Immunocytochemical localization of the pancreatic islet cells in the Japanese quail, Coturnix coturnix japonica

Abstract

The endocrine pancreas of the Japanese quail (Coturnix coturnix japonica) was immunocyto-chemically studied on the distribution and cellular composition of the islets and the fine structure of islet cells. The pancreatic islets of the quail are divided into alpha, beta and mixed type islets on the ground of the cellular composition. The alpha islets are generally composed of A and D cells and restricted to the third and splenic lobes, whereas the beta islets are generally composed of B and D cells and distributed throughout the pancreas. Mixed type islets containing A, B and D cells are restricted to the third and splenic lobes. A cells contain spherical granules immunopositive to anti-glucagon and C-terminal specific anti-glicentin sera. B cells contain polymorphic granules immunopositive to anti-insulin and anti-duck C-peptide sera. D cells contain spherical granules immunopositive to anti-somatostatin serum. Mixed type islets are supposed to be formed by the mingling of A cells into beta islets in the splenic and third lobes. The beta islets composed solely of B cells are conspicuously small, scattered throughout the pancreas and seemed to be the remnants of immature beta islets observed during the development.