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)

We studied the secretion and tissue contents of adrenorphin in human pheochromocytomas. In 17 human pheochromocytomas from 11 patients, we found a remarkably wide distribution in immunoreactive adrenorphin levels (3-7771 pg/mg tissue). Adrenomedullary pheochromocytomas contained a significantly larger amount of immunoreactive adrenorphin (2295 +/- 1092 pg/mg, mean +/- SE) than did extramedullary ones (17.8 +/- 8.4 pg/mg). Gel chromatographic studies revealed that immunoreactive adrenorphin consisted largely of material emerging at the position of synthetic adrenorphin in both pheochromocytoma and normal adrenal medulla tissue. Nicotine (10(-5) M) significantly stimulated the secretion of immunoreactive adrenorphin as well as catecholamines from cultured human pheochromocytoma cells. Adrenorphin was a more potent inhibitor of catecholamine secretion evoked by 10(-5) M nicotine than was met-enkephalin in cultured human pheochromocytoma cells. The 50% inhibitory concentrations (IC50) were 1.1 X 10(-6) and 6.5 X 10(-5) M for adrenorphin and met-enkephalin, respectively. The effect of adrenorphin was much the same as that of dynorphin-(1-13) (IC50, 1.0 X 10(-6) M) and BAM-12P (IC50, 4.5 X 10(-6) M). These results indicate the presence and secretion of adrenorphin in human pheochromocytomas. Adrenorphin may play an important role in regulating catecholamine secretion in human pheochromocytoma.
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PMID:Studies on adrenorphin in pheochromocytoma. 381 99

A specific radioimmunoassay was developed for beta-endorphin (1-18). The content of beta-endorphin (1-18) immunoreactivity in rat tissues was as follows: posterior pituitary 260 ng/fragment, anterior pituitary 1.46 ng/mg, hypothalamus 11.9 pg/mg. The levels were undetectable (less than 3 pg/mg) in extrahypothalamic brain, pancreas, small intestine, prostata and testis. Gel filtration and reverse-phase HPLC studies indicated that most of rat anterior pituitary immunoreactivity is due to native beta-endorphin (1-18), whereas the bulk of posterior pituitary immunoreactivity corresponds to more hydrophobic material, probably N-acetyl-beta-endorphin (1-18). Thus, beta-endorphin (1-18) is a quantitatively important novel pituitary peptide derived from proopiomelanocortin. The posterior pituitary is an especially rich source of (N-acetyl)-beta-endorphin (1-18).
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PMID:Radioimmunoassay for beta-endorphin (1-18), a novel pituitary peptide derived from proopiomelanocortin. 383 75

Peptides derived from both proenkephalin and prodynorphin have been identified in guinea pig adrenal medulla. In extracts of whole adrenal glands radioimmunoassays directed to the prodynorphin-derived peptides alpha-neoendorphin, dynorphin A, and dynorphin B detected high concentrations of immunoreactive material ranging from 113 to 216 pmol/gm. The concentrations measured by radioimmunoassays directed to the proenkephalin products met-enkephalin-Arg-Gly-Leu and met-enkephalin-Arg-Phe were 878 and 484 pmol/gm, respectively. No metorphamide or dynorphin(1-8) could be detected in the adrenals. Leucine-enkephalin immunoreactivity which can be generated from either prodynorphin or proenkephalin could also be measured in the extracts. Gel filtration showed the immunoreactive material, with the exception of that measured by the alpha-neoendorphin radioimmunoassay, to be predominantly of high molecular weight ranging from Mr = 3,000 to 12,000. Immunocytochemistry, using well characterized antisera to alpha-neoendorphin and met-enkephalin-Arg-Gly-Leu, demonstrated that the prodynorphin and proenkephalin products were present in the same cells in the medulla region of the gland. The results show that two opioid peptide precursors can be localized in the same cells and exhibit some common features in their processing. As a relatively homogeneous, localized system, the guinea pig adrenal gland should prove a valuable, in vivo model for the study of co-localized opioid precursors.
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PMID:Co-localization and characterization of immunoreactive peptides derived from two opioid precursors in guinea pig adrenal glands. 390 23

The qualitative and quantitative aspects of beta-endorphin-related peptides present in the human pituitary gland were investigated using autopsy pituitaries as starting material. Beta-endorphin-related peptides were isolated from two batches of autopsy pituitaries (40 and 51 glands) by acid acetone extraction, acetone precipitation, gel filtration (Sephadex G-75 or Bio Gel P 4/P 10), cation exchange chromatography (SP-Sephadex C-25) and different types of reversed phase high performance liquid chromatography (RP-HPLC). Purification was monitored using beta-endorphin radioimmunoassay, which is specific to the 6-17 sequence of beta-endorphin. Methods suitable for microscale structural analyses of the isolated peptides were developed. Amino acid analysis was performed using quantitative precolumn dansylation and RP-HPLC separation of the dansyl amino-acids. Amino-terminal sequences were determined using semi-microscale manual Edman degradation. An RP-HPLC system was set up for sensitive and unambiguous identification of the released phenylthiohydantoin amino acids. The immunoreactive peptide with the highest apparent molecular weight was identified as human beta-lipotropin on the basis of its amino acid composition. The results of amino-terminal sequence analysis, amino acid compositions of the HPLC-isolated tryptic peptides and carboxy-terminal residue analysis were fully compatible with the previously suggested structure of human beta-lipotropin. About 20% of isolated pituitary beta-lipotropin appeared to be in deamidated form. No proteolytically degraded forms of beta-lipotropin were detected. The yield of pure beta-lipotropin was 6.7-7 nmol/gland. A peptide with properties similar to human beta-endorphin was isolated with a yield of 1.5-5 nmol/gland. Amino acid composition, amino-terminal sequence, carboxy-terminal residue and immunochemical properties were identical to those of human beta-endorphin as suggested previously. About 25% of beta-endorphin appeared to be in methionine sulphoxide form as isolated. Several minor components of immunoreactivity with molecular weight similar to beta-endorphin were detected but none of these were obtained pure even after three RP-HPLC purification steps. Further purification was impossible due to the scarcity of the starting material. A previously unidentified beta-endorphin-related peptide with an apparent molecular weight of about 2000 daltons was isolated from the autopsy pituitaries. Amino acid composition, amino-terminal residue, carboxy-terminal sequence and immunochemical properties showed the peptide to be beta-endorphin 1-18. The yield of isolated peptide was 0.4 nmol/gland. This peptide has not been pr
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PMID:Beta-endorphin-related peptides in the human pituitary. Isolation and characterization of major immunoreactive peptides, including the formerly unrecognized peptide beta-endorphin 1-18. 609 13

Gel electrophoretic separation of proteins phosphorylated in a postmitochondrial supernatant fraction of brain in the presence of spermine or adrenocorticotropin (ACTH) indicated modulation in only one region (30 kD) of the gel. The 30-kD (pp30) protein together with enzyme activity catalyzing its phosphorylation and sensitivity of the phosphorylation to spermine and ACTH were retained in a free polyribosomal fraction of this extract. ACTH(11-24) inhibited phosphorylation at all the spermine or Mg2+ concentrations tested. Structure-activity studies revealed that the inhibitory activity within ACTH(1-24) resides in the sequences ACTH(11-24), (5-18, 17Lys, 18Lys)-NH2, (15-24), (7-16)-NH2, and (1-16)-NH2 and can also be found in certain polylysine fragments. Phosphorylation under conditions suitable for measuring protein synthesis revealed only one phosphoprotein (pp30), sensitive to both ACTH(15-24) and spermine. The possibility of a relationship between modulation of pp30 phosphorylation and modulation of brain cell-free protein synthesis is discussed in relation to the effects of ACTH, spermine, and Mg2+.
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PMID:Modulation of phosphorylation of a 30-kD polyribosomal protein (pp30) by ACTH and spermine: comparison with modulation of brain protein synthesis. 609 44

Using a radioimmunoassay for gamma 3-melanotropin (gamma 3-MSH), gamma-melanotropin-like immunoreactivity (gamma-MSH-LI) was detected in plasma extracts of normal subjects before and after metyrapone administration. Plasma gamma-MSH-LI from four normal men rose significantly after a single oral administration of metyrapone (30 mg/kg of body weight). Gel chromatographic study of plasma extract after metyrapone administration showed a single peak of gamma-MSH-LI near the elution position of mouse 16K fragment, however smaller forms of gamma-MSH-LI were not detected.
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PMID:Big form of gamma-melanotropin-like immunoreactivity in normal human plasma. 609 19

The levels of beta-endorphin and adrenocorticotropic hormone (ACTH) were measured by radioimmunoassays in rat plasma, pituitary, hypothalamus and pineal at different times of the day. Significant diurnal variations in the levels of immunoreactive beta-endorphin were detected in the plasma and hypothalamus. Immunoreactive ACTH levels varied significantly during the darklight cycle in the posterior lobe of the pituitary, and in the hypothalamus, but not in the plasma. The hormone levels were high during the dark, except in the posterior pituitary, where the highest levels were detected during the light period. Gel chromatography showed that both beta-endorphin and ACTH immunoreactivities in plasma and tissues consist of multiple components.
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PMID:24-hour pattern of immunoreactive beta-endorphin and adrenocorticotropic hormone (ACTH) in rat plasma and tissues. 609 36

Confluent 3T3-L1 fibroblasts incubated for 72 h with methylisobutylxanthine, dexamethasone, and insulin differentiate and acquire phenotypic characteristics of mature adipocytes, including hormone-sensitive cAMP phosphodiesterase activity located in a particulate fraction of homogenates. About 10 days after initiating differentiation, a maximally effective concentration of insulin (100 pM) increased particulate cAMP phosphodiesterase activity 40 to 60% in 8 min; activation persisted for at least 30 min in the presence of insulin. Incubation of adipocytes for 6-8 min with agents that increased cAMP, e.g. 1 microM epinephrine, 0.1 microM isoproterenol, corticotropin (2 mu units/ml), or thyroid-stimulating hormone (15 ng/ml), also increased particulate phosphodiesterase activity 40-60%. Changes in phosphodiesterase activity produced by epinephrine tended to lag behind changes in cAMP. Insulin, epinephrine, and corticotropin increased Vmax, not Km (0.5 microM), for cAMP. Particulate phosphodiesterase activity, solubilized with detergent, eluted in a single peak from DEAE-Bio-Gel. Insulin and epinephrine increased the activity eluted in this peak. Neither insulin nor lipolytic hormones increased activity in soluble fractions from differentiated cells or particulate or soluble fractions from undifferentiated cells. Incubation of adipocytes for 48 h with 1 microM dexamethasone prevented insulin-induced activation of the particulate phosphodiesterase and did not alter basal activity. After incubation for 72 h with 0.1 microM dexamethasone, insulin and epinephrine activation were abolished. These effects of dexamethasone on hormonal regulation of particulate phosphodiesterase activity could account for some of the so-called permissive effects of glucocorticoids on cAMP-mediated processes as well as the "anti-insulin" effects of glucocorticoids.
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PMID:Hormone-sensitive particulate cAMP phosphodiesterase activity in 3T3-L1 adipocytes. Regulation of responsiveness by dexamethasone. 619 Aug 11

In mammals, calcitonin (CT) is synthesized, stored, and secreted by intrathyroidal C cells. Several reports have suggested the presence of immunoreactive CT in the pituitary gland. We have studied the rat pituitary gland using a radioimmunoassay for CT and have also found immunoreactive CT-like material. Assay of extracts of whole rat pituitary glands was performed using a radioimmunoassay for human CT, which gave identical dilution curves with synthetic human CT (hCT), synthetic rat CT (rCT), and mouse and rat thyroid extracts, but not with a variety of other pituitary and hypothalamic peptides. Immunoreactive CT (iCT) content of extracts of whole pituitary glands ranged from 6 to 72 pg/mg wet weight of tissue (60-840 pg/whole pituitary gland), whereas iCT was not measureable (less than 5 pg/mg tissue) in similar extracts of hypothalamus and cerebral cortex. Gel filtration studies of pituitary extracts showed a peak of iCT, which eluted with 125I-rCT and diluted in parallel with rCT. To investigate whether the pituitary iCT was related to pro-opiomelanocortin, extracts of ACTH-producing AtT20/D16 cells from mice, which contain the ACTH precursor in large quantities, were examined and no iCT was found. Immunohistochemical studies of rat pituitary glands with peroxidase-antiperoxidase and immunofluorescent techniques showed positive staining for CT in cells in the pars anterior, but not in the pars intermedia of pars nervosa; this staining was not eliminated when the antiserum was absorbed with CT under conditions that completely obliterated staining of rat thyroid glands. Double staining demonstrated essentially two distinct populations of cells, one positive for CT and another positive for ACTH, with less than 1% of the cells positive for both ACTH and CT. Immunoreactive CT-like material was present in the pituitary glands of rats thyroparathyroidectomized 18 days before they were killed, but was diminished. Biosynthetic labeling in vitro of rat pituitary glands with 3H-leucine showed incorporation into prolactin; there was no incorporation into CT. No in vitro secretion of iCT by whole rat pituitary glands either basally or after high K+ stimulation was observed. We conclude that: (1) a substance that has certain immunologic and size characteristics of CT is present in minute amounts in the pituitary gland of rats; (2) this material is not a part of the ACTH precursor; and (3) positive immunohistochemical staining in pituitary glands may not be specific for authentic CT.
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PMID:Pituitary immunoreactive calcitonin-like material: lack of evidence for cross-reactivity with pro-opiomelanocortin. 619 Nov 78

The levels of immunoreactive-polypeptide hormones were measured in tissue extracts of eight uterine cervical cancers by specific radioimmunoassays. In one case with argyrophil granules, high levels of somatostatin, pancreatic polypeptide, calcitonin, and vasoactive intestinal polypeptide (VIP) were found, ranging from 160 to 880 ng/g tissue. A second argyrophil cancer contained 310 ng/g tissue of somatostatin, and a third contained 1100 ng/g tissue of adrenocorticotropic hormone (ACTH) and 380 ng/g of beta-melanocyte-stimulating hormone (beta-MSH). In addition, of the five nonargyrophil cancers tested, four contained calcitonin, three had VIP, two had either somatostatin or glucagon, and one contained ACTH and beta-MSH; the measured levels of these hormones ranged from 1.4 to 2.3 ng/g tissue. Gel filtration on a Sephadex G-75 column showed that the immunoreactive-polypeptide hormones in the first case were chromatographically similar to the authentic or prehormones. These results indicate that ectopic production of multiple immunoreactive-polypeptide hormones is common not only in argyrophil cell carcinoma, but also in nonargyrophil cell carcinoma of the cervix.
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PMID:Production of immunoreactive-polypeptide hormones in cervical carcinoma. 619 1


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