Figure 6. Composite data showing fluorescence measurements from fluo-3-loaded cultured human retinal pigment epithelium. Cells were examined before (open bars), during (black filled bars), and after recovery from (filled gray bars) exposure to 100 μM ruthenium red. The effect of ruthenium red was examined in the presence of different extracellular calcium concentrations (0.5, 1, 2, and 5 mM). Values are means±standard error of the mean from five cells (U donor, passage 152). Two-way ANOVA with repeated measures indicated that the lower calcium level in the presence of 100 μM ruthenium red was significant (p<0.01).