Fig. 2. Transient inhibition and desensitization of I_Cl,swell in response to noradrenaline (NA). (A) Time course of I_Cl,swell of a single experiment under isotonic (ISO) and hypotonic conditions in the absence and presence of 1 µM NA. Each circle represents the current obtained every 10 seconds at -100 mV (lower trace) and +100 mV (upper trace). Numbers 1-3 indicate time points during the NA-induced transient reduction phase of I_Cl,swell, 4 after NA wash out and 5-6 during the second NA application. (a) and (b) are close ups of the I_Cl,swell time course as indicated by the windows in A. Data were fitted by single exponential functions during I_Cl,swell reduction (black line) and recovery (grey line), respectively. (B) Representative current-voltage relationships (V_mem ramps from -100 mV to +100 mV) recorded under isotonic conditions, hypotonic conditions in the absence and presence of NA and after wash out of NA. (C) Mean amplitudes of I_Cl,swell under hypotonic conditions in the absence and presence of NA as shown in panel A (n=3-12). Numbers 1-6 in brackets refer to the time points of analyses for every condition as indicated by the same numbers in panel A. (D) Relative inhibition of I_Cl,swell at +100 mV (black bars) and -100 mV (grey bars) by 1 nM, 1 µM and 10 µM NA (n=3-12). Asterisks indicate significant differences to control (CO). Hashes denote significant differences as indicated. Means±SEM; * p<0.05, ** p<0.01, *** p<0.001, **** p<0.0001; # p<0.05, ## p<0.01.