Absorption of Na⁺ across the alveolar epithelium is essential for lung fluid homeostasis. Na⁺ entry at the luminal membrane is predominantly via amiloride-sensitive Na⁺ channels (ENaC) which comprise α, β and γsubunits. Insertion and retrieval of these subunits in the epithelial cell membrane is critical to ENaC function.The human lung adenocarcinoma cell line H441 was transfected with Green Fluorescent Protein (GFP)-tagged αENaC, or GFP alone. RT-PCR was used to amplify mRNA from the transfected constructs, followed by western blotting to confirm the size of the expressed proteins. Fluorescence microscopy was used to visualise cellular expression level and distribution of GFP and GFP-αENaC.Fluorescence studies revealed the distribution of GFP alone as diffuse throughout the cell cytoplasm. In contrast, GFP-αENaC appeared more defined and co-localised with wheat germ agglutinin (WGA), which binds to glycosylated proteins at the plasma membrane.H441 cell monolayers were cultured on permeable supports, and demonstrated short circuit currents (I_sc) of 9.7±2.5 µA cm^-2 (p < 0.05, n = 5). A similar net ion transport of 9.0±0.7 µA cm^-2 (p < 0.05, n = 5) was found in cells expressing GFP alone. In contrast, I_sc was significantly higher in those expressing GFP-αENaC (17.3±2.7 µA cm^-2,p < 0.05, n = 7). Amiloride-sensitive I was also significantly higher in these cells than in control cells and those transfected with GFP alone (15.7±2.5, 6.7±2.5 and 7.7±1.2 µA cm^-2 respectively p < 0.05, n = 5). Taken together these data indicate that transfected GFP-αENaC chimeric proteins are expressed at the plasma membrane in H441 cells and increase amiloride-sensitive transport of Na⁺