Osmotic compression of skinned cardiac and skeletal muscle bundles: effects on force generation, Ca2+ sensitivity and Ca2+ binding.
Osmotic compression of skinned cardiac and skeletal muscle bundles: effects on force generation, Ca2+ sensitivity and Ca2+ binding.
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带皮心脏和骨骼肌束的渗透压：对力产生、Ca2+敏感性和Ca2+结合的影响。
DOI：
10.1016/s0022-2828(05)82385-5
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发表时间：
1995
影响因子：
5
通讯作者：
Fuchs,F
中科院分区：
文献类型：
--
作者：
Wang,YP;Fuchs,F
肌丝Ca 2+敏感性的长度依赖性现在被认为是沿着心脏力-长度曲线的上升肢的主动力和肌节长度沿着之间的陡峭关系的重要组成部分。对带皮心肌制备物的研究表明，随着肌节长度在1.7-2.3 μm范围内增加，Ca 2 +-肌钙蛋白C亲和力显著增加。肌节长度的增加伴随着肌丝间距的减少。在皮肤的纤维制备从心脏和骨骼肌的丝晶格的渗透压缩增强肌丝Ca 2+的敏感性。本研究旨在评估以下假设：细丝分离的变化可能有助于在心肌中观察到的长度依赖性激活。暴露于右旋糖酐T-500（5-10%）引起的丝间间距中度减少导致最大活化和部分活化的去皮牛心室肌制备物中产生的力增加。对于平均肌节长度为1.7 μm的纤维束，添加5%右旋糖酐T-500可使Ca 2+敏感性增加约0.25 pCa单位，并在pCa范围（6.0-5.0）内显著增加Ca 2+结合，在此范围内，可滴定心肌肌钙蛋白C的单一调节位点。该浓度的右旋糖酐T-500产生的纤维宽度减少相当于将纤维从肌节长度1.7 μm拉伸至肌节长度2.3 μm所产生的纤维宽度减少。皮肤的兔腰肌肌纤维的渗透压也增加了Ca 2+的敏感性，但没有显着变化的Ca 2 +-肌钙蛋白C的亲和力。这些数据表明：1）心肌和骨骼肌中长度依赖性Ca 2+敏感性的一个重要组成部分是肌丝间距的变化，2）在心肌中，间距的减少，如长度的增加，导致Ca 2 +-肌钙蛋白C亲和力的特异性增加。因此，细丝重叠和细丝分离都有助于心肌中Ca 2+敏感性和Ca 2+结合的长度依赖性。
Length-dependence of myofilament Ca2+sensitivity is now considered to be an important component of the steep relationship between active force and sarcomere length along the ascending limb of the cardiac force-length curve. Studies with skinned cardiac muscle preparations have demonstrated that Ca2+-troponin C affinity is significantly increased as sarcomere length is increased over the range 1.7–2.3 μm. Increase in sarcomere length is accompanied by a reduction in interfilament spacing. In skinned fiber preparations from both cardiac and skeletal muscle osmotic compression of the filament lattice enhances myofilament Ca2+sensitivity. This study was undertaken to evaluate the hypothesis that a change in filament separation may contribute to the length-dependent activation seen in cardiac muscle. Moderate reduction in interfilament spacing caused by exposure to Dextran T-500 (5–10%) produced an increase in force generation in both maximally activated and partially activated preparations of skinned bovine ventricular muscle. With fiber bundles of mean sarcomere length 1.7 μm the addition of 5% Dextran T-500 produced an increase in Ca2+sensitivity of about 0.25 pCa units and a significant increase in Ca2+binding in the pCa range (6.0–5.0) in which the single regulatory site of cardiac troponin C is titrated. This concentration of Dextran T-500 produced a reduction in fiber width equivalent to that produced by stretching fibers from sarcomere length 1.7 μm to sarcomere length 2.3 μm. Osmotic compression of skinned rabbit psoas muscle fibers also enhanced Ca2+sensitivity but there was no significant change in Ca2+-troponin C affinity. These data suggest that 1) an important component of length-dependent Ca2+sensitivity in both cardiac and skeletal muscle is the change in interfilament spacing, and 2) in cardiac muscle a reduction in spacing, like increase in length, leads to a specific increase in Ca2+-troponin C affinity. Thus both filament overlap and filament separation contribute to the length dependence of Ca2+sensitivity and Ca2+binding in cardiac muscle.
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强直性骨骼肌的缩短导致细胞内钙浓度下降[论文集]。
DOI：
--
发表时间：
1978
期刊：
影响因子：
--
作者：
Allen Dg
通讯作者：
Allen Dg
DOI：
10.1152/ajpcell.1987.253.1.c90
发表时间：
1987-07
期刊：
The American journal of physiology
影响因子：
--
作者：
P. Hofmann;F. Fuchs
通讯作者：
P. Hofmann;F. Fuchs
将心肌肌钙蛋白 C 替换至兔肌肉中不会改变张力的 Ca2 敏感性的长度依赖性。
DOI：
10.1113/jphysiol.1991.sp018708
发表时间：
1991
期刊：
The Journal of physiology
影响因子：
--
作者：
Moss,RL;Nwoye,LO;Greaser,ML
通讯作者：
Greaser,ML
带皮心肌束中的结合钙和力量发展：肌节长度的影响。
影响因子：
5
作者：
Hofmann,PA;Fuchs,F
通讯作者：
Fuchs,F
斯塔林心脏定律是通过肌肉长度和肌丝钙激活之间的密切相互作用来解释的。
影响因子：
24
作者：
E. Lakatta
通讯作者：
E. Lakatta