Objective: To study the change and significance of intracellular-free calcium levels ([Ca2+]i) and inositol 1, 4, 5-trisphosphate (IP3) levels in the process of gastric carcinoma cell apoptosis induced by cisplatin.
Methods: Apoptosis induced by cisplatin in gastric carcinoma BGC823 cell was investigated by light and electronmicroscopy, agarose gel electrophoresis and flow cytometry. [Ca2+]i was determined by Fura-2 fluorescin load technic, IP3 was determined by competitive protein binding method.
Results: When BGC823 cells were treated with cisplatin (2 micrograms/ml) for 24 hours changes appeared typical of apoptosis. [Ca2+]i and IP3 were significantly increased, especially at the initial stage of apoptosis. However, from 2 to 24 hours after cisplatin treatment, IP3 levels progressively decreased, being significantly lower than those of the untreated controls.
Conclusion: In the process of cisplatin induced apoptosis of gastric carcinoma cells, [Ca2+]i and IP3 levels are up-regulated at the very initial stage but down-regulated from 2 hours afterwards.