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)

Previous work indicated that brain contains 3 types of lipolytic-melanotropic peptide: (1) in adenohypophysis: ACTH, alpha-MSH, beta-MSH, peptide I, peptide L', beta-lipotropin and gamma-lipotropin; (2) in neurohypophysis: peptide 7D6, also termed neurophysin I, peptide II or Wuu-Saffran peptide; (3) in extrahypophyseal regions: peptide IIF. Bovine and human neurophysin I prepared by R. Walter has now been found devoid of lipolytic and melanotropic activities. Porcine and bovine peptide 7D6, closely similar or identical to bovine neurophysin I in electrophoretic mobility and amino acid composition, were therefore reexamined to determine whether their lipolytic-melanotropic property resided in a contaminating factor. When peptide 7D6 was analyzed in 100 transfer counter current distribution (1 butanol/0.1M NH4 HCO3), the neurophysin was recovered in tubes 1-9 (7D6-alpha) representing 95% of 7D6. 7D6-alpha was inactive in lipolytic and melanotropic assays. The biologic activities of 7D6 were recovered instead in tubes 50-70 (labeled 7D6-beta), representing 5% of 7D6. 7D6-beta proved to be a peptide with MW 1000-3000, closely similar to peptide IIF in amino acid composition, MW, and Rf values in 4 systems of paper chromatography.
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PMID:Observations on the lipolytic and melanotropic properties of neurophysin proteins. 105 49

Pharmacological data suggest that opiates, acting indirectly via the catecholaminergic system, are involved in the inhibition of LH release and the stimulation of PRL secretion. The aim of this study was to demonstrate on the ultrastructural level whether beta-endorphin-immunoreactive fibers form synaptic contacts with hypothalamic dopaminergic neurons. Light and electron microscopic double immunostaining experiments were performed on vibratome sections prepared from the hypothalamus of acrolein-fixed female rat brains. Immunoreactivity for beta-endorphin was visualized by a dark blue to black nickel ammonium sulfate-intensified diaminobenzidine reaction, and in a consecutive immunostaining procedure, the tyrosine hydroxylase-immunoreactive dopamine cells were labeled with the brown diaminobenzidine reaction product. Under the light microscope, beta-endorphin axon terminals were found to contact dopamine cell bodies and dendrites throughout the hypothalamus. The majority of opiate target dopamine neurons were found in the periventricular area, retrochiasmatic area, and lateral part of the zona incerta. A much smaller number was observed in the dorsomedial hypothalamic nucleus and the anterior hypothalamus, and only a very few dopamine cells could be detected in contact with beta-endorphin axons in the arcuate nucleus (particularly in the posterior part where the beta-endorphin cells are located) and the medial part of the zona incerta. After light microscopic examination and color photography, the double immunostained sections were embedded for correlated electron microscopy to verify and characterize the putative synaptic connections. Electron microscopy revealed symmetric synaptic connections between beta-endorphin-immunoreactive boutons and tyrosine hydroxylase-immunopositive cell bodies and dendrites. These results together with the observation of dopamine innervation of LHRH-producing neurons and progesterone receptor-containing cells indicate that neurons of the hypothalamic dopaminergic system probably mediate opiate effects on hypophyseal hormone secretion.
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PMID:Beta-endorphin innervation of dopamine neurons in the rat hypothalamus: a light and electron microscopic double immunostaining study. 135 5

Central administration of neuropeptide-Y (NPY) inhibits pituitary LH release in ovariectomized rats and stimulates LH release in intact and ovariectomized rats pretreated with ovarian steroids. Although the precise neural mechanism of this dual effect of NPY is not known, experimental evidence suggests an underlying interaction between hypothalamic NPY and the inhibitory beta-endorphin (beta END) systems in the neuroendocrine regulation of pituitary LH release in the rat. The present study was undertaken to examine the morphological basis of the interaction between these two peptidergic systems in the hypothalamus. Sections of the mediobasal hypothalamus of colchicine-pretreated female rats were double immunostained for NPY and beta END and examined by light and electron microscopy. The light brown diaminobenzidine reaction was used to visualize beta END cells, while NPY neurons were labeled with a dark blue nickel ammonium sulfate-intensified diaminobenzidine reaction. Under the light microscope, a dense network of NPY-immunoreactive axons and axon terminals was observed in close apposition with beta END-immunoreactive neurons throughout the medial basal hypothalamus. Electron microscopic examination revealed that NPY-immunoreactive boutons formed axosomatic and axo-dendritic synaptic connections with beta END cells. A majority of these synaptic membrane specializations appeared asymmetrical [corrected]. In light of the previous evidence of excitatory and inhibitory effects on LH release and the existence of direct synaptic connections between NPY and LHRH neurons in the hypothalamus, the current results imply that the dual effects of NPY on LH secretion may involve modulation of LHRH secretion, both by the direct route and indirectly through the hypothalamic beta END system.
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PMID:Neuropeptide-Y innervation of beta-endorphin-containing cells in the rat mediobasal hypothalamus: a light and electron microscopic double immunostaining analysis. 142 43

Preliminary data indicate that the concentration of circulating cortisol may affect the binding of testosterone to plasma proteins. This interdependency was evaluated by the assessment of plasma cortisol, salivary (ST) and plasma total testosterone (TT), testosterone not bound to sex-hormone-binding globulin (n-SHBGT), and free testosterone (FT) in normal and in hyperandrogenemic women during combined dexamethasone/synthetic corticotropin administration. The concentrations of TT, FT, and ST significantly increased (P less than 0.001) during this dynamic test both in the controls and in hirsute women. Remarkably, however, n-SHBGT remained virtually unchanged in normal women in the follicular phase, decreasing in the luteal phase, and decreasing even more markedly in the hirsute women. Both the normal and the hirsute women showed a statistically significant negative correlation between the percentage of n-SHBGT and plasma total cortisol (P less than 0.001). The apparent decrease of n-SHBGT was the result of displacement of T from corticosteroid-binding globulin (CBG) by the increase in cortisol after the infusion of synthetic corticotropin: the CBG-bound T was measured as n-SHBGT because CBG was not precipitated with 50% saturated ammonium sulfate. Our results indicate that ST or FT better represents the clinical status of androgenicity than does n-SHBGT, as assessed by ammonium sulfate precipitation, because n-SHBGT also depends on the concentration of cortisol.
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PMID:Concentrations of salivary testosterone and plasma total, non-sex-hormone-binding globulin-bound, and free testosterone in normal and hirsute women during administration of dexamethasone/synthetic corticotropin. 175 Aug 64

Snake (Ptyas mucosa) brains (400 g) were extracted with a mixture of acetone, water, and hydrochloric acid. The precipitate (5.6 g) that formed upon addition of five volumes of acetone to the extract, designated acid-acetone powder, was subjected to gel filtration on Sephadex G-25. A large unretarded peak (SB-1) with molecular weight greater than 5000 and a small retarded peak (SB-2) with molecular weight smaller than 5000 were obtained. They were then separately subjected to ion-exchange chromatography on CM-cellulose. Adrenocorticotropic activity was detected in the fractions by their ability to stimulate isolated rat adrenal cells to produce corticosterone. Opiate activity was detected in the fractions by their ability to inhibit the binding of (D-Ala2,D-Leu5)-[tyrosyl-3,5-3H]enkephalin to rat brain membranes and their cross-reactivity in a beta-endorphin radioimmunoassay. Adrenocorticotropic and opiate activities were found to be concentrated in fractions strongly adsorbed on CM-cellulose, which were eluted by combined pH and ammonium acetate concentration gradients. There appeared to be a separation between adrenocorticotropic and opiate activities, suggesting that they were due to separate molecular entities.
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PMID:Adrenocorticotropin- and beta-endorphin-like substances in brains of the freshwater snake Ptyas mucosa. 217 78

A saponin fraction was isolated from Momordica charantia seeds by delipidation, saline extraction, ammonium sulfate precipitation, and extraction of the resulting supernatant with n-butanol. Thin-layer chromatography, in the upper phase of the n-butanol--ethyl acetate--water (4:1:5, by volume) system on plastic sheets coated with silica gel 60 F254, revealed the presence of a single spot after spraying with 10% sulfuric acid. The lack of contamination of the saponin preparation with proteins was judged by the absence of protein bands in sodium dodecyl sulfate--polyacrylamide gel electrophoresis, agarose electrophoresis and agarose diffusion, and by the absence of an absorption maximum around 278 nm. The saponin acted as a noncompetitive inhibitor of corticotropin, glucagon, and epinephrine in lipolysis in isolated rat adipocytes, and it also antagonized dibutyryl cAMP induced lipolysis. The antilipolytic activity was resistant to heat, trypsin, chymotrypsin, pronase, and glutathione, in keeping with the chemical nature of saponin. Incorporation of [3-3H]glucose into lipid was inhibited. Adipocyte viability and ATP content were not affected by the saponin, suggesting that its inhibitory effects on lipolysis and lipogenesis were not due to an adverse effect on cell viability.
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PMID:A steryl glycoside fraction from Momordica charantia seeds with an inhibitory action on lipid metabolism in vitro. 302 Nov 85

The alpha-MSH (alpha-melanocyte-stimulating hormone) agonist, Ac-[Nle4, D-Phe7]alpha-MSH4-11NH2 (hereafter called ND4-11 alpha-MSH), is at least 10-fold more potent than alpha-MSH as a stimulus of tyrosinase activity in F1 variant cells of B16 melanoma. The binding to these cells during an incubation with 5 nM (3H)ND4-11 alpha-MSH at 37 degrees C is maximal at 0-30 min, 22 fmol/10(6) cells, but declines to 40% of this value at 4 hr. in the presence of 5 nM (3H)ND4-11 alpha-MSH at 37 degrees C, the acid soluble (cell surface) radioactivity decreased rapidly from 11.4 fmol/10(6) cells at 5 min to 4.6 fmol/10(6) cells at 4 hr. Chromatographic analysis of media and cellular samples revealed that there was no evidence of degradation of (3H)ND4-11 alpha-MSH in the medium but there was evidence of intracellular degradation of (3H)ND4-11 alpha-MSH. Ammonium chloride (10mM) resulted in an increase in acid resistant radioactivity (internalized hormone) at 4 hr. The binding to F1 variant cells during an incubation with 0.155 nM or 5 nM (3H)ND4-11 alpha-MSH at 4 degrees C was constant from 4 hr to 24 hr. Under these conditions, there was no time-dependent change in the acid soluble radioactivity from 4 to 24 hr. Scatchard analysis of (3H)ND4-11 alpha-MSH binding to F1 variant cells at 4 degrees C demonstrated that there were approximately 4500 receptors per cell and an association constant of 17.1 nM-1. These results are consistent with a process of (3H)ND4-11 alpha-MSH binding to its receptor followed by internalization of the receptor-hormone complex and then intracellular degradation of the hormone.
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PMID:Biological activity, binding, and metabolic fate of Ac-[Nle4, D-Phe7]alpha-MSH4-11NH2 with the F1 variant of B16 melanoma cells. 311 Jan 78

Silica-based ion-exchange Sep-Pak cartridges, packed with either carboxymethyl (CM) cation-exchanger or a quaternary methyl ammonium (QMA) anion exchanger, are now available. The feasibility of using ion-exchange Sep-Pak cartridges for the fractionation of pituitary peptides was investigated. Extracts of bovine posterior pituitaries were fractionated at either pH 5 or pH 7 by pairs of cation and anion exchangers, connected in series. The capacity to bind peptides was well correlated with the theoretical charge calculated for a variety of peptides. At pH 5 the entire tissue extract could be fractionated into either basic or acidic pools. In contrast, at pH 7 only the more basic or acidic peptides were retained by the respective ion exchangers. The rest of the peptides passed through both ion exchangers and were recovered in the neutral pool. The ion-exchange fractionation principle was used to facilitate the purification of 35S-labelled intermediate pituitary glycopeptides, prepared by incubating mouse intermediate lobes in explant culture with 35S-labelled sulphate. 35S-labelled glycosylated forms of Lys1 gamma 3MSH, corticotropin-like intermediate lobe peptide, and the amino terminal or 16K fragment of pro-opiomelanocortin (i.e. 16K1-74) were fractionated into separate pools such that they could be purified to homogeneity in a single step by reversed-phase high-performance liquid chromatography (RP-HPLC). Purification by conventional means would require at least two RP-HPLC steps. Thus, radiolabelled peptides can be purified with the minimum of chromatographic manipulation, thereby ensuring maximal recoveries.
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PMID:Use of ion-exchange Sep-Pak cartridges in the batch fractionation of pituitary peptides. 373 37

We have performed experiments to determine possible adrenocorticotropic activity in placental tissue of a sheep at term. The placental tissue was homogenized and extracted with 0.1 mmol/L of ammonium bicarbonate. The adrenocorticotropic activity of the term placental extract was compared to that of the vehicle (saline solution) and synthetic adrenocorticotropic hormone (ACTH). A single bolus injection of term placental extract had no significant effect on the plasma concentration of cortisol or progesterone. In a separate protocol, a bolus injection of ACTH was administered before and after a 48-hour continuous infusion of term placental extract, ACTH, or saline solution. The infusion of term placental extract or ACTH caused a significant increase in the basal cortisol and progesterone concentrations and a greater progesterone response following the second ACTH bolus. In vitro, the isolated adrenal cells from the term placental extract- and ACTH-infused animals showed a significantly greater ability to produce cortisol in the presence of exogenous substrate and ACTH. We concluded that placental tissue from sheep at term contains a substance which, when infused in vivo, has a corticotropic effect on the adrenal glands.
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PMID:Adrenocorticotropic activity of an extract from sheep placental tissue at term. 608 65

Previous work from this laboratory described an association, based on genetic evidence, between a 68 000 dalton protein (p68) and corticotropin (ACTH) sensitive adenylate cyclase activity among variants of the Y1 mouse adrenocortical tumor cell line. To study the nature of this association further, we have purified p68 and raised a polyclonal anti-p68 serum in rabbits. A variant subclone of the Y1 line, in which p68 comprised approximately 10% of total soluble protein, was used as starting material. Purification of p68 was achieved by passage of a 100 000 X g supernatant fraction over DEAE-cellulose, fractionation with ammonium sulfate, and chromatography on hydroxylapatite. The purified protein had an isoelectric point of 7.3, a polarity value of 46%, and a blocked amino terminal end group. A rabbit antiserum raised against the purified p68 had a titer of 1:16 000 and specifically precipitated p68 from extracts of Y1 cells labeled with L-[35S]methionine. Using this antiserum, p68 also was detected in other cell lines including mouse erythroleukemia and Sertoli cells; rat Leydig, ovary, and glioma cells; and Chinese hamster ovary cells. The presence of p68 in a variety of cell types suggests that the function of p68 is not restricted to adrenal cells or to specific actions of ACTH.
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PMID:A 68 000 dalton protein genetically associated with corticotropin-sensitive adenylate cyclase activity. Purification and preliminary characterization using a specific antiserum. 608 78


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