FIGURE 6.

iAng II attenuated caffeine-induced changes of APs and caffeine-induced Ca²⁺ release in mESC-CMs. (A) Raw traces of spontaneous APs at the basal level and upon treatment with caffeine (5 μM) in mESC-CMs. (B) Raw traces of spontaneous APs upon treatment with iAng II (10^–7 M) followed by the subsequent application of caffeine in mESC-CMs. (C–F) Summarized data on the (C) AP rate, (D) DD slope, (E) APD50, and (F) MDP upon treatment with caffeine (5 μM) alone or upon treatment with iAng II (10^–7 M) followed by caffeine (5 μM). (G) Raw traces of changes in Fluo-4 fluorescence at the basal level and upon treatment with caffeine (5 μM) in mESC-CMs. (H) Raw traces of changes in Fluo-4 fluorescence with caffeine in the presence of iAng II (10^–7 M) in mESC-CMs. (I) Summarized data on the effects of iAng II (10^–7 M) on the caffeine-induced Ca²⁺ release in mESC-CMs when external Ca²⁺ was absent. Values are mean ± SEM of 6–10 independent experiments. *p < 0.05 vs. control group.