin inhibitor 2,3-butanedione monoxime (BDM) to the solution. The steady-state force after stretch of an activated fiber was higher than the isometric force produced at the corresponding length in all conditions investigated. Lowering the frequency of stimulation decreased the force and stiffness during isometric contractions, but it did not change force enhancement and stiffness enhancement after stretch. Administration of BDM decreased the force and stiffness during isometric contractions, but it increased the force enhancement and stiffness enhancement after stretch. The relationship between force enhancement and stiffness suggests that the increase in force after stretch may be caused by an increase in the proportion of cross bridges attached to actin. Because BDM places cross bridges in a weakly bound, pre-powerstroke state, our results further suggest that force enhancement is partially associated with a recruitment of weakly bound cross bridges into a strongly bound state.
去皮兔肌纤维中从弱结合状态到强结合状态的跨桥转变的调节。
DOI：
10.1152/ajpcell.1995.269.6.c1532
发表时间：
1995
期刊：
The American journal of physiology.
影响因子：
--
作者：
Regnier,M;Morris,C;Homsher,E
通讯作者：
Homsher,E