Fig. 5

Intracellular Ca²⁺ signaling in empagliflozin or cariporide-treated atrial fibroblasts. Representative intracellular Ca²⁺ tracing from cariporide alone (10 μmol/L, left upper panels), and cariporide (10 μmol/L) mixed with empagliflozin (1 μmol/L, right upper panels). Where indicated, thapsigargin was added to the calcium-free buffer to induce ER Ca²⁺ depletion. After the intracellular Ca²⁺ surge induced by thapsigargin (ER calcium) was returned to the steady state, the extracellular Ca²⁺ concentration was then increased to 2 mmol/L to measure Ca²⁺ entry. F₃₄₀/F₃₈₀ was expressed as the relative intracellular Ca²⁺. The left lower panel displays the change (∆ F₃₄₀/F₃₈₀) of Ca²⁺ measured by area under curve of Ca²⁺ tracing (AUC, statistic test by unpaired t-test), the change from baseline to peak calcium amplitude (statistic test by statistic test by unpaired t-test), and the decay time of Ca²⁺ entry (T50, calculated from the peak to the 50% of the decay or the end of the calcium image recording, statistic test by unpaired t-test) in cariporide alone (n = 5) and cariporide mixed with empagliflozin-treated atrial fibroblasts (n = 5)