Immunocytochemical studies on endocrine cells of alimentary tract of the pig in the embryonic and fetal period of life.

The study aimed at immunocytochemical analysis of alimentary tract endocrine cells between 20th day of embryonal life and 105th day of fetal life of domestic pig. In the pancreas, presence of endocrine cells was detected already in 20th day and, at the time, the cells comprised around 3/4 all cells in primordia of the organ. Starting at that time, numerous endocrine cells produced insulin and glucagon and individual cells synthesized somatostatin and pancreatic polypeptide. In the 20th day, stomach and duodenum contained single endocrine cells but hormone production was not detected until days 27 and 30. Beginning from this days, both organs manifested rapid increase in the number of gastrin-producing cells. In each of the three organs, the number of somatostatin-producing cells exhibited most extensive changes.