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 process used for extracting adrenocorticotropic hormone (ACTH) from plasma in the Searle ACTH immunoassay kit involves a loss of 70-100% of the biological activity of the ACTH.
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PMID:Loss of ACTH biological activity in plasma during extraction with a commercial radioimmunoassay kit. 17 83

beta-Endorphin, an opioid peptide that contains 31-amino acids derived from proopiomelanocortin, has been implicated in a variety of disorders. To understand its role in pathophysiological states, its levels have been determined in body fluids, particularly in serum or plasma, with the use of commercially available radiometric assay kits. Because the circulating levels of this endogenous opioid peptide are small and antibodies can cross-react with chemically related peptides to different degrees and give rise to faulty interpretation of the data, the performance characteristics of the available radioimmunoassay kits for beta-endorphin from the Immuno Nuclear Corporation, Stillwater, Minn, the New England Nuclear Corporation, Boston, Mass, and the Nichols Institute, San Juan Capistrano, Calif, were evaluated. In overall performance, the Nichols kit was found to be the most reliable in this laboratory, even though the sensitivity of the Immuno Nuclear kit was better at lower concentrations of beta-endorphin. Serum was better than plasma in terms of recovery of beta-endorphin. When collected on ice, no significant loss in beta-endorphin immunoreactivity was observed at 1 hour. The use of edetic acid (EDTA), siliconized edetic acid, and aprotinin (Trasylol)-added siliconized edetic acid tubes was not helpful in improving the performance of the assay. The optimal condition to collect the specimen was to use glass tubes, place the glass tubes on ice immediately, separate the serum, and freeze the sample within 1 hour of collection.
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PMID:Detection of beta-endorphin in human blood. A study of performance characteristics of different radiometric systems. 149 63

A commercially available radioimmunoassay (RIA) kit for measurement of human adrenocorticotropin (hACTH) was validated for use in dogs. Assay sensitivity was 3 pg/ml. Intra-assay coefficient of variation (x 100; CV) for 3 canine plasma pools was 3.0 (mean +/- SD, 33 +/- 0.99 pg/ml), 4.2 (71 +/- 2.4 pg/ml) and 3.7 (145 +/- 3.7 pg/ml) %. Interassay CV for 2 plasma pools measured in 6 assays was 9.8 (37 +/- 3.6 pg/ml) and 4.4 (76 +/- 3.4 pg/ml) %, respectively. Dilutional parallelism was documented by assaying 2 pools of canine plasma at 3 dilutions and correcting the measured result for dilution. Corrected mean concentrations for the first pool were 33 (+/- 0.99), 36 (+/- 4.3), and 33 (+/- 6.8) pg/ml; corrected mean concentrations for the second pool were 145 (+/- 5.4), 141 (+/- 10.8) and 125 (+/- 3.4) pg/ml. Recovery of 1-39hACTH added to canine plasma (6.25, 12.5, 25.0, 50.0, and 100.0 pg/ml) was linear and quantitative (slope = 0.890, R2 = 0.961). To test whether anticoagulant or the protease inhibitor, aprotinin, influences ACTH concentration in canine plasma, ACTH was measured in canine blood collected in 4 tubes containing anticoagulant: heparin (H), heparin + 500 kallikrein inhibitor units (KIU) of aprotinin/ml (HA), EDTA (E), and EDTA + aprotinin (EA). Plasma ACTH concentration was the same when samples containing H and HA, or HA and E were compared, and was significantly (P less than 0.01) lower in samples containing EA.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of sample handling on adrenocorticotropin concentration measured in canine plasma, using a commercially available radioimmunoassay kit. 170

Solutions of human beta-endorphin were applied topically to the eyes of rabbits. Atrial blood was collected and plasma beta-endorphin was assayed using a Nichols Diagnostics radioimmunoassay kit. Levels peaked rapidly (within 10-20 min) at greater than 5 ng/ml with 1% beta-endorphin and no enhancer, and then returned to background within 2 h. When the permeation enhancers Brij-78 or BL-9 were added to the formulation applied topically, plasma levels were elevated above 30 ng/ml and remained elevated above 1 ng/ml over 1 h. Plasma levels were actually higher after topical application using either enhancer than after intravenous injection at the collection points of 45 min and later. The data suggest that topical application to the eyes can be an efficacious method of systemic delivery of peptide drugs.
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PMID:Effect of permeation enhancers on beta-endorphin systemic uptake after topical application to the eye. 178 58

The interference of immunoglobulins in the radioimmunoassay (RIA) of human beta-endorphin was investigated. Human IgM showed no cross-reactivity. Human IgA showed a weak cross-reaction, but the dilution curve of IgA did not show parallelism with the standard curve of beta-endorphin, thus indicating its antigenic difference. The dilution curves of human IgG showed 0.18% displacement with respect to the human beta-endorphin standard curve, with good parallelism. Moreover, five patients with multiple myeloma of the IgG type showed falsely elevated beta-endorphin levels. We investigated the possibility that certain IgGs may be responsible for the displacement of [125I]beta-endorphin in the beta-endorphin kit. The apparent beta-endorphin level of plasma from multiple myeloma patients was markedly decreased after affinity chromatography of the serum on protein A-Sepharose. In another 3 patients with multiple myeloma, we examined IgG interference by measuring the beta-endorphin levels in their lyophilized IgG diluted with saline. The results demonstrated high values of 20.2, 25.5 and 21.2 pmol/l respectively, also showing good parallelism. These immunological parallels to human beta-endorphin verify that a part of the amino acid sequence of human IgG is similar to that of human beta-endorphin. Consequently, in the measurement of beta-endorphin with polyclonal antibody, the results may sometimes be spuriously high due to cross-reaction with IgG, e.g., in patients with IgG myeloma. To avoid IgG interference, a specific monoclonal antibody to synthetic beta-endorphin should be used rather than polyclonal antibodies.
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PMID:Interference of immunoglobulins in the radioimmunoassay of human beta-endorphin. 208 65

In this study, we have determined the beta-endorphin concentrations in the plasma of 11 cases during the first 3 months of pregnancy, as well as the corresponding products of conception, collected by hysterosuction, during the course of voluntary abortion. The purpose of this study is to compare the values obtained by the analysis of maternal plasma and the material collected by hysterosuction. The beta-endorphin concentrations were obtained by radioimmunologic methods using a kit which allows a separation from beta-lipotropin. The specimens obtained by hysterosuction (8 +/- 1.7 pmol/l) showed significantly higher levels of beta-endorphin than those observed in the maternal plasma (2.6 +/- 0.3 pmol/l). Thus, already in the earliest gestational period, the data are consistent with a feto-placental origin for this opioid peptide.
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PMID:Maternal and embryonal/fetal beta-endorphin concentrations during the first trimester of pregnancy. 252 58

Recently it was reported that beta-endorphin-like immunoreactivity (beta-ELI) was detectable not only in plasma, but also in erythrocytes. To assess the presence of beta-ELI in human erythrocytes and also to determine if erythrocyte-associated beta-ELI may be released into plasma in stress situations, beta-ELI concentrations in plasma and erythrocytes were measured in pairs in normal menstrual cyclic women, postmenopausal women and pregnant women during delivery. After separating from plasma, erythrocytes pellets were lysed by adding distilled water. Extraction of beta-ELI in plasma and RBC lysate was performed with a Sep-pack C18 cartridge (Waters Associates Inc.), and beta-ELI concentrations were measured with a New England Nuclear radioimmunoassay kit. The following results were obtained: 1) There certainly are two pools of beta-ELI; one in plasma, the other erythrocyte-associated. 2) During delivery beta-ELI concentrations in plasma showed a great change, but beta-ELI concentrations in erythrocytes remained almost unchanged. From these results it is unlikely that erythrocytes act as a peripheral reservoir of circulating beta-ELI.
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PMID:[Beta-endorphin-like immunoreactivity in peripheral blood, especially in erythrocytes during delivery]. 296 89

Modifications in beta-endorphin levels in cerebrospinal fluid have been described following lumbar puncture and metrizamide injection. Cerebrospinal fluid (CSF) samples were obtained from 19 patients before and after lumbar myelography. Two radioimmunoassays were used. One was a commercial kit; and the other one (developed in our laboratory) used a chromatographic removal from beta-lipotrophin. No definite variation of beta-endorphin was observed after myelography, using either the commercial kit or a more sophisticated procedure. Some controls were prepared by adding metrizamide or Iopamidol in vitro to CSF samples in order to evaluate a non specific effect of these contrast media. The results obtained with these controls suggest that the discrepancy of results may be explained simply by assay artifacts due to drug interferences when using the commercial methods.
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PMID:Beta-endorphin levels after intrathecal infusion of iodinated contrast media. 297 14

In 1984 and at the beginning of 1985 the authors carried out radioimmunoassays (SORIN-CIS kit) the plasma levels of ACTH in 116 multiple sclerosis patients (m-52, f-64) and in 10 cases this radioimmunoassay was done in the cerebrospinal fluid (m-5, f-5). The control group comprised 90 patients with ischialgia and neuroses. The normal value in the plasma was from 0 to 80.86 pg/ml, and in the fluid it was from 0 to 77.08 pg/ml. In multiple sclerosis patients the plasma ACTH level was from 0 to 286.9 pg/ml, in the cerebrospinal fluid from 0 to 89 pg/ml. The values of ACTH were significantly higher in multiple sclerosis patients, mainly in males. In the fluid the level of ACTH was significantly higher in the studied patients. No significant differences in ACTH levels were found between males and females with multiple sclerosis, and in the control group this level was higher in females. Raised ACTH level was found mainly in multiple sclerosis with lung duration of the disease (10 years) at the time of exacerbations. The authors continue studies on the axis hypothalamus-hypophysis-adrenals, on various hormones, prostaglandins, beta-endorphin, biochemical markers, cAMP, cCMP, arylosulphatase A and B MBC etc.
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PMID:[ACTH in the plasma and cerebrospinal fluid in patients with multiple sclerosis]. 303 9

The authors determined in 1984 by radioimmunoassay (INEP kit) the serum prolactin concentration in 76 multiple sclerosis patients (33 males and 34 females) aged from 21 to 53 years, with disease duration from 2 to 30 years. The control group comprised 110 healthy subjects. Normal prolactin values were 150-750 mIU/ml in females and 150-500 mIU/ml in males. In about one-third of the patients raised prolactin level was found which failed to correlate with the age of the patients and with increased beta-endorphin level in them. The authors suppose that hyperprolactinaemia may be of importance in certain clinical signs of multiple sclerosis. Further investigations on prolactin are conducted with reference to the circadian rhythm of prolactin secretion and dynamic tests.
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PMID:[Prolactin in the blood serum of patients with multiple sclerosis]. 367 May 26


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