Figure 5.

Synergistic effects on insulin secretion elicited by the induction of Ca²⁺ influx and activation of protein kinase C. (A) Effects of nifedipine on the glucose‐stimulated insulin secretion potentiating effect of fasiglifam. Data are normalized to the vehicle (0 mmol/L glucose) group and shown as means ± SEM (n = 3). ***P < 0.001 versus 0 mmol/L glucose by Dunnett's test, ^$ P < 0.05 by Welch's t‐test. (B) Dose–response effect of (S)‐(‐)‐Bay K 8644 (Bay) on insulin secretion in the absence of glucose in MIN6 cells. Data are normalized to the vehicle group and shown as means ± SEM (n = 3). *P < 0.025 versus vehicle by one‐tailed Williams’ test. (C) Dose–response effect of OAG, with and without 1 μmol/L Bay, on insulin secretion in the absence of glucose in MIN6 cells. Data are normalized to the vehicle (neither OAG nor Bay) and shown as means ± SEM (n = 3). *P < 0.025 versus vehicle by one‐tailed Williams’ test. ^# P < 0.025 versus 1 μmol/L Bay alone by one‐tailed Williams’ test. Two‐way ANOVA: main effect of OAG: P < 0.01; main effect of Bay: P < 0.01; interaction of OAG and Bay: P < 0.01.