Defibrotide (D) inhibits F-Ara–induced apoptosis in HMECs.

Evidence for intracellular antagonism. F-Ara, 10 μg/mL. D, 100 μg/mL. Flow cytometric analysis of the SSC image of PI-negative cells. (A) Reproducible induction of apoptosis by F-Ara. (B) Dose-dependent inhibition of F-Ara–induced apoptosis by D. (C) (left plot) Incubation of HMECs with F-Ara for 1 hour; subsequent incubation with D for 48 hours after washing. (right plot) Incubation of HMECs with D for 1 hour; subsequent incubation with F-Ara for 48 hours after washing. For experimental details, see legend to Figure 1 and “Materials and methods.” Shown is 1 of 3 representative independent experiments.