Fig. 6. Reversible persistent inhibition and desensitisation of I_Cl,swell in response to the Epac- activator 8-pCPT-2-O-Me-cAMP (8pCPT). (A) Time course of I_Cl,swell of a single representative experiment under isotonic (ISO) and hypotonic conditions in the absence and presence of 8-pCPT-2-O-Me-cAMP and after washout of the drug. Each circle represents the current obtained every 10 seconds at -100 mV (lower trace) and +100 mV (upper trace). 1 indicates I_Cl,swell during hypotonicity, 2 during the application of 8-pCPT-2-O-Me-cAMP, 3 after 8-pCPT-2-O-Me-cAMP-washout, 4-5 during second application of 8-pCPT-2-O-Me-cAMP. (B) Representative current-voltage relationships (V_mem ramps from -100 mV to +100 mV) recorded under isotonic and hypotonic conditions in the presence and absence of 8-pCPT-2-O-Me-cAMP. (C) Average amplitudes of I_Cl,swell under hypotonic conditions in the presence and absence of 50 µM 8-pCPT-2-O-Me-cAMP. Results of 3-5 individual experiments as shown in panel A (n=3-5). The corresponding timepoints for every condition (1-5) are indicated in panel A. Asterisks indicate significant differences to control (CO). Hashes indicate significant differences as indicated. Means±SEM; * p<0.05; # p<0.05, ## p<0.01.