Strube C, Beurg M, Georgescauld D, Bournaud R, Shimahara T
Laboratoire de Neurobiologie Cellulaire et Moléculaire, CNRS, Gif-sur-Yvette, France.
Pflugers Arch. 1994 Jul;427(5-6):517-23. doi: 10.1007/BF00374269.
Spatio-temporal changes in the intracellular calcium concentration [Ca2+]i of dissociated mice myotubes from 14-day and 18-day-old fetuses were studied using digital imaging analysis of the Ca2+ indicator fura-2. Myotubes from 18-day-old fetuses displayed a transient [Ca2+]i increase upon electrical stimulation either in nominally calcium-free external solution or in Krebs solution containing 100 microM lanthanum. Thus, at this developmental stage, membrane depolarization appears to increase [Ca2+]i by stimulating Ca2+ release from the sarcoplasmic reticulum independently of extracellular Ca2+ influx. Similarly, myotubes from 14-day-old fetuses also showed a calcium transient upon electrical stimulation in Krebs solution. However, in 46% of these myotubes the calcium transient was abolished when Ca2+ entry through calcium channels was suppressed.
利用钙离子指示剂fura-2的数字成像分析，研究了来自14日龄和18日龄胎儿的解离小鼠肌管细胞内钙浓度[Ca2+]i的时空变化。在无钙的外部溶液或含有100微摩尔镧的Krebs溶液中，18日龄胎儿的肌管在电刺激后显示出[Ca2+]i的短暂增加。因此，在这个发育阶段，膜去极化似乎通过刺激肌浆网释放Ca2+来增加[Ca2+]i，而与细胞外Ca2+内流无关。同样，14日龄胎儿的肌管在Krebs溶液中电刺激后也显示出钙瞬变。然而，在这些肌管中，46%的钙瞬变在通过钙通道的Ca2+内流被抑制时消失。
