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)

Displacement of naloxone from membranes of Rat brain by alpha, beta and gamma-endorphins with and without Na+ in the incubating medium has been studied. beta-endorphin shows a higher affinity for the opiate receptors and a stronger agonist property than morphine. alpha and gamma-endorphins have a much lower affinity than morphine and a marked antagonist characteristic. This study suggests the possibility of naturally occurring antagonists of the opiate receptors.
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PMID:[Comparative activity of endorphins on the opiate receptors]. 19 60

According to the present state of findings there are melanocyte-stimulating hormones (MSH) alpha, beta, gamma and delta with hormone alpha-MSH special physiological importance for man. Our study of special literature shows that the secretion of MSH is affected by exogene factors, different biorhythms and some diseases. Numerous investigation with melanocytes and melanoma cell cultures clearly show the impact of MSH on the function, regulation and the proliferation of pigment cells. The results presented contribute to the discussion of possibilities of improving diagnostics or therapy of malignant melanoma.
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PMID:[Importance and function of the melanocyte-stimulating hormone in malignant melanoma. Importance of MSH]. 196 35

The effects of intravenous self-administration of 30 micrograms infusions of either heroin or cocaine, or saline on the concentrations of beta-endorphin-immunoreactivity (beta E-IR) in the anterior part of the rat brain limbic system were studied. Self-administration of heroin and cocaine for 5 daily sessions resulted in a marked reduction of the concentrations of beta E-IR in the nucleus accumbens, rostral striatum, septum and hippocampus at the time of the scheduled next session on day 6. In pooled extracts of these regions from rats receiving saline, combined application of high-pressure liquid chromatography (HPLC) fractionation and specific radioimmunoassays revealed the presence of a number of beta E-related peptides co-chromatographing with synthetic non-acetylated and acetylated alpha, beta- and gamma-type endorphins. Similar profiles were found after HPLC fractionation of extracts of these regions from rats self-administering heroin and cocaine. Rats self-administering heroin or cocaine, however, showed decreased amounts of all detected forms of beta-endorphin as compared to saline rats. These findings indicate that both self-administration of an opiate that induces psychic as well as physical dependence and of a non-opiate stimulant inducing psychic but not physical dependence, results in a significant decrease of beta E and related peptides in limbic brain regions of the rat. All forms of beta E detected after HPLC were equally affected, suggesting an overall effect of the drugs on peptide turnover. These results suggest that beta E and related peptides may be involved in the neurochemical mechanisms underlying psychic dependence to drugs.
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PMID:Characterization of beta-endorphin-immunoreactivity in limbic brain structures of rats self-administering heroin or cocaine. 297

Proopiomelanocortin (POMC) is a glycoprotein which serves as a multihormonal precursor for corticotropin (ACTH), lipotropins (beta and gamma-LPH), melanotropins (alpha, beta- and gamma-MSH) and endorphins (alpha-, beta- and gamma-endorphins). This precursor protein is primarily synthesized in corticotrophs of the anterior lobe and in melanotrophs of the intermediate lobe of the pituitary, as well as in other organs or tissues such as the genitourinary tract, the gastrointestinal tract and leukocytes. POMC is also present in the central nervous system (CNS) and numerous studies have been conducted to determine the localization, biosynthesis and functions of POMC-derived peptides. The identification of POMC-neuronal systems has been achieved by combining immuno histochemical studies, biochemical analysis, bioassays and radioimmunoassays. Three groups of perikarya containing various POMC-related peptides have been identified. One of these is located in the arcuate nucleus in the basal hypothalamus and projects towards the septum, thalamus and telencephalon. Some fibers originating from the arcuate nucleus terminate in the nucleus of the solitary tract in the brainstem where a second group of POMC-containing nerve cells are located. The latter innervates both the mesencephalon, the brainstem and the spinal cord. A third group of neurons, which contain alpha-MSH but not other POMC-derivates, has been identified in the zona incerta in the dorso-lateral hypothalamus. Processing of POMC in the cell bodies of the arcuate nucleus follows a similar pattern as in the pituitary intermediate lobe. Endopeptidases called "acid-thiol-arginyl-proteases" cleave the prohormone at paired basic amino acids. The basic residues remaining on the resulting peptides are subsequently eliminated by the joint action of the less specific B-type carboxypeptidases and B-type aminopeptidases. alpha-MSH and beta-endorphin are among the major end products. Enzymatic modifications including N-alpha-acetylation by opiomelanotropin-acetyltransferase (OMAT) and/or C-terminal amidation by peptidyl-glycine alpha-amidating monooxygenase (PAM) occur after proteolytic processing. However, the rate of acetylation observed in hypothalamic POMC neurons is much lower than in the melanotrophs of the pars intermedia. Acetylation of MSH and endorphin is crucial in determining the biological potency of these peptides. Desacetyl alpha-MSH is far less active than alpha-MSH (monoacetyl alpha-MSH), whereas acetylated beta-endorphin has no opiate activity. The mechanisms regulating the activity of POMC-containing neurons are still unknown.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Pro-opiomelanocortin neuronal systems]. 331 Jan 84

A simple, rapid method is described for separating neuropeptides. Samples were injected on Sep-Pak disposable reverse phase cartridges and eluted with a step gradient of n-propanol in formate-pyridine buffer. Enkephalins are separated from metabolic products. Separation alpha, beta and gamma-endorphin demonstrated, and Met- and Leu-enkephalin are also separated. This inexpensive, reproducible method a useful in studies of neuropeptide metabolism, purification of synthesized peptides, separation prior to RIA, or concentration of neuropeptides.
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PMID:Rapid separation of enkephalins and endorphins on Sep-Pak reverse phase cartridges. 617 36

Proopiomelanocortin (POMC) is a protein that contains the amino acid sequences of numerous peptide hormones, including the melanocyte-stimulating hormones (MSH). MSH peptides of alpha, beta, and gamma primary structure are present in plasma, and all exhibit natriuretic activity. Intravenous infusion of alpha or beta-MSH leads to a time- and dose-dependent natriuresis, whereas gamma-MSH is reported to be natriuretic at low doses but antinatriuretic at high doses. The natriuretic activity of MSH peptides occurs without change in arterial pressure or renal hemodynamics, suggesting a possible direct tubular inhibition of sodium reabsorption. Intravenously infused gamma-MSH is associated with an increase in the plasma concentration of atrial natriuretic peptide. In addition, gamma-MSH also has a direct intrarenal natriuretic action that is dependent on the renal nerves. In rats, gamma-MSH-related peptides are involved in the reflex control of sodium excretion in situations such as the natriuresis that occurs (a) from the remaining kidney after acute unilateral nephrectomy, (b) from the contralateral kidney shortly after unilateral ureteral pressure elevation, and (c) after unilateral carotid artery traction. POMC-derived peptides (including MSH) are modulated in response to salt loading, and alterations in POMC metabolism and plasma peptide concentrations have been observed in genetically hypertensive rats and during the development of adrenal regeneration hypertension. In addition, plasma gamma-MSH levels are elevated in patients with severe congestive heart failure, and in primary hyperaldosteronism. These observations suggest a possible involvement of MSH-related peptides in sodium homeostasis as well as in certain forms of hypertension.
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PMID:Natriuretic properties of melanocyte-stimulating hormones. 750 15

Adrenocorticotropic hormone (ACTH) and melanocortin peptides (alpha, beta and gamma MSH) have numerous activities in both central nervous system and peripheral tissues, namely the adrenals. Recently, five melanocortin receptors were cloned and characterized. We report here the cloning, pharmacological characterization and expression of the rat fifth melanocortin receptor (MC5), starting from the dopamine D3 receptor sequence to screen a genomic DNA library. The MC5 comprises a sequence of 325 amino acids, displaying 45-62% identity with other melanocortin receptors and 82% identity with its human counterpart that we cloned thereafter. The sequence of the latter is identical to that of a so-called 'MC2' receptor (Chhajlani et al., 1993, Biochem. Biophys. Res. Comm. 195, 866-873). The MC5, stably expressed in CHO cells, mediates increase in cAMP accumulation with a characteristic pharmacology: alpha MSH is twice as potent as NDP alpha MSH, 10 times as ACTH and 100 times as gamma MSH. Very low expression levels were detected in brain, while high levels were found in adrenals, stomach, lung and spleen. In addition, in situ hybridization studies show the MC5 expressed in the three layers of the adrenal cortex, predominantly in the aldosterone-producing zona glomerulosa cells.
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PMID:Molecular cloning and characterization of the rat fifth melanocortin receptor. 817 77

The pituitary prohormone proopiomelanocortin gives rise to melanocortins of alpha, beta, and gamma primary structure in addition to corticotropin. Melanocortins have a variety of actions in mammals, and each is natriuretic. In particular, gamma-melanocyte-stimulating hormone has been shown to mediate reflex natriuresis after acute unilateral nephrectomy. We examined whether this peptide could play a role in longer term adjustments in sodium balance by measuring plasma gamma-melanocyte-stimulating hormone and corticotropin concentrations, as well as pituitary proopiomelanocortin mRNA abundance, in Sprague-Dawley rats ingesting either a low (0.07% NaCl) or high (7.5% NaCl) sodium diet. One week after the high sodium diet, plasma gamma-melanocyte-stimulating hormone concentration was double the value seen in rats on the low sodium diet (158 +/- 5 [SE] versus 76 +/- 9 fmol/mL, P < .001), a change that was accompanied by a fivefold increase in plasma atrial natriuretic peptide concentration but no change in plasma corticotropin. Whole pituitary proopiomelanocortin mRNA abundance, measured with a probe to exon 3 of the rat proopiomelanocortin gene, was significantly increased after 1 week of the high sodium diet compared with the low sodium diet and increased further at 2 and 3 weeks. This increase occurred primarily in the neurointermediate lobe as demonstrated by in situ hybridization; the content of gamma-melanocyte-stimulating hormone immunoreactivity was also increased in this lobe, but not the anterior lobe, after 1 week of the high sodium diet. These results demonstrate that high dietary sodium intake increases neurointermediate lobe proopiomelanocortin mRNA abundance compared with a very low sodium diet and also suggest that proopiomelanocortin is preferentially processed into gamma-melanocyte-stimulating hormone rather than corticotropin. These observations consequently raise the possibility of a role for this peptide hormone system in the adjustments to a high salt diet.
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PMID:Dietary sodium intake modulates pituitary proopiomelanocortin mRNA abundance. 870 89

The adenohypophysis (ADH) of the Mediterranean yellowtail was studied using the peroxidase-antiperoxidase technique. Human corticotropin (ACTH) (1-24)-immunoreactive (ir) cells were found bordering the neurohypophysis (NH) and salmon prolactin (PRL)-ir cells were arranged in thick cords, both in the rostral pars distalis (RPD). Gonadotropin (GTH)-, thyrotropin (TSH)- and growth hormone (GH)-ir cells were observed in the proximal pars distalis (PPD). Anti-chum salmon GTH I and anti-chum salmon GTH II immunostained the same cells in the outermost part of the ADH at the level of the PPD and the PI. In addition to these cells, some cells grouped in the inner areas of the posterior PPD were revealed by catfish alpha, beta-GTH antiserum. Human beta-TSH-ir cells formed small groups and discontinuous strands in the PPD often in contact with the NH. Tilapia GH-ir cells formed cords mainly surrounding the NH in the central PPD, while cod somatolactin- and alpha MSH-ir cells mainly surrounded the NH branches in the PI.
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PMID:The adenohypophysis of Mediterranean yellowtail, Seriola dumerilii (Risso, 1810): an immunocytochemical study. 885 83

Retinoid X receptors (RXRs) are transcriptional factors that belong to the steroid/thyroid hormone receptor superfamily. There are 3 RXR isoforms-alpha, beta, gamma-known to bind 9-cis-retinoic acid as their ligand. The expression of RXRs in human pituitary glands and pituitary adenomas has not been extensively investigated. To determine whether specific RXR isoforms may play roles in the state of differentiation of pituitary adenomas, we have investigated the immunohistochemical expression of RXR alpha and RXR gamma in 6 nontumorous pituitaries and in 60 different pituitary adenomas using isoform-specific antibodies. In the nontumorous pituitaries. RXR alpha was expressed in the nuclei of almost all cells, while RXR gamma was only expressed in thyrotropin (TSH) cells and in some cells positive for growth hormone (GH) and glycoprotein alpha-subunit (alpha SU) but not in luteinizing hormone (LH) beta-subunit, follicle-stimulating hormone (FSH) beta-subunit, prolactin (PRL) or adrenocorticotropin (ACTH) cells by double immunostaining. All 60 adenomas were RXR alpha positive, and 39 of 60 adenomas (65%) were positive for RXR gamma. The incidence of RXR gamma immunoreactivity in the different adenoma types was: 13 of 16 GH-producing adenomas (81.3%), 9 of 14 PRL-secreting adenomas (64.3%), 6 of 6 TSH-secreting adenomas (100%), 2 of 5 ACTH-secreting adenomas (40%) and 9 of 19 nonfunctioning adenomas (47.4%) including immunohistochemically gonadotropin-subunit-positive adenomas. The colocalization of RXR gamma with the TSH beta subunit, GH and alpha SU in the same adenoma cells was frequently observed, and sometimes RXR gamma was colocalized with PRL, ACTH, FSH beta or LH beta as shown by double immunostaining. We conclude that RXR alpha is expressed in both human pituitaries and pituitary adenomas. In contrast, RXR gamma is expressed more broadly in pituitary adenomas than in normal pituitaries and thus may play a role in the differentiation-specific cell types in the human pituitary both under physiological and pathological conditions.
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PMID:Immunohistochemical expression of retinoid X receptor isoforms in human pituitaries and pituitary adenomas. 914 2


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