The animals were included in the experiment at the age of 12 months. The blood glucose level and weights of the animals were determined five‐week after inducing the T2DM model; the OGTT was also performed at that time.

The rats with confirmed T2DM received treatment for 24 weeks according to the following therapy groups (5 animals each), sorting by therapy groups was random. There was also a group of intact animals (10 animals) and group T2DM without therapy (10 animals).

Intact group ‐ control group without T2DM and without therapy.

T2DM without therapy.

T2DM + vildagliptin (1.5 mg per kg).

T2DM + vildagliptin (1.5 mg per kg) + glibenclamide (0.6 mg per kg).

T2DM + vildagliptin (1.5 mg per kg) + gliclazide (0.75 mg per kg).

T2DM + gliclazide (0.75 mg per kg).

T2DM + glibenclamide (0.6 mg per kg).

Blood glucose was determined at 4, 10, and 24 weeks after experiment initiation. The weight of animals was measured at week 24 of the study. Pancreatic tissue sampling and IHC were performed after the end of the experiment.