The key role of cytosola Ca~(2+) in the apoptosis of NIH3T3 cells induced by UVB irradiation

Objective To explore the changes of intracellular Ca2+ in the NIH3T3 cells after UVB-induced apoptosis. Methods With a flow cytometer (EPICS ELITE), the apoptotic rate of the NIH3T3 cells was determined after being irradiated by UVB for 10 min and incubated for 12 h. Results The rates of apotosis in UVB irradiation groups were significantly higher as compared with the control group, and the rates significantly varied depending on the intracellular and extracellular concentration gradient of calcium. Conclusions The apoptosis of NIH3T3 cells induced by UVB was associated with the intracellular and extracellular concentration gradient of calcium, as Ca2+ constitutes the signal transduction mechanism for apoptosis. The increased cytosol Ca2+ came from both intracellular and extracellular calcium pool.