Establishment of Chronic Constraint Stress Animal Model and its Application in the Study of Hyperglycemia

Objective To explore chronic constraint stress (CCS) animal model in the application to observe hyperglycemia by improving the method of constraint, diet food and blood glucose assay. Methods Chronic constraint stress was performed 12 h per day on SD rats for 4 periods with 10 d per periods. The rats were fed normal diet (ND) or high fat diet (HFD) respectively, while HFD+ Streptozotocin (STZ) and HFD as control. Blood glucose was tested on the 3rd day after every bound period. Insulin, cortisone and adrenaline in serum were tested by ELISA at 3 days after the last bound period. The expressions of insulin and glucagon in pancreas were detected by immunohisto-chemical (ICH) straining. Results There were 32.5% rats suffering hyperglycemia after chronic constraint stress. Compared with control group, the serum level of insulin increased significantly in CCS group. The blood glucose and serum insulin levels in the HFD-STZ and HFD group were not significantly different to those of control group (P>0.05). HE and ICH sections showed that the pancreas volume of CCS rats increased, insulin expression in islets decreased. Insulin and glucagon expression in HFD islets decreased. Islets of STZ rats were seriously damaged and no insulin or glucagon positive cells were observed. Conclusion CCS could induce hyperglycemia, which might be used in the further study on type 2 diabetes mellitus.