Distribution of chromogranin A in human fetal pancreas

Immunohistochemical study of distribution of chromogranin A (neuroendocrine cell marker) in the developing human pancreas was carried out. Immunopositive reaction to chromogranin A was detected in the primordial pancreas from the early period of development (8 weeks). The count of chromogranin A-positive cells in early fetuses significantly surpassed that of insulin- and glucagon-containing cells. Chromogranin A immunoreactive cells, but not cells reacting with antibodies to insulin and glucagon were detected in the pancreatic islets and pancreatic ducts during all periods of gestation. These results suggested that hormone synthesis by pancreatic endocrine cells was preceded by the expression of chromogranin A and hence, this marker could be used for studies of the mechanisms of development of the endocrine part of the pancreas.