Fig. 4.

Removal of extracellular Ca²⁺ abolishes the capsaicin-induced increase in [Ca²⁺]_cyt in PASMCs. A and B: representative individual traces showing changes in [Ca²⁺]_cyt in normal and IPAH PASMCs before and during extracellular application of 500 μM (normal) and 100 μM (IPAH) capsaicin when cells were superfused with 1.8 mM Ca²⁺-containing bath solution or in Ca²⁺-free bath solution. C and D: representative averaged traces showing changes in [Ca²⁺]_cyt in normal and IPAH PASMCs before and during extracellular application of 500 μM (normal) and 100 μM (IPAH) capsaicin when cells were superfused with 1.8 mM Ca²⁺-containing bath solution or in Ca²⁺-free bath solution. E and F: summarized data (means ± SE) showing the amplitudes of 500 μM capsaicin-induced increases in [Ca²⁺]_cyt in normal and 100 μM capsaicin-induced increases in [Ca²⁺]_cyt in IPAH in the absence and presence of 1.8 mM extracellular Ca²⁺ (n = 60–90 cells, 3 separate experiments). *P < 0.05 compared with 1.8 mM Ca²⁺.