Immunofluorescence study of the endocrine pancreas in the common pheasant (Phasianus colchicus)

The present study was conducted to investigate the presence and distribution of the endocrine cells in the pancreas of the common pheasant using immunofluorescent staining. Totally, five adult male birds were used in the present work. The tissue samples were prepared, and different antibodies were applied to detect insulin, glucagon, somatostatin, pancreatic polypeptide (PP), and neuropeptide Y (NY). The percentage of staining was estimated using image J software. The glucagon-secreting cells (Alpha cells) with 32.4% ± 12.56 intensity were the most numerous cell type which were populated throughout the large islets especially at the periphery of islets. The insulin-secreting cells (Beta cells) with 27.73% ± 8.34 intensity were accumulated in the center of the small islets. Cells containing somatostatin (Delta cells) showed 13.38% ± 5.09 intensity. Despite their lower intensity, the distribution of D cells was like to A cells throughout the islets. PP cells and NY cells were distinguished with 19.55% ± 3.88 and 18.14% ± 7.15 intensities, respectively. Their distribution was evenly in the large islets. There were two types of islets: large alpha islets which were mainly composed of alpha and delta cells, and small beta islets constituted of beta cells and a few numbers of alpha cells. In conclusion, all investigated cell types were expressed in the endocrine pancreas and distributed in two types of islets as large alpha and small beta islets. Certainly, more detailed investigations are needed to reveal the exact population of each endocrine cells in the pancreas of the common pheasant.