2.4 Biochemical assays
The glycemic status of the rats was determined by measuring hemoglobin A1C (HbA1c) levels in whole blood using a biochemical assay from Crystal Chem and by measuring plasma insulin using ELISA (Mercodia AB, Uppsala, Sweden). Lipid profile was determined by measuring plasma cholesterol, triglyceride, and non-esterified free fatty acid (NEFA) levels using assay kits from Cayman Chemical (Ann Arbor, MI, USA). Plasma low-density lipoprotein (LDL) was measured using a kit from Crystal Chem (Downers Grove, IL, USA). Homeostatic model assessment (HOMA-IR) was carried out to determine insulin sensitivity in experimental groups. HOMA-IR was calculated from fasting blood glucose. Liver enzymes aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were measured using commercial assay kits (Sigma Millipore, St. Louis, MO, USA). Urinary protein and creatinine were measured calorimetrically using assay kits from Cayman Chemical. Urinary levels of albumin and monocyte chemoattractant protein-1 (MCP-1) were determined using ELISAs from Exocell (Philadelphia, PA, USA) and BD Biosciences (San Jose, CA, USA), respectively.