Effects Of Insulinoma On Blood Glucose And Organs In Diabetic Mice

Objective: Constructing a diabetic-insulinoma dual-disease animal model for the functional research of insulinoma as a β-cell replacement cell and evaluating comprehensively the effect of insulinoma growth on hyperglycemia and the environment in the body.Using quantitative pathological techniques to summarize the morphological changes of diabetic animal models and the relationship with blood glucose levels.Methods: In the first part,the diabetic mouse model was constructed by intraperitoneal injection of high-dose streptozotocin(STZ).Then images of HE staining and insulin immunohistochemistry of the pancreas were collected for measuring the number of islets and morphological geometric indicators by image analysis software.Calculating the insulin expression positive unit(PU),area density,numerical densit in unit test area of pancreas,percentage of positive cells and other indicators.Finally the kinetic model about the change of blood glucose through statistical analysis of the differences between the above indicators in diabetic mice and normal mice was built.In the second part,the insulinoma cell line β-TC-6was used to construct an insulinoma model,while the morphological and functional characteristics of the insulinoma cell line were initially explored in vitro by immunocytochemistry and glucose stimulated insulin secretion experiment(GSIS).On this basis,a diabetic-insulinoma dual-disease model was constructed,and finally the normal mouse group(NC),the diabetic mouse group(DM),the diabetic-insulinoma double disease mouse group(DM-INS),and the insulinoma mouse group(N-INS)were established in the third part.Comparing their blood glucose changes and insulin secretion levels.In the last part,we observed and compared the changes of the pancreas and other important organs in each group of mice,analyzed and evaluated the degree of lesions by pathological techniques,and explored whether there is distant metastasis and invasion.Results: The diabetic mouse model constructed by intraperitoneal injection of high-dose streptozotocin(STZ)has the same symptoms with type 1 diabetes.Comparing with normal mice,there are differences in islet morphology,β-cell number,and insulin expression.It has a high correlation with the change of blood glucose.and the kinetic model of it can be constructed to use related factors to predict blood glucose changes.The vitro experiments ofβ-TC-6 cell line initially confirms the strong insulin synthesis ability of insulinoma cells.But its secretion ability which response of the change of blood glucose is weak.After successfully constructed diabetes-insulinoma dual disease model,the growth of insulinoma effectively reduces blood glucose,and has the ability to respond to changes in blood glucose but weaker than normal β cells.Finally,we summarize and analyze the effects of insulinoma growing of pancreas and various organs.The insulinoma is benign growth and there is no peripheral invasion and distant metastasis during the experimental period.The m RNA of PDX-1 and Ngn 3,which related about and differentiation to β cell were significantly up-regulated.Conclusion: The fluctuation of blood glucose in the animal model of diabetes is related to the change of the number and function of β cells.When the β cell damage reaches a certain level,the blood glucose level remains at a stable,high level.The insulinoma which secreting insulin can help diabetic mice that have lost part of their β-cells’ function to regain their ability to regulate blood glucose.At the same time,the restricted growth of tumors provides a certain degree of safety.The preliminary exploration results confirmed insulinoma cells are expected to become the replacement cells of β cells and be used in the research of β cell regeneration therapy.