Exendin-4 effects on islet volume and number in the mouse pancreas.

The aim of this study was to evaluate Exendin-4 (EX-4) effect on islet volume and number in the mouse pancreas.Thirty-two healthy adult male NMRI mice were randomly divided into control and experimental groups. EX-4 was injected intraperitoneally (i. p.) at the doses of 0.25 (E1 group), 0.5 (E2 group), and 1 μg/kg (E3 group), twice a day for seven consecutive days. One day after the final injection, the mice were sacrificed, and pancreas from each animal was dissected out, weighed, and fixed in 10 % formalin for measurement of pancreas, and islet volume and islet number by stereological assessments. There was a significant increase in the weight of pancreases in E3 groups. Islet and pancreas volumes in E1 and E2 groups were not changed compared to control group. E3 group showed a significant increase in islet and pancreas volume (p < 0.05). There were no significant changes in the total number of islets in three experimental groups. The results revealed that EX-4 increased pancreas and islet volume in non-diabetic mice. The increased total islet mass is probably caused by islet hypertrophy without the formation of additional islets (Fig. 5, Ref. 35).