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)

A specific radioimmunoassay was used to measure immunoreactive dynorphin (ir-DYN) and beta-endorphin (ir-BE) in the brain, pituitary and gut, following a pharmacological manipulation of the serotonin system. Administration of the serotonin receptor agonist m-chlorophenylpiperazine (m-CPP, 2.5-5 mg/kg ip) or the serotonin releasing agent fenfluramine (20-40 mg/kg ip) induced a significant increase in the hypothalamic ir-BE content and a decrease in its anterior pituitary level. These effects were antagonized by cyproheptadine (1 mg/kg ip). Similar results were obtained after fluvoxamine (15 mg/kg ip), femoxetine (10 mg/kg ip) and 5-hydroxytryptophan (5-HTP 40-160 mg/kg ip). None of the above treatments altered significantly the ir-DYN content in the brain and pituitary. However, the gut ir-DYN level was dramatically decreased after m-CPP, fenfluramine, fluvoxamine, femoxetine and 5-HTP. The latter effect was antagonized by cyproheptadine. The obtained results suggest that serotonergic activation stimulates the release of beta-endorphin from the anterior pituitary and dynorphin from the gut, while the cerebral beta-endorphin system appears to be inhibited by activation of serotonin neurons.
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PMID:Serotonergic regulation of the brain and gut beta-endorphin and dynorphin content in the rat. 287 Apr 87

A large number of antisera mainly raised against mammalian hormones are tested immunocytochemically on the GEP-endocrine system of mouse and fish (Barbus conchonius). The endocrine pancreas of mouse and fish appeared to contain the same four endocrine cell types; insulin-, glucagon-, PP- and somatostatin-immunoreactive cells. In mouse about 13 GEP endocrine cell types are distinguished: 1. insulin-, 2. somatostatin-, 3. glucagon-, 4. PP-, 5. (entero)glucagon-/PP-like, 6. CCK-like, 7. substance P-, 8. neurotensin-, 9. VIP-, 10. gastrin-, 11. secretin-, 12. beta-endorphin-, 13. serotonin-immunoreactive cells. Based on this and a previous study at least 13 GEP endocrine cell types seems to be present in stomachless fish: 1-9 as described for mouse, 10. (entero)glucagon-like, 11. met-enkephalin, 12. VIP-like, 13. unspecific immunoreactive endocrine cells. Coexistence of glucagon and PP-like peptides is found in the gut and pancreas of mice and in the gut of B. conchonius. In mouse pancreas and fish gut, endocrine cells showing only PP- or glucagon-like immunoreactivity are found too. In mouse stomach some endocrine cells showing only PP-immunoreactivity are demonstrated. In the same region coexistence of C-t-gastrin- and FMRF-amide-immunoreactivity is found in endocrine cells. The importance of these phenomena are discussed. Enteric nerves immunoreactive with antisera raised against substance P and GRP are found in mouse, against somatostatin and met-enkephalin in both mouse and fish and against VIP in fish.
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PMID:Immunocytochemical identification and localization of peptide hormones in the gastro-entero-pancreatic (GEP) endocrine system of the mouse and a stomachless fish, Barbus conchonius. 287 13

In humans, plasma beta-endorphin levels rise during application of acute stressful stimuli (vertigo, cold pain, and transcutaneous electrical stimulation) that induce gut motor disturbances. Whereas it is possible that circulating beta-endorphin participates in the mediation of these central effects on gut motility, its role cannot be established solely on the basis of changes in plasma levels. Therefore, we designed the present study to investigate 1) the dose-related effects of intravenous synthetic human beta-endorphin and naloxone on gastrointestinal pressure activity in fed healthy individuals; and 2) the interactions of the opiate agonist and antagonist. Infusion of beta-endorphin increased pyloric phasic pressure activity (P less than 0.001) and induced intestinal bursts of rhythmic activity (P less than 0.05) which interrupted normal fed motility. These effects were dose related, with the pyloric dose-response profile being essentially linear. The effects in the proximal intestine were obtained with doses of beta-endorphin at 250 ng X kg-1 X min-1 or greater. In the antrum, there was an overall reduction in phasic pressure activity (P less than 0.02), which was predominantly an effect of the highest dose of beta-endorphin infused (2,500 ng X kg-1 X min-1). Naloxone by itself had no significant effect on fed upper gut motility. However, naloxone significantly inhibited the effect of the lower doses of beta-endorphin on the pylorus. In addition, naloxone significantly reduced the probability of beta-endorphin, triggering intestinal bursts of rhythmic activity. These data suggest that beta-endorphin may play a humoral role in the stimulation of fed pyloric contraction at physiological levels.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Dose-related effects of synthetic human beta-endorphin and naloxone on fed gastrointestinal motility. 294 39

It has been suggested that functional dyspepsia might arise from the effect of stress on upper gut motility in susceptible individuals. The aim of this study was to evaluate posticibal antral motility in the presence and absence of sustained experimental stress by means of a transcutaneous electrical nerve stimulator. Two groups of patients could be recognized from these studies: first, those with postcibal antral hypomotility that was not changed during stress; and second, patients with normal postcibal motility which was normally suppressed by stress. Experimental stress significantly increased skin conductance and plasma beta-endorphin levels. However, in these two groups, there were no differences in clinical presentation and personality traits or in autonomic and humoral variables either before or during stress. Stepwise discriminant analysis of the autonomic or humoral responses to stress was unable to predict the different postcibal antral motor responses among the subsets of patients with functional dyspepsia. These data suggest that there are two subtypes of antral motility in functional dyspepsia: disordered gastric function under basal conditions resulting in antral hypomotility, and normal basal antral motility and autonomic and gastric motor responses to stress. In the latter subgroup, the cause of symptoms is unclear, but it appears not to be a motility disorder.
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PMID:Gastric and autonomic responses to stress in functional dyspepsia. 294 8

Recent data on the immunolocalization of regulatory peptides and related propeptide sequences in endocrine cells and tumors of the gastrointestinal tract, pancreas, lung, thyroid, pituitary (ACTH and opioids), adrenals and paraganglia have been revised and discussed. Gastrin, xenopsin, cholecystokinin (CCK), somatostatin, motilin, secretin, GIP (gastric inhibitory polypeptide), neurotensin, glicentin/glucagon-37 and PYY (peptide tyrosine tyrosine) are the main products of gastrointestinal endocrine cells; glucagon, CRF (corticotropin releasing factor), somatostatin, PP (pancreatic polypeptide) and GRF (growth hormone releasing factor), in addition to insulin, are produced in pancreatic islet cells; bombesin-related peptides are the main markers of pulmonary endocrine cells; calcitonin and CGRP (calcitonin gene-related peptide) occur in thyroid and extrathyroid C cells; ACTH and endorphins in anterior and intermediate lobe pituitary cells, alpha-MSH and CLIP (corticotropin-like intermediate lobe peptide) in intermediate lobe cells; met- and leu-enkephalins and related peptides in adrenal medullary and paraganglionic cells as well as in some gut (enterochromaffin) cells; NPY (neuropeptide Y) in adrenaline-type adrenal medullary cells, etc.. Both tissue-appropriate and tissue-inappropriate regulatory peptides are produced by endocrine tumours, with inappropriate peptides mostly produced by malignant tumours.
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PMID:Endocrine cells producing regulatory peptides. 329 70

The distribution of FMRFamidelike peptides was studied in the nervous system of the lobster Homarus americanus by using immunocytochemical and radioimmunological techniques. By radioimmunoassay FMRFamidelike immunoreactivity (FLI) was found in low levels (ca. 1 pmol/mg protein) throughout the ventral nerve cord and in much higher amounts (60-100 pmol/mg protein) in the neurosecretory pericardial organs. Immunocytochemical studies showed FLI in approximately 300-350 cell bodies, and in distinct neuropil regions, neuronal fiber tracts, and varicose endings. Specificity of the immunostaining was tested by preabsorbing the antiserum with FMRFamide, with peptides having similar carboxyl termini to FMRFamide (Met-enkephalin-Arg-Phe, Phe-Met-Arg-Tyr-amide), with several amidated peptides (alpha-melanocyte-stimulating hormone, substance P, oxytocin), and with proctolin, a peptide found widely distributed in the lobster nervous system. Of these substances, only FMRFamide blocked the staining. In addition to the pericardial organs, significant levels of FLI were found in neurosecretory regions associated with thoracic second roots and in the connective tissue sheath that surrounds the ventral nerve cord. In all three regions, immunocytochemical studies showed the FLI to be localized to fine fibers and associated terminal varicosities lying close to the surface of the tissue, with no obvious target in their immediate vicinity. When examined at the ultrastructural level, the immunoreactive varicosities of the thoracic second roots and of the ventral nerve cord sheaths were found a few microns from the surface of the tissue and contained electron-dense granules. In the immunoreactive nerve cord sheath endings, in addition to the large, dense granules, small, clear vesicles were found. The appearance and location of these terminals suggest a neurohormonal role for FMRFamidelike peptides in lobsters. The observation that low levels of FLI are found in the hemolymph supports this suggestion. In addition, the localization of FLI to particular neuronal somata, fiber tracts, and neuropil regions suggests possible functional roles for these peptides in (1) integration of visual and olfactory information, (2) function of the anterior and posterior gut, and (3) the control of exoskeletal muscles.
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PMID:FMRFamidelike peptides of Homarus americanus: distribution, immunocytochemical mapping, and ultrastructural localization in terminal varicosities. 332 67

Neuromedin U is a newly described regulatory peptide, found by radioimmunoassay in significant concentrations in both the brain and gut of the rat. The aim of the present study was to localize this peptide immunoreactivity to discrete structures of the gut and brain and to map its distribution using immunocytochemistry. In the gut, neuromedin U was confined to nerve fibres mainly in the myenteric and submucous plexuses and the mucosa of all areas except stomach. Immunoreactive ganglion cells were seen in both ganglionated plexuses and their number did not increase following colchicine administration. This observation and the finding that the population of neuromedin U-immunoreactive nerves in the ileum was not affected by complete extrinsic denervation indicated that the nerves are mostly intrinsic in origin. Colocalization studies revealed neuromedin U and calcitonin gene-related peptide were present in the same myenteric and submucosal ganglion cells. Transection experiments showed that, like calcitonin gene-related peptide-immunoreactive nerves, fibres containing neuromedin U project for very short distances in both an oral and anal direction. At the electron microscopic level, neuromedin U immunoreactivity, demonstrated using the immunogold technique, was localized to large granular vesicles. In the central nervous system, neuromedin U immunoreactivity was localized to fibres which were widespread throughout the brain, except in the cerebellum. The presence of neuromedin U-immunoreactive cell bodies was restricted to the rostrocaudal part of the arcuate nucleus. Colocalization studies showed that a proportion of the neuromedin U-immunoreactive cell bodies in the arcuate nucleus also contained pro-opiomelanocortin. Neuromedin U-immunoreactive fibres were first detected in the rat intestinal mucosa at day 1 after birth. In the brain, the arcuate nucleus showed neuromedin U-immunoreactive neuronal cell bodies at E16 but not at E14. In conclusion, neuromedin U is a new member of the group of molecules known as brain-gut peptides.
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PMID:Occurrence and developmental pattern of neuromedin U-immunoreactive nerves in the gastrointestinal tract and brain of the rat. 340 30

Using the semi-thin/ultra-thin technique six different immunoreactive endocrine cell types are ultrastructurally identified in 0.5% glutaraldehyde fixed gut of B. conchonius. In addition two of them (gastrin- and PP-immunoreactive cells) are also characterized with the immunogold method, showing that the immunoreactivity is only restricted to the secretory granules. Size distribution histograms and the average diameters of 30% (d30) of the largest granules are given, showing a gradual increase in granule size from unspecific immunoreactive cells, (d30 = 110 nm) via gastrin- (119 nm), VIP-like- (127 nm), met-enkephalin- (143 nm) and PP- (174 nm) to glucagon-immunoreactive cells (178 nm). The presence of PP- and glucagon-immunoreactivity in the same cells and the consequence for their granule size is discussed. In the distal part of the gut endocrine cells are found showing no immunoreactivity with the antisera used; their granules (d30 = 144 nm) were, although not significantly, larger then those of VIP-like-immunoreactive cells, also found in that part of the gut. It is supposed that they represent substance P-immunoreactive cells. Unfortunately, secretory granules of several cell types showed about 20% more shrinkage in 0.5% glutaraldehyde fixed tissue, than in osmicated tissue.
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PMID:Ultrastructural characterization of 6 immunoreactive enteroendocrine cells in Barbus conchonius (Teleostei, Cyprinidae). 353 12

In cultured rat hepatocytes, the effects of gut hormones on bile acid uptake and release were studied. It was found that cultured hepatocytes continued to secrete bile acids into the culture medium and incorporated them effectively as a function of incubation time. Gut hormones such as secretin, glucagon, vasoactive intestinal polypeptide (VIP), peptide histidine isoleucine (PHI), gastric inhibitory polypeptide (GIP), tetragastrin, cholecystokinin-octapeptide (CCK-8), pancreatic polypeptide (PP), neurotensin substance P, beta-endorphin (beta-End), methionine-enkephalin (Met-enk), motilin, bombesin and somatostatin (SS) had no effect on bile acid uptake by cultured hepatocytes. In bile acid release studies, only secretin caused a dose-dependent stimulation of bile acid release, while other gut hormones had no effect on bile acid release into medium. These results indicate that secretin acts directly on cultured rat hepatocytes and/or bile canaliculi, besides its effect on the bile duct, and influences bile acid metabolism.
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PMID:Effects of gut hormones on bile acid uptake and release in cultured rat hepatocytes. 359 53

The endogenous opiate system is involved in the regulation of numerous bodily functions, but the literature suggests that the effects of endogenous opioids differ among species and between animals and man. Naltrexone, a relatively pure opiate antagonist, appears to have significant effects on the secretion of the gonadotropins (luteinizing hormone and follicle-stimulating hormone), adrenocorticotropin (ACTH), cortisol, and probably catecholamines. Naltrexone appears to have minor or no effects on prolactin, the pituitary-thyroid axis, growth hormone, insulin, glucagon, vasopressin, and the gut hormones. Naltrexone also seems to reduce food intake and cause weight loss in humans. The dosages of opiate antagonist and the presence of other variables play a major role in the responses seen in various studies.
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PMID:Endocrine and metabolic effects of opiate antagonists. 608 67


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