Shmigol A, Kostyuk P, Verkhratsky A
Bogomoletz Institute of Physiology, Kiev, Ukraine.
Neuroreport. 1994 Oct 27;5(16):2073-6. doi: 10.1097/00001756-199410270-00021.
The role of calcium stores in cytoplasmic calcium signal termination was studied in acutely isolated small and large DRG neurones from mice. Cytoplasmic calcium concentration ([Ca2+]in) was recorded using indo-1 microfluorometry and membrane potential was monitored by 'perforated' whole-cell patch-clamp. Depolarization-induced [Ca2+]in transients recovered significantly faster in large neurones than in small neurones. Caffeine was able to release Ca2+ from internal stores only in large neurones, while small neurones lacked caffeine-releasable calcium stores. Thapsigargin abolished caffeine-induced Ca2+ release and significantly slowed down recovery of depolarization-triggered [Ca2+]in transients in large neurones. We conclude that [Ca2+]in signals recover faster in large DRG neurones, at least in part due to the higher rate of Ca2+ sequestration by intracellular stores.
在急性分离的小鼠小和大背根神经节（DRG）神经元中研究了钙库在细胞质钙信号终止中的作用。使用indo-1显微荧光测定法记录细胞质钙浓度（[Ca2+]in），并通过“穿孔”全细胞膜片钳监测膜电位。去极化诱导的[Ca2+]in瞬变在大神经元中恢复得明显比小神经元快。咖啡因仅能在大神经元中从内部钙库释放Ca2+，而小神经元缺乏可被咖啡因释放的钙库。毒胡萝卜素消除了咖啡因诱导的Ca2+释放，并显著减缓了大神经元中去极化触发的[Ca2+]in瞬变的恢复。我们得出结论，大DRG神经元中[Ca2+]in信号恢复得更快，至少部分原因是细胞内钙库对Ca2+的摄取速率更高。
