Figure 4.

Compounds 4m–4p activated TRPC3 expressed in HEK293 cells when extracellular solution contained 0.5 mM Ca²⁺. (A) Compound 4o failed to elicit membrane depolarization (A₁) or [Ca²⁺]_i rise (A₂) in TRPC3 cells in normal extracellular solution that contained 2 mM Ca²⁺. (B,C) Representative traces of membrane potential depolarization induced by varying concentrations of compounds 4o (B) and 4n (C) in TRPC3 cells in an extracellular solution that contained 0.5 mM Ca²⁺. (D) Summary data for membrane depolarization induced by compounds 4m–4p in TRPC3 cells bathed in the 0.5 mM Ca²⁺ solution. The data points were fitted by the Hill equation. (E) Compound 4o (10 μM) elicited TRPC3 currents in the bath that contained 0.5 mM Ca²⁺. The I–V curves under basal and 4o-stimulated conditions are shown at right.