| Background and objective: Diabetes mellitus is a common endocrine andmetabolic diseases, which is seriously harm to human health. The occurrence ofdiabetic mellitus is closely related to a lack of insulin secretion and (or) caused by theobstacle of its biological role, the main features reflect high blood glucose. Dependingon the type of insulin deficiency, Diabetes mellitus can be divided into type1diabetesand type2diabetes, IR is the key to distinguish between the two types. In the processof DM, there will be some proteins and cytokines involved at the same time,regulating carbohydrate and lipid metabolic process. To clarify their mechanism ofaction in the DM, will help to prevent and treat diabetes. And thus provide importanttheoretical basis for the treatment of the DM. Previous researches have shown thatMusclin can significantly inhibit glucose uptake and glycogen synthesis which arepromoted by the insulin. So Musclin may be involved in the DM. But the actionmechanism of Musclin in DM is still not clear. Therefore, this paper successfullyestablished the banna mini-pig diabetic model, and observed the expression ofMusclin in the serum and tissues of the Banna mini-pig, on these basis to investigatethe mechanism of how Musclin involved in DM.Methods:1. Animal experiment. Eight male banna mini-pigs were randomizedinto two groups. A control group (CD) or a high-fat/high-sucrose and STZ group(HFSD+STZ).2. Establition of the DM model. CD group is fed with basal diet;HFSD+STZ group fed with high-fat/high-sucrose diet, and in the first one month,intraperitoneal injection STZ (50mg/kg), in the first senven month,continuous threedays intravenous injection small doses of STZ, each injection as50mg/kg. The CDgroup only injected with the volume of structure-rafter acid structure rafter sodiumacetate buffer. Modeling12months.3. Serum biochemical assays. Fasting serum glucose, Insulin, Triglyceride (TG) and Total Cholesterol (TC) were measured eachmonth. Glucose tolerance and Insulin resistance were estimated by intravenousglucose tolerance test (IVGTT) and a modified intravenous glucose tolerance test atthe end of12thmonth. Serum Musclin was measured each month by ELISA.4.Histopathology. Four-Λm-thick sections were prepared and routinely stained withhematoxylin and eosin (H＆E) to examine the general histological changes in thecardiac muscle, skeletal muscle, liver, pancreas and kidney tissues, and periodicacid-Schiff (PAS) to identify changes in glycogen deposition in skeletal muscle andliver tissue. Sudan IV to observe lipid.5. The expression of Musclin in the pancreas,skeletal muscle, liver and kidney tissues was measured by Western Blot andimmunohistochemistry.Results: The high-fat/high-sucrose diet plus STZ induced Banna mini-pigs toappear glucose metabolic and lipid metabolic disorders, showed hyperglucose,hypercholesterol, hypertriglycerides, low insulin and glucose tolerance reduction.Pathological changes in these tissues were observed in the light and electronmicroscopy. Liver glycogen and Muscle glycogen synthesis were abnormal. Thehigh-fat/high-sucrose diet plus STZ enable the content of Musclin in the serum. Asignificant increase in5th month, Musclin expression reached a peak in6th. Andbegin to decline in the7th, but still higher than CD group in12thMonth. Thehigh-fat/high-sucrose diet plus STZ increased the expression of Musclin in thepancreas, skeletal muscle, liver and kidney in Banna mini-pigs.Conclusions:1. The high-fat/high-sucrose diet plus STZ induced Banna mini-pigs to appear highblood sugar, low hyper-insulinemia, hyper-triglyceridemia and hyper-holsterolemia,the glucose tolerance was impaired, insulin sensitivity was decreased, the tissuesperformance pathological changes, successfully established diabetes model ofBanna mini-pig.2. HFSD+STZ injection can upregulate the expression of Musclin in serum and inliver, kidney, skeletal muscle, pancreatic tissues of Banna mini-pig. Speculate Musclin involved in glucose metabolism, may induce insulin resistance. |
PDF Full Text Request