Active and passive characteristics of the canine cricothyroid muscles
Active and passive characteristics of the canine cricothyroid muscles
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DOI：
10.1016/s0892-1997(99)80056-3
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发表时间：
1999-03-01
期刊：
影响因子：
2.2
通讯作者：
Titze, I
中科院分区：
文献类型：
--
作者：
Alipour, F;Titze, I
通过一系列体外实验研究了犬环甲肌的主动和被动特征，并与甲杓肌中的对应物进行了比较。犬环甲肌的不同部分（即直部和斜部）的样本是从狗死前几分钟切除的喉部解剖出来的，并保存在温度为 37 ℃ +/- 1 ℃、pH 为 7.4 +/- 0.05 的 Krebs-Ringer 溶液中。通过一对平行板铂电极对肌肉样本施加场刺激，并使用一系列持续时间为 0.1 毫秒、幅度为 85 V 的方脉冲，在等长和等张条件下获得主动强直应力。使用双伺服系统（测力计）以电子方式获得样品的力和伸长率。结果表明，犬环甲肌的动态响应几乎比甲杓肌慢两倍。直肌和斜部的平均 50% 强直收缩时间分别为 84 ms 和 109 ms，而甲杓状肌的平均 50% 强直收缩时间为 50 ms。对这块肌肉的力-速度响应的检查表明，最大缩短速度为每秒其长度的2至3倍，大约是甲状杓肌缩短速度的一半。直肌和斜部的被动特性与甲杓肌类似。
Active and passive characteristics of the canine cricothyroid muscle were investigated through a series of experiments, conducted in vitro and compared with their counterparts in the thyroarytenoid muscle. Samples from separate portions of canine cricothyroid muscle, namely, the pars recta and pars obliqua, were dissected from dog larynges excised a few minutes before death and kept in Krebs-Ringer solution at a temperature of 37 degrees C +/- 1 degrees C and a pH of 7.4 +/- 0.05. Active tetanic stress was obtained in isometric and isotonic conditions by applying field stimulation to the muscle samples through a pair of parallel-plate platinum electrodes and using a train of square pulses of 0.1-ms duration and 85-V amplitude. Force and elongation of the samples were obtained electronically with a dual-servo system (ergometer). The results indicate that the dynamic response of the canine cricothyroid muscle is almost twice as slow as that of the thyroarytenoid muscle. The average 50% tetanic contraction times for pars recta and pars obliqua were 84 ms and 109 ms, respectively, in comparison to 50 ms for thyroarytenoid. The examination of force-velocity response of this muscle indicates a maximum shortening velocity of 2 to 3 times its length per second, which is about half of the thyroarytenoid shortening speed. The passive properties of the pars recta and pars obliqua portions are similar to those of thyroarytenoid muscle.