[Differences in the Ca2+ signaling in proliferating and differentiating myoblasts in mice]

Specific features of Ca2+ -signaling in proliferating and differentiated C2C12 myoblasts have been studied. It was shown that the system of Ca2+ -signaling is reduced in proliferating myoblasts: the intracellular ATP-regulated stock is insignificant, the buffer protein is absent or present in minimum quantities in endoplasmic reticulum, and the entry of Ca2+ is not registered when its endocellular stocks are exhausted. The formation of the Ca -signaling system occurs during the initial stages of differentiation (within eight to ten hours after transfer of cell to differentiation medium). During this period, the buffer protein is accumulated, and the entry of Ca begins. During the initial stages of myoblast differentiation, the voltage-dependent entry of Ca2+ also appears. It was also shown that the stock of in mitochondria makes an insignificant contribution to increase in Ca2+ concentration in the cytoplasm.