Figure 3. Composite left pulmonary vascular pressure-flow plots in seven conscious dogs during normoxia in the intact (no drug) condition, during normoxia after indomethacin, and during hypoxia after indomethacin (A), and the composite hypoxic pulmonary vasoconstrictor response in the intact (no drug) condition and after indomethacin as a function of left pulmonary blood flow (B). Compared to the no drug condition, there was no change in the left pulmonary vascular pressure-flow relationship after indomethacin. After indomethacin, hypoxia resulted in pulmonary vasoconstriction (*P < 0.01). The hypoxic pulmonary vasoconstrictor response after indomethacin was enhanced (*P < 0.01) compared to the no-drug condition.