FIGURE 4.

Aldosterone treatment increases Ca²⁺ spark frequency in MASMCs. (A) Representative pseudo-colored confocal images of Ca²⁺ sparks (top) and normalized (F/F₀) fluorescence profiles (bottom) from Fluo 4-loaded MASMCs treated or not with aldosterone (ALDO 10 nM, 24 h) and preincubated or not with Nifedipine (1 μM, 10 min). The fluorescence profile was calculated in the region indicated by the green bar. (B) Scatterplot with mean ± SEM illustrates Ca²⁺ spark frequency in Fluo 4-loaded MASMCs from control (empty circles, n = 35 cells/N = 5 rats); ALDO-treated arteries (red circles, n = 29 cells/N = 4 rats); pre-incubated with Nifedipine (NIF, white/black circles, n = 18 cells/N = 4 rats; and red/black circles, n = 11 cells/N = 3 rats, respectively). ^**P < 0.01 vs. control cells. ^#P < 0.05 and ^###P < 0.001 vs. ALDO-treated group.