Fig. 1.

Restoration of acid-sensing ion channel 1 (ASIC1) in pulmonary arterial smooth muscle cells (PASMCs) from ASIC1 knockout (ASIC1^−/−) mice rescues store-operated Ca²⁺ entry (SOCE). A: RT-PCR for ASIC1 and β-actin in PASMCs from ASIC1^+/+ and ASIC1^−/− mice transfected with human (h)ASIC1. B: smooth muscle-22α (SM22α; green) and ASIC1 (red) immunofluorescence in PASMCs from ASIC1^+/+ and ASIC1^−/− mice. PASMCs from ASIC1^−/− mice were additionally transfected with hASIC1. C: summary data showing SOCE-induced changes (Δ) in intracellular Ca²⁺ concentration ([Ca²⁺]_i) [expressed as changes in the 340-to-380-nm fluorescence ratio (ΔF₃₄₀/F₃₈₀)] in PASMCs isolated from ASIC1^+/+ and ASIC1^−/− mice. PASMCs from ASIC1^−/− mice were additionally transfected with hASIC1. All experiments were performed in the presence of cyclopiazonic acid (CPA; 10 μM) and diltiazem (50 μM). Values are means ± SE; numbers of animals (n values) are indicated in bars. *P < 0.05 vs. PASMCs from ASIC1^+/+ mice; #P <0.05 vs. PASMCs from ASIC1^−/− mice.