Department of Environmental and Occupational Health, Robert Stempel College of Public Health and Social Work, Florida International University, 11200 SW 8th Street, HLS-594, Miami, FL 33199, USA.
Adv Exp Med Biol. 2012;740:521-9. doi: 10.1007/978-94-007-2888-2_23.
From beginning of the life to final moment of the life, Ca(2+) functions as an important signaling messenger. The intracellular Ca(2+) concentration, Ca(2+), in resting cells is normally maintained at around 100 nM with a very steep ∼20,000 times concentration gradient of Ca(2+) between extracellular and intracellular compartments. Ca(2+) signals in the form of time-dependent changes in Ca(2+) appear as brief spikes that are organized into regenerative Ca(2+) waves. The release of Ca(2+) from internal stores plays a key role in regulating such Ca(2+) signals. Since global Ca(2+) oscillations arise from Ca(2+) waves initiated locally, it results in generation of stochastic Ca(2+) oscillations. In addition, the hierarchical organization of signaling structures translate the molecular fluctuations of single channels to the whole cell leading to formation of stochastic media. Several recent observations indicate that Ca(2+) changes are fluctuation driven as opposed to a typical deterministic intracellular reaction-diffusion system model. Elucidation of this signaling mechanism can provide detailed knowledge of relationship between cell signaling and cell physiology of living systems.
从生命的开始到生命的最后一刻，Ca(2+) 作为一种重要的信号信使发挥作用。在静止细胞中，细胞内 Ca(2+)浓度 (Ca(2+)) 通常保持在 100 nM 左右，细胞外和细胞内隔室之间的 Ca(2+)浓度梯度非常陡峭，约为 20000 倍。Ca(2+)信号以 Ca(2+) 随时间变化的形式出现，表现为短暂的尖峰，这些尖峰组织成再生性 Ca(2+)波。来自内部储存库的 Ca(2+)释放在调节这种 Ca(2+)信号中起着关键作用。由于全局 Ca(2+)振荡是由局部引发的 Ca(2+)波产生的，因此会导致随机 Ca(2+)振荡的产生。此外，信号结构的层次组织将单个通道的分子波动转化为整个细胞，从而形成随机介质。最近的一些观察结果表明，Ca(2+)的变化是由波动驱动的，而不是典型的确定性细胞内反应扩散系统模型。阐明这种信号机制可以为细胞信号与活系统的细胞生理学之间的关系提供详细的知识。
