Fig. 3. Inhibitors of endocytic vesicular traffic abrogate hypoxic preconditioning-induced cytoprotection from hypoxia. (A) Hepatocytes were incubated for 60 minutes in control or hypoxic conditions. Prior to this incubation, some samples were preconditioned by a 10 minute exposure to hypoxia followed by a 10 minute re-oxygenation (PC). In a parallel set of samples, hepatocytes were treated with 250 nM WM, 10 mM 3MA or 20 µM Cyt D. These drugs were added 15 minutes before the start of preconditioning and were present throughout the entire experimental period. (B) Hepatocyte viability was evaluated after incubation for 60 minutes under control or hypoxic conditions in non-preconditioned and preconditioned cells treated as explained above. The experiment demonstrates that WM, 3MA and Cyt D completely nullified the cytoprotective effect of hypoxic preconditioning against hypoxia. Data are given as means±s.d. of four independent experiments. (^*P<0.001, statistical significance vs hypoxia and vs PC incubated under hypoxia in the presence of inhibitors.)