Kuz'mina G I, Gerasimova L I, Lupandin Iu V
State University, Petrozavodsk.
Fiziol Zh Im I M Sechenova. 1995 Jul;81(7):74-9.
The investigation have been designed to elucidate the background and thermoregulatory activity (TA) of the motor units (MUs) of pelvic floor muscles (m. spincter ani externus, m. levator ani) and hind limb muscle (m. sartorius) in cats under anesthesia. The MUs of m. sphincter ani externus presented two patterns of background activity--the stationary and the rythmical ones. M. levator ani and m. sartorius presented no activity at room conditions (+22 degrees C). General cooling evoked TA in all the investigated muscles. The discharge frequencies of pelvic floor MUs (4-8 imp/s) during TA were shown to overlap with those of hind limb, muscles (5-9 imp/s). The correlation of MUs bioelectrical characteristics with histochemical and contractile properties of m. sphincter ani externus as fast-twitch muscle is discussed. The possible mechanisms responseble for MUs control in skeletal muscles with different specialization in modulated thermoreceptory afferent input are proposed.
本研究旨在阐明麻醉状态下猫的盆底肌（肛门外括约肌、肛提肌）和后肢肌肉（缝匠肌）运动单位（MU）的背景活动和体温调节活动（TA）。肛门外括约肌的运动单位呈现出两种背景活动模式——静止模式和节律模式。在室温（+22摄氏度）条件下，肛提肌和缝匠肌未表现出活动。全身冷却在所有被研究的肌肉中诱发了体温调节活动。结果显示，体温调节活动期间盆底肌运动单位的放电频率（4 - 8次/秒）与后肢肌肉的放电频率（5 - 9次/秒）有重叠。本文讨论了作为快肌的肛门外括约肌运动单位生物电特性与组织化学和收缩特性之间的相关性。提出了在不同特化的骨骼肌中，调制性温度感受器传入输入对运动单位控制的可能机制。
