The effect of simvastatin (Simva, 14.3 μM) on insulin secretion stimulated by tolbutamide (Tol, 100 μM) and potassium chloride (KCl, 40 mM) at 5.5 mM (A) and 16.7 mM glucose concentrations (B); the effect of simvastatin and nifedipine (Nif, 5 μM) on insulin secretion at 5.5 mM (C) and 16.7 mM (D) glucose concentrations; the effect of simvastatin on insulin secretion stimulated by acetylcholine (Ach, 10 μM) at 5.5 mM glucose concentration (E); and the effect of simvastatin on insulin secretion stimulated by phorbol myristate acetate (PMA, 0.5 μM) at 5.5 mM glucose concentration (F); and the effect of simvastatin (14.3 μM) on the PKC activity in MIN6 β-cells at 5.5 and 16.7 mM glucose concentration (G). Insulin secretion was normalized with protein concentration, data are mean ± SEM relative to control (100%). p values were calculated with the Mann-Whitney test, *p<0.05, **p<0.01 compared to control. The number of replicates was 6 for A and E, 8 for B, C, and D, 4 for F, and 2–4 for G.