Patologìâ (Dec 2016)
The features of beta-cells organization in the pancreas of spontaneously hypertensive rat (SHR)
Abstract
The control of b-cells pool in patients with hypertension is an actual problem, as it is possible that the hereditary genetic defects of arterial hypertension formation may affect the mechanisms of endocrine cell mass maintenance in pancreas and cause disruption of glucose metabolism and diabetes. In addition, violation of cytoarchitectonics of pancreatic islets may affect the adequate insulin secretion by the pancreas. This could be provoked by regional blood flow violations in patients with hypertension. The aim of our study was to assess the parameters of the allocation of pancreatic islets and characterize the b-cells morphofunctional state in SHR. Materials and methods. We assessed the amount of b-cells in islets, the concentration of immunoreactive material in them, specific indexes of allocation of islets, b-cells and insulin per unit area using immunohistochemical assay. Results were processed by statistical application package. We used Student’s t-test and Wilcoxon’s w-test when appropriate. Results and discussion. In normoglycemic SHR about 80 % of pancreatic islets are small islets, whereas in normotensive Wistar rats the portion of small islets is less than 45 %. In SHR rats we found the 1/3 decrease of b-cells in islets with area less than 1500 µm2, and 2-fold decrease in islets with area 3500–7500 µm2; decrease of specific amount of b-cells (12,4 % compared with Wistar) and insulin contain (3-fold compared with Wistar). Conclusions: Formation of hereditary hypertension in SHR is accompanied by remodeling of the insular apparatus of pancreas with prevailing of small and middle-sized islets, 2-fold decrease of amount of pancreatic islets and 8-fold decrease of b-cells cell amount. In normoglycemic SHR we found a middle b-cells hypertrophy and increased concentration of insulin. Herewith the specific insulin contain is 3-fold less in hypertensive compared with normotensive rats due to decrease of b-cells cell pool.
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