Detection of Calcium by a confocal laser scanning microscope in Na_2SeO_3-treated SW480 human colonic carcinoma cells

摘要

A number of studies have demonstrated that perturbed cellular calcium homeostasis has been implicated in apoptosis. Some studies showed that selenium compounds were able to induce cell apoptosis. The main objective of this study is to evaluate effect of Na_2SeO_3 on intracellular Ca~(2+) levels in SW480 human colonic carcinoma cells. When SW480 cells were exposed to 25 to 100 μmol/L Na_2SeO_3, we also found that Na_2SeO_3 was able to induce [Ca~(2+)]_i, disruption of mitochondrial membrane potential (Δψm) in SW480 cells by using a confocal laser scanning microscope. Ca~(2+) channel inhibitor CoCl_2 and an intracellular Ca~(2+) chelator BAPTA completely inhibited [Ca~(2+)]_i increase. CoCl_2, BAPTA and ruthenium red also inhibited disruption of Δψm. The results suggest that Na_2SeO_3 is able to increase [Ca~(2+)]_i mitochondria permeability transition and Ca~(2+) is from extraceullar Ca~(2+).