| Objective：To explore the role of Docosahexaenic acid in the preventionand treatment of type1diabetes mice induced with multiple low dosestreptozotocin (STZ) and its possible mechanism.Methods：40male mice were adapted one week and randomly dividedinto4groups after feeding,10mice each. Control group was given citratebuffer,0.2mL for5days by intraperitoneal injection, and given DMSO0.1mLinto the colon with a mice gavage needle；Diabetic group was given STZ(60mg/kg) for5days by intraperitoneal injection,and given DMSO0.1mL intothe colon at the same time；Prevention group was given STZ (60mg/kg) for5days by intraperitoneal injection and while given DHA0.1mL into the colon；Treatment group was given STZ (60mg/kg) for5days by intraperitonealinjection, after the establishment of T1DM model, DHA0.1mL wasadministred continuous into the colon for5days. The blood glucose level wasmonitored every week after the injection of STZ, The mice were considereddiabetic when blood glucose level was equal to or above16.7mmo1/L twice.The four groups were observed for4weeks after administration of DHA beforebeing sacrificed. We dynamically observed the general state of mice,body-weight and blood glucose. Blood serum was used for the measurement ofinsulin levels, while liver tissue were pre-prepared for the measurement levelsof nitric oxide（NO） and nitric oxide synthase (NOS) by nitric acid enzymereduction method, The levels of TNF-α and IL-10were detected withenzyme-linked immunosorbent assay, Immunohistochemistry methods wereused (SP method) for the observation in the mice pancreas of the enpression ofglucagon-like peptide-1receptor (GLP-1R) expression. Results:1. The general state mice the blood glucose and insulin levels: The generalstate and blood glucose of mice with prevention and treatment are closed to thecontrol group. Compared with the other three groups, the general shape ofdiabetic mice is poor, whose blood sugar is stable at a high level until the fourthweek. The serum insulin level of the diabetic is lower than the other threegroups and among the three groups, it have no difference in contrast.2. HE staining: The number of diabetes mellitus islet is very little, theshape is irregular and inflammatory cell infiltration in the islet is visible. Partialislet cells have vacuolation. Compared with diabetic group, islet morphology ofprevention group and treatment group is regular, the shape of islet cells is roundor oval and the boundary of the cytoplasm is clear. The cell cytoplasm,compared with the control group, is slightly swollen.3. The enzymatic reduction of nitrate: NO, NOS levels of diabetic mice’sliver are slightly higher than those in normal control group, both compared, thedifference is significant. NO, NOS levels of prevent group and treatment groupwas significantly lower than that of the diabetic group, and the difference hasstatistical significance.4. ELISA test results: The level of diabetic mice serum TNF-α issignificantly higher than the other three groups, and serum IL-10levels aresignificantly lower than the other three groups. There is no statistical differenceamong three groups.5. Immunohistochemical results: The level of GLP-1R in diabetes mellitusislet cell is low. Brown reaction particles positive rate of the cell cytoplasm issignificantly reduced, which is lower than that in normal control group,GLP-1R of prevention and treatment group mice is slightly lower than that thenormal group.Conclusion： 1. DHA can improve significantly the clinical status of T1DM mice,reduce blood glucose levels, increase insulin level, protec the function of isletcells.2. DHA significantly reduce the injury of oxidative stress to diabeticmice.3. DHA can reduce the level of damaging factor TNF-α, improve the levelof protective factor IL-10, and then adjust the balance of Th1/Th2cells.4. DHA can upregulate the GLP-1receptor of pancreatic islet cells. |
PDF Full Text Request