Figure 3  .

Effects of 1,25-(OH)₂D₃ pre-treatment on the metabolism of [³H]-25-(OH)D₃ and [³H]-1,25-(OH)₂D₃ by F733 synovial fibroblasts. Panels (A-C) are cells incubated with [³H]-25-(OH)D₃ substrate, panels (D-F) are cells incubated with [³H]-1,25-(OH)₂D₃ substrate. (A) Synthesis of [³H]-24,25-(OH)₂D₃; (B) synthesis of an unidentified product (peak D in fig 2 (A)); (C) the radioactivity present in the aqueous phase; (D) synthesis of [³H]-1,24,25-(OH)₃D₃; (E) synthesis of an unidentified product (peak F in figure 2 (B)) and (F) radioactivity present in the aqueous phase. n=3 for each point. Results are shown as mean (SEM). *p<0.05, **p<0.01 compared with vehicle (0.25% ethanol) using ANOVA followed by Dunnett's multiple comparison test.