Flow cytometry measurements of intracellular Ca2+ in K 562 cells

The aim of this study is to show the intracellular Ca2+ changes induced by methotrexate, a cell cycle inhibitor, in order to prove the intracellular Ca2+ implication in cell proliferation processes. The fluorescent dye used to measure this parameter is Fluo-3, a fluorescein derivative useful for measuring the kinetics of Ca2+ transitions, waves and oscillations. The alterations of Ca2+ concentration proper to K562 cells have been studied, using methotrexate as a cell activation factor, both as direct effects on the cell response (1-15 minutes), and effects in time (24h.), using methotrexate in the culture medium. The K562 response at Ca2+ level in time remained constant for the cells grown in methotrexate medium, showing a slight increase in the control medium. We proved that methotrexate, a cell cycle inhibitor decreased the cytoplasmatic Ca2+ concentration in K562 cells, soon after adding methotrexate both to T0 and T1.