Prenatal development of sympathetic innervation of the human pancreas.

Background: The sympathetic nervous system plays an important role in the regulation of pancreatic exocrine and endocrine secretion. The results of experimental studies also demonstrate the involvement of the sympathetic nervous system in the regulation of endocrine cell differentiation and islet formation during the development of the pancreas. However, the prenatal development of sympathetic innervation of the human pancreas has not yet been studied.

Pancreatic endocrine cell arrangement during human ontogeny.

In the human pancreas, various forms of endocrine cell arrangement are found: single endocrine cells, endocrine cell clusters, and mantel, bipolar and mosaic cell (mixed) islets. Our aim was to analyse the distribution and dynamics of insulin-, glucagon- and somatostatin-containing cells within the various forms of endocrine pancreas arrangement during human prenatal development and in adults and to suggest a mechanism of change in the endocrine cell ratio in adult islets. Pancreatic autopsies derived from human foetuses from the 10 to the 40 weeks of development and from adults were examined using histological, immunohistochemical and morphometric methods.

Immunohistochemical detection of vimentin in pancreatic islet β- and α-cells of macrosomic infants of diabetic and nondiabetic mothers.

Background: Expression of the intermediate filament protein vimentin has been recently observed in the pancreatic islet β- and α-cells of humans with type 2 diabetes mellitus. It was suggested that the presence of vimentin in endocrine cells may indicate islet tissue renewal, or potentially represent the dedifferentiation of endocrine cells, which could contribute to the onset of type 2 diabetes or islet cell dysfunction.

Aim: To analyze the expression of vimentin in pancreatic β- and α-cells of macrosomic infants of diabetic and nondiabetic mothers.