Blood samples were collected by cardiac puncture at sacrifice and the serum isolated by centrifugation at 14,000 rpm for 10 min at 4° C. Serum was frozen in liquid nitrogen and stored at −80° C until analysis. All analyses were completed as per manufacturer’s instructions. Insulin and leptin levels were measured using a Mercodia (Uppsala, Sweden) and an RnD Systems (Minneapolis, MN) ELISA kit, respectively, on 4-hour fasted animals. Serum triglyceride, free fatty acid and cholesterol levels were measured using the Sigma-Aldrich (St. Louis, MO) serum triglyceride determination, the Zen-Bio (Research Triangle Park, NC) Elisa and the Pointe Scientific (Canton, MI) colorimetric assay kits, respectively, on samples derived from non-fasted animals.
