Immunohistochemical distribution of ınsulin-, glucagon-, and somatostatin-containing cells in the pancreas of the rat (Wistar albino)

Abstract

Pancreas in the vertebrates is subdivided into two parts: One of them is exocrine part where digestive enzymes are released and the other one is endocrine part where regulatory hormones are released into blood circulation 1 . The endocrine part, formed by the islets of Langerhans, is multihormonal unit composed of at least four types of cells; the insulin (B cells), the glucagon (A cells), the somatostatin (D cells), and the pancreatic polypeptide (PP cells) 2 .Insulin is synthesized in the B cells of the pancreatic islets and regulates the blood glucose levels. Glucagon

Immunohistochemical distribution of glucagon -, insulin -, somatostatin -, gastrin-, and serotonin-containing cells in the pancreas of the Van cat

“…These produce digestive enzymes and regulatory hormones for carbohydrate metabolism, respectively. The endocrine sections are the Langerhans islets and distribution randomly into the exocrine sections (1)(2)(3). The pancreas of cats is formed of a right and left lobe making a U-shape close to the gastric pylorus, and it consists of the duodenal, gastric, anastomotic, and splenic lobes.…”

“…The islets of Langerhans in cats contain 4 different endocrine cells, similar to other mammalian species (4)(5)(6). These cells release regulatory hormones including glucagon (A, alpha, A 2 cell), insulin (B, beta cell), somatostatin (D, delta, A 1 cell), and pancreatic polypeptide (PP, F cell) (1,2,(7)(8)(9)(10)(11)(12)(13). Some researchers have also reported that the islets of Langerhans may contain nonspecific endocrine cells such as neuropeptide Y, substance P, galanin, cholecystokinin-8 (11), serotonin (10,14), gastrin, and ghrelin-releasing cells (15).…”

“…For example, the Langerhans islets in the pancreas of birds comprise alpha islets (A-cell rich), beta islets (B-cell rich), and mixed islets (A-, B-, D-, and PP-cells) (11,17), but are found only as mixed islets in mammalian species (1,9). Many researchers have reported that insulinimmunopositive cells are located in the central zones of Langerhans islets in mammals, and that the glucagon-, somatostatin-, and pancreatic polypeptide-secreting immunopositive cells are located in the mantle zones or periphery (1,2,12). In addition, insulin-immunopositive cells are found in the center of the islets in humans, rats, and mice (9), but in the periphery of the islets in horses (4), monkeys, and kangaroos (18).…”

“…Previous immunohistochemical and electron microscopic studies have suggested heterogeneities of islets in various animals such as nonhuman primates (16), dogs (7), and rats (1). Studies of the regional distribution and the relative frequency and appearance of pancreatic endocrine cells among carnivorous species have already been performed on dogs (7,16) and some domestic cats (5,6,8), but Van cats have not yet been studied.…”

Timokinon Uygulamasının Ratların Pankreas Dokusunda Somatostatin Salgısı Üzerine Etkileri

“…Somatostatinimmunoreactive cells among endocrine cells (islets of Langerhans) in the pancreas were determined by immunohistochemical and morphometric studies. It was claimed that somatostatin-immunoreactive cells were rare among endocrine cells (islets of Langerhans) in the pancreas and that these cells were localized especially in the peripheral regions of islets of Langerhans [25,26] . Our study showed that somatostatinimmunoreactive cells were localized in the peripheral region of the endocrine parts and TQ administration increased somatostatin release in the endocrine cells.…”