Fludarabine induces programmed cell death in HMECs.

HMECs were left untreated or were incubated with F-Ara in descending concentrations for 48 hours and were subjected to flow cytometric analysis (A) or microscopic DAPI stain analysis. (A) Contour plots of the SSC image (x-axis) of PI-negative cells plotted against the forward scatter image (y-axis) as a parameter for cellular granularity versus cell size. (B) Quantitative fluorescence microscopy analysis of DAPI-stained endothelial cells. Results are given in percentage apoptotic HMECs (% apoptotic cells) ± SD (out of n = 10 microscopic fields with an average of 70 cells per field). Representatives of at least 5 independent experiments are shown. *P < .001 of untreated control versus F-Ara (10 μg/mL)–treated cells.