Fig. 4

FGF21 serum concentration and expression in liver and BAT. a FGF21 serum concentration, b hepatic FGF21 relative protein abundance, representative blot and densitometry analysis normalized to GAPDH, and c BAT FGF21 relative protein abundance, representative blot and densitometry analysis normalized to GAPDH. Serum, liver, and brown adipose tissue were obtained from rats fed low (6%), adequate (20%), and high (50%) dietary protein and maintained at room temperature (23 °C) or exposed to a cold environment (4 °C) for 72 h. Protein abundance data are expressed relative to rats fed an adequate protein diet at room temperature. The results are presented as the means ± SEM, n = 5 rats per group. The differences were considered statistically significant at P < 0.05. Mean values with different lowercase letters show statistical differences between each other (a > b > c > d> e)