Figure 3.

Normalized rate constants (k_P) for dithionite (left) and ascorbate (right) reflecting the permeation of the respective anion across the membrane in POPC and POPC/Chol (80/20, mol/mol) LUVs. k_P values determined in the presence of ibuprofen (molar ratio lipid/drug = 5:1) were normalized to those determined in the absence of the drugs. For the dithionite assay, vesicles contained 1 mM lipid and 0.5 mol% NBD-PC. For the ascorbate assay, the lipid concentration was 2.5 mM and 2 mol% SL-PC. The data represent the mean ± SE of ≥ 6 (dithionite) and 8 (ascorbate) independent experiments.