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https://www.readbyqxmd.com/read/28214687/gastroprotective-effect-and-mechanism-of-action-of-croton-rhamnifolioides-essential-oil-in-mice
#1
Cinara Soares Vidal, Anita Oliveira Brito Pereira Bezerra Martins, Andressa de Alencar Silva, Maria Rayane Correia de Oliveira, Jaime Ribeiro-Filho, Thaís Rodrigues de Albuquerque, Henrique Douglas Melo Coutinho, Jackson Roberto Guedes da Silva Almeida, Lucindo Jose Quintans, Irwin Rose Alencar de Menezes
BACKGROUND: Croton rhamnifolioides Pax is a plant species that have been used in the folk medicine to treat ulcers, inflammations and hypertension. However, despite the relevant data obtained from ethnopharmacological studies, the pharmacological properties endorsing the efficacy of this plant to treat ulcer remain to be elucidated. HYPOTHESIS/PURPOSE: The present study aimed to characterize the chemical profile and evaluate the gastroprotective activity of the essential oil obtained from C...
February 16, 2017: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
https://www.readbyqxmd.com/read/28212343/oxyresveratrol-supplementation-to-c57bl-6-mice-fed-with-a-high-fat-diet-ameliorates-obesity-associated-symptoms
#2
Hui Yuan Tan, Iris Mei Ying Tse, Edmund Tsze Shing Li, Mingfu Wang
Oxyresveratrol has been proven effective in inhibiting adipogenesis in a 3T3-L1 cell model. We investigated the preventive effect of oxyresveratrol supplementation on obesity development in high-fat diet-fed mice. Male C57bl/6 mice were randomly subjected to control (5% fat by weight, LF), high-fat (30% fat by weight, HF), and high-fat supplemented with 0.25% and 0.5% oxyresveratrol (OXY1 and OXY2, respectively) diet groups for eight weeks. Oxyresveratrol supplementation effectively alleviated obesity-associated symptoms such as insulin resistance, hyperglycemia, and hepatic steatosis in high-fat diet-fed mice...
February 16, 2017: Nutrients
https://www.readbyqxmd.com/read/28211632/amp-activated-protein-kinase-activator-a-769662-increases-intracellular-calcium-and-atp-release-from-astrocytes-in-an-ampk-independent-manner
#3
Julia M Vlachaki Walker, Josephine L Robb, Ana M Cruz, Amrinder Malhi, Paul G Weightman Potter, Michael L J Ashford, Rory J McCrimmon, Kate L J Ellacott, Craig Beall
AIM: Astrocytes are the main sources of extracellular ATP (eATP) within the brain, which functions as a gliotransmitter, capable of modulating neuronal and astrocytic activity. These cells play an important role in regulating energy homeostasis partly via astrocyte-derived ATP. Given the role of AMPK in regulating intracellular ATP levels, we hypothesised that AMPK may alter ATP release from astrocytes. METHODS: Measurements of ATP release were made from human U373 astrocytoma cells, primary mouse hypothalamic (HTAS) and cortical astrocytes (CRTAS) and wild type and AMPK α1/α2 null mouse embryonic fibroblasts (MEFs)...
February 17, 2017: Diabetes, Obesity & Metabolism
https://www.readbyqxmd.com/read/28202753/mutation-of-the-2-nd-sialic-acid-binding-site-resulting-in-reduced-neuraminidase-activity-preceded-emergence-of-h7n9-influenza-a-virus
#4
Meiling Dai, Ryan McBride, Jos C F M Dortmans, Wenjie Peng, Mark J G Bakkers, Raoul J de Groot, Frank J M van Kuppeveld, James C Paulson, Erik de Vries, Cornelis A M de Haan
The emergence of novel influenza A virus (IAV) H7N9 since 2013 has caused concerns about the ability of this virus to spread between humans. Analysis of the receptor-binding properties of the H7 protein of a human isolate revealed modestly increased binding to α2,6 sialosides and reduced, but still dominant, binding to α2,3-linked sialic acids (SIAs) compared to a closely related avian H7N9 virus from 2008. Here we show that the corresponding N9 neuraminidases display equal enzymatic activity on a soluble monovalent substrate and similar substrate specificity on a glycan array...
February 15, 2017: Journal of Virology
https://www.readbyqxmd.com/read/28195064/catecholamines-reduce-transient-receptor-potential-vanilloid-type-1-desensitization-in-cultured-dorsal-root-ganglia-neurons
#5
A Filippi, C Caruntu, R O Gheorghe, A Deftu, B Amuzescu, V Ristoiu
Sympathetic nervous system and adrenergic receptors are involved in the modulation of dorsal root ganglia neuronal activity, with TRPV1 receptor as an important downstream effector. It is already known that adrenergic sensitization of TRPV1 receptors or catecholamine-induced TRPV1 upregulation are involved in increased excitability and pain via mainly α1 adrenergic receptors, but it is not known if reduced TRPV1 desensitization is involved in this process, as well. Therefore, the aims of this study were to evaluate the effects of epinephrine and norepinephrine on TRPV1 desensitization induced by repeated applications of capsaicin and to assess what would be the involvement of the major α1, α2 and β adrenergic receptor subtypes...
December 2016: Journal of Physiology and Pharmacology: An Official Journal of the Polish Physiological Society
https://www.readbyqxmd.com/read/28192273/gabaa-receptor-subtypes-in-the-mouse-brain-regional-mapping-and-diazepam-receptor-occupancy-by-in-vivo-18-f-flumazenil-pet
#6
Adrienne Müller Herde, Dietmar Benke, William T Ralvenius, Linjing Mu, Roger Schibli, Hanns Ulrich Zeilhofer, Stefanie D Krämer
Classical benzodiazepines, which are widely used as sedatives, anxiolytics and anticonvulsants, exert their therapeutic effects through interactions with heteropentameric GABAA receptors composed of two α, two β and one γ2 subunit. Their high affinity binding site is located at the interface between the γ2 and the adjacent α subunit. The α-subunit gene family consists of six members and receptors can be homomeric or mixed with respect to the α-subunits. Previous work has suggested that benzodiazepine binding site ligands with selectivity for individual GABAA receptor subtypes, as defined by the benzodiazepine-binding α subunit, may have fewer side effects and may even be effective in diseases, such as schizophrenia, autism or chronic pain, that do not respond well to classical benzodiazepines...
February 10, 2017: NeuroImage
https://www.readbyqxmd.com/read/28182735/chrna2-martinotti-cells-synchronize-layer-5-type-a-pyramidal-cells-via-rebound-excitation
#7
Markus M Hilscher, Richardson N Leão, Steven J Edwards, Katarina E Leão, Klas Kullander
Martinotti cells are the most prominent distal dendrite-targeting interneurons in the cortex, but their role in controlling pyramidal cell (PC) activity is largely unknown. Here, we show that the nicotinic acetylcholine receptor α2 subunit (Chrna2) specifically marks layer 5 (L5) Martinotti cells projecting to layer 1. Furthermore, we confirm that Chrna2-expressing Martinotti cells selectively target L5 thick-tufted type A PCs but not thin-tufted type B PCs. Using optogenetic activation and inhibition, we demonstrate how Chrna2-Martinotti cells robustly reset and synchronize type A PCs via slow rhythmic burst activity and rebound excitation...
February 2017: PLoS Biology
https://www.readbyqxmd.com/read/28182698/prevention-of-remifentanil-induced-postoperative-hyperalgesia-by-dexmedetomidine-via-regulating-the-trafficking-and-function-of-spinal-nmda-receptors-as-well-as-pkc-and-camkii-level-in-vivo-and-in-vitro
#8
Yuan Yuan, Zhe Sun, Yi Chen, Yuxin Zheng, Ke-Liang Xie, Ying He, Zhifen Wang, Guo-Lin Wang, Yong-Hao Yu
Remifentanil-induced secondary hyperalgesia has been demonstrated in both animal experiments and clinical trials. Enhancement of N-methyl-D-aspartate (NMDA) receptor trafficking as well as protein kinase C (PKC) and calmodulin-dependent protein kinase II (CaMKII) have been reported to be involved in the induction and maintenance of central sensitization. In the current study, it was demonstrated that dexmedetomidine could prevent remifentanil-induced hyperalgesia (RIH) via regulating spinal NMDAR-PKC-Ca2+/ CaMKII pathway in vivo and in vitro...
2017: PloS One
https://www.readbyqxmd.com/read/28177562/imidazoline-1-receptor-activation-preserves-respiratory-drive-in-spontaneously-breathing-newborn-rats-during-dexmedetomidine-administration
#9
Nana Sato, Chikako Saiki, Junko Tamiya, Toshio Imai, Katsuhisa Sunada
BACKGROUND: Dexmedetomidine is an alpha-2 (α2 ) adrenoceptor and imidazoline 1 (I1 ) receptor agonist that provides sedation without loss of respiratory drive. AIMS: The aim of this study was to elucidate the involvement of α2 -adrenoceptor and I1 receptor in the cardiorespiratory changes induced by dexmedetomidine in spontaneously breathing newborn rats. METHODS: An abdominal catheter to administer drugs and three subcutaneous electrodes to record electrocardiographic data were inserted into 2- to 5-day-old Wistar rats under isoflurane anesthesia...
February 8, 2017: Paediatric Anaesthesia
https://www.readbyqxmd.com/read/28168894/effect-of-combined-opioid-receptor-and-%C3%AE-2-adrenoceptor-blockade-on-anxiety-and-electrically-evoked-startle-responses
#10
Lechi Vo, Peter D Drummond
The R3 component of the electrically evoked blink reflex may form part of a startle reaction. Acoustic startle responses are augmented by yohimbine, an α2-adrenoceptor antagonist that blocks α2-autoreceptors, and are potentiated by opioid receptor blockade. To investigate these influences on electrically evoked startle responses, 16 mg yohimbine, with (16 participants) or without 50 mg naltrexone (23 participants), was administered in separate double-blind placebo-controlled cross-over experiments. In each experiment, R3 (a probable component of the startle response) was examined before and after high-frequency electrical stimulation of the forearm, a procedure that initiates inhibitory pain controls...
January 1, 2017: Journal of Psychopharmacology
https://www.readbyqxmd.com/read/28158247/neuroprotective-effects-of-dexmedetomidine-against-hyperoxia-induced-injury-in-the-developing-rat-brain
#11
Stefanie Endesfelder, Hanan Makki, Clarissa von Haefen, Claudia D Spies, Christoph Bührer, Marco Sifringer
Dexmedetomidine (DEX) is a highly selective agonist of α2-receptors with sedative, anxiolytic, and analgesic properties. Neuroprotective effects of dexmedetomidine have been reported in various brain injury models. In the present study, we investigated the effects of dexmedetomidine on hippocampal neurogenesis, specifically the proliferation capacity and maturation of neurons and neuronal plasticity following the induction of hyperoxia in neonatal rats. Six-day old sex-matched Wistar rats were exposed to 80% oxygen or room air for 24 h and treated with 1, 5 or 10 μg/kg of dexmedetomidine or normal saline...
2017: PloS One
https://www.readbyqxmd.com/read/28153485/loop-f-of-the-%C3%AE-subunit-determines-the-pharmacologic-profile-of-novel-competitive-inhibitors-of-gabaa-receptors
#12
Balázs Mihalik, Adrienn Pálvölgyi, Ferenc Bogár, Katalin Megyeri, István Ling, József Barkóczy, Ferenc Bartha, Tamás A Martinek, István Gacsályi, Ferenc A Antoni
The neurotransmitter γ-amino butyric acid (GABA) has a fundamental role in CNS function and ionotropic (GABAA) receptors that mediate many of the actions of GABA are important therapeutic targets. This study reports the mechanism of action of novel GABAA antagonists based on a tricyclic oxazolo-2,3-benzodiazepine scaffold. These compounds are orthosteric antagonists of GABA on heteropentameric GABAA receptors of αxβ2γ2 configuration expressed in HEK293 cells. In silico modelling predicted that the test compounds docked in the GABA binding-pocket and would interact with amino-acid residues in the α- and β-subunit interface that are known to be important for the binding of GABA...
January 31, 2017: European Journal of Pharmacology
https://www.readbyqxmd.com/read/28150939/antinociceptive-effects-of-a-novel-%C3%AE-2-%C3%AE-3-subtype-selective-gabaa-receptor-positive-allosteric-modulator
#13
Lakeisha A Lewter, Janet L Fisher, Justin N Siemian, Kashi Reddy Methuku, Michael M Poe, James M Cook, Jun-Xu Li
Pain remains a challenging clinical condition and spinal GABAA receptors are crucial modulators of pain processing. α2/α3-subtype GABAA receptors mediate the analgesic actions of benzodiazepines. Positive allosteric modulators (PAMs) at α2/α3-subtype GABAA receptors may have analgesic potential. Here we report a new selective α2/α3-subtype GABAA receptor PAM in in vitro and in vivo pain assays. KRM-II-81 demonstrated similar efficacy at α1/α2/α3 GABAA receptors and negligible efficacy at α4/α5/α6 GABAA receptors, with α2 and α3-subtypes being 17- and 28-fold more potent than α1 subtypes in HEK-293T cells expressing GABAA receptors with different α subunits...
February 2, 2017: ACS Chemical Neuroscience
https://www.readbyqxmd.com/read/28148793/mutations-during-the-adaptation-of-h9n2-avian-influenza-virus-to-the-respiratory-epithelium-of-pigs-enhance-the-sialic-acid-binding-activity-and-the-virulence-in-mice
#14
W Yang, D Punyadarsaniya, R L O Lambertz, D C C Lee, C H Liang, D Höper, S R Leist, A Hernández-Cáceres, J Stech, M Beer, C Y Wu, C H Wong, K Schughart, F Meng, G Herrler
: The natural reservoir for influenza viruses is waterfowl from where they succeeded to cross the barrier to different mammalian species. We analyzed the adaptation of avian influenza viruses to a mammalian host by passaging an H9N2 strain three times in differentiated swine airway epithelial cells. Using precision-cut slices from the porcine lung to passage the parental virus, isolates from each of the three passages (P1-P3) were characterized by assessing growth curves and ciliostatic effects...
February 1, 2017: Journal of Virology
https://www.readbyqxmd.com/read/28143526/tumor-recruited-m2-macrophages-promote-gastric-and-breast-cancer-metastasis-via-m2-macrophage-secreted-chi3l1-protein
#15
Yulei Chen, Siyuan Zhang, Qizhi Wang, Xiaobo Zhang
BACKGROUND: The macrophage, one of the several key immune cell types, is believed to be involved in tumorigenesis. However, the mechanism of macrophages promoting tumor progression is largely unknown. METHODS: The differentially secreted proteins of M1 and M2 macrophages were analyzed by mass spectrometry. We performed GST pull-down assay for the identification of cell-membrane receptors that interact with chitinase 3-like protein 1 (CHI3L1) protein. The mouse model was used to validate the function of CHI3L1 in cancer metastasis in vivo...
February 1, 2017: Journal of Hematology & Oncology
https://www.readbyqxmd.com/read/28139680/ethanol-dependence-abolishes-monoamine-and-girk-kir3-channel-inhibition-of-orbitofrontal-cortex-excitability
#16
Sudarat Nimitvilai, Marcelo F Lopez, Patrick J Mulholland, John J Woodward
Alcohol abuse disorders are associated with dysfunction of frontal cortical areas including the orbitofrontal cortex (OFC). The OFC is extensively innervated by monoamines, and drugs that target monoamine receptors have been used to treat a number of neuropsychiatric diseases, including alcoholism. However, little is known regarding how monoamines affect OFC neuron excitability or whether this modulation is altered by chronic exposure to ethanol. In this study, we examined the effect of dopamine, norepinephrine and serotonin on lOFC neuronal excitability in naïve mice and in those exposed to chronic intermittent ethanol (CIE) treatment...
January 31, 2017: Neuropsychopharmacology: Official Publication of the American College of Neuropsychopharmacology
https://www.readbyqxmd.com/read/28137424/pr-independent-neurosteroid-regulation-of-%C3%AE-2-gaba-a-receptors-mrna-in-the-hippocampus-subfields
#17
Doodipala Samba Reddy, Omkaram Gangisetty, Xin Wu
Progesterone (P) binding to the intracellular progesterone receptors (PRs) plays a key role in epilepsy via modulation of GABA-A receptor plasticity in the brain. This is thought to occur via conversion of P to neurosteroids such as allopregnanolone, an allosteric modulator of GABA-A receptors. In the female brain, the composition of GABA-A receptors is not static and undergoes dynamic spatial changes in response to fluctuations in P and neurosteroid levels. Synaptic α2-containing GABA-A receptors contribute to phasic neuronal excitability and seizure susceptibility...
January 27, 2017: Brain Research
https://www.readbyqxmd.com/read/28137258/ancient-coexistence-of-norepinephrine-tyramine-and-octopamine-signaling-in-bilaterians
#18
Philipp Bauknecht, Gáspár Jékely
BACKGROUND: Norepinephrine/noradrenaline is a neurotransmitter implicated in arousal and other aspects of vertebrate behavior and physiology. In invertebrates, adrenergic signaling is considered absent and analogous functions are performed by the biogenic amines octopamine and its precursor tyramine. These chemically similar transmitters signal by related families of G-protein-coupled receptors in vertebrates and invertebrates, suggesting that octopamine/tyramine are the invertebrate equivalents of vertebrate norepinephrine...
January 30, 2017: BMC Biology
https://www.readbyqxmd.com/read/28122088/preventing-corneal-calcification-associated-with-xylazine-for-longitudinal-optical-coherence-tomography-in-young-rodents
#19
Tianwei Ellen Zhou, Diane N Sayah, Baraa Noueihed, Javier Mazzaferri, Santiago Costantino, Isabelle Brunette, Sylvain Chemtob
Purpose: Spectral-domain optical coherence tomography (SD-OCT) is widely used in clinical ophthalmology and recently gained popularity in laboratory research involving small rodents. Its noninvasive nature allows repeated measurements, thereby decreasing the number of animals required. However, when used at a conventional dosage, xylazine (an α2-adrenoceptor) can cause irreversible corneal calcification, especially among young rodents. In the present study, we test whether corneal calcification associated with xylazine is mediated by the α2-adrenoceptor...
January 1, 2017: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/28115640/clonidine-induces-apoptosis-of-human-corneal-epithelial-cells-through-death-receptors-mediated-mitochondria-dependent-signaling-pathway
#20
Dan Fan, Ting-Jun Fan
Clonidine, an α2-adrenoreceptor agonist, is an anti-glaucoma drug clinically used in many developing countries, and its abuse might damage the cornea and impair human vision. However, its cytotoxicity and precise mechanisms need to be elucidated. Herein, we investigated the cytotoxicity of clonidine and its underlying mechanisms, using an in vitro model of human corneal epithelial (HCEP) cells and an in vivo model of cat corneas, respectively. HCEP cells were treated with various doses of clonidine for 1-28 h, resulting in abnormal morphology, decline of cell viability and G1 phase arrest in a time- and/or dose- dependent manner...
January 23, 2017: Toxicological Sciences: An Official Journal of the Society of Toxicology
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