Search results for "opioid receptor"

Effects of endotoxin on neurally-mediated gastric acid secretion in the rat.

1998

Abstract The effects of a peripheral administration of E. coli endotoxin on neurally-mediated gastric acid secretion and the role of endogenous opioids or PAF receptors in endotoxin effects have been evaluated in the continuously perfused stomach of the anaesthetized rat. Gastric acid secretion stimulated by distension (20 cm H2O) was reduced dose-dependently by single intravenous bolus injection of endotoxin (0.1–10 μg kg−1). Doses of 5 μg kg−1 induced a peak reduction of distension-stimulated acid output and significantly reduced the secretory response induced by an intravenous bolus of 2-deoxy-d-glucose (150 mg kg−1). This dose of endotoxin did not significantly modify mean systemic arte…

Neuroimmune and Mu-Opioid Receptor Alterations in the Mesocorticolimbic System in a Sex-Dependent Inflammatory Pain-Induced Alcohol Relapse-Like Rat …

2021

Evidence concerning the role of alcohol-induced neuroinflammation in alcohol intake and relapse has increased in the last few years. It is also proven that mu-opioid receptors (MORs) mediate the reinforcing properties of alcohol and, interestingly, previous research suggests that neuroinflammation and MORs could be related. Our objective is to study neuroinflammatory states and microglial activation, together with adaptations on MOR expression in the mesocorticolimbic system (MCLS) during the abstinence and relapse phases. To do so, we have used a sex-dependent rat model of complete Freund’s adjuvant (CFA)-induced alcohol deprivation effect (ADE). Firstly, our results confirm that only CFA-…

Effect Of Inflammatory Pain On Alcohol-Induced Dopamine Release In The Nucleus Accumbens: Behavioural Implications In Rat Models

2019

AbstractRecent studies have drawn the attention to the link between Alcohol Use Disorder (AUD) and the presence of pain. Indeed, the correct management of pain in patients with a previous history of AUD has been reported to decrease the risk of relapse in alcohol drinking, suggesting that in this prone population, pain may increase the vulnerability to relapse. Previous data in male rats revealed that inflammatory pain desensitizes mu opioid receptors (MORs) in the ventral tegmental area (VTA) and increases intake of high doses of heroine. Due to the relevant role of MORs in alcohol effects, we hypothesize that pain may also alter alcohol reinforcing properties and therefore affect alcohol …

Possible involvement of nitric oxide in morphine-induced miosis and reduction of intraocular pressure in rabbits.

2006

The role of μ3 opioid receptors in morphine-induced intraocular pressure (IOP) lowering effect and miosis was evaluated in conscious, dark-adapted New Zealand white (NZW) rabbits using a masked-design study. IOP and pupil diameter (PD) measurements were taken at just before and 0.5, 1, 2, 4, 6 h after monolateral instillation of morphine (10, 50 and 100 μg/30 μl) as compared to vehicle administered in the contralateral eye. Morphine-induced ocular effects were challenged by a pre-treatment with the non-selective opioid receptor antagonist, naloxone (100 μg/30 μl), the nitric oxide synthase inhibitor, Nω-nitro-l-arginine methyl ester (l-NAME, 1%, 30 μl), or the non-selective μ3 opioid recept…

Regulation of Cellular Phenotype in the Nociceptive Pathway

1994

Possible association between OPRM1 genetic variance at the 118 locus and alcohol dependence in a large treatment sample: relationship to alcohol depe…

2012

Background Several lines of evidence from previous research indicate that opioid receptors play an important role in ethanol reinforcement and alcohol dependence (AD) risk. Conflicting results were reported on the role of the mu-opioid receptor (OPRM1) polymorphism A118G (Asn40Asp, rs1799971) in the development of alcoholism. Methods We investigated a total number of 1,845 alcohol-dependent subjects recruited from inpatient facilities in Germany and 1,863 controls for the mu-opioid receptor (OPRM1) polymorphism using chi-square statistics. Results An association between the OPRM variant and AD was detected (p = 0.022), in recessive (AA vs. GA/GG) and co-dominant (AA vs. GA) models of inheri…

Multiplicity of Opioidergic Pathways Related to Cardiovascular Innervation: Differential Contribution of All Three Opioid Precursors

1988

The endogenous opioid family consists of the three precursors proenkephalin (proenkephalin A), prodynorphin (proenkephalin B), and proopiomelanocortin (POMC), from which various opioid and nonopioid peptides can be processed, apparently in a tissue-specific manner (cf. Civelli et al. 1984; Goldstein 1984; Herz 1984; Udenfriend and Kilpatrick 1984; Civelli et al. 1985; Khachaturian et al. 1985; Kosterlitz 1985). Their distribution in areas of the CNS which are involved in cardiovascular regulation is well documented. The biochemistry and functions of endocrine (pituitary and adrenal) opioids have also been well characterized (cf. Millan and Herz 1985). The conception that endocrine and CNS o…

Opioid Inhibition of Oxytocin Release, but not Autoinhibition of Dopamine Release May Involve Activation of Potassium (K+) Channels

1991

ABSTRACT Release of oxytocin (Ox) or dopamine (DA) from the isolated neural lobes or neurointermediate lobes, respectively, was evoked by high K + (30 or 45 mM). Naloxone (1-10 μmol/l) which largely enhances the impulse-induced release of Ox had no effect on Ox release evoked by 30 or 45 mM K + . In the presence of 10 mM tetraethylammonium (TEA), Ox release evoked by 30 or 45 mM K + was increased 2-3fold; nevertheless, naloxone caused a further 2-3fold increase. Barium (500 μM) and quinidine (300 μM) antagonized the effect of naloxone observed in the presence of TEA. (-)-Sulpiride (10 μM) enhanced the release of DA evoked by 30 and 45 mM K + by 94 % and 19 %, respectively. TEA enhanced the …

The Concise Guide To Pharmacology 2021/22: G Protein-Coupled Receptors

2021

The Concise Guide to PHARMACOLOGY 2021/22 is the fifth in this series of biennial publications. The Concise Guide provides concise overviews, mostly in tabular format, of the key properties of nearly 1900 human drug targets with an emphasis on selective pharmacology (where available), plus links to the open access knowledgebase source of drug targets and their ligands (www.guidetopharmacology.org), which provides more detailed views of target and ligand properties. Although the Concise Guide constitutes over 500 pages, the material presented is substantially reduced compared to information and links presented on the website. It provides a permanent, citable, point-in-time record that will s…

Synthesis and pharmacological evaluation of enantiomerically pure endo-configured KOR agonists with 2-azabicyclo[3.2.1]octane scaffold

2021

Conformationally restricted bicyclic KOR agonists 10 with an endo configured amino moiety were synthesized to analyze the bioactive conformation of conformationally flexible KOR agonists such as 2-5. A seven-step, chiral pool synthesis starting with (S)-configured 4-oxopiperidine-2-carboxylate 13 was developed. cis and trans configured diesters 12 were obtained in a 3:1 ratio via hydrogenation of the α,β unsaturated ester 14. After establishment of the bicyclic scaffold, a diastereoselective reductive amination of ketone 11 provided exclusively the endo configured bicyclic amines 10a,b. The 3:1 mixtures of enantiomers were separated by chiral HPLC, respectively, leading to enantiomerically …