Fig. 8.

ATP and H₂O₂-induced increase in [Ca²⁺]_i in PASMCs and PLC-dependent norepinephrine (NE)-induced contraction in PAs are greatly enhanced in mice exposed to CH. A: effect of ATP (10 µM) on [Ca²⁺]_i in PASMCs from normoxic and CH mice. B: effect of H₂O₂ (500 µM) on [Ca²⁺]_i in PASMCs from normoxic and CH mice. Cells were obtained from at least four different animals. *P < 0.05 compared with normoxia. C: summary of NE-induced contraction in PA rings from normoxia and CH mice treated with and without U73122 (10 µM). Data were obtained from three normoxic and four CH mice. *P < 0.05 compared with normoxia, and #P < 0.05 compared with CH.