Figure 10. Pseudocolor images of a single aortic endothelial cell during hydrogen peroxide exposure. Hydrogen peroxide (1.0 mM) added at 0 min. Calcium2+idetermined ratiometrically from fura-2 excitation at 334 and 360 nm. Propidium iodide fluorescence at 480 nm excitation, > 610 nm emission. The PI image is visible only after cell death occurs because it must enter the cell from the outside solution and gain access to intracellular DNA. The fura-2 image disappears after cell death because fura-2 (previously loaded intracellularly) diffuses out of the cell through the nonviable plasma membrane.
