Impact of restricted food intake and exercise on circulating RBP4, leptin and resistin levels. (A) Western immunoblot analysis of retinol-binding protein 4 (RBP4) protein levels in the serum. (B) Serum leptin and (C) resistin levels were measured by MultiPlex. Each lane in the immunoblots represents pooled samples from 3 mice. In lower panel A, the relative serum RBP4 level was the mean value of 3 independent Western blot analyses. Data are presented for each group as means ± SEM (n = 6/group). Statistical analyses were done with one-way ANOVA. *p < 0.05, **p < 0.01 vs. LC; #p < 0.05, ##p < 0.01 vs. HC; Δp < 0.05, ΔΔp < 0.01 vs. HRE; N.S.: not significant.