Figure 2

Gas phase NO release from stimulated SAECs/A549 cells and total nitrate/nitrite in culture medium. Data is the mean values from 3 donors. A: Representative real-time NO signal from the NO analyzer. Raw analyzer data was smoothed using a wavelet transformation, and the steady state value determined from an exponential fit as previously described [8]. B: Cytomix or IL-13 was added to the SAEC culture medium at t = 0. Gas phase NO concentration and was measured at different times (0, 6, 10, 24, 30, 34 hours) up to 48 hours, and the NO steady state flux was calculated as described in the Methods. Very low level of basal NO flux was detected from SAECs (n = 6, data from 6 measurements). NO flux was increased by cytomix treatment within 6 hours and reached a peak at 10 hours (n = 10 or 11). At t = 24 hours, 30 μM iNOS inhibitor L-NIL was added to the culture medium in some experiments leading to a significant reduction of NO flux (n = 4). IL-13 induced modest increase in NO flux in SAECs (n = 8 or 9, *P < 0.05 compared to control group, #P < 0.05 compared to cytomix stimulated group). C: Total nitrite+nitrate content in SAECs culture medium after 48 hours exposure to either cytomix or IL-13 was measured (n = 10, *P < 0.05 compared to control group). D: Cytomix or IL-13 was added to A549 cell culture medium at t = 0. NO flux was increased by cytomix treatment within 6 hours and reached a peak at 10 hours. IL-13 did not alter the NO flux (n = 4, *P < 0.05 compared to control group). E: Total nitrite+nitrate content in A549 cell culture medium after 48 hours exposure to either cytomix or IL-13 was measured (n = 8, *P < 0.05 compared to control group).