Fig. 3.
Ligand effects on 1,25(OH)2D in blood and PTH-responsive mRNA levels in bone and kidney. Mice were injected via the tail vein with vehicle, PTHTMR, or PEG-PTHTMR, each ligand at a peptide dose of 50 nmol/kg, and subsequently blood was collected at 2 and 24 hours post-injection and analyzed for changes in blood levels of 1,25(OH)2D (A), and tibia (B) and kidneys (C) were isolated at 24 hours post-injection and analyzed by quantitative real-time RT-PCR for levels of mRNA encoding the indicated gene products. Data in B and C are normalized to the level of mRNA encoding GAPDH detected in each tissue. Asterisks indicate comparisons of PEG-PTHTMR or PTHTMR to vehicle: *<0.05; **<0.01; ***<0.001. Not shown for mice injected with vehicle, PTHTMR or PEG-PTHTMR are the relative levels of kidney mRNA encoding Npt2a (0.49 ± 0.03; 0.58 ± 0.02, and 0.52 ± 0.01, respectively) and 24-(OH) ase (0.05 ± 0.01; 0.09 ± 0.01, and 0.17 ± 0.01, respectively), and tibia mRNA encoding RANKL (0.014 ± 0.001; 0.014 ± 0.001, and 0.019 ± 0.003, respectively); OPG (0.009 ± 0.003; 0.005 ± 0.001, and 0.005 ± 0.001, respectively); FGF23 (0.019 ± 0.003; 0.018 ± 0.001, and 0.020 ± 0.004) and sclerostin (0.0018 ± 0.0005; 0.0012 ± 0.0003, and 0.0012 ± 0.0002, respectively), for which ligand-injected levels were not significantly different from vehicle-injected levels.