| Objective：To establish a big animal model of obesity and type2diabetes and investigatethe possibility and observe the effect of endoscopic operation on obesity and type2diabetes through endoscopic Esophagus-Jejunum stent implantation bypasssimulating of classic gastric bypass on Beagle dogs.Method：Ten healthy, mature and male Beagle dogs were chosen and divided into twogroups at random in the first part of the experiment, one is model group and the otheris control group. The five dogs in model group were fed with high-fat andhigh-calorie diet and given small dose of streptozotocin through intravenous injectionin the twelfth week. Meanwhile, the five ones in control group were fed with basicstandardized diet for the whole experiment. Such clinical indicators related to obesityand type2diabetes as weight, length, fasting food glucose, intravenous glucosetolerance test (IVGTT), and blood fat, etc. were tested regularly in the4th week,12thweek before STZ injection and first week,4th week,8th week after STZ injectionrespectively so as to judge the establishment of experimental model of obesity andT2DM in Beagle dogs.In the second part of experiment, take the5modeling successful Beagle dogs inthe first part as objects to implement endoscopic (Joint open surgery)Esophagus-Jejunum stent implantation bypass, and take the5Beagle dogs of normalcontrol group in the first part as control group to take laparotomy. Test theObesity-related indicators (weight, Lee index, abdominal circumference),Diabetes-related indicators (fasting blood glucose, fasting Insulin, intravenousglucose tolerance test(IVGTT)) regularly before surgery, and4weeks,8weeks,12weeks after surgery, comparing to preoperative and postoperative changes of eachindicator to observe the effect of surgical treatment.Results:(1) Establishment of experimental model of obesity in Beagle dog：the weight of Beagle dog in model group has already been higher than that of control group in the4th week（P<0.05，and difference of weight gradually intensified with time (P<0.01);8weeks after STZ injection, the average weight of Beagle dogs in model group was25.1%higher than that of control group, and Lee index of model group wassignificantly higher than that of control group（P<0.01, prompting that Beagle dogs inmodel group were already obese.(2) Establishment of experimental model of T2DM in Beagle dog: insulin andHOMA-IR of dogs in model group increased significantly compared with the controlgroup（P<0.01）in the twelfth week, indicating that Beagle dogs in model group hadalready got insulin resistance. One week after STZ injection, the fast blood glucose ofdog in model group was significantly higher than control group（P<0.05, IVGTT-2hglucose(143±7.4mg/dl) was higher than that before the injection (127±4.2mg/dl)（P<0.05, but insulin decreased significantly after STZ injection（P<0.01）, indicatingthat the pancreatic β cell function of Beagle dogs in model group had been damaged.Eight weeks after STZ injection, the fast blood glucose(178.2±9.0mg/dl)of dog inmodel group was significantly higher than that of control group(82.8±3.6mg/dl)（P<0.01）, IVGTT-2h glucose(323±12.1mg/dl) was higher than that before injection(127±4.2mg/dl)（P<0.01）, showing that T2DM model had been successfullyestablished on Beagle dogs in model group.(3) Endoscopic (Joint open surgery) Esophagus-Jejunum stent implantationbypass has already been implemented successfully on all Beagle dogs in surgicalgroup, and operation time was90±11.6min, blood loss during operation was57.5±12.9ml. There were no obvious complications and death during operations. Thesurgery is simple and safe.(4) Postoperative results of Beagle dogs’ obesity: the weight and Lee index ofdogs in surgical group was gradually close to that of control group with the growth ofPostoperative time. Twelfth weeks after surgery, there was no significant differenceof weigh（t15±0.53kg vs.16.4±0.67kg, P>0.05） and Lee indicato（r355.2±12.37vs.352.5±10.25, P>0.05） between model group and control group, prompting thatBeagle dogs in surgical group has gradually returned to normal weight and achievedweight loss. (5) Postoperative results of T2DM in Beagle dogs:4weeks after surgery, in thesurgical group, the fast blood glucose(120.74±21.4mg/dl) and IVGTT-2hglucose(215.64±26.49mg/dl) was lower than that before operation (178.2±9.57mg/dl,P<0.01)(321±7.08mg/dl, P<0.05), and the difference with the control group reducedcompared with preoperative. Serum insulin secretion decreased significantlycompared with preoperative（P<0.01）.12weeks after surgery, in the surgical group,fast blood glucose（171±9.0mg/dl vs88.75±15.27mg/dl, P>0.05）and IVGTT-2hglucose （163.9±20.71mg/dl vs155.6±19.94mg/dl, P>0.05） was no significantdifference with control group, indicating that glucose metabolism disorder of Beagledogs in surgical group has improved. Postoperative HOMA-IR showed a gradualdownward trend, while HOMA-β showed a rise trend, showing that the pancreatic βcell function of Beagle dogs in surgical group has improved after Esophagus-JejunumBypass surgery.Conclusion:1. A big animal model of obesity and type2diabetic can be successfullyestablished on Beagle dogs through combination of high-fat hyper caloric diet andintravenous injection of small dose of streptozotocin. This model resembles naturehistory and metabolic characteristics of human type2diabetes. They can be used inthe research of surgery and endoscopic interventional therapy for obesity and type2diabetes.2. Endoscopic Esophagus-Jejunum stent implantation bypass can successfullysimulate classic Roux-en-Y gastric bypass. Postoperative body weight and bloodsugar decreased significantly. And it can also reduce Insulin resistance, improvepancreatic B cells and correct the disorder of glucose metabolism. |
PDF Full Text Request