Comparison of RBP4 mRNA levels in glucagon-injected wild-type and Hmga1 -deficient mice, and liver RBP4 expression in wild-type mice during fasting and fed. Total RNA was isolated from liver and fat of 3-h-fasted mice, before (time 0) and after 9 h of intraperitoneal injection of glucagon, and RBP4 mRNA was measured by qRT-PCR and normalized to RPS9 mRNA abundance. Results are the mean values ± s.e.m. from 6–8 animals per group. Black bars, Hmga1
+/+, n = 8; gray bars, Hmga1
+/-, n = 6; white bars, Hmga1
-/-, n = 6. *P < 0.05 versus each control (time 0). Western blots for HMGA1 protein expression are shown in liver and fat from all three genotypes (top). The levels of RBP4 mRNA and protein (shown at the bottom of the figure) were measured in liver of fed and 6-h-fasted wild-type mice (6 animals per group), using qRT-PCR and Western blot (WB), respectively. *P < 0.05 versus fed mice. Inset, cAMP was measured in liver from control and Hmga1-deficient mice, in both basal conditions and 3 h after the intraperitoneal injection of glucagon (1 mg/kg body weight), as described in the Methods section. The data are mean ± s.e.m. for 4–6 animals per group.