Reaction of islet and extra islet endocrinocytes in diabetes type 1 and 2
The aim of the investigation. Models of type 1 and 2 diabetes were obtained to compare and evaluate pathological changes according to morphometry and biochemical tests. Materials and methods. Male Wistar rats were administered alloxan in a dosage of 170 mg/kg to simulate DM1. Nicotinamide (110 mg/kg) and streptozotocin (65 mg/kg) were administered to simulate DM2. The histological and immunohistochemical analyses of pancreatic sections were performed, biochemical parameters were tested. Results. The increase in glucose level in DM1 and DM2 was accompanied by a decrease in the pancreatic islets number, the β-cells number and insulin concentration in β-cells. In the DM1 model, a decrease in the number of islet β-cells, insulin content in β-cells and in extra-islet cells agglomerates was accompanied by a decrease in the plasma insulin level and the glycated hemoglobin accumulation. In the DM2 model, a decrease in the number of β-cells and insulin deficiency in the islets were compensated by an increase in the number of single extra-islet insulin-synthesizing cells. Conclusion. The streptozotocin-nicotinamide model obtains pathogenetic changes similar these in type 2 diabetes, such as hyperglycemia with a normal level of insulin in the blood plasma, which is supported by an increase in the number of single extra-island insulin-synthesizing cells and the remaining normal insulin production in agglomerates of extra-island insulin-synthesizing cells. In the alloxan model, hyperglycemia is accompanied by the accumulation of glycated hemoglobin and urea, and the decrease in insulin production is noted not only in the islets, but also in agglomerates of extra-island insulin-synthesizing cells, which is confirmed by a reduced insulin level in rat blood plasma.