EFFECTS OF GLUCAGON-LIKE PEPTIDE-1 ON THE PANCREAS OF OLETF RATS

Xiaojuan Tian^{1, #}, Xuedong Sun^{2, #}, Yanhui Wang³, PengCheng Zhao^{4, *}

¹Department of Gastroenterology and Hepatology, Shenzhen University General Hospital, Shenzhen 518055, PR China - ²Department of Emergency Medicine, Shenzhen University General Hospital, Shenzhen 518055, PR China - ³Department of Gastroenterology and Hepatology, The First Affiliated Hospital of Baotou Medical College, Inner Mongolia University of Science and Technology, Baotou 014010, PR China - ⁴Shenzhen Sami Medical Center, Shenzhen 518055, PR China 

Objective: With the development of the social economy and related lifestyle changes, diabetes has become the third-largest chronic non-communicable disease that seriously endangers human health after cardiovascular diseases and tumours, and its global prevalence increases yearly. This trend leads to a huge economic burden on individuals and society. Therefore, this article reports the effect of glucagon-like polypeptide-1 (GLP-1) on blood glucose and glucose tolerance in Otsuka Long–Evans Tokushima Fatty (OLETF) rats and its protective effect on pancreatic cells. 

Methods: The method adopted in this paper is to divide 12-week-old male OLETF rats into GLP-1 treated and untreated groups, using non-diabetic Long–Evans Tokushima Otsuka (LETO) rats of the same strain as controls. At 12, 14 and 20 weeks, all rats were tested for oral glucose tolerance. The corresponding conclusions are drawn through data comparison. 

Results: The areas under the blood glucose curves of the GLP-1 treatment group of OLETF rats at 14 and 20 weeks are lower than that of the corresponding untreated OLETF group, 29.93±3.15 vs 34.99±4.30, P < 0.01 and 38.37±3.18 vs 42.38±2.37, P < 0.01, respectively. The areas under the insulin curves of the GLP-1 treatment group of OLETF rats at 14 and 20 weeks were higher than those of the untreated OLETF group, which were 10.86±1.56 vs 9.07±1.28, P<0.01 and 13.00±1.50 vs 10.35±0.86, P<0.01, respectively. In the 20-week GLP-1 treatment group, the insulin content of the islets of the OLETF rats and the number of B cells in the islets increased, and the ultrastructure of the B cells improved. 

Conclusions: Therefore, the experimental results indicate that GLP-1 can inhibit the apoptosis of pancreatic islet cells by increasing their proliferation, increasing their numbers and improving the morphology of the endocrine granules, thereby improving the glucose tolerance of rats with type 2 diabetes.