Figure 6.

The indirect response model for simultaneous fitting of all data on plasma 1,25(OH)₂D₃ and FC of vitamin D receptor target genes, CYP27B1 and CYP24A1. (A) Simultaneous fitting of single dose (left) and single and repeated dose (right) plasma 1,25(OH)₂D₃ concentration. Simultaneous fitting for (B) inhibition of CYP27B1 FC and (C) stimulation of CYP24A1 FC. Observed plasma 1,25(OH)₂D₃ concentrations and CYP27B1 and CYP24A1 FC are shown as mean ± SEM (n = 3–4 different mice) with fitted values shown as a solid line. Data for vehicle-treated mice (basal level) were averaged and joined by the dashed line (n = 9).