Figure 1

Timescale ofex vivoexperimental setup. A total of six hypoxic maneuvers (3% O₂ in an inhaled gas mixture) were performed. The second hypoxic maneuver was used as a control, because the second and subsequent hypoxic maneuvers induced HPV of stable and reproducible strength. Nebulization was initiated at the onset of the third hypoxic maneuver. In dose titration experiments, nitrite nebulizations were performed beginning with the third maneuver. The concentration that was delivered increased with each subsequent nebulization.