Fig. 2: The BH4 domain of Bcl-2 does not inhibit IP₃R-induced Ca²⁺ release in PACs.

a–c Typical traces of the Fluo-4AM single-cell Ca²⁺ measurements performed in mouse PACs. At the start of each experiment cells were perfused with NaHEPES containing DMSO (vehicle). After establishing the baseline (200 s), ACh (75 nM) was added and IP₃R-mediated oscillations were measured for 5 min. Then, 50 µM of either the control peptide (a), the BH4 domain of Bcl-2 (b), or the BH4 domain of Bcl-X_L (c) were added for 10 min, in the continuous presence of 75 nM ACh. d Quantification of the experiments: The area under the curve per second (AUC/sec) of the ACh-induced Ca²⁺ release after peptide addition (10 min recording) was compared to the AUC/sec before peptide addition (5 min recording). Each data point represents the measurement of an individual cell. The average values ± SEM are shown (P-value 0.3467). At least three independent experiments were performed per condition (N ≥ 3). For each condition at least 14 cells were recorded