Figure 1.

Sensitivity of I_hERG to erythromycin (a), terfenadine (b) and thioridazine (c). Top panels show representative traces for I_hERG recorded at 37ºC before and during exposure to 3 or 30 µM erythromycin (Ery) (ai), 100 nM terfenadine (Terf) (bi) or 100 nM thioridazine (Thior) (ci). Currents were elicited using the protocol shown in the lower panels. Bottom panels show the isochronal concentration–response relationships obtained for erythromycin (aii) (IC₅₀ 94 µM (CI 38.4–230.1 µM); n = 5 to 8 to cells per concentration), terfenadine (bii) (IC₅₀ 128.5 nM (CI 68.0–243.3 nM); n = 4 to 6 to cells per concentration) and thioridazine (cii) (IC₅₀ 62 nM (CI 52.7–73.1 nM); n = 5 to 7 cells per concentration). Respective n_H values yielded from fit were of 0.40 (CI 0.25–0.54), 0.57 (CI 0.36–0.77), 0.55 (CI 0.50–0.61) for erythromycin, for terfenadine and for thioridazine