[Formation of human islands of Langerhans cells from the epithelium of the acini and ducts].

The contents of endocrine cells in the epithelium of ducts and the number of acino-insular elements in exocrine parenchyma and in pancreatic islets were estimated by means of the dotted method in semithin sections prepared from the pancreas of the human embryos (4--7 months of embryogenesis) and of adult persons (40--50 years of age). Endocrine cell formation was noted in all stages studied in ontogenesis. Quantitative data demonstrated that the epithelium of the ducts is the main source for insulocyte formation. In the pancreas of both human embryos and adult persons, acino-insular transformation participated in the formation of endocrine elements. The data obtained gave a certain evidence on entodermal origin of the pancreatic islets in the human pancreas.