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 effect of acute and chronic nicotine treatment of rats on the mRNA levels coding for the three opioid peptide precursors, for provasopressin and for the alpha 3 subunit of nicotinic receptors in brain, pituitary and/or adrenal medulla of rats was investigated. Nicotine was found to increase the levels of proenkephalin mRNA in the adrenal medulla, but did not affect the levels of PENK mRNA in striatum, hypothalamus and hippocampus. The mRNA levels of prodynorphin were increased together with that of provasopressin in the hypothalamus after nicotine, whereas the prodynorphin mRNA levels in the hippocampus and the striatum remained unchanged. Nicotine treatment resulted in an increase in the pro-opiomelanocortin mRNA levels in the anterior pituitary and in a decrease in the intermediate pituitary, but did not change the levels of pro-opiomelanocortin mRNA in the hypothalamus. The levels of mRNA coding for the alpha 3 subunit of nicotinic receptors in the hypothalamus and the adrenal medulla remained unchanged. The increase in the prodynorphin and provasopressin mRNA levels in the hypothalamus was most pronounced 1 day after s.c. application of two doses of 0.4 mg/kg nicotine (about 100% above control). A smaller increase in mRNA concentrations (about 30%) was found after tonic infusion of the drug for 4 days (4 mg/kg per day), whereas no change was observed after tonic infusion of nicotine for 7 and 14 days indicating the development of complete tolerance.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of nicotine on mRNA levels encoding opioid peptides, vasopressin and alpha 3 nicotinic receptor subunit in the rat. 152 Oct 36

Our previous studies indicate that endogenous opioids (primarily beta-endorphin) released during stressful stimuli can interact with peripheral opioid receptors to inhibit nociception in inflamed tissue of rats. This study sought to localize opioid precursor mRNAs and opioid peptides deriving therefrom in inflamed tissue, identify opioid containing cells and demonstrate their functional significance in the inhibition of nociception. In rats with Freund's adjuvant-induced unilateral hindpaw inflammation we show that: (i) pro-opiomelanocortin and proenkephalin-mRNAs (but not prodynorphin mRNA) are abundant in cells of inflamed, but absent in non-inflamed tissue; (ii) numerous cells infiltrating the inflamed subcutaneous tissue are stained intensely with beta-endorphin and [Met]enkephalin (but only few scattered cells with dynorphin) antibodies; (iii) beta-endorphin is present in T- and B-lymphocytes, monocytes and macrophages; and (iv) whole-body irradiation suppresses stress-induced antinociception in the inflamed paw. Taken together, these data suggest that endogenous opioid peptides are synthesized and processed within various types of immune cells at the site of inflammation. Immunosuppression abolishes the intrinsic antinociception in inflammatory tissue confirming the functional significance of these cells.
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PMID:Gene expression and localization of opioid peptides in immune cells of inflamed tissue: functional role in antinociception. 160 30

The level of opioid peptides in several brain areas and in the pituitary was estimated in WAG/Rij rats, which are considered to be a genetic animal model for human absence epilepsy. In comparison with three groups of non-epileptic controls, these epileptic rats had an elevated level of the proenkephalin-derived peptide Met-enkephalin-Arg6-Gly7-Leu8 in the mesencephalon and striatum, while the level of the prodynorphin-derived peptide alpha-neoendorphin was increased in the striatum and hippocampus. In addition various age- and/or strain-related changes in these peptide levels were found in the hippocampus, thalamus, striatum, frontal cortex and neurointermediate lobe of the pituitary. No difference in the hypothalamic beta-endorphin level were found between epileptic and non-epileptic rats, though strain- and/or age-related changes in the peptide content were detected in both lobes of the pituitary. The increased level of proenkephalin and prodynorphin opioid peptides in brain structures, essential for the appearance of spike-wave discharges, suggests that these opioid systems, but not proopiomelanocortin one, may play a role in absence epilepsy.
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PMID:Endogenous opioid peptides in brain and pituitary of rats with absence epilepsy. 163 Jun

Peptides derived from prodynorphin and preproenkephalin are located in GABAergic striatal projection neurons. We have used nucleic acid hybridization techniques to investigate the role of GABA in the regulation of striatal opioid peptide gene expression. Rats were treated with the GABA-transaminase inhibitors aminooxy acetic acid, ethanolamine O-sulphate and gamma-vinyl-GABA for one week. The GABA levels in the striatum were significantly elevated after each treatment. The GABA-transaminase-inhibitors decreased the striatal levels of the opioid peptides met-enkephalin and dynorphin(1-8) and concomitantly decreased the concentrations of the mRNAs coding for proenkephalin and prodynorphin. These findings indicate that GABA exerts an inhibitory influence on prodynorphin and proenkephalin gene expression in the striatum. The mechanisms underlying these inhibitions are discussed.
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PMID:GABAergic regulation of striatal opioid gene expression. 164 82

Each class (mu, delta kappa and epsilon) of opioid receptors has a characteristic pattern of distribution in the nervous system, which may, however, exhibit species differences. The effects of opioid receptor stimulation depend on the class of receptor involved, the localization of these specific receptors and the animal species under investigation. Endogenous ligands of opioid receptors, which include more than twenty peptides, derive from three precursors:proopiomelanocortin (beta-endorphin), proenkephalin A (enkephalins) and prodynorphin (dynorphins, neo-endorphins). Generally, the endogenous ligands do not exhibit a marked selectivity toward a given receptor class. Most of the clinically used morphinomimetics, including morphine, bind preferentially to mu receptors. However, this interaction is not exclusive and these drugs are most often mixed ligands which also bind to the other classes of opioid receptors. Peripheral targets for morphinomimetics have been suspected for a long time, and recent data confirmed that opioids do act on receptors located on peripheral terminals of primary afferent fibers. The dorsal horn of the spinal cord is well known as a central site of action of morphinomimetics. At this level, opioids reduce the activity of spinal neurones that convey the nociceptive messages. The classes of opioid receptors (certainly mu [mu 2?] and a, perhaps kappa) involved in this effect, and their pre- or postsynaptic location are not firmly established to date. Further developments on these points can be expected from the use of new ligands which are highly selective of the various classes of opioid receptors.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Endorphins, opioid receptors and site of action of morphinomimetics]. 168 19

In this study the rats were repeatedly placed in a conditioning box, and 30 min later were subjected to a mild foot-shock. Anticipation of painful stimuli resulted in development of antinociception before a painful stimulus was applied. This conditioned fear-induced antinociception was antagonized by naloxone (1 mg/kg IP), as well as by ipsapirone (10 mg/kg IP), as measured by a tail-flick test. Stressed rats were hypersensitive to the analgesic action of morphine (1 mg/kg SC), but not to the specific kappa agonist U69,593 (0.1 mg/kg SC). In order to determine the involvement of the proopiomelanocortin and prodynorphin systems in stress we measured levels of their represenative peptides beta-endorphin and alpha-neoendorphin using selective RIAs. Biochemical data showed that conditioned stress evoked a marked decrease in the beta-endorphin level in the hypothalamus and both lobes of the pituitary, together with a three-fold increase in the peptide level in the plasma. In contrast, the level of alpha-neoendorphin in the hypothalamus, pituitary and spinal cord remained unchanged. Only in the plasma a decrease in that peptide content was found. Furthermore, in vitro studies showed that the spontaneous and K(+)-stimulated release of beta-endorphin from the hypothalamus of rats which had been exposed to a conditioned stimulus was enhanced, whereas the release of alpha-neoendorphin from that tissue was attenuated. These results suggest a major role of the proopiomelanocortin system and, to the lesser extent, of the prodynorphin one in the mechanism of a conditioned fear-induced stress.
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PMID:The influence of conditioned fear-induced stress on the opioid systems in the rat. 198 94

1. Aggregating fetal rat brain cells express a significant amount of proenkephalin A (PENK) mRNA, a selective radioimmunoassay shows that this mRNA is also translated into enkephalins. 2. Depolarization with potassium chloride (KCl) or veratridine increases the expression of PENK mRNA in a time-dependent fashion, with a maximal increase of sixfold. It is interesting, however, that depolarization of the same cultures with KCl has no effect on the expression of prodynorphin mRNA. 3. An increase in PENK mRNA levels has been also observed in cultures treated with 8-Br-cAMP, phorbol 12-myristate-13-acetate (TPA), or dexamethasone. 4. However, incubation of the cultures with the opioid agonist etorphine or the antagonist naltrexone did not alter PENK gene expression, suggesting that there is not feedback control of opioids on PENK biosynthesis in these cells. 5. The increase in PENK mRNA in depolarized and in TPA-dexamethasone-, or 8-Br-cAMP-treated cultures was not accompanied by a significant increase in the amount of free immunoreactive met-enkephalin. Fetal brain cell cultures are therefore a useful neuronal model system for studying the mechanism that regulated the expression of PENK mRNA.
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PMID:Regulation of proenkephalin A gene expression in aggregating fetal rat brain cells. 202 27

Serial sections from araldite-embedded rat and man pancreata were investigated immunohistochemically for the presence of prodynorphin-related peptides and alpha-endorphin. Immunoreactivities were visualized by the avidin/biotin-peroxidase complex (ABC) technique. In the human pancreas, none of the endocrine cells could be immunostained for prodynorphin-, proopiomelanocortin-related peptides and enkephalins. In the rat pancreas, however, all glucagon cells exhibited immunoreactivities for both beta-neoendorphin and dynorphin A. In addition, these cells contain alpha-endorphin-like immunoreactivity but no immunoreactivities for corticotropin, melanotropin, 16 K-fragment, alpha-N-acetyl-alpha-endorphin and enkephalins. All specificity controls confirmed that the rat endocrine pancreas might be an other source of dynorphin and endorphin with a biosynthetic pathway different from that in the pituitary or in other locations. However, concerning synthesis or degradation of peptide precursor substances interspecies differences may exist.
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PMID:Immunohistochemistry of beta-neoendorphin and dynorphin in the endocrine pancreas of rat and man. 241 98

The distribution pattern of opioid-immunoreactive nerve cell bodies and varicose fibres in the rat superior cervical ganglion after chronic administration of the tricyclic antidepressant imipramine, various receptor blockades (muscarinic antagonist, atropine sulphate; opiate antagonist, naloxone; kappa-antagonist, MR2266BS), and denervation was investigated immunohistochemically using a biotin-streptavidin-peroxydase complex method. Antisera to four peptides derived from two different precursors of the opioid family were used. In control superior cervical ganglia sparsely scattered nerve fibres and no neuronal cell bodies were immunoreactive when antisera to dynorphin A (1-17) or alpha-neo-endorphin (cleavage products of prodynorphin) were applied. A moderate number of nerve fibres and neuronal perikarya were immunoreactive to antisera directed against met-enkephalin-arg-phe (cleavage product of proenkephalin) and leu-enkephalin (cleavage product of prodynorphin and proenkephalin); non-identical cell bodies contained met-enkephalin-arg-phe- or leu-enkephalin-immunoreactivity. After drug treatment specific changes in the immunoreactivity of the investigated peptides in the superior cervical ganglion were demonstrated. (a) Treatment with imipramine resulted in an increase of nerve fibres demonstrating immunoreactivity to antisera against dynorphin A and alpha-neoendorphin. In contrast, no alteration in the numbers of nerve fibers but a numerical increase of postganglionic cell bodies immunoreactive to either met-enkephalin-arg-phe or leu-enkephalin antisera was demonstrated. Moreover, some perikarya exhibited immunoreactivity to both these opioids. (b) Receptor blockade with the muscarinic antagonist atropine sulphate or the general opiate antagonist naloxone had no effect on the number and distribution of dynorphin A or alpha-neoendorphin immunoreactive fibres, whereas both met-enkephalin-arg-phe and leu-enkephalin-immunoreactive fibres and postganglionic perikarya were increased in number. (c) After the kappa antagonist (MR2266BS), an increase of fibres with prodynorphin-derived opioid immunoreactivity as well as those with met-enkephalin-arg-phe- or leu-enkephalin-immunolabelling was visible and the met-enkephalin-arg-phe and leu-enkephalin-immunoreactive cell bodies were increased in number. The preganglionic origin of the investigated fibres with prodynorphin cleavage products was concluded from the complete disappearance of such fibres after preganglionic denervation. Denervation also resulted in an increase of met-enkephalin-arg-phe- and leu-enkephalin-immunoreactive perikarya. Small intensely fluorescent (SIF) cells, which in controls were nonrea
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PMID:Immunohistochemical evidence for different opioid systems in the rat superior cervical ganglion as revealed by imipramine treatment and receptor blockade. 257 80

Current investigations on the immunohistochemical occurrence and co-occurrence of biogenic polypeptides in the mammalian carotid body were reviewed and extended by our own recent findings. The family of chromogranins and related peptides in glomus cells appears to have a widespread interspecies distribution, whereas other peptides investigated occur in a species-specific pattern. Immunoreactivity to antisera against opioids, which derive from the proenkephalin sequence, appears to be present in glomus cells of the rabbit, cat, dog, and a shrew. Conversely, glomus cells of pig and guinea pig predominantly are immunoreactive to cleavage products of prodynorphin, which co-occur in some cells with substance P and met-enkephalin-arg-phe, respectively. In the rat and Callithrix jacchus, opioid immunoreactivity is present in nerve fibres but not in glomus cells. Immunoreactivity to other peptides, such as neurotensin, cholecystokinin, neuropeptide Y, and galanin, is found only in one or two particular species. Neurotensin immunolabelling occurs in beagle dog glomus cells, which are known to lack substance P. Cholecystokinin immunoreactivity is present in glomus cells of dog and Callithrix, and co-exists with chromogranin A, neuropeptide Y, and substance P. Substance P appears to exist in both carotid body glomus cells and nerve fibres. Substance P immunoreactivity is present in glomus cells of all species investigated, except dog. Coexistence of substance P and calcitonin gene-related peptide (CGRP) is demonstrated in nerve fibres of the guinea pig carotid body, which originate in the petrosal and jugular ganglia. Other peptides visualized immunohistochemically in mammalian carotid body nerve fibres are vasoactive intestinal peptide and neuropeptide Y. The functional significance of the various peptides present in the carotid body is discussed.
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PMID:Immunohistochemical distribution and colocalization of regulatory peptides in the carotid body. 267 3


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