A quantitative kinetic model for ATP-induced intracellular Ca2+Ca2+ oscillations

A quantitative kinetic model is proposed to simulate the ATP-induced intracellular Ca2+Ca2+ oscillations. The quantitative effect of ATP concentration upon the oscillations was successfully simulated. Our simulation results support previous experimental explanations that the Ca2+Ca2+ oscillations are mainly due to interaction of Ca2+Ca2+ release from the endoplasmic reticulum (ER) and the ATP-dependent Ca2+Ca2+ pump back into the ER, and the oscillations are prolonged by extracellular Ca2+Ca2+ entry that maintains the constant Ca2+Ca2+ supplies to its intracellular stores. The model is also able to simulate the sudden disappearance phenomenon of the Ca2+Ca2+ oscillations observed in some cell types by taking into account of the biphasic characteristic of the Ca2+Ca2+ release from the endoplasmic reticulum (ER). Moreover, the model simulation results for the Ca2+Ca2+ oscillations characteristics such as duration, peak [Ca2+]cyt[Ca2+]cyt, and average interval, etc., lead to prediction of some possible factors responsible for the variations of Ca2+Ca2+ oscillations in different types of cells.