Leptin, which is synthesized in adipocytes, functions via different regions of the hypothalamus to, respectively, suppress appetite and enhance adipocyte lipolysis and hepatic fatty acid oxidation [21]. Under the non-fasting conditions, serum leptin levels in WT mice increased 5-fold on the HFD (p<0.05), but remained unchanged in the Cyp1b1-ko mice (Figures 4A and 4B), and correlated with adipose tissue mass (Figure 4C).
