Appearance Of Endocrine Cells Research Articles

Immunocytochemistry of somatotrophs, gonadotrophs, prolactin and adrenocorticotropin cells in larval sea bream (Sparus auratus) pituitaries.

The chronological appearance of endocrine cells in the pituitary of sea-bream (Sparus auratus) larvae was studied using antisera against salmon prolactin, trout growth hormone, salmon gonadotropin and N-terminal human adrenocorticotropin. The larval pituitary (1-12 days after hatching) was oval in shape and was composed of a dense mass of cells with few neurohypophysial fibres. By 60 days after hatching it began to resemble the adult and was divisible into a distinct rostral pars distalis containing prolactin and adrenocorticotropin cells; a proximal pars distalis containing somatotrophs and gonadotrophs and a pars intermedia. Cells immunoreactive with antisera against growth hormone were observed immediately after hatching (2 days post-fertilization). Weakly staining prolactin cells were observed 2 days later in the region corresponding to the rostral pars distalis. Cells immunoreactive with antigonadotropin and anti-adrenocorticotropin sera were observed in the pituitary 6 and 8 days after hatching, respectively. All the cell-types studied were immunoreactive from the time they were first identified until the final samples 90 days after hatching.

Appearance of immunoreactive endocrine cells during the development of the rat pancreas, with special reference to polypeptide-secreting cells.

The chronological appearance of PP cells in fetal pancreatic islets was studied using specific anti-PP serum and the direct peroxidase method. The presence of A and B cells was also studied, using the same immunocytochemical technique, as a reference pattern related to data previously reported. Our data confirm that the A cell is the earliest endocrine cell type, appearing on the 12th day of gestation, followed by B cells (14th day) and later on by PP cells (19th day). Primitive islets were identified in the pancreas after the 15th day. However, the spatial cell disposition observed in the adult islet was only recognized at the 20th day of gestation. The data reported provide the necessary information to establish the complete chronology in the rat fetus. Consequently, the development of pancreatic islets in the rat fetus could be employed as a useful model to study the existence of factors that control the sequential appearance of endocrine cells and the possible changes occurring in the islets of animals with genetic diabetes during the fetal period.

The first appearance of endocrine cells in the splenic lobe of the embryonic chick pancreas.

In seeking a source of a pure population of a single type of endocrine cell, the splenic lobe of the chick pancreas was investigated. This was because, in adult life, this lobe contains an abundance of glucagon cells and only a few endocrine cells of other types. The presence of cells containing insulin, glucagon, somatostatin, and pancreatic polypeptide was sought by immunocytochemical means in splenic lobes of normal chicks of 6, 7, and 8 days incubation as well as in splenic lobes which had been removed from donors of the same ages and cultured in isolation from the rest of the pancreas as chorioallantoic grafts. Insulin and glucagon cells were present in all specimens. Somatostatin cells were found in all splenic lobes except one from a normal 6-day embryo. Avian pancreatic polypeptide (APP)-immunoreactive cells were detected in all grafts from donors of 6 or more days incubation and, in normal splenic lobes, were first found at 7 days of incubation. In all grafted and normal splenic lobes older than 7 days on original isolation, glucagon- and APP-immunoreactivities were occasionally present in the same cells. Thus, although the splenic lobe cannot be used as a pure endocrine cell source, this study has demonstrated APP immunoreactivity in the chick pancreas at an earlier stage than has previously been reported, and has also revealed "double staining" of some pancreatic endocrine cells with antisera raised to glucagon and APP.

Does pancreatic mesoderm elicit the appearance of endocrine cells in gastric epithelium?: [formula omitted], [formula omitted] and [formula omitted]. Departments of Anatomy and General Anatomy, University of the Witwatersrand, Johannesburg 2001, S. Africa

Does pancreatic mesoderm elicit the appearance of endocrine cells in gastric epithelium?: [formula omitted], [formula omitted] and [formula omitted]. Departments of Anatomy and General Anatomy, University of the Witwatersrand, Johannesburg 2001, S. Africa

Observations on the ultrastructural appearance of endocrine cells of the small intestine of the calf.

AbstractThe endocrine cells of the small intestine of neonatal calves are described, with the aid of transmission and scanning electron microscopy. It is demonstrated that endocrine cells have long microvilli, and are organized into two populations, similar to those of other species.

A novel subtyping of intestinal metaplasia of the stomach, with special reference to the histochemical characterizations of endocrine cells.

Intestinal metaplasia of the stomach was grouped into 3 subtypes (A, B and C) according to the degree of pyloric gland involution which was judged from patterns of paradoxical Concanavalin A staining after Katsuyama and Spicer. The appearance of endocrine cells was investigated with immunohistochemical and silver methods. Type A metaplasia with slightly to moderately atrophic pyloric glands corresponded to the incomplete type in the previous classification, while Type C showing complete disappearance of pyloric glands corresponded to the complete type. Type B with severely atrophic pyloric glands was an intermediate. This subtyping reflects the cell kinetics in the intestinalized mucosa well. Regarding the endocrine cells, their total number varied in the order Type A greater than Type B greater than Type C. The selective populations of the endocrine cells including glicentin-containing cells, Grimelius-positive argyrophil cells without argentaffinity and intestinal-type enterochromaffin cells frequently formed hyperplastic foci in the intestinalized areas, where the other gut-type and proper gastric-type endocrine cells were scarcely noted. Immunoreactivity of glucagon or bovine pancreatic polypeptide were occasionally identified in a subpopulation of the glicentin-containing cells.

Immunohistochemical evidence of gastro-entero-pancreatic neurohormonal peptides of vertebrate type in the nervous system of the larva of a dipteran insect, the hoverfly, Eristalis aeneus

Using rabbit and guinea-pig antisera, raised against GEP neurohormonal peptides of mammalian origin, cells were observed in the brain and/or in the fused ventral ganglia of the last (fifth) larval instar of the hoverfly, Eristalis aeneus, being immunoreactive with antisera against insulin, somatostatin, glucagon, PP, secretin, gastrin/CCK/caerulein; substance P, enkephalin and endorphin. Most of these GEP neurohormonal peptides also occurred in nerve fibers. No immunoreactive cells or nerve fibers could be detected with antisera against GIP, VIP, (the central fragments of) CCK, bombesin or neurotensin. The antisera tested failed to reveal any immunoreactive cells or nerves in Weusmann's ring (fused corpus allatum/corpus cardiacum and thoracic gland) or in different parts of the alimentary tract. The observations support the hypothesis that neuronal GEP hormonal peptide production in the brain is a genuinely original mechanism and the appearance of endocrine cells in the gut a later feature in evolution.