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)

The liver is innervated by sympathetic efferent, spinal afferent, vagal afferent and probably also vagal efferent fibres. To assess potential functional roles of the various neuronal subsets, data on transmitter systems are of crucial importance. This study was aimed at elucidating a possible opioidergic system in the mouse and rat liver. In particular relationships of opioidergic neurons to immune cells were emphasised. Material from perfusion-fixed mice ( n=29) of different strains (BALB/c, NMRI, C57Bl6, SV 129 inbred) and Wistar rats ( n=7) was cryosectioned at 12-14 microm and incubated for single or double immunofluorescence. Antibodies directed against dynorphin A, met-enkephalin, endomorphin 1 and 2, mu, kappa- and delta-opioid receptors (MOR, KOR, DOR), tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DBH), CD4, CD8 and macrophages were used. Binding sites were detected using Cy3-, FITC-, DTAF-, Cy2-, Alexa 555- and Texas red-tagged secondary antibodies. Specimens were analysed using confocal laser scanning microscopy (CLSM). Numerous nerve fibres staining for dynorphin were found in periportal areas of both mouse and rat livers. Neither met-enkephalin nor endomorphin could be detected in axons. No immunopositive neuronal cell bodies or other cellular elements were seen. All dynorphin positive fibres costained for TH while not every TH-positive fibre costained for dynorphin. Thus, most if not all dynorphin-positive nerve fibres may be of sympathetic origin. KOR immunostaining could be localised to round mononuclear cells which often costained for CD4, less frequently for CD8 and rarely for the pan-macrophage marker BM8. Altogether, about 45% of KOR-positive cells were identified as T-lymphocytes. In some instances, close appositions of dynorphin-positive axons to KOR-positive cells were revealed by CLSM. No KOR immunoreactivity was detected in nerve fibres. Hence, sympathetic neurons innervating the liver may interfere with inflammatory processes, in addition to their well-established beta(2)-adrenergic effect, via an opioidergic action on immune cells.
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PMID:Close apposition of dynorphin-positive nerve fibres to lymphocytes in the liver suggests opioidergic neuroimmunomodulation. 1290 70

The ability of neuropeptide Y to potently stimulate food intake is dependent in part upon the functioning of mu and kappa opioid receptors. The combined use of selective opioid antagonists directed against mu, delta or kappa receptors and antisense probes directed against specific exons of the MOR-1, DOR-1, KOR-1 and KOR-3/ORL-1 opioid receptor genes has been successful in characterizing the precise receptor subpopulations mediating feeding elicited by opioid peptides and agonists as well as homeostatic challenges. The present study examined the dose-dependent (5-80 nmol) cerebroventricular actions of general and selective mu, delta, and kappa1 opioid receptor antagonists together with antisense probes directed against each of the four exons of the MOR-1 opioid receptor gene and each of the three exons of the DOR-1, KOR-1, and KOR-3/ORL-1 opioid receptor genes upon feeding elicited by cerebroventricular NPY (0.47 nmol, 2 ug). NPY-induced feeding was dose-dependently decreased and sometimes eliminated following pretreatment with general, mu, delta, and kappa1 opioid receptor antagonists. Moreover, NPY-induced feeding was significantly and markedly reduced by antisense probes directed against exons 1, 2, and 3 of the MOR-1 gene, exons 1 and 2 of the DOR-1 gene, exons 1, 2, and 3 of the KOR-1 gene, and exon 3 of the KOR-3/ORL-1 gene. Thus, whereas the opioid peptides, beta-endorphin and dynorphin A(1-17) elicit feeding responses that are respectively more dependent upon mu and kappa opioid receptors and their genes, the opioid mediation of NPY-induced feeding appears to involve all three major opioid receptor subtypes in a manner similar to that observed for feeding responses following glucoprivation or lipoprivation.
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PMID:NPY-induced feeding: pharmacological characterization using selective opioid antagonists and antisense probes in rats. 1594 35

We have shown that supplementation of proinflammatory agent with a high dose of morphine not only abolishes inflammation-related pain symptoms but also inhibits influx of leukocytes to the inflamed peritoneal cavity. Present investigations focused on effects of morphine on proopiomelanocortin and prodynorphin systems during zymosan-induced peritonitis. Males of SWISS mice were ip injected with zymosan (Z, 40 mg/kg) or zymosan with morphine (ZM, 20 mg/kg). At time 0 (controls) and 4 and 24h after stimulation, peritoneal leukocytes (PTLs) were counted, PTL levels of opioid peptides (beta-endorphin and dynorphin) measured by radioimmunoassays, while mRNAs coding their respective precursors (POMC and PDYN) and receptors (MOR and KOR) determined by QRT-PCR. Influx of inflammatory PTLs, mainly PMNs, was significantly delayed by morphine co-injection. Total levels of beta-endorphin and dynorphin corresponded with PTL numbers, while levels per cell were similar in all groups except of beta-endorphin, decreased in ZM at 4h. Levels of both peptides in peritoneal fluid were increased in Z and ZM groups at 4h, while at 24h only in case of beta-endorphin in Z group. POMC was increased only in ZM group at 4h of peritonitis, while PDYN in both Z and ZM groups at the same time. MOR mRNA was increased 24h after injection in Z and ZM groups, while KOR mRNA was similar in all groups except of decrease in Z at 24h. In conclusion, endogenous opioids and their receptors are involved in zymosan-induced peritonitis and affected in various ways by morphine co-injection.
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PMID:Morphine-induced changes in the activity of proopiomelanocortin and prodynorphin systems in zymosan-induced peritonitis in mice. 1597 27

The inferior colliculus is a critical structure for processing auditory information and receives ascending and descending synaptic auditory projections. In addition to GABAergic and glutamatergic innervations, other neurotransmitter systems are also reported in the inferior colliculus, including opioid peptides. In the present study, the relative distribution of each type of opioid receptor, mu (MOR), delta (DOR) and kappa (KOR) within GABAergic neurons in the inferior colliculus was examined. GABA immunoreactivity was expressed by small, medium and large neurons and distributed in the central nucleus and the pericentral nucleus of the inferior colliculus. Immunostaining for MOR, DOR and KOR receptors was found in both disc-shaped cells and stellate cells. Punctiform beta-endorphin immunolabelling was observed in the proximity of GABA-positive neurons. Co-localization of GABA and MOR receptors was observed in neurons and nerve terminals in the central nucleus, dorsal cortex and external cortex of the inferior colliculus. Quantification of the co-localization patterns determined that a higher proportion of GABA neurons was associated with MOR receptors compared with KOR or DOR receptors.
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PMID:Relationship of opioid receptors with GABAergic neurons in the rat inferior colliculus. 1704 Apr 71