Herzog W, Leonard T R
Faculty of Kinesiology, University of Calgary, Alberta, Canada.
J Biomech. 1997 Sep;30(9):865-72. doi: 10.1016/s0021-9290(97)00046-8.
The purpose of this study was to test the hypothesis that force depression following muscle shortening is caused by stress-induced inhibition of the cross-bridges in the zone of new overlap between thick and thin filaments. Force depressions following shortening were assessed in five separate tests on the cat soleus. It was found that force depressions following shortening were inversely related to the speed of shortening and were directly related to the amount of shortening, which is in agreement with published results on muscles and fibre preparations. It was further observed that the force depressions were directly related to the force produced during the shortening phase, and that the force depressions were systematically reduced by relaxing the stress on the muscle following shortening. These latter results could not be compared with corresponding literature values for lack of systematic testing of these properties in mammalian skeletal muscle. All results of this study supported the predictions which were made based on our working hypothesis proposed above. The results also confirmed that there are long-lasting, time-dependent properties of skeletal muscle which are not part of the cross-bridge theory of muscular force production and which are ignored in Hill-type models of skeletal muscle.
肌肉缩短后的力下降是由应力诱导的粗细肌丝新重叠区域横桥抑制所致。在对猫比目鱼肌进行的五项独立测试中评估了缩短后的力下降情况。结果发现，缩短后的力下降与缩短速度呈负相关，与缩短量呈正相关，这与已发表的关于肌肉和纤维制剂的结果一致。进一步观察到，力下降与缩短阶段产生的力呈正相关，并且通过在缩短后放松对肌肉的应力，力下降会系统性地降低。由于缺乏对哺乳动物骨骼肌这些特性的系统性测试，后一组结果无法与相应的文献值进行比较。本研究的所有结果都支持基于上述工作假设所做出的预测。结果还证实，骨骼肌存在长期的、时间依赖性特性，这些特性不属于肌肉力量产生的横桥理论范畴，并且在骨骼肌的希尔型模型中被忽略。
