Effect Of Ursodeoxycholic Acid On Blood Glucose And Islet Function In Rats With Bile Duct Ligation

Objective:To investigate the effects of ursodeoxycholic acid on blood glucose and islet function in rats with bile duct ligation.Methods:Thirty-two male SD rats were randomly divided into four groups: group A(normal group,n = 8),group B(sham operation group,n = 8),group C(operation group,n = 8),group D(operation + intervention group,n = 8)on the basis of group C,ursodeoxycholic acid intervention(0.25% of food intake,once a day)intervention for 4 weeks.The changes of general condition and body weight rate of rats in each group after operation were observed.The concentrations of serum ALT,AST,serum albumin and total bile acid were measured 4 weeks after operation.Glucose tolerance test(OGTT),insulin release test and C peptide release test were performed at 0h,1h and 2h.The concentration of glucagon-like peptide 1(GLP-1)was measured at 0,15,30 and 60 min.At the end of the week,the pancreas and ileum were collected,and the histopathological changes of pancreas and intestine were observed by HE staining,and the expression of NF-КB-p65 and IКBα in pancreas and intestine were detected by immunohistochemistry.Results:1.General condition: on the 3rd day after operation,compared with group A,the activity of rats in group B basically returned to the preoperative level,and compared with group B,the activity of group C was worse,the fur was rough and dull,and obvious yellow staining appeared in sclera,ear margin,limbs and tail.the color of urine gradually changed to dark yellow and the color of feces gradually became lighter.The rats in group D began to intervene from the 5th day.Compared with group C,group D gradually became more active,more energetic and lighter in urine color.From the 14 th day of feeding,jaundice in group C and D gradually faded,and the color of urine returned to the color before operation,but compared with group C,group D still had less activity,poor spirit,rough and dull skin.Compared with group A,the body weight rate of group B was not significantly different(P > 0.05).Compared with group B,the body weight rate of group C was significantly lower than that of group B(P < 0.05),and that of group D was significantly higher than that of group C(P < 0.05).General indexes: compared with group A,there were no significant changes in AST,ALT,TBA,and albumin in group B(P>0.05).Compared with group B,ALT,AST and TBA in group C were significantly increased(P<0.05),and albumin levels in group C were significantly reduced(P<0.05);compared with group C,the ALT,AST and TBA in group D were not significantly changed(P>0.05),and albumin levels were significantly increased(P<0.05).Glucose metabolism index: compared with group A,there were no significant changes in OGTT,insulin release test and C-peptide release test at all time points in group B,but the concentrations of insulin and C-peptide at 1 h and 2 h in group C were significantly higher than those in group B,but there was no significant increase in OGTT at each time point.Compared with group C,the blood glucose of 1 hour and 2 hours in group D decreased significantly(P < 0.05),and the concentration of insulin in 2 hours decreased significantly(P < 0.05),but there was no significant difference in C peptide(P > 0.05).Compared with group A,there was no significant difference in AUCG,AUCI and AUCc in group B,but AUCG,AUCI and AUCc in group C were significantly higher than those in group B.compared with group C,AUCG in group D decreased significantly,but AUCc and AUCI did not decrease significantly.2.Pathological results: Pancreatic HE pathology: The exocrine part of the pancreas and islet cells in group A are arranged neatly,the structure is intact,and there is no obvious difference in the number of islets;compared with group A,there is no obvious difference in the number of islets in group B;compared with group B,there is a disorder in the order of islet cells in group C,the morphology is not regular,the number of islets in group C is reduced,and the area of islets islets is not significantly changed(P>0.05);compared with group C,the morphology of islets in group D islets is not regular,the number of islets in group D islets is increased significantly(P<0.05).Intestinal HE pathology: group A intestinal mucosa is smooth,epithelial villi are densely arranged,there are fewer inflammatory cells,and there is no obvious damage to the mucosal muscle layer;compared with group A,there is no obvious change in group B;compared with group B,the ileal chorionic part of group C is broken,the arrangement is more disordered,the gap is wider,the crypt structure is changed,and there is a large number of inflammatory cell infiltrates in the submucosal layer;compared with group C,the chorionic arrangement of group D is more neat,the mucosal space is more regular,and the submucosal inflammatory cell infiltration is significantly reduced compared with group C.3.Immunohistochemistry results: Pancreatic immunohistochemistry:(1)Expression of NF-КB-p65: The nuclear brown stain of pancreatic cells in group B is shallow,and the number of nucleus-positive cells is rare;Compared with group B,the pancreatic nuclei in group C were deeply stained with brown,and the number of positive cells in the pancreatic cell nuclei increased;Compared with group C,the nucleus of pancreatic cells in group D was slightly shallower,and the number of positive nuclei was relatively reduced.(2)Expression of IКBα: the nuclear brown stain of pancreatic cells in group B is shallow,and the number of nucleus-positive cells is rare;Compared with group B,the pancreatic nuclei in group C were deeply stained with brown,and the number of positive cells in the pancreatic cell nuclei increased;Compared with group C,the pancreatic nuclei in group D were deeply stained and the number of positive nuclei increased relatively.(3)Quantitative analysis: Compared with group B,the expression of NF-КB-p65 in group C increased,the expression of IКBα increased,and the expression of NF-КB-p65/IКBα was significantly increased(P<0.05);compared with group C,the expression of NF-КB-p65 in group D decreased,the expression of IКBα was upregulated,and the expression of NF-КB-p65/IКBα was decreased(P<0.05).Intestinal immunohistochemistry:(1)Expression of NF-КB-p65: The nucleus in the layer structure of the ileum in group B is shallow,and the number of nucleus-positive cells is rare;Compared with group B,the ileal mucosal layer,submucosal layer and muscle layer of group C were deeply stained with brown,and the positive area was larger;Compared with group C,the nucleus brown stains in each layer of the D group were relatively shallow and relatively few positive.(2)Expression of IКBα: the nuclei in the layer structure of the ileum of group B are deep brown stained,and the number of nucleus-positive cells is large;Compared with group B,the IКB α of group C had a deeper brown staining of nuclei,and the number of nucleus positives increased relatively;Compared with group C,the nucleus brown stain of each layer in group D was deeper,and the positive area was significantly increased.(3)Quantitative analysis: Compared with group B,the expression of NF-КB-p65 in group C was upregulated,the expression of IКBα was upregulated,and the expression of NF-КB-p65/IКBα was significantly increased(P<0.05);compared with group C,the expression of NF-КB-p65 in group D decreased,the expression of IКBα was upregulated,and the expression of NF-КB-p65/IКBα was significantly reduced(P<0.05).Conclusion:Bile duct ligation rats can activate the NF-КB pathway,cause an inflammatory response to pancreatic tissue and intestinal tissue,and increase blood glucose;ursodeoxycholic acid intervention can increase the area of the islets,promote the secretion of GLP-1 by L cells in the ileum,downregulate the expression of inflammatory factors in the pancreas and intestines NF-КB,and improve blood sugar.