An immunohistochemical study of the endocrine pancreas of ducks.

Pancreatic tissue specimens of domestic ducks were fixed in PAF, paraformaldehyde and Bouin's fluid. Sections were immunohistochemically stained with antisera against insulin, glucagon, somatostatin and 5-hydroxytryptamine (5-HT). Immunoreactive cells were detected in both exocrine and endocrine pancreas. The endocrine cells were grouped into three islet types: A, B and mixed islets. A islets comprised glucagon, somatostatin and 5-HT immunoreactive cells. B islets showed insulin, somatostatin and 5-HT immuno-reactive cells. Mixed islets were composed of all four immunoreactive cytotypes. Using a double immunofluorescent technique, it was observed that 5-HT immunoreactivity was present in some of the glucagon and in some of the insulin immunoreactive cells. B islets were observed throughout the pancreas. A and mixed islets were more concentrated in the splenic lobe, and decreased in number in the other lobes. These results were compared with those obtained in other avian species.