In order to study the regional distribution and relative frequency of the immunoreactive endocrine cells in the pancreatic islets of the Mongolian gerbil, pancreatic sections of Meriones unguiculatus were immunostained using an immunohistochemical (PAP) method with four types of specific antisera against insulin, glucagon, somatostatin and human pancreatic polypeptide (PP). The pancreatic islets were subdivided into three portions (central region, mantle zone and peripheral region) according to their composition of immunoreactive cells. Spherical to spindle shaped insulin, glucagon, somatostatin and PP-immunoreactive cells were observed in this study. Insulin-immunoreactive cells were present in the central regions with high frequency, and a few of these cells were also demonstrated in the mantle zones. Glucagon-immunoreactive cells were mainly restricted to the mantle zones. However, rare examples were found in the peripheral regions. As for the glucagon-immunoreactive cells, somatostatin-immunoreactive cells were detected in the mantle zones and peripheral regions with moderate and rare frequencies, respectively. PP-immunoreactive cells were found in the mantle zones and peripheral regions with rare and moderate frequencies, respectively. In the mantle and the peripheral regions, cytoplasmic process of glucagon-, somatostatin- and PP-immunoreactive cells were intermingled. In conclusion, the regional distribution of endocrine cells in the pancreatic islets of Mongolian gerbil was found to be similar to that of other mammals, especially other rodents, except for the topographical different distribution of somatostatin which differs that of other rodents.
Animals ; Gerbillinae ; Glucagon/analysis ; Humans ; Immunohistochemistry/methods/veterinary ; Insulin/analysis ; Islets of Langerhans/anatomy & histology/*cytology ; Pancreatic Polypeptide/analysis ; Somatostatin/analysis

The regional distribution and relative frequency of some endocrine cells in the principal pancreatic islets of two teleosts, Silurus asotus Linne (Siluridae) and Siniperca scherzeri Steindachner (Centropomidae), which have similar feeding habits, were observed using specific antisera against insulin, glucagon, somatostatin and bovine pancreatic polypeptide (bovine PP) using the peroxidase antiperoxidase (PAP) method. Spherical to spindle shaped cells were demonstrated in the principal pancreatic islets in both species of teleost fishes. However, they were not detected in the exocrine portions nor the pancreatic ducts. Insulin-immunoreactive cells were located in the central regions of the principal pancreatic islets at high frequency in both species. Glucagonimmunoreactive cells were restricted to the peripheral regions of the principal pancreatic islets in both species. They formed a mantle zone in the peripheral regions of Silurus asotus with moderate frequency, and occupied a narrower mantle zone in Siniperca scherzeri with moderate frequency. In addition, glucagonimmunoreactive cell cores were also found in the peripheral zone of some principal pancreatic islets of Siniperca scherzeri. Somatostatin-immunoreactive cells were dispersed in the central zone of the principal pancreatic islets of Silurus asotus with moderate frequency, but were located in the peripheral regions with low frequency in Siniperca scherzeri. Bovine PPimmunoreactive cells were found in the peripheral region and the mantle zone of the principal pancreatic islets with low and rare frequency, respectively in both species. In conclusion, the regional distribution and relative frequency of endocrine cells in the principal pancreatic islets of Silurus asotus showed general patterns similar to those of other teleostean fishes. But, some speciesdependent distributional patterns and/or relative frequencies, particularly in glucagon-, somatostatin- and bovine PP-immunoreactive cells, were detected in the principal pancreatic islets of Siniperca scherzeri
Animals ; Catfishes/*anatomy & histology/physiology ; Cattle ; Glucagon/analysis/immunology ; Immune Sera/diagnostic use/immunology ; Immunohistochemistry/veterinary ; Insulin/analysis/immunology ; Islets of Langerhans/*cytology/physiology ; Pancreatic Polypeptide/analysis/immunology ; Perciformes/*anatomy & histology/physiology ; Somatostatin/analysis/immunology