Expression And Distribution Of DCLK1 And Ki-67 In Pancreas After Pancreatic Duct Ligation

Objective To study the expression and distribution of DCLK1 and Ki-67 in islet regeneration after PDL,and then it can provide an experimental basis for the mechanism of molecular regulation of islet neogenesis.Methods 35 Sprague dawley(SD)rats(body weight 250±10.8g)were randomly divided into the normal control group(n=5)and the PDL model group(n=30),which were subdivided into 6 subgroups,with 5 in each one subgroups.The rats in the model group were treated with 4% chloral hydrate intraperitoneal anesthesia,and then ligatured the main pancreatic duct in pancreatic tail.The body and tail of pancreas samples in post-operation 1d,3d,5d,7d,9d,12 d,and normal control group,which were gathered in both normal control and model group to be investigated the expression and distribution of DCLK1 and Ki-67 in pancreas by immunohistochemical technique SABC.Furthermore,the regeneration of pancreatic islets was observed by H-E staining,Insulin and Glueagon immunostaining.Results DCLK1 and Ki-67 was less expressed in normal pancreatic tissue,which was mainly concentrated on mesenchyme among the pancreatic duct,acini and pancreatic islet.Day 1,3 post PDL: high degree of edema of pancreatic tissue,degeneration and necrosis of acinar cells,destruction of islet morphology,denaturation and necrosis of?-cells in pancreatic islets,and Glucagon immunopositive reaction were demonstrated in a-cells of the edge of pancreatic islets;DCLK1,as a start,were aberrantly expressed in pancreas;Ki-67 showed positive expression at day 3 post PDL,but its distribution have no special.Day 5 post PDL: the necrotic pancreas tissue was fattened,the large numbers of acinar lobules in the pancreas was fat-like,and the tubular complexes(TC)appeared in the pancreatic lobules.DCLK1 was strongly immunoreactive in the tubular composite epithelium,and the number of Ki-67 positive cells was more obviously.Day 7,9 post PDL: exocrine gland atrophy obviously,many acinar lobules were replaced by tubular complex structure and adipose tissue,DCLK1 expression decreased,the pancreas began to appear Insulin immune positive reaction.At day 12 post PDL,pancreatic acinar structure gradually restored,the islets among the external secretion showed the normal islet tissue.DCLK1 had no significant expression,but Insulin and Glucagon immunoreactive were more obviously,and the numbers of Ki-67 positive cells were constant and its distribution was clear,which mainly distributed in the duct,acinar and islets.The distribution was different,the difference was statistically significant(P<0.05).Conclusion The pancreatic exocrine tissue was fattened after pancreatic duct ligation(PDL),and DCLK1 was abnormally expressed in TC.At later stages,the expression of DCLK1 decreased and the morphology and endocrine function of islet cells returned to normal.Ki-67-positive cells were most pronounced with ductal epithelium,followed by acinar and islets,and the distribution was different.