Morphogenesis of a canalicular-hypertensive model of pancreatitis

Abstract

83parts of the pancreas proceed synchronously and preferentially involve the endocrine elements. The specific features of the process in the exocrine part are hypertrophy of acini and hypertrophy and hyperplasia of the mucous glands of the large ducts.The compensation of endocrine function in the ligated part of the pancreas is realized through secondary differentiation of the epithelium of the acino-ductal structures and is limited by the peculiarities of the forming connective tissue. In the intact part of the pancreas the prevailing processes are hypertrophy, insulocyte proliferation with preferential B cell differentiation, and, later, acino-insular transformation.

Morphometric analysis of the pancreas regenerating after resection

“…There was no outgrowth of pancreatic tissue from the resection zone. Morphometric and information parameters of the islets indicate that peak compensatory changes occur between days 20 and 30 (Table 2), which is similar to the corresponding period in the ligation model [3]. However, the contribution of [3-cell mitoses in this process is insignificant.…”

“…Changes in the exocrine pancreas after resection were typical in both species and occurred at the same interval as after ligation of the pancreatic ducts [3]. Some specific changes were observed in pancreatic islets.…”

“…After resection, an increase in mitotic activity of ductal epithelium was recorded earlier (on days 2-5) than after ligation (day 7). This may be due to instantaneous loss of a considerable volume of the organ, while progressive degradation of two thirds of pancreatic parenchyma as a result of atrophy requires at least 7 days in the ligation model [3]. After resection, the weight of the pancreas was not restored either in rats or guinea pigs.…”

“…Although regeneration of the exocrine pancreas was studied in sufficient detail [1,4,5], the problem of [3-cell recovery was not solved. Our aim was to study regeneration of the pancreatic islets after partial resection of the organ in comparison with our previous data obtained in experiments with ligation of the pancreatic duct [3]. …”