[Acinar epithelium as a source for the formation of the human pancreatic islets in embryogeny].

By electron microscopy in the islets of Largenhans and acini of the pancreas of the human fetuses 4-7 months old acinar-islet (transitional) cells were revealed. The cytoplasm of some transitional elements contained zymogen and endocrine A-granules, while in others zymogen and endocrine B-granules were found. Acinar-islet cells differed by the structure of organelles and by the quantity of endocrine granules, which can be regarded as transformation of acinar cells into endocrine cells. A conclusion was drawn that during human pancreas embryogenesis the acinar epithelium is one of the sources of islet tissue formation.