Fig 1: Inhibition of Notch signaling attenuates hypoxia-induced increase in pulmonary arterial pressure (PAP) in isolated perfused/ventilated mouse lungs. (a) Representative records (left panel) showing changes of PAP induced by ventilation of hypoxic gas (1% O2 in N2 for 4 min) before, during, and after perfusion of DAPT (30 µM, a γ-secretase inhibitor). Summarized data (means ± SE, right panel, n = 5 mouse lungs) showing the hypoxia-induced increases in PAP before (Cont), during (DAPT), and after (Rec) perfusion with PSS containing DAPT. (b) Representative Western blot images (left panel) and summarized data (means ± SE, right panel, n = 3 independent experiments from five mice) showing Notch3 expression levels in lung tissues isolated from WT and notch3–/– mice. ***p < 0.001 vs. WT. (c) Representative records (left panels) of PAP before, during, and after ventilation of hypoxic gas (1% O2 in N2 for 4 min) in WT and Notch3 knock-out (notch3–/–) mice. Summarized data (means ± SE, n = 5 mouse lungs, right panel) showing acute hypoxia-induced increase in PAP in WT and notch3–/– mice. ***p < 0.001 vs. WT (c).ND: not detectable.