Adult male Fischer 344 rats (n = 24) were equally divided into sham-control (WT-SC), WT-IR, and WT-IR-Sita (oral sitagliptin 400 mg/kg/day for 3 days) groups, whereas adult male DPP4-deficiency (DPP4D) rats (n = 16) were equally divided into DPP4D-SC and DPP4D-IR groups. Here, DPP4 is linked to hyperinsulinemic hypoglycemia, familial, 4.