Shuttleworth T J, Thompson J L
Department of Physiology, University of Rochester School of Medicine and Dentistry, NY 14642, USA.
Biochem J. 1996 Feb 1;313 ( Pt 3)(Pt 3):815-9. doi: 10.1042/bj3130815.
As in many cells, the frequency of agonist-induced cytosolic Ca2+ concentration ([Ca2+]1) oscillations in exocrine avian nasal gland cells is dependent on the rate of Ca2+ entry. Experiments reveal that the initiation of each oscillatory spike is independent of the relative fullness of the stores and, furthermore, the oscillating pool is normally fully refilled by the end of each [Ca2+]1 spike. Therefore, contrary to current models, the interspike interval (which essentially sets the frequency) does not reflect the time taken to recharge the oscillating stores. Instead, the data show that it is the previously demonstrated role that Ca2+ entry plays in triggering the repetitive release of Ca2+ from the oscillating stores, rather than the recharging of those stores, that provides the basis for the observed effects of Ca2+ entry rate on oscillation frequency.
与许多细胞一样，外分泌性禽鼻腺细胞中激动剂诱导的胞质钙离子浓度（[Ca2+]i）振荡频率取决于钙离子内流速率。实验表明，每个振荡尖峰的起始与储存库的相对充盈程度无关，此外，振荡池通常在每个[Ca2+]i尖峰结束时完全重新充盈。因此，与当前模型相反，尖峰间隔（基本上决定了频率）并不反映重新填充振荡储存库所需的时间。相反，数据表明，正是先前证明的钙离子内流在触发振荡储存库中钙离子的重复释放中所起的作用，而非这些储存库的重新填充，为观察到的钙离子内流速率对振荡频率的影响提供了基础。
