Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Total RNA has been prepared from human leukocytes from patients with chronic lymphoblastic leukemia (CLL) as well as from post mortem human caudate nucleus, hypothalamus, cerebellum and cerebral cortex. Dot-blot and Northern blot analysis, using a human proenkephalin A clone and SP-6 derived "complementary" proenkephalin A RNA respectively, revealed the existence of proenkephalin A-like RNA:s in CLL-leukocytes with the same characteristics as in caudate nucleus, hypothalamus, and cortex. Furthermore, RIA and Western blot analysis confirmed that immunoreactive pro-enkephalin A activity is present in human CLL-leukocytes. The progress in DNA recombinant technology has allowed the study of opioid peptide regulation at the transcriptional and translational-posttranslational level. Studies on the distribution and quantitation of preproenkephalin A mRNA in bovine, rat and human central nervous system (CNS) have recently been reported. Different opioid peptides, related to the enkephalins, dynorphins and beta-endorphin have also been detected in tissues outside the CNS including the adrenal medulla and in pheochromocytomas. Northern blot analysis and cDNA-cloning confirmed that the proenkephalin A gene is indeed expressed in these tissues. Proenkephalin A derived peptides are potentially significant in nervous disorders. We have chosen to investigate whether the corresponding gene is expressed not only in CNS-tissues but also in human leukocytes, cells readily obtained in individual patients.
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PMID:Proenkephalin A-like mRNA in human leukemia leukocytes and CNS-tissues. 378 78

Opioid peptides derived from prodynorphin were localized immunocytochemically to dentate granule cells and mossy fibers of the rat hippocampus with antisera against dynorphin A(1-17) and dynorphin B. Extracts of microdissected hippocampal regions were resolved by reverse phase and molecular exclusion chromatography to identify the molecular forms of the dynorphin A immunoreactivity and to quantify regional contents. Results demonstrated that the relative concentration of dynorphin A within each dissected region of hippocampus agreed well with the distribution of dynorphin A detected by immunocytochemical methods. Immunostaining of proenkephalin-derived opioid peptides, [Leu5]enkephalin and bovine adrenal medullary peptide-22P, was concentrated in cell bodies of the entorhinal cortex, nerve fibers in the perforant pathway, and terminals in the outer molecular layer of the dentate gyrus. Light immunostaining of granule cells and mossy fibers with these antisera was also found. The relative concentration of [Leu5]enkephalin immunoreactivity in each microdissected region of the hippocampus also agreed well with the distribution of [Leu5]enkephalin immunostaining. Chromatography of hippocampal regional extracts demonstrated that the immunoreactivity measured was due to the presence of authentic [Leu5]enkephalin. The probable neurotransmitter function of both [Leu5]enkephalin and dynorphin A was shown by their calcium-dependent release after in vitro depolarization of hippocampal tissue. The reported presence of beta-endorphin in hippocampus was not verified. Comparison of the hippocampal distribution and content of prodynorphin and proenkephalin-derived opioids suggests that separate populations of neurons containing these two peptide families form distinct neurotransmitter systems of roughly equal concentration.
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PMID:Characterization of the prodynorphin and proenkephalin neuropeptide systems in rat hippocampus. 383 45

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

Evaluation of hypotheses concerning the role of opioid peptides in the human adrenal is handicapped by the lack of information concerning the nature of these peptides. We studied the content of opioid peptides in whole adrenal tissue using several RIAs, including one which cross-reacts with all opioid peptides tested. Opioid peptides were localized to granules which behaved like chromaffin granules on crude sucrose density separation. beta-Endorphin immunoreactivity was a minor component, which was found principally in the form of beta-endorphin-(1-31). The majority of the remaining peptides probably were products of proenkephalin. The human postmortem tissue differed from bovine tissue in that the major accumulating products of this precursor were the size of the enkephalins and their small congeners, and not the intermediate-sized (mol wt, approximately 1500-4000) peptides that predominated in bovine tissue. We also found evidence of the presence of the 25-amino acid complex opioid, peptide E, in human tissue.
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PMID:Opioid peptides in human adrenal: partial characterization and presence of adrenal peptide E. 403 Oct 11

The three endogenous opioid precursors of almost 30000 Da are pro-opiocortin, proenkephalin and prodynorphin. Pro-opiocortin contains beta-endorphin, melanotropins and ACTH. Proenkephalin yields one [Leu5]enkephalin, three [Met5]enkephalins, one [Met5] enkephalyl-Arg-Arg-Val-NH2 (metorphamide or adrenorphin), one [Met5]enkephalyl-Arg-Gly-Leu and one [Met5]enkephalyl-Arg-Phe. [Leu5]enkephalin is common to all fragments of prodynorphin; its carboxyl extension by Arg-Lys leads to alpha- and beta-neo-endorphin and its carboxyl extension by Arg-Arg gives two dynorphins A and B of 17 and 13 amino acids, respectively. Another endogenous peptide is dynorphin A (1-8). The three main opioid binding sites are mu, delta and kappa. Their analysis has been facilitated by the synthesis of analogues of peptides and non-peptide compounds, which have selective agonist or antagonist action at only one site. The various physiological roles of the three types of the opiate receptor have so far not been sufficiently investigated.
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PMID:Radioligands for probing opioid receptors. 609 50

Dynorphin(1-8) immunoreactivity was visualized by immunohistofluorescence in hypothalamic magnocellular neurons of the rat. No immunoreactive met-enkephalin-Arg6-Gly7-Leu8, a fragment of the adrenal medulla pro-enkephalin molecule, was detected in magnocellular neurons. However, a strong met-enkephalin-Arg6-Gly7-Leu8-like immunostaining was seen in other regions of the brain. These results suggest that in magnocellular neurons dynorphin(1-8) exists independently from pro-enkephalin and therefore the magnocellular neurons represent a third opioid peptide neuronal system in brain. These observations, however, do not rule out a coexistence of proenkephalin and dynorphin-related peptides in other regions of the brain.
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PMID:Immunohistochemical localization of dynorphin (1-8) in hypothalamic magnocellular neurons: evidence for absence of proenkephalin. 613 Apr 34

The receptor preferences of opioids in the mouse vas deferens was tested by means of tolerance and cross-tolerance studies. The preparations were rendered tolerant in situ by superfusion with the kappa-receptor agonist dynorphin and with alpha-neoendorphin, respectively, and set up in vitro in the presence of the respective peptide to maintain tolerance. The investigations revealed strong kappa-agonistic activities both of alpha-neoendorphin and of dynorphin and its fragments 1-13 and 1-11. As the dynorphin chain shortened, the kappa-receptor activity declined and delta-receptor activity became progressively apparent. Interestingly, the octapeptide met-enkephalin[Arg6,Gly7,Leu8], a fragment of the adrenal medulla proenkephalin, also displayed considerable kappa-agonistic properties under the experimental conditions employed. Presumably, the decapeptide alpha-neoendorphin and the octapeptide met-enkephalin[Arg6,Gly7,Leu8] cover in addition to the kappa-receptor population in the MVD further opiate receptors, most probably delta-receptors.
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PMID:Endogenous ligands for kappa-opiate receptors. 613 66

The nucleotide sequence of a 6.8-kb region of human DNA containing the proenkephalin gene and flanking regions is reported. The gene consists of four exons separated by three introns and spans approximately 5.3 kb of DNA. Location and identification of several repetitive DNA sequences within and flanking the gene are also described. The distribution of CpG dinucleotides as well as the extent of CpG methylation at several restriction sites within and surrounding the gene is also presented. The structural organization of the human proenkephalin gene exhibits striking similarities to the organization of the human pro-opiomelanocortin (POMC) gene. Nucleotide sequence homologies suggest that two opioid peptide precursors, proenkephalin and prodynorphin, may have arisen by duplication from a common ancestral gene.
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PMID:Primary structure of the human proenkephalin gene. 631 26

Opioid peptides are synthesized in the form of large precursors, which contain the information for more than one biologically active peptide. Using recombinant DNA technology, three opioid precursors have been sequenced: pro-opiomelanocortin (POMC), proenkephalin and prodynorphin. Analysis of the structures of these three precursors and their corresponding genes show striking similarities suggesting a common evolutionary mechanism. Regulation of POMC gene expression has been analyzed in different rat tissues. Detection of POMC mRNA in brain tissues supports the hypothesis that ACTH and endorphin peptides are synthesized in these tissues. Quantitation of POMC mRNA levels in pituitaries of rats subjected to adrenalectomy and glucocorticoid treatment shows that the feedback effect of the glucocorticoids occurs at the level of the rate of transcription of POMC mRNA.
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PMID:Regulation of opioid gene expression. 631 1

This study addressed the possible coexistence of products of the proenkephalin and prodynorphin opioid peptide precursors in single neurons of the central nervous system of the rat. Antisera directed against met-enkephalin-arg-gly-leu and against Dyn B were used in immunohistochemical preparations of sections through the rat medulla. Examination of serial three micron frozen sections stained alternately with the two different antisera revealed that the majority of labelled neurons stain with only one of the two antisera. In specific area, however, immunoreactive m-enk and Dyn B could be detected in the same neuron. This was particularly true of the caudal ventrolateral nucleus of the solitary tract, where the two peptides were colocalized in most neurons. Other areas where the two peptides coexist include the midline raphe and the nucleus reticularis paragigantocellularis. These data provide the first evidence for colocalization of different opioid peptide families in single CNS neurons.
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PMID:Colocalization of immunoreactive proenkephalin and prodynorphin products in medullary neurons of the rat. 639 21


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