Figure 1. Effect of ethanol pre-exposure on adenosine-induced epithelial ion transport.

Calu-3 cells were cultured at an air-liquid interface on membrane filters and basolaterally exposed to 0, 25, 50 and 100 mM of ethanol for 24 hours. These Calu-3 epithelia were placed in an Ussing chamber with asymmetrical buffers of chloride (apical 10.4 mM and basolateral 139.8 mM). Following voltage clamp, stable short circuit baselines were attained in 15 to 20 min. I_SC was measured after blocking Na⁺ channels with 100 µM of apical amiloride and stimulated with 100 µM of apical adenosine. Alterations in ion transport are expressed as difference in I_SC from their baseline. Ethanol pre-exposure decreased 100 µM adenosine mediated epithelial ion transport in a dose-dependent manner. Asterisks indicate significant differences between groups by One-way ANOVA test (p<0.05, n = 5 for each condition).