Gastric endocrine cells in rats with uremia and after thyroparathyroidectomy.

The decrease in active kidney parenchyma amount causes disorders in hormone secretion processes and their inactivation failure. Experimental thyroparathyroidectomy is connected with an abrupt reduction in endocrine cells and hormones produced by them, which can be a stimulating factor as far as the increase and intensity of endocrine gastric cells activity is concerned. The aim of the study was the histomorphological and immunohistochemical evaluation of these cells in the gastric pylorus. Thyroparathyroidectomy was performed in rats 30 days after nephrectomy. Fragments of gastric pylorus were collected 14 days after the operation. Paraffin sections were stained with H+E and silver method. Immunohistochemical reactions were conducted using antibodies against calcitonin gene-related peptide (CGRP), somatostatin (ST), synaptophysin (SPh), neuron-specific enolase (NSE), and chromogranin (CgA). The results showed an increase in number of endocrine cells in stomachs of rats in experimental group as compared to controls. Endocrine cells were larger and contained more secretory granules.

An immunohistochemical study of the endocrine cells within the pancreas, intestine, and stomach of the gar (Lepisosteus osseus L.)

The distribution and identity of the various endocrine cell types were examined in the pancreas, stomach, and anterior intestine of the phylogenetically ancient actinopterygian, the gar (Lepisosteus osseus L.), using immunohistochemistry. Antisera used were directed against several insulins (INSs) and somatostatins (SSTs), and members of the pancreatic polypeptide (PP, aPY, NPY) and glucagon (GLUC, GLP) families. In the gar pancreas the most pronounced aggregation of islet tissue is among the exocrine acini near the union of extrahepatic common bile duct with the gastrointestinal junction. Four immunoreactive cell types were identified within well-defined islets (A, B, D, and F cells) but immunoreactive cell types were also seen isolated among the exocrine acini. Centrally located B cells were immunoreactive with mammalian and lamprey INS antisera whereas the widely dispersed D cells immunostained with anti-SST-14, -25, and -34. SST was also localized in the epithelium of the pancreatic ducts. There was a colocalization of immunoreactivity for each member of the PP and GLU families at the periphery of each islet to identify F and A cells, respectively. However, colocalization of peptides from both families is suspected for at least some cells. Although the gastric and intestinal mucosae showed a similar pattern of immunoreactivity to GLP and not GLU, they had contrasting immunoreactivity with the two INS antisera. SST immunoreactivity was restricted to the stomach, whereas three of the four PP-family peptides were only immunoreactive in the intestine. Immunoreactivity to the various antisera used in the study imply that there may be an organ-specific processing of preproinsulin, that the gar SST profile may be more similar to agnathan and bowfin rather than either elasmobranch or teleost SSTs, and that only the GLP portion of the preproglucagon gene is expressed in the gastrointestinal mucosa. Our results are consistent with other recent endocrine studies showing that the gar is a widely distinct actinopterygian.

Células endócrinas gastrointestinais: breve histórico e principais métodos de identificaçäo à microscopia óptica / Gastrointestinal endocrine cells: brief history and main identification methods under light microscopy

O trato gastrointestinal apresenta um amplo espectro de células endócrinas distribuídas difusamente ao longo da mucosa, intercaladas com as células exócrinas. Essas células compartilham diversas características como a capacidade de produzir vários peptídios. Apesar do grande desenvolvimento da endocrinologia digestiva, especialmente na última década e no que tange ao conhecimento bioquímica e localizaçao celular dos peptídios reguladores gastrointestinais, seu significado funcional e papel na fisiopatologia digestiva permanecem em parte desconhecidos. É apresentado um resumo das principais informaçoes sobre características morfológicas, histoquímicas, origem embriológica, dados históricos e métodos de identificaçao das células endócrinas do trato gastrointestinal.

[Gastrointestinal endocrine cells: brief history and main identification methods under light microscopy]. / Células endócrinas gastrointestinais: breve histórico e principais métodos de identificação à microscopia óptica.

The gastrointestinal tract shows a wide spectrum of endocrine cells diffusely distributed along the mucosa, interspersed among the exocrine cells. These cells share several features such as the capacity to produce a series of peptides. Despite the development of digestive endocrinology, especially in the last decade and with respect to the biochemical knowledge and cellular localization of gastrointestinal regulatory peptides, their functional significance and their role in digestive phisiopathology remain partially unknown. This review represents a summary of the principal information about morphological and histochemical features, embryologic origin, historical data, methods of identification and types of endocrine cells, of gastrointestinal tract.

Carcinoid tumor with uterine location. Case report.

A carcinoid is defined as a tumor arising from endocrine cells with neurosecretory characteristics belonging to the APUD system. These cells are most frequently observed in the digestive tract and lungs. Uterine location is rare. This paper presents the case of a 21-year old patient with uterine carcinoid tumor. In order to establish the histopathologic diagnosis of the carcinoid tumor, we used optical microscopy examination in haematoxylin-eosin, argentic impregnation in Fontana-Masson staining and an immunohistochemical reaction using monoclonal antibody to the S100 protein. Due to the intracytoplasmatic granulations shown in Fontana-Masson staining and in the immunohistochemical reaction to S100 protein which confirm the neurosecretory character of the tumoral cells, we included this tumor in the group of tumors with neuroendocrine differentiation.

Identification of R-GRAMP, a membrane glycoprotein of regulated secretory granules in primate cells.

Investigation of membrane assembly and traffic in the regulated secretory pathway may be facilitated by identification of membrane components that are unique to regulated secretory granules. To identify such markers, we isolated integral membrane proteins by Triton X-114 extraction from well-differentiated monolayers of an exocrine cell line, the goblet cell subclone (18N2) of the human colon carcinoma cell line HT29, and used the extracts as immunogens to produce monoclonal antibodies (mAbs). Immunofluorescence microscopy of HT29 goblet cell monolayers identified one mAb (MG-1) that labeled a component of mucin granule membranes. Immunofluorescence of frozen semithin sections of normal intestine, and various other human and monkey tissues, showed that this antigen is present in regulated secretory granule membranes of primate exocrine cells, endocrine cells, and tissue granulocytes. EM immunogold labeling of goblet cells, enteroendocrine cells and eosinophils confirmed that the antigen is associated with secretory granule membranes and not with plasma membranes. The antigen was identified by SDS-PAGE autoradiography of immunoprecipitates from HT29 goblet cells metabolically labeled with [35S]methionine and [35S]cysteine or [3H]glucosamine, as a glycoprotein with an apparent molecular mass ranging from 23 to 37 kDa. Digestion of immunoprecipitates with N-glycosidase F reduced the apparent mass to 16 to 19 kDa. This small, highly-glycosylated protein was named "R-GRAMP" (for regulated granule-associated membrane protein) to reflect its wide distribution in secretory granule membranes of regulated exocrine, endocrine and granulocytic cell types. This distribution suggests that it may play a common functional role in regulated secretion.

Morphological aspects of endocrine cells in human fetal gastrointestinal mucosa. Microscopical, electronmicroscopical and immunohistochemical studies.

This paper describes the morphological features and distribution of endocrine cells in the human fetal gastrointestinal mucosa between the 8-9th and the 36th the weeks of gestation. We used techniques of argentic impregnation, techniques with chromogranine and neuron specific enolase, electronmicroscopical techniques and immunohistochemical techniques as well (PAP and ABC) with antibodies for G cells, EG cells, D cells, S cells CCK (I) cells and EC cells. The first argyrophilic and/or argentaffin cells appear in the fetal gut of 8-9 weeks old. We describe the appearance, distribution, morphology of the identified endocrine cells with immunohistochemical techniques and we discuss the possible morphofunctional interrelations between them, but also with the neighbouring structures like lymphoid tissue in ileum, colon and appendix in embryofetal period.

Immunocytochemical study of intestinal endocrine cells in germ-free mice.

Morphological and functional modifications have been described in the gastrointestinal tract of germ-free rodents in comparison to their conventional counterparts. These differences have been related to the absence of normal flora, but peptides and biogenic amines may also be involved. Enteroglucagon-, peptide YY-, somatostatin-, serotonin-, neurotensin-, chole-cystokinin-, and secretin-producing cells were studied by immunocytochemistry in the ileum, cecum and colon of 10 germ-free, 10 conventional and 5 conventionalized CFW adult male mice. In the cecum and colon of germfree mice, enteroglucagon- and peptide YY-positive cells appeared enlarged, were globular in shape and strongly immunostained. Enlarged and strongly immunostained serotonin- and neurotensin-positive cells were also seen in some germ-free mice. Somatostatin-positive cells and all the endocrine cells of the ileum were similar in the 3 groups, and no cholecystokinin- or secretin-positive cells were observed. Our results are consistent with higher enteroglucagon and peptide YY production in germ-free mice that may be related to the lower cellular renewal rates and slower gastrointestinal transit reported in these animals. Locally produced biogenic amines and peptides may be important factors in the mediation of the effect of the intestinal flora on gastrointestinal structure and function and germ-free mice seem to be a good model for the study of the mechanisms involved.

Immunocytochemical detection of endocrine cells in the gut of Viviparus ater (Mollusca, Gastropoda).

The presence of endocrine cells was investigated by immunocytochemical procedures in the gut and salivary gland of Viviparus ater, a freshwater prosobranch gastropod. The endocrine cells were scanty and both of closed and open cell type. Most of them were located in the esophagus (immunostaining with anti-gastrin, anti-insulin, anti-serotonin and anti-substance P antisera), very few in the stomach (immunoreactive only to anti-gastrin antibody) and in proximal part of the intestine (immunoreactive to anti-serotonin and anti-substance P antibodies). In the salivary glands, occasional endocrine cells scattered among the glandular cells in the adenomera stained with anti-neuropeptide Y, anti-pancreatic polypeptide and anti-somatostatin sera were detected.

Immunocytochemical and ultrastructural characterization of endocrine cells and nerves in the intestine of Rana temporaria.

Endocrine cells have been identified in the intestine of the frog Rana temporaria after application of the Grimelius and Masson-Fontana techniques. These endocrine cells were examined using immunocytochemical techniques on paraffin and semithin sections for light microscopy. After testing 19 antisera, 12 immunoreactivities were identified. Numerous serotonin-, somatostatin- and GLP-1-immunoreactive cells; a moderate number of PYY-, glucagon-, VIP-, gastrin/CCK-immunoreactive cells and few human PP-, bombesin-, substance P- and neurotensin-immunoreactive cells were found. VIP- and met-enkephalin were identified in nerve fibers of the muscular layer. Using semithin-thin sections five types of endocrine cells (serotonin-, somatostatin-, gastrin/CCK-, glucagon- and bombesin-immunoreactive cells) have been characterized according to their immunocytochemical reaction and the ultrastructure of the secretory granules.

The presence of immunoreactive vertebrate bioactive peptide substances in hemocytes of the freshwater snail Viviparus ater (Gastropoda, Prosobranchia).

1. Using an immunocytochemical procedure a wide range of immunoreactive vertebrate bioactive peptides (BAPs) has been found in hemocytes of Viviparus ater: bombesin, calcitonin, CCK-8, CCK-39, GH, glucagon, insulin, oxytocin, neurotensin, secretin, serotonin, somatostatin, substance P, vasopressin, and VIP. 2. No immunostaining was observed for antigastrin and antithyroglobulin antibodies. 3. The presence of BAP-like molecules in hemocytes suggests a correlation between hemocyte and APUD cells and is evidence of a relationship between the neuroendocrine and the immune systems.

Methionine-enkephalin immunoreactivity in Merkel cell dense-core granules of nude mice sinus hair. A post-embedding immunogold electron-microscopic study.

The ultra-immunocytochemical technique applied in the present study revealed the occurrence of methionine-enkephalin (met-enkephalin)-like substance in the dense-core granules of Merkel cells of nude mice sinus hair. Incubation of ultra-thin sections of sinus hair with met-enkephalin antisera conjugated with gold particles showed specific association of gold particles on the dense-core granules of the Merkel cells. Gold particles were heavily and specifically located on the dense-core granules as well as in the adjacent cytoplasm. Dense-core granules of degenerating Merkel cells also exhibit met-enkephalin immunoreactivity. The nerve terminals associated with the Merkel cell did not show met-enkephalin immunoreactivity. Therefore, it is concluded that a met-enkephalin-like substance is present and stored in nude mice Merkel cell dense-core granules and it might act as a neurotransmitter or neuromodulator which could be involved in the functioning of the cell. Non-osmicated tissue should be used to locate this substance because of the possibility of cross-linkage of the amino acid sequence with osmium tetroxide.

Co-occurrence of immunoreactive calcitonin and calcitonin gene-related peptide in neuroendocrine cells of rat lungs.

Neuroendocrine cells of the lung, occurring singly or in clusters known as neuroepithelial bodies, contain a variety of biologically active compounds, including several neuropeptides. We have investigated the localization of calcitonin and calcitonin gene-related peptide (CGRP) within single and grouped neuroendocrine cells in the respiratory epithelium of rats by an immunohistochemical double-staining technique which uses specific antisera raised in heterogeneous animal species. Calcitonin- and CGRP-immunoreactivities were nearly totally co-localized in both single neuroendocrine cells and neuroepithelial bodies. CGRP-immunoreactivity was also present in neurons in the jugular, nodose and dorsal root ganglia. The calcitonin-immunoreactivity in neuroendocrine cells, as in thyroid parafollicular (C) cells, was abolished by preincubation of the anti-calcitonin serum with synthetic calcitonin. The CGRP-immunoreactivity in neuroendocrine cells and in the neuronal cells was abolished by preincubation of anti-CGRP serum with synthetic CGRP. Thus, while the calcitonin gene is expressed exclusively or predominantly as either calcitonin or CGRP in all other tissues except thyroid C-cells, our results strongly suggest that both peptides are expressed in the rat bronchopulmonary neuroendocrine cells.

[Comparative analysis of monoamine producers in the major duodenal papilla and lungs of rabbits]. / Sravnitel'nyi analiz produtsentov monoaminov v ampule bol'shogo sosochka dvenadtsatiperstnoi kishki i v legkikh u krolikov.

By means of incubation of slices in 2% solution of glyoxylic, acid adrenergic nervous structures and endocrine cells (APUD cells) have been studied in the ampule wall of the duodenal large papilla and in the lungs in 6 mature male rabbits. Topographic proximity of APUD cells and adrenergic nervous fibers is noted. Contents of serotonin and catecholamines in the structures mentioned have been investigated microfluorometrically. Simultaneous revealing of producers of monoamines make possible to suppose that serotonin and catecholamines get paracrinically from the APUD cells into terminals of the adrenergic nervous fibers.