Fig. 5.

Effect of 1 μM nifedipine on intrinsic activity of the rat bladder. A: tension traces from SCT and normal rat bladder sheets. Addition of 1 μM nifedipine to the perifusion solution abolished the intrinsic contractions in both preparations. B: Ca²⁺ and voltage trace maps from before (i and ii) and after (iii and iv) addition of nifedipine. Before the addition of nifedipine, Ca²⁺ transients and voltage signals are clearly observed. After nifedipine is added, voltage activity is completely abolished. However, Ca²⁺ transients are still observed from the mucosal surface, indicating intrinsic activity may originate from cells in the mucosa.