Tanaka H, Tanaka M, Sugi H
J Biochem. 1979 Nov;86(5):1587-93. doi: 10.1093/oxfordjournals.jbchem.a132676.
The effect of sarcomere length and stretching on the tension and the rate of ATP splitting was studied using small fiber bundles from glycerinated rabbit psoas muscle. The rate of ATP slitting was determined by measuring ADP production, while the tension development in response to a contracting solution (at pCa 5.3) was recorded in the same preparation. The isometric tension developed by the preparation decreased when the sarcomere length was increased. The decrease of tension development was accompanied by a decrease in the rate of ATP splitting. If a preparation exerting steady isometric tension was stretched by 5--10% at a velocity of 0.1 mm/s, the rate of ATP splitting was increased after stretching, while the steady isometric tension attained after stretching was also higher than the initial value. The extent of the excess ATP splitting caused by stretching decreased with increasing sarcomere length. These results suggest that the rate of the interaction cycle between actin and myosin molecules may increase as a result of stretching.
利用甘油处理过的兔腰大肌的小纤维束，研究了肌节长度和拉伸对张力以及ATP分解速率的影响。通过测量ADP生成量来确定ATP分解速率，同时在同一标本中记录对收缩溶液（在pCa 5.3）的张力发展情况。当肌节长度增加时，标本产生的等长张力降低。张力发展的降低伴随着ATP分解速率的降低。如果以0.1毫米/秒的速度将施加稳定等长张力的标本拉伸5%-10%，拉伸后ATP分解速率增加，且拉伸后达到的稳定等长张力也高于初始值。拉伸引起的额外ATP分解程度随肌节长度增加而降低。这些结果表明，拉伸可能导致肌动蛋白和肌球蛋白分子之间相互作用循环的速率增加。
