Fig. 1.

Phospholipase C-γ1 (PLCγ1) play an important role in hypoxia-induced pulmonary vasoconstriction (HPV). A: pulmonary artery (PA) and mesenteric artery (MA) rings were exposed to a physiological saline solution (PSS) bubbled with a normoxic gas (21% O₂, 5% CO₂, and the balance with N₂) for 10 min and then a hypoxic gas (1% O₂, 5% CO₂, and the balance with N₂) for 30 min. B: graph summarizes the tension generated in response to hypoxia in PAs and MAs (n = 4; *P < 0.05 compared with PA). C: representative Western blots of PLCγ1 expression in pulmonary artery smooth muscle cells (PASMCs) and mesenteric artery smooth muscle cells (MASMCs). D: graph summarizes the quantification of Western blots of PLCγ1 from three independent experiments. *P < 0.05 compared with MASMCs. E: representative traces show a hypoxia-induced increase in [Ca²⁺]_i in PASMCs preincubated without or with U73122 (1 µM) or U73433 (1 µM) for 30 min. F: quantification of the hypoxic increase in [Ca²⁺]_i in PASMCs untreated and treated with U73122 or U73433. Data were obtained from at least four different animals. *P < 0.05 compared with control.