Fig. 6.

Deletion of the CaSR gene casr or the TRPC6 gene trpc6 attenuates acute hypoxia-induced pulmonary vasoconstriction. A, left: representative record of mean pulmonary arterial pressure (PAP) before, during, and after airway ventilation of hypoxic gas (Hyp; 1% O₂) in isolated perfused/ventilated lungs from wild-type (WT), casr^+/−, or casr^−/− mice. A, right: summarized data (means ± SE) showing the increases in mean PAP induced by hypoxia challenges in isolated perfused/ventilated lungs from WT, casr^+/−, or casr^−/− mice. **P < 0.01 and ***P < 0.001 vs. WT. B: representative record of mean PAP before, during, and after superfusion of solutions with different K⁺ concentrations (10, 20, 30, 40, 60, 80, or 120 mM) and airway ventilation of Hyp (1% O₂; shadowed) in isolated perfused/ventilated lungs from WT (top), trpc6^−/− (middle), or casr^−/− (bottom) mice. C: summarized data (means ± SE) showing the dose-response curves of high K⁺-induced increases in mean PAP in isolated perfused/ventilated lungs from WT, trpc6^−/−, or casr^−/− mice. No significant differences seen between WT and trpc6^−/− or casr^−/− mice. D, left: representative record mean PAP before, during, and after airway ventilation of Hyp in isolated perfused/ventilated lungs from WT, trpc6^−/−, or casr^−/− mice. D, right: summarized data (means ± SE) showing the amplitudes of hypoxia-induced increases in mean PAP in isolated perfused/ventilated lungs from WT, trpc6^−/−, or casr^−/− mice. ***P < 0.001 vs. WT.