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)

1 Intracarotid injection of [Leu]enkephalin and [Met]enkephalin produced a dose-dependent biphasic change in blood pressure of the rat consisting of an initial shortlasting fall followed by a longlasting increase of blood pressure. Naloxone consistently depressed or abolished the effects of enkephalins on blood pressure. 2 Intracarotid injection of beta-endorphin only occasionally produced a hypotension, or did not produce any change in the blood pressure of the rat. 3 All three opioids ([Leu]enkephalin, [Met]enkephalin and beta-endorphin) significantly depressed or abolished the hypertensive response to intravenous injection of physostigmine. This depressive action of opioids was easily reversed by naloxone. 5 It is concluded that opioids depress the central cholinergic link implicated in the hypertensive response to physostigmine most probably by inhibiting acetylcholine and/or noradrenaline release in the structures relevant for the action of physostigmine on blood pressure of the rat. This interaction is realized through the activation of opioid receptor(s).
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PMID:The effect of enkephalins and of beta-endorphin on the hypertensive response to physostigmine in the rat. 295 44

Prepubertal ewes can, under certain circumstances, be stimulated to ovulate by the novel introduction of a ram. The endocrine response to the presence of the ram is characterized by a rapid increase in the frequency of episodic release of LH. The purpose of this study was to investigate the effect of the presence of a ram on LH pulse frequency in vivo, gonadotrophin-releasing hormone (GnRH) and beta-endorphin concentrations in the median eminence, and on the influence of the endogenous opioid peptide agonist [D-Ala2,N-Phe4,Met(0)ol5]-enkephalin (FK 33-824) on basal and depolarization-induced release of GnRH from median eminence tissue superfused in vitro. The study was performed at two prepubertal ages in August and September. In September, the introduction of a ram resulted in an increase in pulsatile release of LH, which was associated with an increase in the rate of basal release of GnRH from median eminence tissue superfused in vitro, and the development of a marked ability of FK 33-824 to suppress depolarization-induced release of GnRH. The concentration of beta-endorphin in the median eminence was reduced in animals exposed to the ram at this time. In contrast, the introduction of a ram in August failed to stimulate an increase in LH pulse frequency, basal release of GnRH in vitro was not altered and FK 33-824 was ineffective in reducing depolarization-induced release of GnRH. These results suggest that the premature onset of reproductive activity induced by exposure to the ram may involve the participation of the endogenous opioid peptide system.
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PMID:Involvement of endogenous opioid peptides in the neuroendocrine response of ewe lambs to the introduction of a ram. 296 89

By the use of two different double-staining techniques (simultaneous staining of adjacent serial sections and the double-staining elution method) it was possible to demonstrate that a corticotropin-releasing factor (CRF) immunofluorescence co-existed with an adrenocorticotropin (ACTH) and beta-endorphin (beta-END) immunoreactivity, but not with a Met-enkephalin (Met-ENK) immunostaining, within perikarya subpopulations of both the myenteric and submucousal plexus of the rat duodenum. Not a single Met-ENK-positive neuronal cell body was stained also for CRF, ACTH or beta-END. Even nerve fibres, localized in both the myenteric plexus and closely to submucousal blood vessels (probably arterioles), revealed a CRF immunofluorescence, which is also colocalized with an beta-END staining. These results are quite different to the recent observations in the mammalian hypothalamus, suggesting that some myenteric and submucousal plexus neurons may synthesize CRF as well as beta-END and ACTH, but not Met-ENK. The colocalized peptides might be concomitantly released into the synaptic cleft after terminal stimulation.
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PMID:Corticotropin-releasing factor: immunohistochemical colocalization with adrenocorticotropin and beta-endorphin, but not with Met-enkephalin, in subpopulations of duodenal perikarya of rat. 298 78

The conversion of BAM-12P to Met-enkephalin and the hydrolysis of the Phe-Met and Phe-Leu bonds of met-enkephalin-Arg-Phe and Leu-enkephalin-Arg-Arg, respectively, by rabbit brain endo-oligopeptidase A were demonstrated. Peptide fragments were isolated by high performance liquid chromatography and identified by amino acid analysis. BAM 22P was not hydrolysed by the enzyme. The concentration dependent inhibition of BAM-12P conversion into Met-enkephalin by bradykinin and vice-versa provided additional evidence that endo-oligopeptidase A cleaves both the Phe5-Ser6 bond in bradykinin and the Met5-Arg6 bond of BAM-12P.
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PMID:Conversion and inactivation of opioid peptides by rabbit brain endo-oligopeptidase A. 299 91

Previous studies have provided evidence for adrenocorticotropic hormone (ACTH) effects on a wide variety of behaviors. However, the precise sites of action and the mechanisms by which these effects may be mediated have yet to be clearly elucidated. Although ACTH was shown to augment cyclic AMP levels in glial cells isolated from whole brain, other studies found little or no effect of ACTH peptides on cyclic nucleotide metabolism in slices of cerebral cortex or homogenates of whole brain. In the present study, our objective was to determine whether ACTH peptides regulate intracellular cyclic AMP levels in neurons of the cerebral cortex in primary culture. ACTH peptides stimulated cyclic AMP synthesis up to threefold in a dose-dependent manner; stimulation was complete within 5-10 min of exposure to agonists. Neurohormone efficacy was augmented by 0.1 microM forskolin (which was virtually ineffective alone); potency was unaffected. The order of potency (EC50) for increasing intracellular cyclic AMP levels was as follows: ACTH (1-24), ACTH (1-17) (10 nM) greater than alpha-melanocyte stimulating hormone, beta-melanocyte stimulating hormone (alpha-MSH, beta-MSH) (100 nM) greater than ACTH (1-10) (1 microM) greater than ACTH (4-10) (5 microM). The hexapeptide ACTH (4-9) as well as ACTH (11-24) were inactive at concentrations as high as 10 microM. Other neuropeptides derived from proopiocortin, such as beta-endorphin and Met- and Leu-enkephalin were without effect on basal or hormonally stimulated cyclic AMP synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Corticotropin-peptide regulation of intracellular cyclic AMP production in cortical neurons in primary culture. 299 15

Binding of 125I-labeled camel beta-endorphin (125I-beta C-endorphin) to cells of several mouse thymoma cell lines was examined and was highest to EL4 cells. 125I-beta C-endorphin binding to EL4 cells was temperature-dependent; it was further characterized at 4 degrees C and exhibited saturability, complete reversibility, structural specificity and pH-dependence. 125I-beta C-endorphin binding was not inhibited by the opioid pentapeptides [Leu] enkephalin or [Met] enkephalin (which share common sequences with the N-terminus of beta C-endorphin) or by the N-terminal beta C-endorphin fragments beta C-endorphin (1-16) or beta C-endorphin (1-27). In contrast, binding was inhibited by beta C-endorphin (1-31), indicating that beta C-endorphin binding to EL4 cells was with a C-terminal beta C-endorphin segment. We suggest that binding of beta-endorphin to such nonopioid binding sites may precede its apparent effects on the proliferation of T-lymphocytes (5,6).
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PMID:Beta-endorphin: interaction with specific nonopioid binding sites on EL4 thymoma cells. 299 56

We investigated the psychoneuroendocrine and emotional correlates of the natural stress situation of human labor. State anxiety, subjective pain, plasma ACTH, peripheral plasma beta-lipotropin (Beta-LPH), beta-endorphin (Beta-EP), and met-enkephalin (Met-Enk) were serially evaluated at six predetermined time points before, and after labor in a sample of 14 women with normal pregnancies. State anxiety and subjective pain showed a progressive increase during labor, with a levelling during the final stage. Plasma Beta-EP and ACTH showed a similar progressive increasing from baseline until the end of labor. Beta-LPH showed no significant modification. Met-Enk remained at nearly baseline values throughout labor, with a marked progressive rise in the postpartum stage. The findings of this study seem to confirm the role of plasma Beta-EP as a stress hormone. Possible relationship between pain and anxiety curves and plasma Beta-EP are discussed in light of psychobiological studies on stress, the opioid system and analgesia. Plasma Met-Enk, according to our findings, should probably not be regarded as a stress hormone. Its rise in the postpartum stage might be as one of the psychoneuroendocrine mechanisms maintaining elevated prolactin levels during lactation.
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PMID:ACTH, beta-endorphin and met-enkephalin: peripheral modifications during the stress of human labor. 299 23

Opioid narcotics are present in seminal plasma, although their physiological effect on spermatozoa is still unknown. This study reports data on metabolic parameters of human spermatozoa in the presence of a met-enkephalin analogue: D-Ala2-Mephe4-Met-(o)-ol-Enkephalin, FK 33824, Sandoz, Basel, Switzerland (DAMME), and its receptor antagonist naloxone hydrochloride, Endo Laboratories, Garden City, New York. Our findings indicate that the metenkephalin analogue reduces sperm motility and cellular O2 consumption without affecting cellular ATP content and viability. The hypothesis that DAMME acts on adenylate-cyclase is briefly discussed.
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PMID:Effects of a met-enkephalin analogue on motility, O2 consumption, and ATP content of human spermatozoa. 299 93

Opioid receptors have been solubilized from human striatal and rat whole-brain membranes by use of 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS). Tritiated human beta-endorphin (3H-beta h-EP) binding revealed high-affinity competition by morphine, naloxone, and various beta-EP analogues, suggesting predominantly mu-type binding. Lack of high-affinity competition by (+/-)-3,4-dichloro-N-methyl-N-[2-(1-pyrrolidinyl)cyclohexyl]benzeneaceta mide methanesulfonate (U50-488, Upjohn) indicated that kappa sites were not labeled by 3H-beta h-EP under these conditions. Affinities were similar in both soluble and membrane preparations except for [Met]enkephalin, which appears to be rapidly degraded by the solubilized extract. Size differences between human and rat solubilized 3H-beta h-EP-receptor complexes were revealed by exclusion chromatography.
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PMID:Characterization of solubilized human and rat brain beta-endorphin-receptor complex. 300 26

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


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