Fig. 3
From: Soluble adenylyl cyclase mediates hydrogen peroxide-induced changes in epithelial barrier function
Phospholipase C is an integral part of the H2O2-induced changes in resistance and permeability. Panel a. Fully differentiated NHBE cells were mounted in Ussing chambers, treated with 10 μM amiloride and the phospholipase C inhibitor U73122 (20 μM) in the apical and basolateral compartments for 20 min. Cells were then stimulated with apical 1 mM H2O2 in the presence of current pulses to determine the membrane resistance before and after H2O2 exposure. Pre-treating NHBE cells with U73122 (n = 8 cultures from 8 donors, * = p < 0.05) attenuated the H2O2-induced decrease in membrane resistance in a similar fashion to that seen with the EP1 receptor antagonist sc19220 (n = 8 cultures from 8 donors, * = p < 0.05). Panel b. Parallel mannitol flux experiments also showed an attenuation of the concomitant increase in permeability associated with apical 1 mM H2O2 exposure (n = 4 cultures from 2 lung donors, * = p < 0.05 compared to control). Panel c. Inhibition of the IP3 receptor with 2-APB (200 μM) also attenuates H2O2-induced decreases in resistance, further supporting a role for [Ca2+]i in the pathway (n = 3 cultures from 3 donors, * = p < 0.05)