大鼠尾骨肌兴奋与抑制的电生理学基础。

The electrical basis of excitation and inhibition in the rat anoccygeus muscle.

Creed K E, Gillespie J S, Muir T C

J Physiol. 1975 Feb;245(1):33-47. doi: 10.1113/jphysiol.1975.sp010833.

Abstract

The transmembrane potential of smooth muscle cells of the rat anococcygeus muscle was studied with micro-electrodes. The muscle had a mean resting membrane potential of --61-5 mV and normally lacked spontaneous mechanical and electrical activity. 2. Stimulation of intramural nerves with single pulses produced a small depolarization and contraction. At frequencies greater than 0.5 Hz a second component occurred which had a maximum value of 35--51 mV with short trains at 30 Hz. Spike potentials were rarely seen. Depolarization was accompanied by a decrease in membrane resistance. 3. Noradrenaline (3 times 10-minus 5 M) and guanethidine (3 times 10-minus 5 M) both depolarized the membrane and produced contraction. Initially, oscillations in the membrane potential were oftern seen. 4. Intramural nerve stimulation in the presence of guanethidine damped the oscillations and produced relaxation. This was accompanied by neither hyperpolarization nor a change in membrane resistance. 5. TEA (1 mM) depolarized the membrane (--47-6 mV) and initiated spontaneous activity. Field stimulation evoked spikes with overshoot.

摘要

用微电极研究了大鼠肛尾肌平滑肌细胞的跨膜电位。该肌肉的平均静息膜电位为-61.5 mV，通常缺乏自发的机械和电活动。2. 用单个脉冲刺激壁内神经会产生小的去极化和收缩。在频率大于0.5 Hz时，会出现第二个成分，在30 Hz的短串刺激下其最大值为35 - 51 mV。很少见到锋电位。去极化伴随着膜电阻的降低。3. 去甲肾上腺素（3×10⁻⁵ M）和胍乙啶（3×10⁻⁵ M）都会使膜去极化并产生收缩。最初，经常可以看到膜电位的振荡。4. 在胍乙啶存在的情况下刺激壁内神经会抑制振荡并产生松弛。这既不伴有超极化，也不伴有膜电阻的变化。5. 四乙铵（1 mM）使膜去极化（-47.6 mV）并引发自发活动。场刺激诱发有超射的锋电位。