Figure 3.

Roles of Ca²⁺ influx from extracellular side in F₃₄₀/F₃₈₀ signals after a mechanical stretch equivalent to 30% strain. Representative traces of changes in F₃₄₀/F₃₈₀ ratio in a Ca²⁺-free solution (A) and in the presence of 10 μM Gd³⁺, a stretch-activated cation channel inhibitor (B). (C) Effects of extracellular Ca²⁺, 10 μM Gd³⁺, or 10 μM nifedipine (Nif) on levels of F₃₄₀/F₃₈₀ ratio in response to 30% mechanical stretch. Extracellular medium contains either 2 mM (normal solution) or 0 mM (Ca²⁺-free solution) of Ca²⁺. Bars represent means ± SD (n = 6). *Significantly different from values corresponding to stretched condition in normal solution (P < 0.001; one-way ANOVA with Bonferroni test). (D) Representative trace of F₃₄₀/F₃₈₀ ratio after application of 1 μM thapsigargin in Ca²⁺-free solution.