Fig. 9. (A) Representative recording of the transepithelial voltage (V_t) before and after the addition of 0.2 mmol l^–1 diphenylamine-2-carboxylate (DPC) to the bathing saline. DPC briefly depolarises V_t but does not inhibit the spontaneous voltage oscillations. Nor does it prevent the reduction of V_t by 10 µmol l^–1 Tenmo-ADFb (thin arrow; ADFb). (B) A representative recording of the basal membrane voltage (V_b) showing this is not affected by the addition of either 10 µmol l^–1 Tenmo-ADFb or 1 nmol l^–1 Achdo-KII (AKII). Thick arrows mark the point of insertion (downward) and withdrawal (upward) of the microelectrode, and horizontal bars show when peptides were present in the perfusate.