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)

The release of the neuropeptide Met-enkephalin (Met-ENK) from isolated nerve terminals (synaptosomes) of the rat forebrain was characterized with respect to the subcellular distribution, the release upon addition of various stimulatory agents, the release kinetics, the cation-dependence of release and the relationship between Met-ENK release and elevations of the intraterminal free Ca(2+)-concentration ([Ca]i). A highly specific radioimmunoassay was developed for determination of Met-ENK (H-Tyr-Gly-Gly-Phe-Met-OH). Truncated and elongated forms of Met-ENK, Leu-enkephalin, beta-endorphin and dynorphin displayed negligible cross-reactivity. Met-ENK-like immunoreactivity (Met-ENK-LI) is enriched in the purified synaptosomal fraction of rat forebrain homogenates and is released in a strictly Ca(2+)-dependent manner upon chemical depolarization or stimulation with the Ca2+ ionophore, ionomycin. A correlation exists between the release of Met-ENK-LI and the elevations of [Ca]i. Barium ions are able to replace Ca2+ in triggering Met-ENK-LI release. The release of Met-ENK-LI is initiated within 20 s after depolarization and is terminated after 3-5 min, although depolarization and [Ca]i elevation are maintained. At this time, > 90% of the initial Met-ENK-LI is still present inside the synaptosomes. Repolarization and renewed stimulation again evokes Ca(2+)-dependent release of this retained Met-ENK-LI. It is concluded that Met-ENK release from isolated nerve terminals is exocytotic, and that exocytosis is terminated by a regulatory mechanism in synaptosomes after 3-5 min of depolarization, a process which can be reversed by repolarization.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Characterization of the release of Met-enkephalin from isolated nerve terminals: release kinetics and cation-dependence. 148 89

Authors have often experienced that psychological stress influences rheumatoid arthritis (RA). In addition, recent reports show a modulatory role for neuropeptide such as substance P in arthritis. These findings prompted us to study endogenous opioid peptides in RA, which are found mainly in the brain and have an effect on the central nervous system. We examined methionine-enkephalin (Met-enk), leucine-enkephalin (Leu-enk) and beta-endorphin (beta-end) in opioid peptides. We measured these peptides in plasma and synovial fluid samples obtained from 28 knees of 24 RA patients and the quantity in the synovial tissue of 13 knees. We also measured plasma and synovial fluid samples from patients with osteoarthritis of the knee and plasma samples from healthy candidates. Leu-enk and beta-end levels in synovial fluid were significantly higher than plasma levels only in RA. Larger quantity of Leu-end and beta-end were contained apparently in the synovial tissue than Met-enk. The synovial tissue with proliferative change tends to contain larger quantity of opioid peptides. These results indicate that the synovial tissue produces or secretes Leu-enk and beta-end and that opioid peptides are related to the degree of inflammation in RA.
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PMID:[A study of opioid peptides in synovial fluid and synovial tissue in patients with rheumatoid arthritis]. 152 70

Melanin-concentrating hormone (MCH) is a cyclic peptide which behaves as an antagonist of the pituitary melanotropic hormone alpha-melanocyte-stimulating hormone in fishes. Cloning of the rat MCH cDNA precursor recently revealed the presence of an additional putative peptide named NEI. The present work examined the susceptibility of these novel peptides to hydrolysis by various purified exo- and endo-peptidases including endopeptidases 24.11 (NEP), 24.15, 24.16, angiotensin-converting enzyme, leucine aminopeptidase and carboxypeptidase A. NEP attacked MCH at three sites of the molecule with an apparent affinity of about 12 microM and a kcat. of 4 min-1. The first site of cleavage was at Cys-7-Met-8, i.e. within the peptide loop formed by the internal disulphide bridge. NEP could therefore be considered as an MCH-inactivating peptidase since the degradation products generated are probably devoid of biological activity. In contrast, NEI neither inhibited the degradation of the NEP chromogenic substrate glutaryl-Phe-Ala-Phe-p-aminobenzoate nor was susceptible to proteolysis by NEP. Unlike NEP, angiotensin-converting enzyme, endopeptidase 24.15 and endopeptidase 24.16 appeared totally unable to cleave MCH, whereas the peptide was readily degraded by aminopeptidase M and carboxypeptidase A.
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PMID:Hydrolysis of rat melanin-concentrating hormone by endopeptidase 24.11 (neutral endopeptidase). 152 Feb 71

Recent studies have shown that neuropeptides, such as substance P, are responsible for arthritis. We therefore studied opioid peptides (beta-endorphin, Methionine-enkephalin, Leucine-enkephalin) in order to confirm our belief that mental status may have some influence on the activity of rheumatoid arthritis (RA). We examined opioid peptides, lymphocyte subsets, psycologic test (Cornell Medical Index-Health questionnaire (CMI), the Face scale) and clinical data in patients with RA. Plasma Leu-enk, % Leu2a+ Leu15- cells,% Leu3a+ Leu8- cells and % Leu11+ Leu7- cells were higher in patients with a larger number of psycologic complaints in CMI. Plasma Leu-enk concentration was higher while % Leu11+ Leu7- cells was lower in proportion to the degree of neurosis, as indicated by the descrimitive chart of CMI. Plasma Met-enk concentration, % Leu2a+ Leu15- cells, and Lansbury's index were significantly higher in the group of patients whose facial expression was more severe. These findings suggest that mentala status have some relationship with the plasma level of opioid peptides (enkephalins) and immunologic functions, and that it may exert indirect effects on RA.
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PMID:[Psychosomatic medicine in rheumatoid arthritis]. 158 48

Our previous studies indicate that endogenous opioids (primarily beta-endorphin) released during stressful stimuli can interact with peripheral opioid receptors to inhibit nociception in inflamed tissue of rats. This study sought to localize opioid precursor mRNAs and opioid peptides deriving therefrom in inflamed tissue, identify opioid containing cells and demonstrate their functional significance in the inhibition of nociception. In rats with Freund's adjuvant-induced unilateral hindpaw inflammation we show that: (i) pro-opiomelanocortin and proenkephalin-mRNAs (but not prodynorphin mRNA) are abundant in cells of inflamed, but absent in non-inflamed tissue; (ii) numerous cells infiltrating the inflamed subcutaneous tissue are stained intensely with beta-endorphin and [Met]enkephalin (but only few scattered cells with dynorphin) antibodies; (iii) beta-endorphin is present in T- and B-lymphocytes, monocytes and macrophages; and (iv) whole-body irradiation suppresses stress-induced antinociception in the inflamed paw. Taken together, these data suggest that endogenous opioid peptides are synthesized and processed within various types of immune cells at the site of inflammation. Immunosuppression abolishes the intrinsic antinociception in inflammatory tissue confirming the functional significance of these cells.
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PMID:Gene expression and localization of opioid peptides in immune cells of inflamed tissue: functional role in antinociception. 160 30

The effects of opioid peptides on a 1.1-kb long proopiomelanocortin messenger RNA (POMC mRNA) have been investigated in rat hypothalamic cells maintained in culture. Most opioid peptides exerted an inhibitory control on POMC mRNA steady-state concentrations. beta-Endorphin caused a 65% maximal inhibitory effect (IC50 = 6.1 x 10(-9) M) while slightly less inhibition was caused by Met- and Leu-enkephalin, dynorphin A and DADLE ([D-Ala2,D-Leu5] enkephalin). The effects of beta-endorphin and of Met-enkephalin were completely reversed by the delta opioid antagonist ICI 174,864 while the kappa-receptor specific antagonist binaltorphimine or the sigma-receptor specific antagonist DTG (1,3-di(2-tolyl) guanidine) respectively blocked the inhibitory actions of dynorphin A and of DADLE. The mu-receptor specific agonist DAGO ([D-Ala2,N-Me-Phe4,Gly5-OL]enkephalin) did not affect POMC mRNA levels. The failure of the dopaminergic D2 antagonist haloperidol to modify the inhibitory effects of opioid peptides argues for a direct inhibitory opioid peptide modulation of hypothalamic POMC mRNA levels mediated by the delta-, kappa- and sigma- (but not mu-) receptors in vivo.
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PMID:Regulation of proopiomelanocortin messenger RNA concentrations by opioid peptides in primary cell cultures of rat hypothalamus. 164 65

The binding and internalization of a novel adrenocorticotropic hormone (ACTH) analog having a potent neuromodulating effect, ebiratide (H-Met(O2)-Glu-His-Phe-D-Lys-Phe-NH(CH2)8NH2), by isolated bovine brain capillaries, were examined. Metabolism of [5-125I-His]ebiratide occurred during a 30-min incubation with bovine brain capillaries at 37 degrees C. In the presence of 20 mM EDTA, added to inhibit this metabolism, the medium, after 30 min of incubation, contained 82.3 +/- 0.5% of the unchanged ebiratide. The total binding and acid-resistant binding of [125I]ebiratide increased with time and reached an equilibrium at about 15 min. The total binding and acid-resistant binding at 30 min (as the cell/medium ratios corrected with [14C]sucrose) were 13.07 +/- 0.86 and 5.00 +/- 0.18 microliters/mg of protein, respectively. The acid-resistant binding showed significant dependence on temperature and medium osmolarity. The [125I]ebiratide binding was significantly inhibited by dansylcadaverine, an endocytosis inhibitor. The saturable acid-resistant binding was obtained by the addition of unlabeled ebiratide (100 nM-5 mM), and the maximal internalization capacity (Bmax) at 30 min was 144.2 pmol/mg of protein, with the half-saturation constant (KD) of 62.1 microM. The nonsaturable acid-resistant binding [cell/medium ratio in the presence of the unlabeled compound (1 mM or more)] was 2.2 microliters/mg of protein. The acid-resistant binding was significantly inhibited by human ACTH, poly-L-lysine, protamine and E-2078, a basic peptide, but was not inhibited by poly-L-glutamate, insulin or transferrin. These results demonstrate that ebiratide is transported through the blood-brain barrier via a basic peptide-specific absorptive-mediated endocytosis.
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PMID:Transport mechanism of a new behaviorally highly potent adrenocorticotropic hormone (ACTH) analog, ebiratide, through the blood-brain barrier. 165 Aug 27

Adrenocorticotropic (ACTH) and melanocyte stimulating (MSH) hormones have been demonstrated in the same cells in the cephalic half of the pars distalis of the chicken pituitary glands in three ways: (I) immunohistochemistry, (II) radioimmunoassay (RIA) using both anti-human or porcine ACTH and synthetic alpha-MSH antibodies, and (III) isolation and purification, followed by the determination of amino acid compositions of both hormones. The contents of ACTH and alpha-MSH are estimated by RIA to be 1600 and 10 ng/gland, respectively. ACTH missed 1 (des-Phe39-ACTH) or 2 residues (des-Glu38, Phe39-ACTH) from the C-terminal portion was also isolated. The recoveries of these ACTHs are differed from preparation to preparation. The complete amino acid sequence of chicken ACTH (39 residues) has been determined as NH2-Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Val-Gly-Arg-Lys-Arg- Arg- Pro-Ile-Lys-Val-Tyr-Pro-Asn-Gly-Val-Asp-Glu-Glu-Ser-Ala-Glu-Ser-Tyr-Pro- Met-Glu-Phe-OH Strikingly the amino acid sequence of chicken ACTH shows a closer resemblance to that from an amphibian, Xenopus (3 residue substitution) than that from another bird, the ostrich (7 residue substitution) or the turkey (at least 9 residue substitution).
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PMID:Characterization of chicken ACTH and alpha-MSH: the primary sequence of chicken ACTH is more similar to Xenopus ACTH than to other avian ACTH. 165 32

Intermediate pituitaries of the reptile, Anolis carolinensis, were separately pulse labeled with [3H]Trp and [3H]Tyr. The major form of alpha-MSH was purified by immunoprecipitation and isolated by reverse phase HPLC. Tryptic peptide analysis indicated that the [3H]Trp-labeled C-terminal fragment of Anolis alpha-MSH had the same retention time as mammalian ACTH(9-13) amide; however, the [3H]Tyr-labeled N-terminal fragment did not coelute with either mammalian ACTH(1-8) or N-acetyl-ACTH(1-8). Purification of alpha-MSH from 76 Anolis intermediate pituitaries confirmed that a sequence change had occurred in the N-terminal region of Anolis alpha-MSH. The tissues were acid extracted and purified by Sephadex G-25 chromatography and reverse phase HPLC to yield 4.5 micrograms of purified Anolis alpha-MSH for amino acid composition analysis and automated Edman degradation sequence analysis. The major form of Anolis alpha-MSH is nonacetylated and has the following novel primary sequence: Ser-Tyr-Ala-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro(Val-amide). The presence of Val-amide was verified by immunological analysis, tryptic peptide analysis and amino acid composition analysis.
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PMID:Detection of a novel sequence change in the major form of alpha-MSH isolated from the intermediate pituitary of the reptile, Anolis carolinensis. 166 89

The present experiments were performed to determine whether the age-related loss of striatal D2 receptors could be localized to a kainic acid-sensitive neuronal population. This neurotoxin selectively destroys intrinsic neurons. Thus, if kainic acid reduced striatal D2 receptor concentrations such that age differences in this parameter were no longer observed, it would be a good indication that the D2 receptors lost through aging are also sensitive to kainic acid. Mature (6 months) and senescent (24 months) rats were stereotaxically, unilaterally injected with 3 micrograms/0.5 microliter kainic acid into the right striatum. Seven days later striatal D2 receptors were assessed with [3H]-spiperone in one group of mature and senescent rats. A second group of mature and senescent unilaterally lesioned rats was anesthetized and perfused. Brains were dissected and processed for striatal cell counts using cresyl violet staining, tyrosine hydroxylase and met-enkephalin using immunocytochemistry, and acetylcholinesterase using histochemistry. Age-related differences in D2-receptor concentrations were observed in intact, but not lesioned, striata. Kainic acid was less effective in reducing D2-receptor concentrations in senescent animals, suggesting that some proportion of the receptors was already lost prior to lesioning. Kainic acid also reduced total neuronal numbers, as well as Met-Enk and AChE positive staining, to approximately the same extent in mature and senescent rats. No age differences were seen in any of the other parameters following kainic acid administration.
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PMID:The deleterious effects of aging and kainic acid may be selective for similar striatal neuronal populations. 168 53


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