Impact of High-Intensity Interval Training on GLP-1R/ PKBα Axis in Pancreatic Tissue of Diabetic Rats Induced by High-Fat Diet and STZ

Apart from hormonal factors and oxidative stress, insulin synthesis is strongly dependent on transcription factors in the pancreas. The aim of the present study was to assess the impact of high-intensity interval training (HIIT) on genes affecting insulin synthesis in diabetic obese rats.

Type 2 diabetes (T2D) was induced by a 6-week high-fat diet (HFD) and intraperitoneal injection of streptozotocin (25 mg /kg) in 14 male Wistar rats (10 week old, 220±10 g). Rats with fasting glucose levels between 400 and 150 were considered T2D. The diabetic rats were randomly assigned to exercise (HIIT: 6 weeks/5 sessions weekly, n= 7) or control (n= 7) groups. Forty-eight hours after the intervention, fasting GLP-1R and PKBα gene expression in pancreatic tissue and plasma insulin and glucose levels were compared between the groups. Data were compared by independent t-test used to compare variables, version 22 between groups. A P< 0.05 was considered significant.

HIIT led to significant increase in PKBα gene expression (P: 0.001) and insulin (P: 0.031) and decreases in glucose concentration (P: 0.001) compared with the control group. No change was observed in the GLP-1R gene expression response to HIIT (P: 0.093).

HIIT is associated with increased serum insulin levels in T2D obese rats. Despite no change in GLP-1R, this improvement is probably rooted in increased expression PKBα in pancreas in response to this type of exercise training.