Serum levels of IGF-1, IGFBPs, GH, and insulin in control, ALSKO, LID, and LID+ALSKO mice. (a) Serum was treated with acid/ethanol to remove IGFBPs. Total IGF-1 was determined by RIA (provided by the National Hormone and Pituitary Program)in single serum samples from control (Ctl) mice (n = 23), ALSKO mice (n = 36), LID mice (n = 21), and LID+ALSKO mice (n = 61). *P < 0.01 compared with control mice. ^†P < 0.01 compared with LID or ALSKO mice. (b) GH levels were determined in the serum of control mice (n = 9), ALSKO mice (n = 11), LID mice (n = 10), and LID+ALSKO mice (n = 28). (c) Serum insulin levels, measured in the fed state, were determined in the serum of control mice (n = 12), ALSKO mice (n = 10), LID mice (n = 17), and LID+ALSKO mice (n = 35) (d) Upper panel shows a representative ligand blot assay performed on sera from control, ALSKO, LID, and LID+ALSKO mice. Serum proteins were separated by 4–20% SDS-PAGE and IGFBPs were detected by incubating the blots with ¹²⁵I–IGF-1, as described in Methods. The graph shows quantification of ¹²⁵I–IGF-1 binding to IGFBP-3 in samples from control (n = 11), ALSKO (n = 9), LID (n = 14), and LID+ALSKO (n = 17) mice. (e) IGFBP-3 mRNA expression does not differ significantly between control, ALSKO, LID, and LID+ALSKO mice. Upper panel shows a representative Northern blot assay. The graph shows quantification of IGFBP-3 mRNA detected by Northern blot analysis (n = 6 per group).