Serum and Hepatic Metabolite Analysis

As described previously [32 (link)], serum ALT and FBG levels were determined using commercially available kits (Wako). Serum IRI levels were measured using a mouse insulin ELISA kit (Funakoshi, Tokyo, Japan). The stored liver samples (100 mg) were lysed and homogenized using a polytron homogenizer (NS-310E; MicroTech Nichion, Tokyo, Japan) for 1 min in a 2-mL solution containing 150 mM NaCl, 0.1% Triton X-100, and 10 nM Tris. Hepatic TG, FFA, and β-hydroxybutyrate levels were measured using a triglyceride detection kit (Wako), free fatty acid detection kit (Wako), and β-hydroxybutyrate assay kit (Cayman Chemical, Ann Arbor, MI, USA), respectively. Serum TG and FFA levels were also measured using a triglyceride detection kit (Wako) and a free fatty acid detection kit (Wako), respectively.