Glucose tolerance test (GTT) and insulin tolerance test (ITT)

GTT: rats were fasted beginning at 5 PM on the day before the experiment and were allowed to drink water after 9 AM the next morning. Glucose solution is intraperitoneally injected at a dose of 2 g/kg. Blood glucose level was measured before injection in each rat with an interval of 1 min. Furthermore, blood glucose levels were measured at time points of 15, 30, 60, 90, and 120 min after glucose injection by an electronic glucometer using blood samples collected from the tail vein.

ITT: rats fasted for four hours. The insulin solution was intraperitoneally injected at a dose of 1 U/kg. Blood glucose level was measured before injection in each rat with an interval of 1 min. Furthermore, blood glucose levels were measured at time points of 15, 30, 60, and 90min after insulin injection by an electronic glucometer using blood samples collected from the tail vein.