Figure 6.

High-dose corticosterone causes different metabolic effects than dexamethasone. Mice received a high-fat diet mixed with dexamethasone (DEX) or vehicle (VEH) and were subcutaneously implanted with high-dose corticosterone (CORT20) or vehicle pellets for 3.5 weeks. The VEH and DEX groups are identical as those depicted in Figures 1–5. (A–C) CORT20-treated mice had strongly elevated CORT levels and decreased adrenal weight but not spleen weight. (D–F) CORT20 increased body weight and fat mass, but decreased lean mass. (G, H) CORT20 did not affect 6 h-fasted glucose levels, but increased insulin levels. (I, J) After 6 h-fasting at ZT1, CORT20 did not affect the plasma clearance of [¹⁴C]-deoxyglucose or uptake in peripheral tissues. (K–M) CORT20 did not influence 4 h-fasted plasma free fatty acids, triglycerides or liver weight. (N, O) After 6 h-fasting at ZT1, CORT20 did not affect plasma clearance of [³H]oleate. (P) Upon an oral olive oil bolus at ZT1, CORT20 did not affect peak plasma triglyceride levels. (Q) DEX and CORT20 similarly induced Fkbp5 expression in iBAT, sWAT, gWAT and liver. In hippocampus, Fkbp5 expression was increased by CORT20, and decreased by DEX. (R) Mt2a expression was similarly induced by DEX and CORT20 in iBAT, sWAT, gWAT, liver and hippocampus. Statistical significance was calculated using 2-way ANOVA analysis in (A, I); with one-way ANOVA analysis in B–C, G–H, J–M, O, Q-S and with linear mixed models in D-F, N and P. Depicted below the graphs are the P-values of the ANOVA tests for either steroid treatment (S), Time (T) or the interaction between treatment and time (I). *P < 0.05, ** P < 0.01, ***P < 0.001. 'ns' means 'not significant'.