Fig. 4.

Transepithelial flux and uptake of glucose and fructose across airway epithelial monolayers. a Uptake of ¹⁴C-d-glucose and ¹⁴C-D-fructose across the apical membrane of H441 monolayers, n = 8. b Uptake of ¹⁴C-d-glucose and ¹⁴C-d-fructose across the basolateral membrane of H441 monolayers, n = 8. c Basolateral-to-apical transepithelial flux of d-glucose, d-fructose and l-glucose across H441 monolayers, measured by adding radiolabelled sugar to the basolateral surface and monitoring its appearance of the apical surface over 1 h, n = 4. d Calculated basolateral-to-apical transepithelial flux of d-glucose and d-fructose across H441 monolayers, after compensation for epithelial uptake, n = 4. *p < 0.05, **p < 0.01, ***p < 0.001