Osteopathy and resistance to vitamin D toxicity in mice null for vitamin D binding protein
J. Clin. Invest. Fayez F. Safadi, et al. 103:239 doi:10.1172/JCI5244 [Go to this article.]

Figure 5
Accelerated clearance of 25(OH)[³H]D₃ from the plasma of DBP^–/– mice. (a) 25(OH)[³H]D₃ was preincubated with aliquots of serum from either DBP^+/+ or DBP^–/– mice, and these were injected intravenously into mice of homologous genotype. Plasma was sampled at the indicated times after injection, and tritium counts were obtained. Data were normalized to the calculated total plasma volume and expressed as a percentage of total cpm injected. Data for the time interval from 0 to 24 h represent the mean ± SEM of five replicate experiments, and data in the inset depict the mean ± SEM of four experiments examining the 0–40-min time interval. (b) 25(OH)[³H]D₃ was preincubated with aliquots of DBP^+/+ or DBP^–/– serum and injected intravenously into mice of the same respective genotype. Urine was collected for 24 h using metabolic cages and was counted. Data are the mean ± SEM of six determinations (P < 0.01). (c) Aliquots of plasma from one of the 0–40-min studies in a were extracted in organic solvent and analyzed by TLC. Data were expressed as a percentage of total cpm chromatographed. The percentage of cpm migrating in the 25(OH)D region (left) and the polar region (right) of the chromatograph for each time point were plotted.