Figure 5.

Contraction requires voltage-dependent Ca²⁺ influx. Histogram comparing the mean amplitudes of contractile responses to 10 μM linopirdine or 1 μM XE991 under control conditions and in the presence of Ca²⁺-free (0Ca) bathing solution (n = 6 for both drugs), 1 μM nifedipine (Nif; n = 5 for both drugs) or 10 μM levcromakalim (Lev; n = 4 for linopirdine; n = 5 for XE991). Responses were measured in each vessel as a percentage of the contractile response to 50 mM KCl. ***p < 0.001, **p < 0.01, *p < 0.05 compared with paired control.