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)

Cardiac atrial muscle cells produce a polypeptide hormone that plays a role in the control of water and electrolyte balance and blood pressure. The circulating form of this hormone is the atrial natriuretic peptide (ANP), which contains 28 amino acids. Various immunohistochemical studies have shown that ANP is present in many areas of the central nervous system, including the median eminence. In our studies, we investigated the effect of ANP in a superfused rat pituitary cell system. When ANP was administered at increasing concentrations (0.01 microM to 1 microM), it caused a significant dose-related stimulation of the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). The lowest effective dose of ANP in our system was 0.03 microM. When ANP and LH-releasing hormone were administered together, the response was prolonged and had the characteristics of ANP-stimulated LH and FSH release. In contrast with some previous reports, ANP in high concentration (1 microM) consistently induced a small but significant stimulation of the release of corticotropin. ANP did not influence the basal release of prolactin, growth hormone, and thyrotropin.
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PMID:Effect of atrial natriuretic peptide on gonadotropin release in superfused rat pituitary cells. 301 Feb 98

Ten polypeptides that stimulated the release of corticotropin from superfused rat pituitary cells and that are structurally related to porcine corticotropin-releasing factor were isolated from porcine hypothalami. The purification was carried out by gel filtration followed by reversed-phase HPLC using trifluoroacetic acid or heptafluorobutyric acid as the ion-pairing agent in water/acetonitrile solvent systems. The purified peptides were homogeneous by chromatography and by sequence analysis. One major polypeptide was characterized. Its structure is -H-Ser-Glu-Glu-Pro-Pro-Ile-Ser-Leu-Asp-Leu-Thr-Phe-His-Leu-Leu-Arg-Gl u-Val -Leu-Glu-Met-Ala-Arg-Ala-Glu-Gln-Leu-Ala-Gln-Gln-Ala-His-Ser-Asn-Arg-Lys -Leu-Met-Glu-Asn-Phe-NH2 [Patthy, M., Horvath, J., Mason-Garcia, M., Szoke, B., Schlesinger, D. H. & Schally, A. V. (1985) Proc. Natl. Acad. Sci. USA 82, 8762-8766]. This 41-amino acid sequence is thought to represent porcine corticotropin-releasing factor. Based on automated gas-phase sequencing of the intact and CNBr-cleaved peptides, amino acid analysis, and carboxypeptidase Y digestion, the other nine polypeptides were found to be structurally similar to this 41-amino acid sequence. Modifications of this structure include deamidation of glutamine at position 26 or 29, oxidation of methionine at positions 21 and/or 38, a blocked N terminus, and deletion of phenylalanine amide at the C terminus. Eight of these nine modified peptides retained significant corticotropin-releasing factor activity as shown by the stimulation of corticotropin release from superfused rat and pig pituitary cells. Some of these peptides may be present in pig hypothalami, while the others could have been produced during the isolation.
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PMID:Purification and characterization of peptides with corticotropin-releasing factor activity from porcine hypothalami. 301 Mar 25

We present a study of the cleavage specificity of IRCM-serine protease 1 from frozen porcine pituitary neurointermediate lobes using polypeptide substrates representing different segments of human pro-opiomelanocortin. Using 125I-labeled ACTH(11-24) and a 125I-labeled model beta-lipotropin (beta-LPH) peptide, the preference of this protease for cleavage C-terminal to the pairs of basic residues Lys-Arg and Lys-Lys was clearly seen. This study was extended to larger unlabeled natural human polypeptides including ACTH(1-39), beta-LPH(1-89), and the N-terminal glycopeptide (1-76), which are known to serve as substrates for further cleavage in vivo. In these substrates IRCM-serine protease 1 cleaved C-terminal to all pairs of basic residues known to be cleaved in vivo. In addition, the enzyme cleaved between two pairs of basic amino acids found in NT(1-76) which are also known to be cleaved in vivo. Many potential "tryptic-like" cleavage sites were not cleaved by the enzyme. However, IRCM-serine protease 1 cleaved C-terminal to Phe-Arg in the three melanocyte-stimulating hormone sequences of pro-opiomelanocortin. In order to better understand the physiological role of IRCM-serine protease 1, differential centrifugation was used to study the subcellular distribution of the enzyme from porcine pituitary anterior lobe homogenates. We present evidence that the active enzyme form, isolated from the subcellular fractions, possesses a similar molecular architecture as the enzyme isolated from frozen tissue (Mr 38,000 catalytic domain linked via disulfide bridge(s) to another polypeptide chain(s) to form an Mr 88,000 monomeric structure). The majority of IRCM-serine protease activity is found to be associated with small vesicles (150,000 X g for 5 h) of as yet undetermined nature. In addition, a latent activity was found to be associated with a 27,000 X g (15 min) pellet containing the majority of mature secretory granules. If IRCM-serine protease 1 participates in prohormone maturation in vivo, we propose a model in which this protease is present in an enzymatically active form in small vesicles, possibly within clathrin-coated structures (prosecretory granules) which are then transformed to mature secretory granules by a process which would also inactivate most of the enzyme.
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PMID:Selective cleavage of human ACTH, beta-lipotropin, and the N-terminal glycopeptide at pairs of basic residues by IRCM-serine protease 1. Subcellular localization in small and large vesicles. 301 45

The possible production of the opioid polypeptide beta-endorphin (beta-EP) was investigated in paraffin-embedded tissue from 17 ovarian tumors with the use of a specific anti-beta-EP antibody and the avidin-biotin-peroxidase staining technique. Only sex cord-stromal tumors (ten cases) showed positive staining. Strong beta-EP immunoreactivity was present in Leydig's cells of Sertoli-Leydig cell tumors; weaker sporadic staining was present in cells of granulosa cell tumors, and faint staining was present in occasional, luteinized theca cells of fibrothecomata. These findings suggest that cells with the sex cord-stromal phenotype that are capable of steroid production can also produce beta-EP. The latter may be a component of the "functional" status associated with some ovarian sex cord-stromal tumors and may serve as a helpful marker in distinguishing this type of tumors from germ cell or epithelial neoplasms.
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PMID:Immunoreactive beta-endorphin in ovarian sex cord-stromal tumors. 303 26

The present study was performed mainly to determine whether interleukin-1 (IL-1), a polypeptide produced by immunologically activated monocytes, plays a physiological role in the regulation of adrenocorticotropic hormone (ACTH) using primary monolayer cultures of rat anterior pituitary cells. Neither human IL-1 alpha nor IL-1 beta stimulated the ACTH release from normal pituitary cells in concentrations ranging from 0.01 to 10 nM. IL-1 beta caused a slight, but significant, increase in ACTH release at a concentration of 100 nM, while IL-1 alpha did not, even at the highest dose tested. IL-1 beta exhibited a synergistic action with corticotropin-releasing factor (CRF) in ACTH secretion at 10 and 100 nM of CRF, but the interaction was not striking. Both of the monokines failed to cause any change in the secretions of growth hormone, prolactin, follicle-stimulating hormone and luteinizing hormone throughout concentrations ranging from 0.01 to 100 nM. The effects of possible sex-related differences and prolonged preincubation of cultured pituitary cells in serum-free medium prior to assay incubation were also tested, providing no significantly different findings. These results suggest that the physiological significance of IL-1 as a tissue CRF is indeed questionable and should be further clarified.
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PMID:Effects of interleukin-1 on hormone release from normal rat pituitary cells in primary culture. 303 7

Opioid peptides have been demonstrated to stimulate prolactin secretion, and it has been postulated that this is mediated, at least in part, by an effect on hypothalamic prolactin releasing and release-inhibiting factors and neurotransmitters. The aim of this study was to investigate the effect of opioid peptides and depolarizing concentrations of K+ on the release of both vasoactive intestinal polypeptide (VIP) and thyrotropin releasing hormone (TRH) from perifused rat hypothalami. Both met-enkephalin and beta-endorphin stimulated the release of VIP significantly whilst not affecting the release of TRH. In addition, leu-enkephalin was found to have no effect on the release of either VIP or TRH. In contrast, depolarizing concentrations of K+ (50 mM) were found to cause the immediate release of TRH, but not VIP, from the same perifusion. The results suggest a role for VIP, but not TRH, in opioid peptide stimulated release of prolactin. In addition, the data indicates that a substance may be released in response to K+ depolarization which is inhibitory to the release of VIP.
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PMID:Effect of opioid peptides and potassium on the release of vasoactive intestinal polypeptide and thyrotropin releasing hormone from perifused rat hypothalami. 310 70

The pathophysiology of Hirschsprung's disease has not been fully elucidated but is known to have a neurogenic basis. In recent years, new neural proteins and peptides have been discovered and our aim in this study was to use immunocytochemistry to investigate their involvement in the neuronal abnormalities associated with this condition. Large bowel samples from 9 children undergoing surgery for Hirschsprung's disease were compared with those taken from 8 children with other gastrointestinal diseases but no aganglionosis. Immunocytochemistry was carried out using antibodies to a wide range of neuron specific proteins and peptides. Examination of sections immunostained for the general neuronal markers, protein gene product 9.5, neuron specific enolase and neurofilament triplet proteins, allowed rapid identification of aganglionic segments. Nerves containing vasoactive intestinal polypeptide/peptide histidine methionine (VIP/PHM), galanin, substance P, somatostatin, met-enkephalin or calcitonin gene-related peptide (CGRP) showed a marked reduction in all layers of the aganglionic bowel. However, scattered VIP/PHM immunoreactive fibres were also found in the hypertrophied nerve bundles. In contrast with these reduced peptide-containing nerves, fibres displaying NPY immunoreactivity showed a marked increase in all aganglionic segments, particularly in the circular muscle where few are found normally. Our findings shed further light on the neurobiology of aganglionic bowel and suggest that immunostaining of neural proteins and the peptide NPY can aid rapid histopathological diagnosis of congenital aganglionosis.
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PMID:Increased neuropeptide Y-immunoreactive innervation of aganglionic bowel in Hirschsprung's disease. 311 47

The observation that suckling evokes a modest rise in serum TSH when compared with that of prolactin is inconsistent with the hypothesis that TRH serves as a hypophysiotropic mediator of this response. In the present study we attempted to provide an explanation for this discrepancy by determining whether any of a growing number of putative prolactin releasing factors could alter pituitary responsiveness to TRH. Anterior pituitaries from lactating (day 14) rats were monodispersed with trypsin, cultured for 2 days, and then incubated in the presence of medium alone or medium containing TRH, dopamine, or a combination of these secretagogues. Companion sets of cultures were incubated concurrently with either beta-endorphin, neurotensin, oxytocin, serotonin, vasoactive intestinal polypeptide, or lysine vasopressin. As expected, TRH stimulated and dopamine suppressed prolactin release. None of the substances tested except oxytocin had a significant effect on pituitary cell responsiveness to TRH or dopamine. Oxytocin had no effect on prolactin secretion when tested alone or in combination with TRH and dopamine. TRH alone stimulated TSH release by these cultures, while oxytocin and dopamine were ineffective by themselves. However, TSH secretion by cultures treated simultaneously with TRH and oxytocin could be suppressed to approximately half of that released by cells incubated with TRH alone. These results demonstrate that oxytocin attenuates TRH-induced TSH release by a direct action on pituitary cells without affecting the prolactin response. This selectivity of responsiveness imparted by oxytocin might contribute to the blunted release of TSH after suckling.
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PMID:Oxytocin attenuates TRH-induced TSH release from rat pituitary cells. 315 75

An extensive array of nerve fibers ramify around the afferent blood vessels of the liver and the extrahepatic and intrahepatic biliary pathways, and are thought to be involved in regulation of blood flow. Although the role of sympathetic innervation is established, little is known about the location or role of regulatory peptidergic innervation in the liver. We examined the anatomic distribution of a wide variety of regulatory peptides and several neural antigens by in situ immunohistochemistry in the rat and in man. A rich peptidergic plexus of nerve fibers and ganglion cells was observed around the arterial vessels in both species, with intense immunoreactivity for neuron-specific enolase, neurofilaments, neuropeptide Y, substance P, and vasoactive intestinal polypeptide. S-100 protein immunoreactivity was seen principally in large nerve bundles, suggesting that the majority of nerves in this area were unmyelinated. In contrast, the portal vessels revealed very little peptidergic innervation. No staining was observed with antibodies directed against insulin, glucagon, gastrin, serotonin, met-enkephalin-Arg-Gly-Leu, cholecystokinin, or growth hormone. These findings indicate the presence of a rich, although selective, peptidergic plexus surrounding afferent hepatic blood vessels. This plexus may play an important role in regulation of hepatic blood flow.
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PMID:Neuroendocrine innervation of the hepatic vessels in the rat and in man. 318 22

A 65-year-old woman presenting with back pain, difficulties in walking and watery diarrhea. A right adrenal tumor and high excretion of catecholamines were found. Laboratory examinations showed raised levels of vasoactive intestinal polypeptide, pancreatic polypeptide, gastrin and calcitonin. Histology showed a combined pheochromocytoma-ganglioneuroma. The neoplastic cell population was immunohistochemically shown to contain tyrosine hydroxylase, neuropeptide Y, met-enkephalin, substance P, vasoactive intestinal polypeptide, calcitonin and calcitonin gene-related peptide. Postoperatively, the patient recovered fully and the hormone levels returned to normal.
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PMID:Adrenal pheochromocytoma-ganglioneuroma producing catecholamines and various neuropeptides. 318 92


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