Cooper D S, Rice D H
Department of Otolaryngology, School of Medicine, University of Southern California, Los Angeles.
Ann Otol Rhinol Laryngol. 1990 Mar;99(3 Pt 1):228-33.
The objective of the experiment was to provide data from dogs, the best nonprimate model for the contractile properties of laryngeal muscles, on the fatigue characteristics of vocal fold muscle. Isometric muscle force was recorded from a transducer attached to the section of the thyroid cartilage on which the muscle inserted. Twitch contractions were recorded during supramaximal indirect electrical stimulation by DC pulses for at least 30 minutes. At 5 pulses per second (p/s), potentiation was observed in all records, peaking at an average of 7.5 minutes after stimulation onset. At 10 p/s, the peak of the potentiated average trace was earlier. One third of these records did not show potentiation. Where moderate or large potentiation was observed, the peak twitch tension declined and reached an asymptote above the initial tension, while when potentiation was small or absent, the final force was smaller than initially. Canine vocal fold muscle was observed to be fatigue-resistant, but in phonation other factors may produce fatigue.
该实验的目的是提供来自狗的数据，狗是研究喉肌收缩特性的最佳非灵长类动物模型，以了解声带肌肉的疲劳特征。通过连接到肌肉附着的甲状软骨部分的传感器记录等长肌力。在通过直流脉冲进行超最大间接电刺激至少30分钟期间记录单收缩。在每秒5次脉冲（p/s）时，在所有记录中均观察到增强作用，在刺激开始后平均7.5分钟达到峰值。在每秒10次脉冲（p/s）时，增强后的平均轨迹峰值出现得更早。这些记录中有三分之一未显示增强作用。在观察到中度或大量增强作用的情况下，单收缩张力峰值下降并达到高于初始张力的渐近线，而当增强作用较小或不存在时，最终力量小于初始力量。观察到犬声带肌肉具有抗疲劳能力，但在发声过程中其他因素可能会导致疲劳。
