Figure 1. Norgestimate inhibits TRPC3- and TRPC6-mediated Ca²⁺ influx.

OAG-induced changes of [Ca²⁺]_i in fluo-4-loaded TRPC3 CHO cells (A) and TRPC6 HEK-FITR cells (C) were measured in 96-well plates using a fluorometric imaging plate reader. Pre-incubation of cells with 30 µM norgestimate (NG) significantly reduced TRPC3 and −6 mediated Ca²⁺ entry. Representative fluorescence traces are shown. Concentration-response curves for inhibition of TRPC3 (B) and TRPC6 (D) by norgestimate were derived from the area under the fluorescence curves for each given concentration. The solid lines represent the best fit of the data to the Hill model with slopes of n = 1.67 (TRPC3) and n = 0.97 (TRPC6). Means ± SEM of 3 wells (B) or 4 wells (D) are shown. The chemical structure of norgestimate is illustrated in B.