Exocrine Part Of Pancreas Research Articles

Influence of macrophages on the insulin-synthesizing system under normal conditions and in alloxan diabetes

Insulin-synthesizing cells (ISCs) of pancreatic gland are localized both in its islets, and in exocrine portion, as single cells or cellular agglomerates. ISCs differ in their morphological and functional characteristics, depending on characteristics of the microenvironment. Resident macrophages are also involved into formation of their microenvironment. Our purpose was to assess the effect of functional macrophages upon the insulinsynthesizing system (pancreatic islets, cell agglomerates, and separately lying insulin-synthesizing cells) under normal conditions and in alloxan diabetes.Alloxan diabetes was induced in mature male Wistar rats by intraperitoneal injection of alloxan (30 mg/100 g). Functional activity of macrophages was modeled with anti-inflammatory drug aminophthalhydrazide (AMP). Contents of insulin, glucose, and glycosylated hemoglobin were measured in blood of experimental animals. The levels of IL-1α, TNFα and IFNγ were determined in pancreatic homogenate. The number of macrophages was counted in histological preparations from the insular and exocrine parts of the organ, as well as the number of pancreatic islets, agglomerates, and single ISCs. The amounts of proliferating cells (insulin+Ki-67+), apoptotic forms (TUNEL+insulin+), and insulin content of ISCs at different sites (according to their fluorescence intensity) were determined. All pancreatic islets were divided into 3 types, according to intensity of insulin fluorescence, i.e., islets with high, median and low levels of fluorescence.In healthy rats, immunomodulation reduced total level of IL-1α in pancreatic parenchyma, without changing the overall parameters of carbohydrate metabolism. In the exocrine part of pancreas, the content of single ISCs in ductal epithelium was increased. Likewise, proliferation of the ISC agglomerates became higher. The intensity of β-cell apoptosis increased in pancreatic islets. The proportion of islets with high-level insulin fluorescence was decreased, along with lower density of macrophages and proliferation rates of β-cells, and higher apoptosis rates, than in intact animals. We have also revealed there an increased ratio of cells with average insulin levels. In the islets with low insulin content, immunomodulation did not cause morphological changes. Administration of AMP in alloxan diabetes contributes to a significantly decreased concentration of IFNγ in pancreatic tissues, stabilizes IL-1α content, along with reduced apoptosis of ISCs and macrophage infiltration in all parts of the gland. In the ductal epithelium, a large number of single ISCs with high synthetic activity was observed, with retained number of agglomerates and their increased cellularity. The number of dividing β-cells is increased in pancreatic islets.Modulation of the functional activity of pancreatic macrophages under physiological conditions provides a multidirectional effect on the insulin-synthesizing cells, depending on their localization. In exocrine part of the organ, where M2 macrophages are located, we have observed activated differentiation and proliferation of ISC precursors. Meanwhile, in the islets where M1 macrophages are present, apoptosis of β-cells was enhanced. In alloxan diabetes, immunomodulation was associated with reduced destruction of insulinocytes, along with high intensity of their proliferation. Heterogenous response of ISCs to the changes in the microenvironment depends on their synthetic activity. In healthy rats, the islets with high level of insulin fluorescence, the level of apoptosis is increased, and β-cell proliferation is reduced, while the morphological and functional characteristics of islets with low-level insulin fluorescence did not change. In alloxan diabetes, apoptosis prevailed in islets with high fluorescence values, whereas β-cell proliferation predominated in the islets with low insulin contents.

Localisation of S100 Protein and Acetylated Tubulin in Sheep Pancreas

Abstract The pancreas plays a critical role in the control of nutritional homeostasis. It consists of two major parts, the exocrine pancreas, and the endocrine pancreas. In the present study S100 protein and acetylated α-tubulin were used to identify positive structures in both the exocrine and endocrine part of the ovine pancreas. In the exocrine part of the pancreas, a positive reaction to S100 protein was confined to centroacinar cells, intercalated, and intralobular ducts cells. In addition, the S100 protein was localized in the Schwann cells of nerve fibres. On the pancreatic islets, the S100 protein has been observed in Schwann cells of nerve axons, where they form a fine envelope that invests the islet surface. Inside the pancreatic islets, the Schwann cells positive for S100 protein envelope the endocrine cells of the islets. The difference in positivity of the S100 protein was found in relation to the endocrine cells. The relationship between endocrine cell positivity and positive exocrine duct cells was discussed. Acetylated α-tubulin (AT) was restricted to axons of the nerve fibres and was located within the connective tissue accompanying intralobular and inter-lobular ducts, and between secretory acini in close contact with secretory cells.

Insulin-positive cells in liver and exocrine part of pancreas in animals with experimental diabetes mellitus

Aim. To compare the number of insulin + cells in the liver and exocrine part of the pancreas with the type of experimental diabetes, blood glycose and glycated hemoglobin (HbA 1с ) level and with the number of Pdx1 + cells. Materials and methods. The experiment was carried out on 25 male Wistar rats (weighting (303.0 ± 25.3) g) that were divided into 3 groups: the first group consisted of intact animals, the second had animals with experimental diabetes type 1, and the third with animals with experimental diabetes type 2. Biochemical, immunohistochemical, ELISA methods and statistical analysis were used. Results. Insulin + and Pdx1 + cells of rats with experimental diabetes were found in the liver and exocrine part of pancreas. The highest number of insulin + cells in the liver was detected in type 2 diabetes (T2D). A strong positive correlation between the number of insulin + cells in the liver and level of glycosylated hemoglobin in theblood was revealed in both type 1 and type 2 diabetes. Conclusion . Insulin + cells are detected in the liver and acinar part of pancreas of both intact rats and rats with experimental diabetes. Group with T2D is characterized by the highest number of insulin + cells in the liver compared with type 1 diabetes (T1D). The localization of insulin + cells in the liver changes depending on the type of diabetes. In T2D insulin + cells are located in all parts of liver acini, meanwhile in animals with T1D such cells are mainly detected in the periportal area. The expression of Pdx1 + in acinar cells of pancreas and liver cells is likely a mechanism for their reprogramming into insulin + cells in experimental diabetes mellitus.

Auto-antibodies in patients with inflammatory bowel disease unclassified.

Inflammatory bowel disease unclassified (IBDU) is considered to be an aberrant immune response with loss of tolerance to many antigens. This paper tries to address whether there is any value to test for auto-antibodies in such patients. 60 patients with inflammatory bowel disease unclassified participated in the study. Auto-antibodies to nuclear antigen, intestinal goblet cell, exocrine part of pancreatic acinar cells, perinuclear antineutrophil cytoplasmic, cytoplasmic antineutrophil cytoplasmic and Saccharomyces cerevisiae were tested and compared to 20 ulcerative colitis (UC) patients and 30 healthy controls matched for age and sex. There was a significant difference (p=0.000) between patients and control group in anti-exocrine part of pancreatic acinar cells, perinuclear antineutrophil cytoplasmic and Saccharomyces cerevisiae auto-antibodies. There was also a significant difference between IBDU and UC patients in the auto-antibodies directed against intestinal goblet cells, (p=0.000) exocrine part of pancreas (p=0.000) and anti Saccharomyces cerevisiae antibody (p=0.000). Due to the autoimmune nature of indeterminate colitis, involvement of some antigens from gastrointestinal tract or the bile system in the initiation of this disease is likely.