Effect of lipopolysaccharides (LPS) on resting pH_i and NHE activity in HRASMCs superfused with HEPES-buffered Tyrode solution.

<p><b>A, C, E:</b> The top bar shows the buffer system used in the superfusate. The periods of application of NH₄Cl and LPS (1∼10000 ng/ml) are shown with bars above or below the trace. Traces A represents experiments showing the effect of different concentrations of LPS (1∼10000 ng/ml) on resting pH_i in HEPES-buffered Tyrode solution in HRASMCs (pH_o = 7.4, 37°C). The left part of traces C and E shows a typical pH_i recovery from an intracellular acidosis induced by a 7 min NH₄Cl (20 mM) pre-pulse in HEPES-buffered solution (pH_o = 7.4, 37°C) in HRASMCs. The right part of traces C and E represents experiment showing the effect of different concentrations of LPS (1∼10000 ng/ml) on pH_i recovery in HRASMCs. B, D: Histograms, showing the change in resting pH_i and pH_i recovery slope of acid extrusion after NH₄Cl-induced intracellular acidosis averaged for 7 and 6 experiments similar to those shown in A and C (measured at the range between the two dash lines of the figure), respectively. *: p<0.01 vs. control.