Effects of metformin and exercise on GLP-1 and GIP secretion in rats

Exercise or exercise capacity is a physiological function of vital importance. It also has important effects in the prevention and treatment of many diseases. Exercise applications are involved in the regulation of glucose metabolism. Metformin, which is widely used in the treatment of diabetes, is also effective in glucose homeostasis. Various combination studies have been conducted with exercise and metformin, which have common mechanisms of action in glucose homeostasis. This study aimed to determine the effects of exercise and metformin on GLP-1, GIP, insulin, and ghrelin levels. In this study, 42 male Wistar rats aged 2-3 months and weighing 230±30 g were used. Animals were randomly divided into 6 subgroups as control, exercise only (EGZ), metformin 100 mg/kg (Met100), metformin 200 mg/kg (Met200), metformin 100 mg + exercise (Met100+EGZ), and metformin 200 mg + exercise (Met200+EGZ). Metformin was administered intraperitoneally and exercise was performed according to an augmented exercise protocol. A 10-week study was conducted, including exercise familiarization. At the end of the study, GLP-1, GIP, insulin, and ghrelin levels were determined by the ELISA method in serum samples taken from rats. Blood glucose levels of the Met200 group were significantly lower than control, exercise, and combination groups. Insulin levels of metformin and combination groups were significantly lower than the control group. Although the mean insulin level of the exercise group was lower than the control group, it was not statistically significant. The GLP-1 level of the exercise group was found to be significantly higher than all groups. The GIP level of the exercise and combination groups was significantly higher than the control and Met100 groups. The ghrelin level of the exercise and Met200 group was significantly higher than the control group. As a result of our study, it was determined that exercise and metformin had significant effects on glucose homeostasis and caused significant results on GIP, GLP-1, insulin and ghrelin. Keywords: Exercise, Insulin, GIP, GLP-1, Ghrelin, Metformin