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.