[Change in the blood serotonin level and reaction of the enterochromaffin system in gastrointestinal disorders in patients with recent myocardial infarct].
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Adult↗
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Results for “CHROMAFFIN SYSTEM”
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Ultrastructure of enterochromaffin cells and associated neural and vascular elements in the mouse duodenum.
Enterochromaffin cells of adult mouse duodenum were studied with light- and electron-microscopical techniques. They were distinguished from other enteroendocrine cells by their pleomorphic, electron-dense secretory granules in the basal cytoplasm. At the apices of enterochromaffin cells, tufts of short microvilli bordered the gut lumen. At their bases, irregular cytoplasmic extensions were either in contact with or passed through the basal lamina. The presence of cytoplasmic extensions in close proximity to fenestrated capillaries and subepithelial nerves suggested an endocrine or paracrine function. Electron micrographs of serial thin sections were used to reconstruct an enterochromaffin cell from the crypt epithelium in three dimensions and to determine its relationship with the underlying neural plexus. Although extensions from the serially sectioned and reconstructed cell and other enterochromaffin cells studied in crypt epithelia protruded through the basal lamina, no synaptic contacts were seen. Evidence of a synaptic contact between a neurite and another type of enteroendocrine cell (possibly an intestinal A cell), suggested a neurocrine role for some of the basally-granulated cells. Possible functions of enterochromaffin cells are discussed in the light of recent literature on the system of enteroendocrine cells, also known as APUD (amine precursor uptake and decarboxylation) cells and/or paraneurons.
Animals↗
The effects of gastroenteroanastomosis, antral exclusion and antral resection on the enterochromaffin cells in the rat gastrointestinal tract.
The effects of gastroenteroanastomosis, antral exclusion and antral resection on the enterochromaffin (argentaffin) cell system in the rat alimentary tract were studied 6 weeks after the operation. When measured as cell density per mm3 mucosa, the number of enterochromaffin cells was decreased in most gastrointestinal regions following the three surgical procedures. In the antral exclusion group this decrease was most apparent in the caecum and large intestine, and in the animals with antral resection it was most pronounced in the proximal and middle regions of the small intestine. When expressed per segment mucosa, the enterochromaffin cells were even more reduced in number in all three experimental groups, as a result of mucosal atrophy in the entire gastrointestinal tract. The atrophy was most pronounced in animals with gastroenteroanastomosis, and least pronounced in those with antral exclusion. The underlying mechanisms of the effects on the enterochromaffin cell system under these experimental conditions are discussed.
Animals↗
[Functional changes in the argentaffin cells of the stomach and electrical activity of the brain of the rat after injection of neurotensin into the hypothalamus and 3d ventricle of the brain].
Administration of neurotensin or its analogue into the hypothalamic structures altered the degree of activity synchronization among hypothalamic and brain-stem structures, the synchronization becoming most obvious among ventro-medial nucleus, amygdala and the central grey matter. Administration of the drugs into the 3rd ventricle and paraventricular nuclei suggested antagonistic effects of these peptides at the hypothalamic level. The data obtained could be regarded as local effects of the neuropeptides upon neurons of the paraventricular nucleus and as systemic effects upon argentaffin cells of the stomach antral portion.
Amygdala↗
Application of 31P NMR to model and biological membrane systems.
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Animals↗
[Changes in the enterochromaffin and pituitary-adrenal systems in the immediate postoperative period in children with nephroblastomas].
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Biogenic Amines↗
The paraganglia, a persisting endocrine system in man.
The paraganglia have been traced in surgical samples of para-aortic and pelvic retroperitoneal tissues using the formal-dehyde-induced fluorescence method for catecholamines. Clusters of catecholamine-storing cells were found in all (12) patients studied. Microspectrofluorometric recordings showed high amounts of catecholamine in the well-vascularized cell groups. A large proportion of the paraganglia, which are most prominent during the fetal period, also persist during postnatal life.
Adult↗
The enterochromaffin cells in the mouse gastrointestinal tract after streptozotocin treatment.
Effects of 5 weeks streptozotocin treatment on the mouse gastrointestinal tract were studied with special emphasis on enterochromaffin (EC) cells. In the streptozotocin-treated animals the frequency of EC cells was reduced in the antral area and in the small intestine, but increased in the colon. The length of the intestinal tract and the mucosal thickness were increased in these animals. Possible mechanisms underlying these abnormalities of the EC cell system are discussed.
Animals↗
[pH changes in the matrix of serotonin organelles of stimulated thrombocytes].
The changes of pH gradient on serotonin organelle membranes can be observed using the fluorescent marker acridine orange. This gradient decreases with thrombin activation of the blood plates. The fall of delta pH can be induced by ammonium salts which also influence the ADP-induced cellular aggregation. NH4 ions added simultaneously with low doses of ADP potentiate cellular aggregation, and added after ADP-induced interaction of cells lead to another wave of intercellular contacts inhibited by mepacrin. Fluorescent acridin aminoderivatives can be used both for kinetic observations of delta pH on the serotonin organelle membranes of native platelets and for studying the interaction of the systems responsible for maintaining this gradient with the systems of prostaglandin and adenine nucleotide metabolism.
Adenosine Diphosphate↗
[On the possibility to demonstrate the presence of catecholamines in enterochromaffin cells: critical review (author's transl)].
Various data contributing to support, after Lillie et al., the presence of catecholamines instead of (or in addition to) 5-hydroxytryptamine in the enterochromaffin cells, are submitted to analytical criticism by the Author. Topics of the discussion are mainly the behaviour of the diazo-reaction (in acid medium), the fluorescence induced by formaldehyde, and various reactions carried out either directly or following a chemical block. The Author demonstrates that 5-HT is present in the enterochromaffin cells and that it is impossible, at present time, to prove the presence of catecholamines in these cells on the basis of histochemical data. The Author debates also how biochemical or pharmacological tests may supply the lacking of histochemical proofs in demonstrating the presence of catecholamines; it is possible by applying these procedures to study situations like those postulated by Lillie et al., extending a comparative research also to other elements of the enterochromaffin cell system after ERSPAMER; the examples here reported however do not agree perfectly in some of the cases with these views.
Animals↗
Characterization of the monoamine uptake system in catecholamine storage vesicles isolated from a pheochromocytoma taken from a child.
The catecholamine storage vesicles of a pheochromocytoma taken from a child have been isolated and characterized. The tumor contained almost exclusively noradrenaline and a large proportion of this amine was vesicle-bound. The noradrenaline-containing vesicles showed great resemblance to bovine chromaffin granules. Their catecholamine and dopamine beta-hydroxylase contents were that of chromaffin granules; their morphology and density were similar to those of the subpopulation of these granules that contain noradrenaline. The pheochromocytoma vesicles contained in their membranes an abundant polypeptide of mol. wt 110,000, which was not apparent in bovine adrenal medulla vesicle membranes. Monoamine uptake by pheochromocytoma noradrenaline vesicles did not differ significantly from that observed in bovine chromaffin granules. The time-course, plateau level and KM for noradrenaline were similar for both types of organelles. Both had an oligomycin-resistant ATPase with similar properties. Investigations using the tetrabenazine derivative [2-3H]dihydrotetrabenazine (2-hydroxy-3-isobutyl-9,10-dimethoxy-1,2,3,4,6, 7-hexahydro-11b-H-benzo[a]quinolizine), which binds specially to the bovine chromaffin granule monoamine carrier indicated that granule membranes from the tumor have a 10-fold increased number of [2-3H]dihydrotetrabenazine binding sites, with no change in dissociation constant. As in the case of bovine chromaffin granules, [2-3H]dihydrotetrabenazine can be totally displaced by noradrenaline and serotonin. To account for the discrepancy observed between the uptake data (which indicated no difference with bovine chromaffin granules) and the [2-3H]dihydrotetrabenazine binding studies (which showed a large excess of binding sites in the tumor membranes), we propose that granules in the investigated tumor contained a large amount of inactive monoamine carrier.
Adenosine Triphosphate↗
[Endocrine apparatus of human gastric mucosa].
Endocrine cells of the gastric fundal and pyloric mucosa in patients suffering from gastric and duodenal ulcers with different gastric juice acidity, were studied. At hyperacid ulcers, the number of argyrhilic endocrine cells of gastric fundus was increased to 218 +/- 21.1 as compared with the normal acidity 164 +/- 14.8, while it was decreased to 97 +/- 15.1 as compared with hypoacidity. Argentaffinic cells were found in patients with hypo- and unacid gastric juice only. The electron microscopy revealed six types of endocrine cells (A-like, ECL, G, D, D1, EC). The ultrastructural changes of A-like, ECL, and G cells in patients with hyperacid gastric juice indicated their high functional activity. A balance seems to exist between activating and inhibiting systems of the endocrine apparatus of gastric mucosa which accounts for the hyperacidity of the gastric juice.
Cell Count↗
[Effect of the acetyl derivatives of 4,5,6,7-tetrahydroindole on the enterochromaffin cells and mediator metabolism of the rat brain].
It was reported previously that the analogues of dimecabin (1,2-dimethyl-3-carbethoxy-5-oxyindole),2-methyl-3-carbethoxy-5-oxyindole and the derivatives of 2-methyl-3-carbethoxy-4, 5, 6, 7-tetrahydroindole substituted in the 1st position reduce the content of argentaffinic substance in enterochromaffin cells (EC) for a long period of time. It has been shown that "recognizability" of the acetyl derivatives of 4, 5, 6, 7-tetrahydroindole by the EC receptor systems is preserved. Administration of the acetyl derivatives into the stomach (10 mg/kg for 5 days) induce a prolonged decrease in the argentaffin substance content in EC, and augment the noradrenaline level without exerting a pronounced effect on the dopamine content. These substances also inhibit monoamine oxidase and acetylcholinesterase activity in the rat brain. Detection in EC of the biologically active substances common to the APUD-system and the brain suggests a new trend in the study into the action mode of indole compounds.
Animals↗
Transplantation of monoamine-producing cell systems in oculo and intracranially: experiments in search of a treatment for Parkinson's Disease.
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Adrenal Medulla↗
New technologies in exocytosis and ion movement.
Evolving new technologies for the study of exocytosis have been successfully exploited for the analysis of secretory events in the well-characterized chromaffin cell system. These technologies include amperometry, fluorescence resonance energy transfer (FRET), confocal and total internal reflection fluorescence (TIRF), and organelle-targeted aequorins.
Animals↗
Melatonin and enterochromaffine cells.
As a result of investigations active biosynthesis of melatonin was found in enterochromaffin cells of gastrointestinal tract. It is suggested to unify epiphysis and enterochromaffine cells into a united functionally active neuroendocrine system, which plays an important role in the control of rhythms of biological processes in the body.
Animals↗
Expression of neurofilament subunits in neurons of the central and peripheral nervous system: an immunohistochemical study with monoclonal antibodies.
The extent to which all neurofilament (NF) subunits (NF68, NF150, NF200) are expressed by different populations of mature CNS and PNS neurons is controversial. We addressed this issue in immunohistochemical studies of mature bovine tissues using monoclonal antibodies specific for each bovine NF subunit. All three NF subunits were detected in the perikarya and neurites of both CNS and PNS neurons; they were seen in nearly all PNS neuronal perikarya, and in all identifiable CNS and PNS axons. Most, but not all, CNS neuronal perikarya contained each of these NF antigens. CNS neurons devoid of immunodetectable NF antigens were generally small. The presence of low levels of NF antigens in neurons with scant perikaryal cytoplasm may account for the apparent absence of NF immunoreactivity in some classes of neurons, although other explanations, such as microheterogeneity among NF proteins, could account for this finding. NF antigens were also seen in some cells of the diffuse neuroendocrine system (adrenal chromaffin cells and cells of the pars distalis and pars intermedia), but not in other cell types. We suggest that the expression of all three NF subunits is a common feature of CNS and PNS neurons and their processes, and of some cells of the diffuse neuroendocrine system. These findings have implications for hypotheses concerning the structure and function of the intermediate filaments of neurons, and for hypotheses concerning neurodegenerative diseases involving NF proteins.
Animals↗
Human adrenal cells express tumor necrosis factor-alpha messenger ribonucleic acid: evidence for paracrine control of adrenal function.
Tumor necrosis factor (TNF) is gaining increasing importance in clinical medicine. It plays a role in the interaction of the immune system with the hypothalamic-pituitary-adrenal axis. In the present study various morphological methods, including immunohistochemistry, electron microscopy, and in situ hybridization were applied to characterize the localization and distribution of TNF in the human adrenal gland. Double immunostaining revealed an astonishing degree of intermingling of steroid-producing cells and chromaffin cells. Macrophages could be found in all regions of the adrenal gland, but particularly in the transition zone of cortex and medulla. The steroid-producing cells of the inner zone of the cortex express major histocompatibility complex class II molecules. On the ultrastructural level, immune cells, steroid cells, and catecholamine-producing cells were found in direct contact. The combination of immunohistochemistry and in situ hybridization was optimally suited to define the exact cellular source of TNF in the human adrenal. TNF is produced in macrophages, but above all in 17 alpha-hydroxylase-positive cells (steroid-producing cells) in the zona reticularis and medulla. No signal was found in chromaffin cells. TNF may induce major histocompatibility complex class II in human adrenal gland in a paracrine or autocrine manner. It is concluded that TNF may have an important role in normal human adrenal physiology.
Adrenal Cortex↗