Figure 5. Nisoldipine reveals increased I_CaL sensitivity in severely affected iPSC-CMs.

(A–E) The effect of 0.05 μM nisoldipine on both trios. Data are depicted as macroscopic action potential record, APD summary data, and I_CaL comparison between no drug and nisoldipine. Between 8 and 11 cells were analyzed for the effects of nisoldipine on APD and 5–8 cells for the effects of nisoldipine on I_CaL in A–E. See Supplemental Table 4 for exact numbers of replicate measures (n) and statistical analysis (paired Student’s t test). Dose-response relationship for nisoldipine (Supplemental Figure 1) was determined before selection of the concentration used in these experiments (a concentration lower than EC₅₀ was chosen because the objective was to shorten the APD and I_CaL to levels more like those of control iPSC-CMs). *P < 0.05; as determined by paired 2-tailed Student’s t test.