Fig. 3.

CFTR-mediated chloride currents across excised membrane patches are reduced by pre-treating BHK-CFTR cells with wiskostatin or latrunculin B. A,B. Representative macroscopic currents recordings for inside-out membrane patches excised from a control BHK-CFTR cell (A) or from a cell pre-treated with 5 μM wiskostatin for 2h (B). Inhibitory PKA peptide (PKI; 1.4 μg/ml) ) was added at the first arrow followed by glibenclamide (250 μM), a voltage-dependent pore blocker. Currents were elicited using a voltage ramp protocol (see Methods). C. Mean glibenclamide-sensitive currents (at −80 mV) for membrane patches excised from control cells and from cells pre-treated for 2h with wiskostatin (5 μM) or latrunculin B (1 μM). Data are means ± S.D. calculated from 4–7 experiments. Asterisk indicates p<0.05 relative to control. ( p = 0.09, for latrunculin B-treated cells)