Effects And Mechanisms Of Gastric Bypass Surgery On Blood Glucose In Diabetic Rats

ChapterⅠ Improvement and evaluation of DJB operation modelObjective Improve the traditional DJB operation model,in order to establish a simple DJB operation model that can cure diabetes mellitus in diabetic rats.Methods The diabetic rats were randomly divided into three groups:the DM control group(n=10), sham operation group(n=10), DJB operation group(n=10), and anther 10 normal SD rats as normal control group. Fasting blood glucose were measured at before operation and 1, 2, 4, 6 weeks after operation, fasting plasmatic insulin levels were measured before operation and 6 weeks after operation,the rats were killed at 6 weeks after operation,pancreatic tissue were stained in hematoxylin-eosin(HE),and observe islet morphology.Results The blood glucose of DJB operation group gradually decreased,at the 6th week after operation,compared with the normal control group,there was no significant difference(P>0.05).and the insulin level,compared with the normal control group,there was no significant difference(P>0.05).the islet morphology of DJB operation group was lighter than that of DM control group and sham group.Conclusions The modified DJB operation model were successfully established in rats,and it can effectively reduce the blood glucose of diabetic rats and improve the function of islet.ChapterⅡ Effects and mechanisms of Gastric bypass surgery on blood glucose in Diabetic RatsObjective To establish four different models of gastrointestinal bypass surgery,to further explore exclusion of the foregut,food touch the hindgut in advance and bile and pancreatic juice,the role and mechanism of these three factors in the operation of the treatment of diabetes.Methods The diabetic rats were divided into five groups:group A:sham operation;group B:nastomosis of gastric-jejunum; group C:anastomosis of gastricjejunum plus side to sideanastomosis of intestinal;group D: anastomosis of gastric-jejunum plus side to side anastomosis of intestinal plus input loop ligation; group E:modified DJB(gastric jejunum Y anastomosis).Detect the level of blood glucose, insulin, GIP and GLP-1 in each diabetic rat at a specific point in time.The rats were killed at 6 weeks after operation,pancreatic tissue were stained in hematoxylin-eosin(HE),and observe islet morphology.Results 1 The rats’ detection of indicators of group A has no significant difference at the time points for each detection after the operation(P>0.05),the blood glucose level of other group gradually decreased,the insulin value of other group gradually increased,until the 6th week after operation,the rats’ blood glucose level of each group were lower than those of preoperative(P<0.05),the relationship between the four groups was group B>group C>group D>group E.However,the rats’ insulin value and oral glucose tolerance test were higher than those of the preoperative.The relationship between the four groups was:group B<group C<group D<group E. 2 The rats’ GLP-1 value of each group gradually increased,at the time points for each detection after the operation,until the 6th week after operation,the rats’ GLP-1 value were higher than that of the preoperative.The relationship between the four groups was:group B<group C<group D<group E. 3 There was no significant change in the concentrations of rats’ plasmatic GIP in each group at each point of the experiment(P>0.05). 4 The atrophy state of rats’ islet cell atrophy in those groups obviously better than that of group A, the volume of pancreatic islet cells increased and the number of cells increased.5 The anatomical results showed postoperative rats’ gastrointestinal anastomosis mouth and intestinal a nastomotic stoma healed well, except for group A, the intestinal canal of rats in the other groups had different degree of compensatory thickening,which in group D and E is more obvious.Conclusions 1 In the 6 weeks of observation, four kinds of gastric bypass surgery all can reduce the level of blood glucose of diabetic rats, improve their islet function,among them, the effect of E was the best. 2 Exclusion of the foregut,food touch the hindgut in advance and bile and pancreatic juice,these factors may all were involved in the improvement of blood glucose. 3 Expedited bile and pancreatic juice flow to the terminal ileum,lead to the rise of the plasma GLP-1 concentrations,these may be one of the mechanisms of the improvement of diabetes.