Exenatide induce the impairment of autophagy flux to damage rat pancreatic tissue / 中华内分泌外科杂志

ABSTRACT

Objective To explore the alteration and effect of autophagy in pancreas tissue of rat injected by exenatide.Methods Diabetes model rats were induced by two-month high-sugar and high-fat diet and streptozotocin injection (35 mg/kg) in normal rats.50 SD male rats were divided into four groups according to the principle of complete random design,namely normal control group (n=10),normal exenatide-injected group (n=10),diabetes-model control group (n=l5) and diabetes-model exenatide-injected group (n=15).Rats in exenatide-injected groups were subcutaneously injected with exenatide respectively in 5 μg/kg dose each time,twice a day,at 8 a.m.and 6 p.m.Animal weights were weighted weekly and the dose of exenatide was adjusted according to current weight.Rats in the two control groups were injected with the corresponding amount of saline.Mter 10 weeks of treatment,all rats were killed and pancreatic tissues were disposed.Immunohistochemistry was used to measure the expression of GLP-1R in pancreatic tissues.Western blot was used to test the expressions of LC3-Ⅰ,LC3-Ⅱ and p62 in pancreatic tissues,and LC3-Ⅱ/Ⅰ ratio and p62 were compared between any two groups.All specimens were stained with hematoxylin-eosin (HE).The data were expressed as means ± standard deviation and were analyzed by unpaired Student t test using SPSS 18.0 statistics software.P value ＜0.05 was considered to be statistically significant for all tests.Results The pancreatic tissues from 13 rats (6 from the normal exenatide-injected group and 7 from the diabetes-model exenatide-injected group) appeared pathological changes such as gland structure damage,pancreatic cells atrophy and cells compartment broadening.The expressions of GLP-1R,LC3-Ⅱ and p62,and LC3B-Ⅱ/Ⅰ ratio in the two exenatide-injected groups were higher than those in the respective control group,and the differences had statistical significance (P＜0.05).Conclusions Long-term subcutaneous injection of exenatide can upregulate the expression of GLP-1R in rat pancreatic acinar cells and may induce the impaiment of autophagy flux in rat pancreatic cell.