Calcium and A23187-induced cytolysis of mouse thymocytes

The cytotoxic effects of ionophore A₂₃₁₈₇ were studied in parallel with its action on calcium uptake in isolated mouse thymocytes. Under conditions where the cells were preincubated in a calcium-containing medium prior to ionophore treatment a close relationship could be observed between the extent of cell lysis and the stimulation of calcium uptake in the presence of A₂₃₁₈₇. In addition, increasing concentrations of calcium ions in the incubation medium lead to a pronounced decrease of cell viability and to a stimulation of calcium uptake suggesting that calcium is critical for cell survival.