A MODEL DESCRIBING DIFFERENT KINDS OF OSCILLATIONS OF CYTOSOLIC CALCIUM IN HEPATOCYTES
描述肝细胞中两类不同特性钙离子浓度振荡

As a second messenger, the intracellular calcium transfers biological message by concentration oscillations. The experiments on rat hepatocytes showed that intracellular calcium concentration has two very different forms of oscillations stimulated by different agonists. One consists of simple spikes with a high frequency, and the other consists of complex burstings with every bursting composed of multi-peaks of the concentration. The peak concentration is often limited under 500 nmol/L to 800 nmol/L for both kinds of oscillations. A four-variable dynamical model is constructed by combining different models and considering experimental facts published before. This model describes the change of the oscillations from simple spikes to complex bursting. Numerical simulations are in good accordance with experiments in both frequency and amplitude of Ca2+ oscillations. The dynamics of the system shows that the complexity of oscillations depends on the accelerate active Gα subunit and the forming of active PLC.