Potent inhibition of TRPC3- and TRPC6-mediated currents by norgestimate.

Effect of 10 µM norgestimate (NG) on whole-cell currents evoked by AlF₄⁻ infusion into TRPC3 (A) and TRPC6 (B) expressing cells. Current-voltage (I–V) relationships (left panels) and time course of currents recorded at −70 mV (right panels) are shown. For measurement of I–V curves voltage ramps from −100 to +80 mV were applied at the time points indicated. Background currents were isolated by blocking of TRPC3 and −6 with 100 µM La³⁺. Comparison of the mean inhibition of TRPC3 and −6 by 10 µM norgestimate (C) demonstrates equipotent suppression of both channels. N denotes the number of tested cells. Concentration-response relationship of the inhibition of TRPC6 by norgestimate (D). Means ± SEM of n≥3 experiments per concentration are shown. The line represents the best fit of the data to the dose-response equation with a Hill slope of 1.19.