Fig. 3.

Sensitivity of ATP-activated K⁺ secretion to K_Ca1.1 blockers. Isolated mucosae were stimulated by ATP (100 μM) addition to the mucosal solution from the standard basal condition with electrogenic secretion monitored by I_sc. A: adjacent mucosae were stimulated by ATP with one pretreated by IbTx (200 nM) addition to the mucosal solution 25 min prior to ATP (dotted line). B: adjacent mucosae were stimulated by ATP with one pretreated by paxilline (1.0 μM) addition to both mucosal and serosal solutions 20 min prior to ATP (dotted line).