Cestari I A, Marques E, Leirner A A
Bioengineering Division, University of São Paulo, Medical School, Brazil.
Artif Organs. 1995 Mar;19(3):217-21. doi: 10.1111/j.1525-1594.1995.tb02316.x.
An experimental protocol was designed to study the mechanical response of the canine latissimus dorsi muscle stimulated to contract isometrically. Active and passive tensions were measured with the muscle's initial length varying within 10% of its physiologic length in situ. The force-frequency relationship was obtained at frequencies of stimulation of 1, 10, 15, 30, and 60 Hz. Muscle fatigability was assessed during 3 min of successive contractions. Tests were performed in pedicled muscles of anesthetized mongrel dogs (n = 10). Force-length characteristics were found to affect evoked tension markedly. Maximal active tension was generated near the muscle length in situ. Specific isometric tension measured with unit pulse stimulation was 2 +/- 0.4 N/cm2, and the time to peak twitch was 92.8 +/- 2.67 ms. With 60 Hz of stimulation frequency, the tension was 9.31 +/- 0.32 N/cm2, and the time to peak tension was 216.05 +/- 16.28 ms. After the fatigue test, the tension generated decreased to 62.5% of its initial value, and this decline was paralleled by the rate of tension development and tension relaxation.
设计了一个实验方案来研究犬背阔肌在等长收缩刺激下的力学反应。在肌肉初始长度在其原位生理长度的10%范围内变化时，测量主动张力和被动张力。在1、10、15、30和60Hz的刺激频率下获得力-频率关系。在连续收缩3分钟期间评估肌肉疲劳性。在麻醉的杂种犬（n = 10）的带蒂肌肉上进行测试。发现力-长度特性显著影响诱发张力。在接近原位肌肉长度时产生最大主动张力。单位脉冲刺激测量的比等长张力为2±0.4N/cm2，峰值抽搐时间为92.8±2.67ms。在60Hz的刺激频率下，张力为9.31±0.32N/cm2，峰值张力时间为216.05±16.28ms。疲劳测试后，产生的张力降至其初始值的62.5%，并且这种下降与张力发展速率和张力松弛平行。
