Acute LPS-induced hypophagia is abolished in leptin-deficient mice. Cumulative food intake 2, 14 and 24 h food intake (A), 24 h changes in body weight (B) and number of pSTAT3 positive cells (C) in hypothalamic arcuate nucleus (ARC) in wild type (WT) and leptin-deficient mice (ob/ob) treated with saline or LPS (100 μg/kg, ip), 2 and 4 h after injection. In the bottom panel (D), representative photomicrographs showing pSTAT3 expression (brown dots) or pAKT expression (green) in the ARC 2 and 4 h after saline or LPS injection, in WT and ob/ob mice. 3V = third ventricle. Scale bar: 50 μm. Two-way ANOVA followed by Tukey's post hoc test was performed. Data are expressed as mean ± SEM. (n = 6/group for food intake and BW measurements and n = 3/group for immunostaining). *p < 0.05: WT Saline vs WT LPS; #p < 0.05: ob/ob Saline vs ob/ob LPS; a p < 0.05: WT LPS 2 h vs ob/ob LPS 2 h; b p < 0.05: ob/ob LPS 2 h vs ob/ob LPS 4 h.