| PART ONEEstablishment of Animal Model of Type2Diabetes in Diannan small-ear PigsObjective:To establish type2diabetic model with high-carbohydrate-fat diet and streptozotocin in Diannan small-ear pigs.Methods:Healthy female small-ear pigs, weighing14.30±2.94kg (2-3months old, n=30), were purchased from Animal Science Center of Kunming Medical University. They were equally and randomly grouped into6sties (5in each sty), and housed at room temperature (18-25℃) with a relatively humidity of50%on a12h light on cycle. Food and water were available ad libitum.5-1days after purchased, pigs in number2sty were chosen as in normal group, while others were experimental groups. Pigs in normal group (n=5) were given ordinary feed, while in experimental group (n=25) were high-carbohydrate-fat diet. Raised for4weeks, experimental animals was injected with streptozotocin at a dose of40mg/kg via posterior auricular vein, while normal group animals was administered with corresponding dose of citrate sodium buffer solution. At the end of0,2,4,6and8weeks after grouping, animals were fasted overnight and empty stomach blood samples were collected the second day to determine the blood glucose in plasma and insulin in serum.Results:After four weeks high-carbohydrate-fat diet, the small-ear pigs began to show hyperinsulinemia and insulin resistance. After administration of STZ, compared with normal control group, the blood glucose levels and insulin resistance index in the experimental group were increased significantly (P<0.05), while the serum insulin levels were decreased significantly (P<0.05).Conclusions:The experimental model of type2diabetes can be successful established in Diannan small-ear pigs by high-carbohydrate-fat assisted with low-dose intraperitoneal injection of streptozotocin.With characteristics of short time-consuming, simple procedure, easy to master and good security, this can be used in the experimental study of type2diabetes. PART TWOA Study on the effects of Different digestive tract reconstruction on blood glucose in diabetic animalsObjective:To evaluate the necessarities of gastrectomy in Roux-en-Y gastric bypass surgery, and whether the intestinal loop length for intestine-intestinal anastomosis after Roux-en-Y gastric bypass surgery(the distance from where Jejunum was cut under Trietz ligament) at different distances affect the effect of Roux-en-Y gastric bypass surgery on type2diabetes, through comparison of the treatment effect of different gastric bypass surgeries on type2diabetes.Methods:The normal group in Part One was again defined as the normal control group (NC group, n=5). At the end of the8th week,25small-ear pigs in experimental group of Part One was randomly grouped into diabetic control group (DC group, n=5) and four groups of diabetes surgery (DO1,2,3,4, n=5each). NC and DC group were under no surgical treatment. DO1:jejunum was resected3m under the Trietz, jejunectomy end to end anastomosis was then conducted. DO2:Duodenum was divided2cm under pylorus, and jejunum was divided3m under Treitz ligament; Distal jejunum and inferior pylorus duodenum were anastomosed, while proximal jejunum and jejunum were conducted end to side anastomosis at50cm distal from the site of stomach and jejunum anastomosis. DO3: Animals were under Roux-en-Y surgery and distal gastrictomy. Jejunum was divided40cm under Treitz ligament, with its distal end anastomosed with remnant gastric and near end end to side anastomosed with jejunum50cm distal from the site of stomach and jejunum anastomosis. DO4:Same with DO3. Monitor fast glucose levels,2-hour postprandial blood sugar and insulin in serum before and2,4,6and8weeks after surgery (i.e. the end of8th,10th,12th,14th and16th week for feeding), and calculate the insulin resistant index and insulin sensitive index and analyzed using t test and multivariate analysis of variance in SPSS software.Results:Compared with DC group, fast plasma glucose and2-hour postprandial blood sugar in DO1group have not been significantly controlled after the surgery(P>0.05), whereas fast plasma glucose and2-hour postprandial blood sugar after surgery in DO2, DO3and DO4group were significantly reduced (P<0.05), and concentration of serum insulin increased steadily and constantly (P<0.05), and insulin resistance was improved (P<0.05). Fasting plasma glucose and2-hour postprandial blood sugar in DO2and DO3group wre not significantly different(P>0.05). Fasting plasma glucose and2-hour postprandial blood sugar in DO3group decreased more significantly than in DO4group (P<0.05).Conclusion:1. Direct removal of jejunum is not an effective treatment of type2diabetes, the treatment of Roux-en-Y gastric bypass on T2DM is clear.2. Distal gastrectomy and no gastric resection in Roux-en-Y gastric bypass surgery have no significantly different effects on short term glucose control.3. The effects of Roux-en-Y gastric bypass surgery on T2DM were clearly related with the intestinal loop length for intestine-intestinal anastomosis after Roux-en-Y gastric bypass surgery was significantly correlated, and the longer distance brings a better glucose control. |
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