FIGURE 7.
Effects of PYO, ATP, and thapsigargin on Cai in CF15 cells. CF15 cells grown to confluency on cover glasses were loaded with fura-2 and mounted in the imaging microscope for measurements of Cai. Calibrations of 350:385 ratio in terms of Cai (in nm, shown on y axis) were performed at the end of the experiment (data not shown). Bold line shows average response of ∼30 cells in the field, and lighter lines show responses of five single cells. 500-s time bar is also shown. Addition of 100 μm of PYO had no effects on Cai, whereas subsequent addition of 100 μm ATP caused a characteristically rapid spike in Cai followed by a secondary slower response. Further addition of 1 μm thapsigargin (TG) also caused a large increase in Cai. Experiments are typical of three similar experiments.