Shinlova O P, Fomin V P, Burdyga F V, Kosterin S A
Izv Akad Nauk SSSR Biol. 1990 May-Jun(3):383-90.
Ca2+ concentration has been estimated in isolated myometrium cells using Ca2(+)-sensitive quin-2 fluorescent probe. Two components of Ca permeability of the plasmatic membrane have been determined, a potential-independent one (activated by K+ depolarization and nitrendipine-sensitive), and a basal one (not sensitive to nitrendipine). Smooth muscle cells could maintain intracellular Ca2+ concentration at the physiological level. In the presence of nitrendipine, orthovanadate, an inhibitor of sarcolemma Ca pump, induced the increase in the basal tonus depending on the presence of the Ca2+ in the medium. This suggests that in conditions of the blockage of electrically controlled Ca channels and Ca pump of the plasmatic membrane, the noncompensated basal Ca2+ influx activates the tonic contraction of smooth muscles.
已使用Ca2(+)-敏感的喹啉-2荧光探针估计了分离的子宫肌层细胞中的Ca2+浓度。已确定质膜Ca通透性的两个组成部分，一个是电位非依赖性的（由K+去极化激活且对尼群地平敏感），另一个是基础的（对尼群地平不敏感）。平滑肌细胞可将细胞内Ca2+浓度维持在生理水平。在尼群地平存在的情况下，原钒酸盐（一种肌膜Ca泵抑制剂）根据培养基中Ca2+的存在诱导基础张力增加。这表明在电控制的Ca通道和质膜Ca泵受阻的情况下，未补偿的基础Ca2+内流激活了平滑肌的强直性收缩。
