Fig. 1
Brain leptin signaling increases liver TG secretion and reduces hepatic steatosis. a Protocol for acute ICV leptin infusion experiments. b Plasma TG accumulation in ICV leptin/vehicle-infused rats after a tyloxapol bolus injection (Leptin: 1 µg/h; n ≥ 12 per group). c VLDL secretion rate calculated from the slopes depicted in Fig. 1b. d Western blot of ApoB100 and ApoB48 in plasma samples at timepoint 180 min from acute ICV leptin/vehicle infusion experiments. e Quantification of the Western blot analysis from Fig. 1d (n ≥ 7 per group). f Protocol for chronic ICV leptin/vehicle experiments. g Body weights and h hepatic lipid content assessed by 1H-MRS after 28 days of chronic ICV leptin/vehicle infusion (Leptin: 0.3 µg/day). i Western blot analysis of ApoB100 and ApoB48 from plasma after chronic leptin/vehicle infusion collected at the end of the experiment. j Quantification of the Western blot analysis in Fig. 1i (n = 8 per group). k Relative changes compared to baseline in hepatic lipid content after 28 days of chronic ICV leptin/vehicle infusion. l Protocol for chronic ICV leptin receptor antagonist experiments. m Relative changes in hepatic lipid content assessed by 1H-MRS during 28 days of blocking endogenous leptin signaling with an ICV infused peptide leptin receptor antagonist (Leptin receptor antagonist: 6 µg/day; n = 5 per group). All data are mean ± SEM; *p < 0.05; **p < 0.01; vs vehicle group by two-tailed Student’s t test; open circles: ICV vehicle; black squares: ICV leptin except for (m): ICV leptin receptor antagonist
