Fig. 2.

Injected RBP4 binds to endogenous TTR in the circulation but is cleared within 24 h. A: normal FVB mice were injected with 400 µg of recombinant mouse RBP4 intraperitoneally (ip) in the ad libitum-fed state and killed after 0, 1, 2, 6, and 24 h. Mice were euthanized, cardiac bleeds were performed, and plasma RBP4 was measured by Western blotting; n = 5 at each time point. *P < 0.001 vs. levels at times 0 and 24 h. B: plasma from mice killed 2 h after injection with mouse RBP4 (mRBP4 injected) and from control littermates that were not injected (no injection control) was subjected to gel filtration chromatography. Fractions 7.2–21.6 ml were subjected to SDS-PAGE and Western blotting for RBP4 and TTR. These data are representative of 2 experiments on a total of 8 mice/genotype.