Kinetics of HN analogues in WT and IGFBP-3−/− mice. Following ip injection with HN analogues, HN levels were measured with ELISA in the 3 treatment groups: WT mice treated with HNG (solid line, squares), WT mice treated with HNGF6A (hatched line, circles), and IGFBP-3−/− mice treated with HNG (dotted line, triangles). The half-lives of HNGF6A in WT mice and of HNG inIGFBP-3−/− mice were longer than the half-life of HNG observed in WT mice.