CONTRACTION TIMES AND FIBRE TYPES IN INTACT HUMAN MUSCLE
CONTRACTION TIMES AND FIBRE TYPES IN INTACT HUMAN MUSCLE
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DOI：
10.1111/j.1748-1716.1970.tb04744.x
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发表时间：
1970-01-01
期刊：
影响因子：
--
通讯作者：
SCHMALBR.H
中科院分区：
文献类型：
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作者：
BUCHTHAL, F;SCHMALBR.H
通过连接到肌腱中的针的小型传感器，可以记录正常人原位肌肉的抽搐。抽搐是由终板区域的刺激引起的，最小抽搐的力量相当于一个或两个运动单位的平均值。测量每块肌肉中 20-30 束纤维的收缩峰值时间。收缩时间的直方图与组织化学结果一致；收缩时间超过 60 毫秒对应于富含线粒体的纤维比例。因此，长收缩时间在比目鱼肌和腓肠肌中占主导地位，其中一半是在胫骨前肌，三分之一是在肱二头肌（长头），百分之几是在肱三头肌（侧头）。收缩时间短的纤维束，线粒体含量低的纤维束比收缩时间长的纤维束具有更高的峰值时间温度系数。缺氧期间收缩时间缩短。首先自愿激活的运动单位的收缩时间接近于电激活的束的平均值。束状纤维的收缩时间在电诱发抽搐的范围内；其兵力大约是自愿激活部队的三倍。
Twitches were recordedin situin muscles of normal humans by small transducers connected to a needle in the tendon. The twitches were elicited by stimuli in the endplate zone, the force of the smallest twitches corresponding to the average of one or two motor units. The time to peak contraction was measured of 20–30 bundles of fibres in each muscle examined. The histograms of contraction times agreed with histochemical findings; contraction times longer than 60 msec corresponded to the proportion of fibres rich in mitochondria. Thus, long contraction times predominated in the soleus and gastrocnemius muscles, comprised half the times in the anterior tibia], a third in the brachial biceps (long head) and a few per cent in the brachial triceps muscle (lateral head). Bundles of fibres with short contraction times, those poor in mitochondria had a higher temperature coefficient of the time to peak than bundles with long contraction times. During hypoxia the contraction times shortened. The contraction time of motor units first activated voluntarily lay near the mean of bundles activated electrically. The contraction times of fasciculating fibres were in the range of electrically evoked twitches; the force was about three times that of voluntarily activated units.