FIGURE 3.

Ba²⁺ uptake and Mn²⁺ quenching of Indo-1 are increased in magnitude and speed in EBV B95–8-infected cells but unchanged in P3HR-1-infected cells. Experiments were done on BL-30 (left panels) and BL-41 cells (right panels). In both experiments, cells were pretreated for 10 min with 1 μm TG in Ca²⁺-, Ba²⁺-, and Mn²⁺-free medium to induce Ca²⁺ release from the ER and the opening of the store-operated channels. Experiments were done on at least five different batches of noninfected cells (EBV-free), B95–8 infected cells (B95–8), and P3HR-1 infected cells (P3HR-1). A and B, at t = 0 s, 5 mm BaCl₂ was added (in the place of 1 mm CaCl₂), and [Ba²⁺]_cyt was measured. [Ba²⁺]_cyt was calculated as [Ca²⁺]_cyt, according to Indo-1 fluorescence. C and D, at t = 30 s, 100 μm MnCl₂ was added instead of 1 mm CaCl₂, inducing the quenching of Indo-1 fluorescence.