Both nifedipine and TTA-P2 maximally inhibit aldosterone secretion. A, TTA-P2 does not alter nifedipine-induced inhibition of aldosterone production from human adrenal slices. B, Nifedipine does not alter TTA-P2 inhibition of aldosterone production from human adrenal slices (n = 5). C, Effects of different concentrations of nifedipine or TTA-P2 on CaV3.2/3 and CaV1.2/3 channel currents in H295R cells. D, 100 nm/L nifedipine and 200 nm/L TTA-P2 showed additive effect on basal aldosterone secretion. #, p < 0.05 compared with nifedipine or TTA-P2 alone.