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Kor Antagonist

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https://www.readbyqxmd.com/read/28726402/opioid-receptor-modulators-with-a-cinnamyl-group
#1
Lokesh Ravilla, N Venkata Subba Naidu, Shalini Dogra, Deepmala Umrao, Prem N Yadav, Ansuman Biswas, Daliah Michael, Kanagaraj Sekar, Kuppuswamy Nagarajan
To obtain selective and potent opioid receptor ligands, we synthesized dehydro derivatives of alvimopan and found compound (28f), a selective but modest affinity MOR antagonist, weaker than alvimopan (1). We replaced the aryl piperidine unit by an aryl piperazine to obtain the 1-(α-carboxycinnamyl)-4-arylpiperazines like (13h), which to our surprise had no MOR or DOR activity but was a KOR agonist with moderate affinity. In contrast, literature examples of aryl piperazines (4) and (5) were reported to be pan opioid receptor antagonists, while (6) was a MOR agonist...
July 20, 2017: Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/28674176/effects-of-chronic-social-defeat-stress-on-sleep-and-circadian-rhythms-are-mitigated-by-kappa-opioid-receptor-antagonism
#2
Audrey M Wells, Elysia Ridener, Clinton A Bourbonais, Woori Kim, Harry Pantazopoulos, F Ivy Carroll, Kwang-Soo Kim, Bruce M Cohen, William A Carlezon
Stress plays a critical role in the neurobiology of mood and anxiety disorders. Sleep and circadian rhythms are affected in many of these conditions. Here we examined the effects of chronic social defeat stress (CSDS), an ethological form of stress, on sleep and circadian rhythms. We exposed male mice implanted with wireless telemetry transmitters to a 10-day CSDS regimen known to produce anhedonia (a depressive-like effect) and social avoidance (an anxiety-like effect). Electroencephalography (EEG), electromyography (EMG), body temperature, and locomotor activity data were collected continuously during the CSDS regimen and a 5-day recovery period...
July 3, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28649993/kappa-opioid-receptor-activation-in-dopamine-neurons-disrupts-behavioral-inhibition
#3
Antony D Abraham, Harrison M Fontaine, Allisa J Song, Mackenzie M Andrews, Madison A Baird, Brigitte L Kieffer, Benjamin B Land, Charles Chavkin
The dynorphin/kappa opioid receptor (KOR) system has been previously implicated in the regulation of cognition, but the neural circuitry and molecular mechanisms underlying KOR-mediated cognitive disruption are unknown. Here, we used an operational test of cognition involving timing and behavioral inhibition and found that systemic KOR activation impairs performance of male and female C57BL/6 mice in the differential reinforcement of low response rates (DRL) task. Systemic KOR antagonism also blocked stress-induced disruptions of DRL performance...
June 26, 2017: Neuropsychopharmacology: Official Publication of the American College of Neuropsychopharmacology
https://www.readbyqxmd.com/read/28642282/kappa-opioid-receptors-mediate-heterosynaptic-suppression-of-hippocampal-inputs-in-the-rat-ventral-striatum
#4
Julie Brooks, Patricio O'Donnell
Kappa opioid receptors (KOR) are highly enriched within the ventral striatum (VS) and are thought to modulate striatal neurotransmission. This includes presynaptic inhibition of local glutamatergic release from excitatory inputs to the VS. However, it is not known which inputs drive this modulation and what impact they have on the local circuit dynamics within the VS. Individual medium spiny neurons (MSNs) within the VS serve as a site of convergence for glutamatergic inputs arising from the prefrontal cortex (PFC) and limbic regions, such as the hippocampus (HP)...
June 22, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28590714/reaching-out-for-sensitive-evaluation-of-the-mu-opioid-receptor-in-vivo-positron-emission-tomography-imaging-of-the-agonist-11c-ah7921
#5
Waqas Rafique, Shivashankar Khanapur, Mona Milde Spilhaug, Patrick J Riss
Imaging of the mu-opioid receptor availability with PET is a pertinent challenge in Neuroscience. Both, regulation of receptor expression and occupancy by endogeneous opioids play into cognitive and behavioural phenotypes of healthy function and disease. Receptor expression in the active and inactive states can be measured using high affinity radioagonist and radioanatonist PET tracers, respectively. Occupancy assessment requires radioligands showing competitive and reversible binding with moderate affinity to the MOR, which may lead to physical extinction of the receptor specific signal in vivo...
June 7, 2017: ACS Chemical Neuroscience
https://www.readbyqxmd.com/read/28589966/role-of-%C3%AE%C2%BA-opioid-receptors-in-the-bed-nucleus-of-stria-terminalis-in-reinstatement-of-alcohol-seeking
#6
A D Lê, Douglas Funk, Kathleen Coen, Sahar Tamadon, Yavin Shaham
κ-Opioid receptors (KORs) and their endogenous ligand dynorphin are involved in stress-induced alcohol seeking but the mechanisms involved are largely unknown. We previously showed that systemic injections of the KOR agonist U50,488, which induce stress-like aversive states, reinstate alcohol seeking after extinction of the alcohol-reinforced responding. Here, we used the neuronal activity marker Fos and site-specific injections of the KOR antagonist nor-BNI and U50,488 to study brain mechanisms of U50,488-induced reinstatement of alcohol seeking...
June 7, 2017: Neuropsychopharmacology: Official Publication of the American College of Neuropsychopharmacology
https://www.readbyqxmd.com/read/28512665/involvement-of-%C3%A2%C2%B5-opioid-receptors-and-%C3%AE%C2%BA-opioid-receptors-in-itch-related-scratching-behaviour-of-imiquimod-induced-psoriasis-like-dermatitis-in-mice
#7
Nobuaki Takahashi, Mitsutoshi Tominaga, Ryohei Kosaka, Yayoi Kamata, Yoshie Umehara, Hironori Matsuda, Azumi Sakaguchi, Hideoki Ogawa, Kenji Takamori
The pathogenesis of psoriatic itch is poorly understood. The aim of this study was to investigate the involvement of opioid receptors in scratching behaviour of imiquimod-induced psoriasis-like dermatitis model mice. Topical application of 5% imiquimod cream to the rostral back skin of mice induced antihistamine-resistant scratching behaviour. The expression of µ-opioid receptor (MOR) protein increased in the epidermis, dorsal root ganglia (DRG) and spinal cord of imiquimod-treated mice. In contrast, the expression of κ-opioid receptor (KOR) protein decreased in the DRG and spinal cord of imiquimod-treated mice, and was undetectable in the epidermis of both groups...
May 17, 2017: Acta Dermato-venereologica
https://www.readbyqxmd.com/read/28501425/the-effects-of-kratom-on-restraint-stress-induced-analgesia-and-its-mechanisms-of-action
#8
José Luis Vázquez López, Lorenz Schild, Thomas Günther, Stefan Schulz, Hartmud Neurath, Axel Becker
ETHNOPHARMACOLOGICAL RELEVANCE: Mitragyna speciosa and its extracts are called kratom (dried leaves, extract). They contain several alkaloids with an affinity for different opioid receptors. They are used in traditional medicine for the treatment of different diseases, as a substitute by opiate addicts, and to mitigate opioid withdrawal symptoms. Apart from their medical properties, they are used to enhance physical endurance and as a means of overcoming stress. PURPOSE: The aim of this study was to determine the mechanisms underlying the effects of kratom on restraint-stress-induced analgesia which occurs during or following exposure to a stressful or fearful stimulus...
May 10, 2017: Journal of Ethnopharmacology
https://www.readbyqxmd.com/read/28449351/long-term-plasticity-of-corticostriatal-synapses-is-modulated-by-pathway-specific-co-release-of-opioids-through-kappa-opioid-receptors
#9
Sarah L Hawes, Armando G Salinas, David M Lovinger, Kim T Blackwell
Synaptic plasticity in striatum adjusts behaviour adaptively during skill learning, or maladaptively in the case of addiction. Just as dopamine plays a critical role in synaptic plasticity underlying normal skill learning and addiction, endogenous and exogenous opiates also modulate learning and addiction-related striatal plasticity. Though the role of opioid receptors in long-term depression in striatum has been characterized, their effect on long-term potentiation (LTP) remains unknown. In particular, direct pathway (Dopamine D1 Receptor containing; D1R) - spiny projection neurons (SPNs) co-release the opioid neuropeptide dynorphin, which acts at presynaptic kappa opioid receptors (KORs) on dopaminergic afferents and can negatively regulate dopamine release...
April 27, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/28425121/role-of-the-dynorphin-kappa-opioid-receptor-system-in-the-motivational-effects-of-ethanol
#10
REVIEW
Rachel I Anderson, Howard C Becker
Evidence has demonstrated that dynorphin (DYN) and the kappa opioid receptor (KOR) system contribute to various psychiatric disorders, including anxiety, depression, and addiction. More recently, this endogenous opioid system has received increased attention as a potential therapeutic target for treating alcohol use disorders. In this review, we provide an overview and synthesis of preclinical studies examining the influence of alcohol (ethanol [EtOH]) exposure on DYN/KOR expression and function, as well as studies examining the effects of DYN/KOR manipulation on EtOH's rewarding and aversive properties...
April 20, 2017: Alcoholism, Clinical and Experimental Research
https://www.readbyqxmd.com/read/28376659/kappa-opioid-receptor-antagonists-a-possible-new-class-of-therapeutics-for-migraine-prevention
#11
Jennifer Y Xie, Milena De Felice, Caroline M Kopruszinski, Nathan Eyde, Justin LaVigne, Bethany Remeniuk, Pablo Hernandez, Xu Yue, Naomi Goshima, Michael Ossipov, Tamara King, John M Streicher, Edita Navratilova, David Dodick, Hugh Rosen, Ed Roberts, Frank Porreca
Background Stress is the most commonly reported migraine trigger. Dynorphin, an endogenous opioid peptide acting preferentially at kappa opioid receptors (KORs), is a key mediator of stress responses. The aim of this study was to use an injury-free rat model of functional cephalic pain with features of migraine and medication overuse headache (MOH) to test the possible preventive benefit of KOR blockade on stress-induced cephalic pain. Methods Following sumatriptan priming to model MOH, rats were hyper-responsive to environmental stress, demonstrating delayed cephalic and extracephalic allodynia and increased levels of CGRP in the jugular blood, consistent with commonly observed clinical outcomes during migraine...
July 2017: Cephalalgia: An International Journal of Headache
https://www.readbyqxmd.com/read/28347824/participation-of-dorsal-periaqueductal-gray-5-ht1a-receptors-in-the-panicolytic-like-effect-of-the-%C3%AE%C2%BA-opioid-receptor-antagonist-nor-bni
#12
Jhonatan Christian Maraschin, Camila Biesdorf Almeida, Marcel Pereira Rangel, Camila Marroni Roncon, Caio César Sestile, Hélio Zangrossi, Frederico Guilherme Graeff, Elisabeth Aparecida Audi
Panic patients may have abnormalities in serotonergic and opioidergic neurotransmission. The dorsal periaqueductal gray (dPAG) plays an important role in organizing proximal defense, related to panic attacks. The 5-HT1A receptor (5-HT1A-R) is involved in regulating escape behavior that is organized in the dPAG. Activation of κ-opioid receptor (KOR) in this region causes anxiogenic effects. In this study, we investigated the involvement of KOR in regulating escape behavior, using systemic and intra-dPAG injection of the KOR antagonist Nor-BNI...
June 1, 2017: Behavioural Brain Research
https://www.readbyqxmd.com/read/28339199/structure-based-discovery-of-new-antagonist-and-biased-agonist-chemotypes-for-the-kappa-opioid-receptor
#13
Zhong Zheng, Xi-Ping Huang, Thomas J Mangano, Rodger Zou, Xin Chen, Saheem A Zaidi, Bryan L Roth, Raymond C Stevens, Vsevolod Katritch
The ongoing epidemics of opioid overdose raises an urgent need for effective antiaddiction therapies and addiction-free painkillers. The κ-opioid receptor (KOR) has emerged as a promising target for both indications, raising demand for new chemotypes of KOR antagonists as well as G-protein-biased agonists. We employed the crystal structure of the KOR-JDTic complex and ligand-optimized structural templates to perform virtual screening of available compound libraries for new KOR ligands. The prospective virtual screening campaign yielded a high 32% hit rate, identifying novel fragment-like and lead-like chemotypes of KOR ligands...
April 13, 2017: Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/28328155/does-dynorphin-play-a-role-in-the-onset-of-puberty-in-female-sheep
#14
J A Lopez, M N Bedenbaugh, R B McCosh, P W Weems, L J Meadows, B Wisman, L M Coolen, R L Goodman, S M Hileman
Puberty onset involves increased gonadotrophin-release (GnRH) release as a result of decreased sensitivity to oestrogen (E2 )-negative feedback. Because GnRH neurones lack E2 receptor α, this pathway must contain interneurones. One likely candidate is KNDy neurones (kisspeptin, neurokinin B, dynorphin). The overarching hypothesis of the present study was that the prepubertal hiatus in luteinising hormone (LH) release involves reduced kisspeptin and/or heightened dynorphin input. We first tested the specific hypothesis that E2 would reduce kisspeptin-immunopositive cell numbers and increase dynorphin-immunopositive cell numbers...
December 2016: Journal of Neuroendocrinology
https://www.readbyqxmd.com/read/28285326/endogenous-opioid-system-a-promising-target-for-future-smoking-cessation-medications
#15
REVIEW
Haval Norman, Manoranjan S D'Souza
BACKGROUND: Nicotine addiction continues to be a health challenge across the world. Despite several approved medications, smokers continue to relapse. Several human and animal studies have evaluated the role of the endogenous opioid system as a potential target for smoking cessation medications. METHODS: In this review, studies that have elucidated the role of the mu (MORs), delta (DORs), and kappa (KORs) opioid receptors in nicotine reward, nicotine withdrawal, and reinstatement of nicotine seeking will be discussed...
May 2017: Psychopharmacology
https://www.readbyqxmd.com/read/28275339/nicotine-increases-alcohol-intake-in-adolescent-male-rats
#16
Armando Lárraga, James D Belluzzi, Frances M Leslie
Background: Use of alcohol and tobacco, the two most concurrently abused drugs, typically first occurs during adolescence. Yet, there have been no systematic analyses of ethanol (EtOH) and nicotine (Nic) interactions during adolescence. Recent animal studies report that kappa-opioid (KOR) receptor activation mediates age differences in drug reinforcement. Our hypothesis is that concurrent self-administration of EtOH and Nic will be greater in adolescent rats because of age differences in KOR function. Furthermore, exposure to alcohol and nicotine during adolescence has been reported to increase EtOH intake in adulthood...
2017: Frontiers in Behavioral Neuroscience
https://www.readbyqxmd.com/read/28163104/age-dependent-regulation-of-gaba-transmission-by-kappa-opioid-receptors-in-the-basolateral-amygdala-of-sprague-dawley-rats
#17
K R Przybysz, D F Werner, M R Diaz
Anxiety disorders are one of the most common and debilitating mental illnesses worldwide. Growing evidence indicates an age-dependent rise in the incidence of anxiety disorders from adolescence through adulthood, suggestive of underlying neurodevelopmental mechanisms. Kappa opioid receptors (KORs) are known to contribute to the development and expression of anxiety; however, the functional role of KORs in the basolateral amygdala (BLA), a brain structure critical in mediating anxiety, particularly across ontogeny, are unknown...
May 1, 2017: Neuropharmacology
https://www.readbyqxmd.com/read/28119127/antagonizing-the-different-stages-of-kappa-opioid-receptor-activation-selectively-and-independently-attenuates-acquisition-and-consolidation-of-associative-memories
#18
Ryan Loh, Lily Chau, Ali Aijaz, Kevin Wu, Roberto Galvez
Previous work from our laboratory has shown that nonspecific kappa opioid receptor (KOR) antagonism in primary somatosensory cortex (S1) can inhibit acquisition for the forebrain-dependent associative task, Whisker-Trace Eyeblink conditioning (WTEB). Although studies have demonstrated that KOR activation can alter stimuli salience, our studies controlled for these factors, demonstrating that KOR also plays a role in facilitating learning. KOR has two distinct phases of activation followed by internalization/downregulation, that each independently activate kinases and transcription factors known to mediate task acquisition and memory consolidation respectively...
April 14, 2017: Behavioural Brain Research
https://www.readbyqxmd.com/read/28088389/nalfurafine-is-a-g-protein-biased-agonist-having-significantly-greater-bias-at-the-human-than-rodent-form-of-the-kappa-opioid-receptor
#19
Selena S Schattauer, Jamie R Kuhar, Allisa Song, Charles Chavkin
Nalfurafine is a moderately selective kappa opioid receptor (KOR) analgesic with low incidence of dysphoric side effects in clinical development for the treatment of uremic pruritis. The basis for its reduced dysphoric effect compared to other KOR agonists is not clear, but prior studies suggest that the aversive properties of KOR agonists require p38α MAPK activation through an arrestin-dependent mechanism. To determine whether nalfurafine is a functionally selective KOR agonist, we measured its potency to activate the G protein-dependent early phase of Extracellular Signal-Regulated Kinase (ERK1/2) phosphorylation and the arrestin-dependent late phase of p38 MAPK signaling...
January 11, 2017: Cellular Signalling
https://www.readbyqxmd.com/read/28072601/risk-factors-and-clinical-outcomes-associated-with-perioperative-transfusion-associated-circulatory-overload
#20
Leanne Clifford, Qing Jia, Arun Subramanian, Hemang Yadav, Darrell R Schroeder, Daryl J Kor
BACKGROUND: Transfusion-associated circulatory overload remains underappreciated in the perioperative environment. The authors aimed to characterize risk factors for perioperative transfusion-associated circulatory overload and better understand its impact on patient-important outcomes. METHODS: In this case-control study, 163 adults undergoing noncardiac surgery who developed perioperative transfusion-associated circulatory overload were matched with 726 transfused controls who did not develop respiratory complications...
March 2017: Anesthesiology
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