FIGURE 3.

Effect of SR-BI inhibitors on vitamin K₁ apical transport by differentiated Caco-2 TC-7 monolayers. A, effect of BLT1 on vitamin K₁ uptake. The apical sides of the cell monolayers were preincubated for 60 min with either BLT1 at 10 μm or DMSO (control), before receiving FBS-free medium containing phylloquinone-enriched mixed micelles at a 2.5 μm concentration and supplemented with either BLT1 at 10 μm or DMSO. The basolateral sides received FBS-free medium. Incubation time was 60 min. Data are means ± S.E. (error bars) of three assays. *, significant difference with the control. B, effect of SR-BI-blocking antibody on vitamin K₁ uptake. The apical side of the cell monolayers was pre-incubated for 5 min with either 3.75 μg/ml of anti-human SR-BI antibody or 3.75 μg/ml of anti-human CD13 antibody (control), before receiving FBS-free medium containing phylloquinone-enriched mixed micelles at a 2.5 μm concentration. The basolateral side received FBS-free medium. Incubation time was 60 min. Data are means ± S.E. of 3 assays. *, significant difference from the control. C, effect of BLT1 on vitamin K₁ apical efflux. Cell monolayers were first enriched in phylloquinone during 4 h. The apical side of the monolayers was then carefully rinsed and received either FBS-free medium containing vitamin K₁-free mixed micelles or the same mixture plus BLT1. The basolateral side received FBS-free medium. Efflux time was 60 min. Data are means ± S.E. of three assays. *, significant difference from the control (assay performed without BLT1).