4.2. Intraperitoneal Glucose Tolerance Test

After overnight (9:00 p.m. to 9:00 a.m.) fasting, mice were administered a glucose solution (2.0 g glucose/kg, i.p.). Blood samples were collected from the tail vein at 0, 15, 30, 60, and 120 min after glucose administration. Plasma was separated by centrifugation and stored at −76 °C for later analyses of glucose and insulin by the Glucose Assay kit (Sigma, St Louis, MO, USA) and Mouse Insulin ELISA kit (ALPCO, Salem, NH, USA), following the manufacturers’ instructions.