Figure 7
NDEA Exposure and Chronic HFD Feeding Impair Insulin and IGF-1 Receptor Binding in Liver and Brain. Long Evans rats were treated with NDEA or vehicle (VEH) by i.p. injection (N = 12/group), and then chronically fed with high fat (HFD) or low fat (LFD) containing chow for 6 weeks (see Figure Legend 1). Competitive equilibrium binding studies were used to measure specific insulin and IGF-1 binding to their corresponding receptors. Reactions were incubated with 50 nCi/ml of [125I] (2000 Ci/mmol; 50 pM) insulin or IGF-I in binding buffer in the presence or absence of 0.1 μM unlabeled ligand. Radiolabeled bound ligand was harvested onto 96-well GF/C filter plates and measured in a TopCount. Specific binding was calculated by subtracting non-specifically bound from the total bound isotope. Box plots depict mean ± S.D. of specific binding for (A, B) insulin and (C, D) IGF-I in (A, C) liver and (B, D) temporal lobe. Inter-group comparisons were made using ANOVA with the post-hoc Bonferroni test of significance. Significant P-values are indicated within the panels.