Immunohistochemical studies on the splenic lobe of the pancreas in young Japanese quails (Coturnix c. japonica)

The splenic lobe (Lobus splenicus) of the pancreas of young meat-type quails (Coturnix c. japonica) was examined by immunohistochemical and light microscopic methods. The endocrine cells are mainly grouped as alpha, beta and mixed islets. A large region consisting of alpha cells is located in the central region of the splenic lobe whereas numerous beta islets are detected in the periphery of the splenic lobe. Alpha islets are in the majority composed of toluidine blue positive A cells and a few toluidine blue negative D and / or avian pancreatic polypeptide (APP) endocrine cells. Beta islets contain only a few toluidine blue negative B and a few D cells. Immunohistochemical staining of the splenic lobe reveal in the centre of beta islets numerous insulin immunoreactive cells and scarcely in alpha islets, exocrine tissue and / or among acinar cells. Somatostatin immune-reactive cells form a circular layer in the periphery of beta islets whereas these cells are uniformly distributed throughout the alpha islet parenchyma and exocrine tissue. In conclusion, the morphology but also the endo- and exocrine functions of the splenic lobe of quails are similar to observations in other avian species such as chicken, duck, goose and pigeon.