Hepatic lipid and metabolite analysis

Hepatic lipids were extracted and process for gas chromatography (GC), ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UPLC/MS/MS) and liquid chromatography coupled to tandem mass spectrometry (LC/MS/MS) as described [43 (link),47 (link)]. Fatty acid standards for the GC analysis were purchased from Nu-Chek Prep and Cayman Chemical Company. Oxylipin standards were purchased from Cayman Chemical Company [47 (link)]. Hepatic glutathione (GSH and GSSG) and selected metabolites were fractionated and quantified using the metabolomic approach described previously [57 (link)], while hepatic bile acids were fractionated and quantified as described [58 (link)].