Figure 2.

Change in MPT ROS threshold (t_MPT) under reoxygenation and hypoxic and pharmacologic PC. (A) Hypoxia/reoxygenation causes a rapid and progressive decline in t_MPT (control, black squares; after reoxygenation, red triangles; O₂ in the buffer, blue trace). (B) Hypoxic (HPC) (three 5-minute cycles of hypoxia/reoxygenation) improves t_MPT (red triangles compared with control, shown in black squares). (C) Dz pretreatment (30 ∝M for 15 minutes, red bar) prevents the decline in t_MPT after hypoxia/reoxygenation. (D) 5HD treatment (500 ∝M, during hypoxic PC phase only, red bar) abolishes the hypoxic PC_mediated protection against the decline in t_MPT after hypoxia/reoxygenation. (E) Summary of the effects of hypoxia/reoxygenation and hypoxic and pharmacologic PC on t_MPT. *P < 0.01 vs. control (Con). (F) Both cyclosporin A (CSA) (0.2 ∝M) and SFA (1 ∝M) enhance MPT ROS threshold (measured more than 60 minutes after washout). *P < 0.01 vs. control.