H2O2 inhibition of forskolin-stimulated IS C. NHBE cultures were mounted in Ussing chambers and treated with either 10 μM forskolin or 1mM H2O2 followed by 10 μM forskolin. Panel a, representative traces of forskolin-induced CFTR activity with (red trace) and without (black trace) H2O2 pre-treatment. Panel b, ISC values with (treated) and without (control) H2O2 pre-treatment (mean ± s.e.m., n = 9 lung donors). H2O2 treatment reduced the forskolin-stimulated ISC by approximately 50 %. Figure S2. Recovery of resistance and forskolin-stimulated ISC after H2O2 treatment. NHBE cultures were exposed to apical 1 mM H2O2 for 1h. After removal of H2O2 the cultures were returned to the CO2 incubator for 23h and then placed in Ussing chambers for measurement of both resistance and forskolin-stimulated IS C (time point 24h). Panel a, ISC before and 23h after treatment are shown (mean ± s.e.m., n = 3 lung donors). Forskolin-stimulated ISC currents returned to normal within 23h after treatment. Panel b, Epithelial resistance before and 23h after treatment are shown (mean ± s.e.m., n = 3 lung donors). Resistance returns to normal within 23h after treatment. (DOCX 633 kb
