Fig. 3

Effects of treatment of Caco-2 cell monolayers with a basolateral supply of holo-Tf or an apical supply of ferric NTA on subsequent iron transport across the cell layer. Values shown indicate a total cellular iron uptake (sum of iron retained within the cells and iron transported from the apical to the basolateral medium) and b apical to basolateral iron transport of iron supplied to the apical side of the Caco-2 cell monolayer on day 21, following incubation from day 14 to 21 with medium containing metal-depleted FBS in the absence of any added iron (Control), presence of 10 μM ferric NTA added to the apical side of the cells only (10 μM FeNTA) or of 30 μM holo-Tf added to the basolateral side of the cells only (30 μM holo-Tf). Bars and error bars indicate mean + SD (n = 8 comprised of 4 replicate wells for each treatment from each of two separate plates set up in parallel). Data were compared by one-way ANOVA with Tukey’s post hoc test. Asterisks indicate statistically significant differences between treatments (*p < 0.05 and **p < 0.01)