Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have examined the presence of 5-hydroxytryptamine (serotonin; 5-HT) in the intermediate lobe of the frog pituitary and investigated the effect of exogenous 5-HT on alpha-melanocyte-stimulating hormone (alpha-MSH) release from the perifused neurointermediate lobe (NIL). Using a specific antiserum against 5-HT, the indirect immunofluorescence technique revealed the presence of 5-HT-like immunoreactivity (5-HT-LI) in discrete cells, generally gathered in small clusters among parenchymal cells, and in numerous neurites surrounding melanotrophic cells. At the electron microscopic level, using a silver-gold intensification procedure, 5-HT-LI was localized in dense-core secretory vesicles within specific pituitary cells which appear to be different from pituitary melanotrophs. Dense accumulation of gold particles was also observed in nerve fibres running between parenchymal cells. A combination of high-performance liquid chromatography analysis and electrochemical detection showed the presence of both 5-HT and its metabolite 5-hydroxyindol acetic acid (5-HIAA) in frog NIL extracts (534 +/- 40 and 1245 +/- 65 (S.E.M.) pg/mg wet tissue respectively). Administration of graded doses of 5-HT (from 1 to 30 mumol/l) to perifused frog NIL induced a dose-dependent inhibition of alpha-MSH release. Repeated pulses of 5-HT (10 mumol/l each) induced a reproducible inhibition of alpha-MSH without any desensitization phenomena. The inhibitory effect of 5-HT was partially blocked by the serotonergic antagonists methysergide and ICS-205-930 (10 mumol/l each). Concomitant administration of methysergide and ICS-205-930 (10 mumol/l each) totally abolished 5-HT-evoked inhibition of alpha-MSH. Fenfluramine, a releaser of 5-HT, induced a slight but significant reduction of alpha-MSH secretion. While 5-HT caused a marked inhibition of alpha-MSH release from intact NIL, 5-HT was devoid of effect on acutely dispersed pars intermedia cells suggesting that 5-HT does not exert a direct action on pituitary melanotrophs. We have examined the effect of specific dopaminergic, GABAergic and alpha-adrenergic antagonists on 5-HT-induced alpha-MSH inhibition. We observed that sulpiride and SR 95531 (10 mumol/l each) did not affect the response of NIL to 5-HT while yohimbine (10 mumol/l) suppressed the inhibitory action of 5-HT. Taken together, our results indicate that discrete cells of the frog pars intermedia contain the neurotransmitter 5-HT which may act locally to inhibit alpha-MSH release.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Effect of serotonin on alpha-melanocyte-stimulating hormone secretion from perifused frog neurointermediate lobe: evidence for the presence of serotonin-containing cells in the frog pars intermedia. 254 46

Because so-called 'carcinoid' tumour of the breast has proven to be a difficult entity to define, we studied in-situ carcinoma as there were reasons to believe that this might help clarify the complex problems involved. We studied a consecutive series of 30 cases of ductal carcinoma in-situ (DCIS) by light microscopy and silver impregnation methods and identified a relatively common endocrine variant of DCIS. This variant was studied by immunocytochemical and ultrastructural methods, using conventional DCIS as a control. Endocrine DCIS is identified by its organoid pattern, stromal 'inclusions', festooned structure and a distinctive type of polypoid invagination. It is argyrophilic and rich in neuron-specific enolase. Ultrastructurally it contains abundant dense core granules which are impregnated selectively by Grimelius' method. This tumour type frequently contains peptide hormones of the ACTH family. Three of seven cases contained cells reactive for ACTH and corticotropin-like intermediate lobe peptide CLIP or their precursor, pro-opiomelanocortin. A fourth tumour contained neurotensin, recently identified in a variety of endocrine tumours. Argyrophil invasive carcinomas are a much more heterogeneous group of tumours than argyrophil DCIS and only a minority have an endocrine structure comparable to that described here.
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PMID:A morphological and immunocytochemical study of a distinctive variant of ductal carcinoma in-situ of the breast. 1789 2

A recently developed immunocytochemical double-staining method for ultrathin Epon and Lowicryl K4M sections has been adopted for use on ultrathin cryosections. The essential features of the method include: staining for the first antigen by the indirect method using sufficient concentrations of second antibodies conjugated to colloidal gold particles to saturate available epitopes on the primary antibodies; supporting the cryosections by methyl cellulose followed by paraformaldehyde vapour treatment (30-60 min at 80 degrees C); removal of the methyl cellulose followed by staining for the second antigen using primary antiserum from the same species and another size class of colloidal gold particles conjugated to second antibodies. Contaminating staining does not occur if the paraformaldehyde vapour treatment exceeds 30 min, as this treatment destroys the combining sites on the second antibodies applied in the first staining cycle. Successful double-staining was documented using primary rabbit antibodies to growth hormone and corticotropin and anti-rabbit IgG conjugated to 5 and 15 nm colloidal gold particles. Following double-staining, the ultrathin cryosections may be silver-enhanced to improve detectability of the markers at low magnification.
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PMID:Simultaneous demonstration of two antigens in ultrathin cryosections by a novel application of an immunogold staining method using primary antibodies from the same species. 282 Sep 8

Immunocytochemical studies have shown that adrenalectomy produces changes in the content and distribution of [arginine-8]vasopressin (AVP) immunoreactivity in the paraventricular nucleus of the hypothalamus. The purpose of this study was to determine whether manipulation of adrenal hormones affects the levels of AVP mRNA. In situ hybridization assays with highly specific synthetic oligodeoxyribonucleotide probes and immunocytochemistry were used to detect the distribution of AVP mRNA and AVP-immunoreactive perikarya. AVP mRNA is codistributed with AVP immunoreactivity in the posterior magnocellular subdivision of the paraventricular nucleus and its accessory nuclei, the supraoptic nucleus and the suprachiasmatic nucleus. In adrenalectomized rats, the density and distribution of the hybridization signal were increased in the paraventricular nucleus; a 2-fold increase in the area comprising the signal was observed. At the cellular level, silver grains were detected in corticotropin-releasing-factor-immunoreactive neurons throughout the medial parvocellular subdivision of the paraventricular nucleus. No changes were seen in the distribution of AVP mRNA in the supraoptic or suprachiasmatic nuclei. Treatment with dexamethasone prevented the increase in AVP mRNA produced by adrenalectomy. In contrast, adrenalectomy did not alter the hybridization signal obtained with a probe for alpha-tubulin mRNA. These results suggest, at the cellular level, that adrenalectomy induces a glucocorticoid-sensitive stimulation of AVP mRNA synthesis in the central nervous system. Thus, considerable plasticity in gene expression is retained in the hypothalamus of the adult rat.
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PMID:Glucocorticoid sensitivity of vasopressin mRNA levels in the paraventricular nucleus of the rat. 345 67

Neuroendocrine (NE) neoplasms range from well to poorly differentiated types. These neoplasms usually contain neurosecretory (NS) granules demonstrated by either transmission electron microscopy (TEM) or silver reduction methods. By using the uranaffin reaction, one can differentiate NSG from other membrane-bound organelles. Recently, a variety of antibodies reactive against specific peptides or neurotransmitter substances have been advocated as being diagnostically useful. Using the peroxidase-anti-peroxidase (PAP) or Avidin-Biotin technics, we studied 41 NE neoplasms using anti-sera specific for neurospecific enolase (NSE), bombesin, adrenocorticotropic hormone (ACTH), calcitonin, and serotonin. All cases were shown to contain NS granules with a positive uranaffin reaction. In all 25 well-differentiated cases, at least one anti-serum gave a positive reaction. NSE was positive in 22 of the 25. In the poorly differentiated group, 7 (43.2%) of 16 were negative for all anti-sera tested. In these negative cases TEM using the uranaffin reaction remains an important diagnostic test.
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PMID:Comparison of the usefulness of histochemistry and ultrastructural cytochemistry in the identification of neuroendocrine neoplasms. 375 79

A nonrepetitive complementary RNA probe specific for an intervening sequence of the rat pro-opiomelanocortin (POMC) gene primary transcript was used to analyze the hormonal regulation of POMC gene transcription in individual cell nuclei in the rat pituitary by in situ hybridization. This probe recognized only full-length POMC heterogeneous nuclear RNA, as verified by Northern blots of pituitary RNA. When pituitary sections were hybridized with this 3H-labeled POMC intron A probe, silver grains were predominantly localized over the nuclei of cells that expressed POMC in the anterior and intermediate lobes. Adrenalectomy increased both the average grain density over corticotroph nuclei and the number of cells in the anterior pituitary with significant numbers of silver grains over their nucleus. Dexamethasone administration to intact or adrenalectomized rats results in the rapid (within 30 minutes) disappearance of silver grains over the nuclei of corticotrophs in the anterior lobe, suggesting that POMC gene transcription had been inhibited. However, adrenalectomy or dexamethasone administration did not alter the silver grain density over nuclei of intermediate lobe melanotrophs. Thus, this in situ hybridization assay utilizing an intervening sequence-specific POMC probe can measure rapid physiological changes in POMC heterogeneous nuclear RNA in individual cell nuclei.
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PMID:Regulation of pro-opiomelanocortin gene transcription in individual cell nuclei. 377 85

A morphologic, histochemical, and immunocytochemical study of 20 cases of pure gastrointestinal carcinoids, adenocarcinomas, and mixed neoplasms composed of both elements, so-called composite carcinoma-carcinoid tumors (CCC), was undertaken in order to correlate the morphologic patterns with the immunocytochemical localization of carcinoembryonic antigen (CEA), serotonin, and a battery of polypeptide hormones (calcitonin, glucagon, insulin, gastrin, somatostatin, and adrenocorticotropin [ACTH]). Paraffin sections from five pure carcinoids, seven pure adenocarcinomas, and eight CCC from the stomach, small bowel, appendix, and colon were studied with mucicarmine, silver impregnation stains, and a peroxidase-anti-peroxidase technic. Of the eight CCC, all were mucin positive, four were argyrophilic, and three were argentaffin positive. CEA was present in all eight, serotonin in seven, and calcitonin in one. No other neurohormonal peptides were demonstrated. The distribution of serotonin and CEA generally corresponded to the morphologic pattern, but discordance was observed in two cases, i.e., serotonin was not always localized to areas of carcinoid and CEA not always confined to areas of carcinoma. All five pure carcinoids demonstrated intracytoplasmic localization of serotonin, whereas none contained intracytoplasmic CEA. In two cases, CEA was present within acinar lumens only. The seven colonic adenocarcinomas were argyrophil and argentaffin negative. All contained CEA within the cytoplasm and in gland lumens. None contained serotonin. None of the neurohormonal peptides was localized in either pure adenocarcinomas or carcinoids. This study reveals that among gastrointestinal neoplasms displaying morphologic patterns of adenocarcinoma and carcinoid, immunocytochemical localization of CEA and serotonin confirms their bidirectional differentiation and justifies the designation "composite carcinoma-carcinoid."
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PMID:Composite carcinoma-carcinoid tumors of the gastrointestinal tract. A morphologic, histochemical, and immunocytochemical study. 389 86

Fourteen of fifty-three cases of endometrial carcinoma (26 per cent) contained varying, usually small numbers of argyrophil cells, as demonstrated by Grimelius silver nitrate staining of formalin-fixed paraffin-embedded sections. In eight cases the argyrophilia was present in the apical region of glandular cells (type 1 cells) or throughout the cytoplasm of glandular or squamous cells (type 2 cells). The distribution of argyrophilia in these cells closely paralleled that of mucin or glycogen, and pretreatment of the sections with disease resulted in a loss of argyrophilia in the glycogen-rich tumors. In six cases individual round, ovoid, and flask-shaped argyrophilic cells were present also within the glandular epithelium (type 3 cells). In all six cases, similarly distributed cells were positive immunohistochemically for serotonin. Immunohistochemical staining for a battery of polypeptide hormones (calcitonin, gastrin, somatostatin, adrenocorticotropin [ACTH], and neurotensin) revealed positive staining for ACTH in one of the six tumors that contained type 3 cells and positive staining for somatostatin in another. Ultrastructural examination of the ACTH- and serotonin-positive tumor disclosed cells with granules 80 nm in diameter. Types 1 and 2 argyrophil cells were found in small numbers in several specimens of normal proliferative and secretory endometrium, but type 3 argyrophil cells were not identified in these specimens. Although focal argyrophilia is a frequent feature of endometrial carcinomas (26 per cent), the presence of type 3 argyrophil cells containing hormones, as evidenced by the immunohistochemical demonstration of serotonin and occasionally polypeptide hormones, is much less common (11 per cent).
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PMID:Endometrial carcinoma with argyrophil cells: a histochemical and immunohistochemical analysis. 614 92

A series of 25 apudomas of the gastrointestinal tract (22 cases), bronchus (2 cases), and thymus (1 case) were subjected to staining with silver impregnation (Masson-Fontana and Grimelius) techniques and with the commercial immunoperoxidase kits for the peptide hormones adrenocorticotropin, calcitonin, gastrin, glucagon, growth hormone, human chorionic gonadotropin (hCG), insulin, somatostatin, and vasoactive intestinal peptide. Of the tumors studied, 16 were regarded as malignant, and 5 of the patients showed clinical symptoms due to inappropriate hormone secretion. A total of 16 tumors contained cells positive for 1 or more (6 were multihormonal) of the hormones studied. One bronchial carcinoid stained for hCG, which has not been previously reported. In addition, one of the rectal carcinoids contained somatostatin-positive cells, only once described previously. The thymic tumor proved frankly malignant, most probably identical to the oat-cell carcinoma recently described. The findings also substantiate the recent suggestion that gastrointestinal carcinoids cannot be adequately classified on the basis of silver stains only and strongly advocate the use of the immunoperoxidase kits in routine assessments of all the endocrinologically active tumors, whatever their localization might be.
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PMID:Stainability of the peptide hormones in gastrointestinal apudomas as demonstrated by immunoperoxidase kits. 614 78

A total of 87 surgical cases of gastric carcinoma including 3 carcinoid tumors were investigated with the methods of silver reaction and immunoperoxidase stain for 8 different brain-gut hormones. Argyrophil (AP) cells were demonstrated in 38 cases (44%), argentaffin (AF) cells in 18 (21%) and endocrine cells in 13 (14%). The occurrence of endocrine cells had no relation with histological types. Glicentin cells were demonstrated in 10 cases, somatostatin in 7, motilin in 3, beta-endorphin in 2 and gastrin in one. Endocrine cells appeared generally in small numbers except one carcinoid tumor which had numerous somatostatin cells. No single cell positive for more than two kinds of hormones could be demonstrated. Two undifferentiated carcinomas looking like carcinoid tumors had argyrophil cells and endocrine cells of either somatostatin or beta-endorphin. These results suggest that carcinoid-like carcinoma or endocrine cell carcinoma may lie on the intermediate state between carcinoma and carcinoid tumor.
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PMID:Immunohistochemical localization of brain-gut hormones in gastric carcinoma with relation to argyrophil cells. 614 33


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