Fig. 2
From: Bicarbonate transport of airway surface epithelia in luminally perfused mice bronchioles
Effects of luminal HCO3−–CO2 removal on pHi in bronchiole epithelial cells. a The experimental protocol used for the measurement of HCO3− efflux across the apical membrane of microperfused bronchioles. Isolated bronchioles were first bilaterally perfused with the standard HCO3−-buffered solution and the luminal perfusate was switched to the standard Hepes-buffered HCO3−–CO2-free solution. It was assumed that the transient alkalinization was due to CO2 diffusion out of the cell and the subsequent recovery was due to HCO3− efflux mostly across the apical membrane. Means ± SD of 8 experiments. b Isolated bronchioles were first bilaterally perfused with the standard HCO3−-buffered solution and the luminal perfusate was switched to the solution which first contained 25 mM HCO3− but which was equilibrated with 100% O2 (pH: ~ 7.8) and thus was nominally free of CO2. Means ± SD of 8 experiments