Distribution of islet hormones in human adult pancreatic ducts

The source of insulin-secreting cells from adult duct system is attractive, but its clinical practice remains poorly understood. Here, we aimed at identifying the distribution of secreted hormone reactive cells in adult ducts.

Consecutive pancreatic slices from nondiabetic subjects were subjected to immunohistochemistry and immunofluorescence to screen islet hormones (insulin; glucagon, Glu; somatostatin, Som; pancreatic polypeptide, PP) and exocrine biomarkers (cytokeratin 19, CK19; chromogranin A, CgA; amylase). All pancreatic sections were imaged using an optical or confocal microscope.

Immunostaining results showed that insulin was expressed in adult ducts, in which the cell count was more than other islet hormone immunoactive cells. CK19-positive cells are mainly distributed in the ducts, whereas CgA-labeled cells are localized in endocrine cells. The duct branches visibly exhibited cell populations that co-expressed islet hormones in exocrine cell populations.

In this report, our findings demonstrate that adult ductal cells that produce insulin may contribute to beta-cell proliferation.