Fig. 1.
Leptin reverses hyperglycemia and excess gluconeogenesis from pyruvate and glycerol in streptozotocin-induced type 1 diabetic (T1D) rats. (a)–(d) Fasting plasma glucose, insulin, glucagon, and leptin concentrations. In panel (d), n=16 for all groups. (e) Hepatic gluconeogenesis from pyruvate (lower bars) and glycerol (upper bars). P-values over the bars represent comparisons of total gluconeogenic flux. Gluconeogenesis from both pyruvate and glycerol was increased (P<0.05 and P<0.0001, respectively) in T1D rats vs. controls, and decreased (P<0.001 and P<0.0001, respectively) in T1D-leptin treated vs. T1D rats. (f)–(h) Whole-body glycerol, fatty acid (palmitate), and acetate turnover. (i) Liver acetyl CoA concentration. (j) 12 p.m. plasma corticosterone concentrations. Data are mean ± S.E. If not otherwise specified, n=6–8 per group. *P<0.05, ***P<0.001, ****P<0.0001 vs. control; ##P<0.01, ###P<0.001, ####P<0.0001 vs. T1D; §§§P<0.001 vs. T1D-leptin 6 hr.