Gurkovskaia A V, Chaprina L P
Biull Eksp Biol Med. 1975 Oct;80(10):13-5.
Experiments were performed on the smooth muscle cells of rabbit a. pulmonalis using the microelectrode technique. No spontaneous electrical or mechanical activity was recorded in normal Krebs solution. The current-voltage relation in these smooth muscle cells showed marked rectification. No changes in the isometric tension were observed due to the anodal or cathodal stimulating currents. Strong depolarization of the muscle cells produced only local potentials on the cathelectrotone which never developed into a spike. Noradrenaline (10(-8) g/ml) caused depolarization of the 5-7 mV in the muscle cell membrane and a considerable contraction of the muscle strip as well. Under such conditions the contractile apparatus of the muscle cells became sensible to the resting potential level. Anodal stimulation was accompanied by relaxation of the muscle strip, whereas cathodal stimulation--by its contraction. The alpha-adrenoblocking agent (phentolamine) blocked the effect of noradrenaline evidencing the fact that noradrenaline exerted its excitatory action on the smooth muscle cells of the a. pulmonalis through the alpha-adrenoreceptors.
采用微电极技术对家兔肺动脉平滑肌细胞进行了实验。在正常的 Krebs 溶液中未记录到自发的电活动或机械活动。这些平滑肌细胞的电流 - 电压关系呈现出明显的整流特性。由于阳极或阴极刺激电流，未观察到等长张力的变化。肌肉细胞的强烈去极化仅在阴极通电时产生局部电位，且这些局部电位从未发展成动作电位。去甲肾上腺素（10(-8) g/ml）可使肌细胞膜去极化 5 - 7 mV，同时也使肌条发生明显收缩。在这种情况下，肌肉细胞的收缩装置对静息电位水平变得敏感。阳极刺激伴随着肌条舒张，而阴极刺激则伴随着肌条收缩。α - 肾上腺素能阻滞剂（酚妥拉明）可阻断去甲肾上腺素的作用，这证明去甲肾上腺素是通过α - 肾上腺素能受体对肺动脉平滑肌细胞发挥其兴奋作用的。
