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Sample records for m2 muscarinic receptor

  1. Multiple promoters drive tissue-specific expression of the human M2 muscarinic acetylcholine receptor gene

    Czech Academy of Sciences Publication Activity Database

    Krejčí, Alena; Bruce, A. W.; Doležal, Vladimír; Tuček, Stanislav; Buckley, N. J.

    2004-01-01

    Roč. 91, č. 1 (2004), s. 88-98 ISSN 0022-3042 R&D Projects: GA AV ČR IAA5011306 Institutional research plan: CEZ:AV0Z5011922 Keywords : M2 muscarinic receptor * neuron-restrictive silence factor * promoter Subject RIV: ED - Physiology Impact factor: 4.824, year: 2004

  2. Non-Neuronal Functions of the M2 Muscarinic Acetylcholine Receptor

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    Ritva Tikkanen

    2013-04-01

    Full Text Available Acetylcholine is an important neurotransmitter whose effects are mediated by two classes of receptors. The nicotinic acetylcholine receptors are ion channels, whereas the muscarinic receptors belong to the large family of G protein coupled seven transmembrane helix receptors. Beyond its function in neuronal systems, it has become evident that acetylcholine also plays an important role in non-neuronal cells such as epithelial and immune cells. Furthermore, many cell types in the periphery are capable of synthesizing acetylcholine and express at least some of the receptors. In this review, we summarize the non-neuronal functions of the muscarinic acetylcholine receptors, especially those of the M2 muscarinic receptor in epithelial cells. We will review the mechanisms of signaling by the M2 receptor but also the cellular trafficking and ARF6 mediated endocytosis of this receptor, which play an important role in the regulation of signaling events. In addition, we provide an overview of the M2 receptor in human pathological conditions such as autoimmune diseases and cancer.

  3. Effects of muscarinic receptor antagonists on cocaine discrimination in wild-type mice and in muscarinic receptor M1, M2, and M4 receptor knockout mice.

    Science.gov (United States)

    Joseph, Lauren; Thomsen, Morgane

    2017-06-30

    Muscarinic M 1 /M 4 receptor stimulation can reduce abuse-related effects of cocaine and may represent avenues for treating cocaine addiction. Muscarinic antagonists can mimic and enhance effects of cocaine, including discriminative stimulus (S D ) effects, but the receptor subtypes mediating those effects are not known. A better understanding of the complex cocaine/muscarinic interactions is needed to evaluate and develop potential muscarinic-based medications. Here, knockout mice lacking M 1 , M 2 , or M 4 receptors (M 1 -/- , M 2 -/- , M 4 -/- ), as well as control wild-type mice and outbred Swiss-Webster mice, were trained to discriminate 10mg/kg cocaine from saline. Muscarinic receptor antagonists with no subtype selectivity (scopolamine), or preferential affinity at the M 1 , M 2 , or M 4 subtype (telenzepine, trihexyphenidyl; methoctramine, AQ-RA 741; tropicamide) were tested alone and in combination with cocaine. In intact animals, antagonists with high affinity at M 1 /M 4 receptors partially substituted for cocaine and increased the S D effect of cocaine, while M 2 -preferring antagonists did not substitute, and reduced the S D effect of cocaine. The cocaine-like effects of scopolamine were absent in M 1 -/- mice. The cocaine S D attenuating effects of methoctramine were absent in M 2 -/- mice and almost absent in M 1 -/- mice. The findings indicate that the cocaine-like S D effects of muscarinic antagonists are primarily mediated through M 1 receptors, with a minor contribution of M 4 receptors. The data also support our previous findings that stimulation of M 1 receptors and M 4 receptors can each attenuate the S D effect of cocaine, and show that this can also be achieved by blocking M 2 autoreceptors, likely via increased acetylcholine release. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Organophosphorus pesticides decrease M2 muscarinic receptor function in guinea pig airway nerves via indirect mechanisms.

    Directory of Open Access Journals (Sweden)

    Becky J Proskocil

    Full Text Available BACKGROUND: Epidemiological studies link organophosphorus pesticide (OP exposures to asthma, and we have shown that the OPs chlorpyrifos, diazinon and parathion cause airway hyperreactivity in guinea pigs 24 hr after a single subcutaneous injection. OP-induced airway hyperreactivity involves M2 muscarinic receptor dysfunction on airway nerves independent of acetylcholinesterase (AChE inhibition, but how OPs inhibit neuronal M2 receptors in airways is not known. In the central nervous system, OPs interact directly with neurons to alter muscarinic receptor function or expression; therefore, in this study we tested whether the OP parathion or its oxon metabolite, paraoxon, might decrease M2 receptor function on peripheral neurons via similar direct mechanisms. METHODOLOGY/PRINCIPAL FINDINGS: Intravenous administration of paraoxon, but not parathion, caused acute frequency-dependent potentiation of vagally-induced bronchoconstriction and increased electrical field stimulation (EFS-induced contractions in isolated trachea independent of AChE inhibition. However, paraoxon had no effect on vagally-induced bradycardia in intact guinea pigs or EFS-induced contractions in isolated ileum, suggesting mechanisms other than pharmacologic antagonism of M2 receptors. Paraoxon did not alter M2 receptor expression in cultured cells at the mRNA or protein level as determined by quantitative RT-PCR and radio-ligand binding assays, respectively. Additionally, a biotin-labeled fluorophosphonate, which was used as a probe to identify molecular targets phosphorylated by OPs, did not phosphorylate proteins in guinea pig cardiac membranes that were recognized by M2 receptor antibodies. CONCLUSIONS/SIGNIFICANCE: These data indicate that neither direct pharmacologic antagonism nor downregulated expression of M2 receptors contributes to OP inhibition of M2 function in airway nerves, adding to the growing evidence of non-cholinergic mechanisms of OP neurotoxicity.

  5. The modulatory role of M2 muscarinic receptor on apomorphine-induced yawning and genital grooming.

    Science.gov (United States)

    Gamberini, Maria Thereza; Bolognesi, Maria Laura; Nasello, Antonia Gladys

    2012-12-07

    The interaction between dopaminergic and cholinergic pathways in the induction of behavioral responses has been previously established. In the brain, M2 receptors are found predominantly in presynaptic cholinergic neurons as autoreceptors, and in dopaminergic neurons as heteroceptors, suggesting a control role of acetylcholine and dopamine release, respectively. Our aim was to investigate the role of M2 receptors on the yawning and genital grooming of rats induced by apomorphine, a dopaminergic receptor agonist, focusing on the interaction between cholinergic and dopaminergic pathways. Initially, the effect of atropine, a non-selective muscarinic antagonist, on yawning and genital grooming induced by apomorphine (100 μg/kg s.c.) was analyzed. Atropine doses of 0.5, 1 and 2 mg/kg i.p. were administered to Wistar rats 30 min before induction of the behavioral responses by apomorphine. Number of yawns and time spent genital grooming were quantified over a 60 min period. Apomorphine-induced yawning was increased by low dose (0.5 mg/kg i.p.) but not by high doses (1 and 2 mg/kg, i.p.) of atropine. Genital grooming was antagonized by 2 mg/kg i.p. of atropine and showed no changes at the other doses tested. Tripitramine, a selective M2 cholinergic antagonist, was used as a tool for distinguishing between M2 and all other muscarinic receptor subtypes in yawning and genital grooming. Tripitramine doses of 0.01, 0.02 and 0.04 μmol/kg i.p. were administered to Wistar rats 30 min before apomorphine (100 μg/kg s.c.). Number of yawns and time spent genital grooming were also quantified over a 60 min period. Tripitramine 0.01 μmol/kg increased all parameters. Higher doses, which possibly block all subtypes of muscarinic receptor, did not modify the response of apomorphine, suggesting a non-selective effect of tripitramine at these doses. Given that low doses of tripitramine increased the behavioral responses induced by apomorphine and that the main distribution of the M2

  6. Coupling of g proteins to reconstituted monomers and tetramers of the M2 muscarinic receptor.

    Science.gov (United States)

    Redka, Dar'ya S; Morizumi, Takefumi; Elmslie, Gwendolynne; Paranthaman, Pranavan; Shivnaraine, Rabindra V; Ellis, John; Ernst, Oliver P; Wells, James W

    2014-08-29

    G protein-coupled receptors can be reconstituted as monomers in nanodiscs and as tetramers in liposomes. When reconstituted with G proteins, both forms enable an allosteric interaction between agonists and guanylyl nucleotides. Both forms, therefore, are candidates for the complex that controls signaling at the level of the receptor. To identify the biologically relevant form, reconstituted monomers and tetramers of the purified M2 muscarinic receptor were compared with muscarinic receptors in sarcolemmal membranes for the effect of guanosine 5'-[β,γ-imido]triphosphate (GMP-PNP) on the inhibition of N-[(3)H]methylscopolamine by the agonist oxotremorine-M. With monomers, a stepwise increase in the concentration of GMP-PNP effected a lateral, rightward shift in the semilogarithmic binding profile (i.e. a progressive decrease in the apparent affinity of oxotremorine-M). With tetramers and receptors in sarcolemmal membranes, GMP-PNP effected a vertical, upward shift (i.e. an apparent redistribution of sites from a state of high affinity to one of low affinity with no change in affinity per se). The data were analyzed in terms of a mechanistic scheme based on a ligand-regulated equilibrium between uncoupled and G protein-coupled receptors (the "ternary complex model"). The model predicts a rightward shift in the presence of GMP-PNP and could not account for the effects at tetramers in vesicles or receptors in sarcolemmal membranes. Monomers present a special case of the model in which agonists and guanylyl nucleotides interact within a complex that is both constitutive and stable. The results favor oligomers of the M2 receptor over monomers as the biologically relevant state for coupling to G proteins. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  7. Unraveling a molecular determinant for clathrin-independent internalization of the M2 muscarinic acetylcholine receptor

    Science.gov (United States)

    Wan, Min; Zhang, Wenhua; Tian, Yangli; Xu, Chanjuan; Xu, Tao; Liu, Jianfeng; Zhang, Rongying

    2015-01-01

    Endocytosis and postendocytic sorting of G-protein-coupled receptors (GPCRs) is important for the regulation of both their cell surface density and signaling profile. Unlike the mechanisms of clathrin-dependent endocytosis (CDE), the mechanisms underlying the control of GPCR signaling by clathrin-independent endocytosis (CIE) remain largely unknown. Among the muscarinic acetylcholine receptors (mAChRs), the M4 mAChR undergoes CDE and recycling, whereas the M2 mAChR is internalized through CIE and targeted to lysosomes. Here we investigated the endocytosis and postendocytic trafficking of M2 mAChR based on a comparative analysis of the third cytoplasmic domain in M2 and M4 mAChRs. For the first time, we identified that the sequence 374KKKPPPS380 servers as a sorting signal for the clathrin-independent internalization of M2 mAChR. Switching 374KKKPPPS380 to the i3 loop of the M4 mAChR shifted the receptor into lysosomes through the CIE pathway; and therefore away from CDE and recycling. We also found another previously unidentified sequence that guides CDE of the M2 mAChR, 361VARKIVKMTKQPA373, which is normally masked in the presence of the downstream sequence 374KKKPPPS380. Taken together, our data indicate that endocytosis and postendocytic sorting of GPCRs that undergo CIE could be sequence-dependent. PMID:26094760

  8. ZMS regulation of M2 muscarinic receptor mRNA stability requires protein factor

    International Nuclear Information System (INIS)

    Zhang Yongfang; Xia Zongqin; Hu Ya'er

    2010-01-01

    Aim The aim of this work is to study the elevation mechanism of ZMS on muscarinic M2 receptor mRNA expression. Methods Actinomycin D was added to cultured CHOm2 cells to stop the de novo synthesis of M2 receptor mRNA and samples were taken at various times to determine the time course of mRNA of M2 receptor with real-time quantitative RT-PCR. Half-life of M2 receptor mRNA and the effect of ZMS on the half-life was obtained from the slope of the exponential curves. Cycloheximide was added at 4 h prior to and 24 h after the addition of ZMS to examine the effect of de novo protein synthesis on the action of ZMS. Results The half-life of m2 mRNA was prolonged by ZMS treatment without cycloheximide (4.75±0.54 h and 2.13 h±0.23 h for ZMS and vehicle treated groups, respectively, P<0.05). When cycloheximide was added to the culture medium 4h prior to the addition of ZMS, the effect of ZMS in prolonging the half-life of m2 mRNA disappeared (3.06 h±0.23 h and 3.00 h±l.20 h for cells with and without ZMS, respectively). However, when the ZMS was added to the medium 24h prior to the addition of cycloheximide, the action of ZMS was not abolished by cycloheximide (half-life was 5.43 h±1.13 h and 2.46 h±0.09 h for cells with and without ZMS, respectively). Conclusion These data suggest that de novo protein synthesis was required for the increase in M2 mRNA stability induced by ZMS. (authors)

  9. Ventricular, but not atrial, M2-muscarinic receptors increase in the canine pacing-overdrive model of heart failure.

    Science.gov (United States)

    Wilkinson, M; Giles, A; Armour, J A; Cardinal, R

    1996-01-01

    To investigate the effects of heart failure induced by chronic rapid ventricular pacing (six weeks) on canine atrial and ventricular muscarinic receptors. Dogs (n = 4) were fitted with a bipolar pacing electrode connected to a Medtronic pacemaker set at 240 stimuli/min. Pacing was maintained for six weeks. Tissue samples obtained from the left atrium and ventral wall of the left ventricle were frozen at -70 degrees C. Control tissue was obtained from normal dogs (n = 6) following anesthesia and thoracotomy. M2-muscarinic receptors were characterized and quantified in tissue micropunches using the hydrophilic ligand [3H] N-methyl-scopolamine (NMS). Cardiac tissue bound [3H] NMS with the specificity of an M2 subtype. Tachycardia-induced heart failure did not affect atrial muscarinic receptors but signify left ventricular myocytes (control 160.0 +/- 10.0 fmol/mg protein versus heart failure 245.0 +/- 25.0 fmol/mg protein; P failure was accompanied by an increase (+ 53%) in ventricular, but not atrial, M2 receptors compared with normal dogs.

  10. Activation of multiple G-proteins by muscarinic M1 and M2 receptors

    Czech Academy of Sciences Publication Activity Database

    Michal, Pavel; El-Fakahany, E. E.; Doležal, Vladimír

    2006-01-01

    Roč. 27, č. S1 (2006), s. 404-404 ISSN 1671-4083. [World Congress of Pharmacology /15./. 02.07.2006-07.07.2006, Beijing] R&D Projects: GA ČR(CZ) GP305/05/P209; GA ČR(CZ) GA305/05/0452; GA MŠk(CZ) LC554 Grant - others:NIH(US) NS25743 Institutional research plan: CEZ:AV0Z50110509 Keywords : muscarinic receptors * multiple G-protein coupling Subject RIV: ED - Physiology

  11. Why does the agonist [18F]FP-TZTP bind preferentially to the M2 muscarinic receptor?

    International Nuclear Information System (INIS)

    Ravasi, L.; Kiesewetter, D.O.; Shimoji, K.; Lucignani, G.; Eckelman, W.C.

    2006-01-01

    Preferential binding of FP-TZTP at the M 2 receptor in vivo led to investigation of [ 18 F]FP-TZTP as a potential PET tracer for Alzheimer's disease, in which a substantial reduction of M 2 receptors has been observed in autopsy studies. We hereby investigated in vitro the FP-TZTP behavior to further elucidate the properties of FP-TZTP that lead to its M 2 selectivity. Chinese hamster ovarian cells expressing the five subtypes of human muscarinic receptor as well as the wild type were harvested in culture to assess equilibrium binding. Specific binding was calculated by subtraction of non-specific binding from total binding. Internal specific binding was calculated by subtraction of external specific binding from the total specific binding. Saturation assays were also performed to calculate B max , K i , and IC 50 . In addition, equilibrium binding and dissociation kinetic studies were performed on rat brain tissue. Selected regions of interest were drawn on the digital autoradiograms and [ 18 F]FP-TZTP off-rates were determined by measurement of the rate of release into a buffer solution of [ 18 F]FP-TZTP from slide-bound cells that had been preincubated with [ 18 F]FP-TZTP. At equilibrium in vitro, M 2 subtype selectivity of [ 18 F]FP-TZTP was not evident. We demonstrated that ATP-dependent mechanisms are not responsible for FP-TZTP M 2 selectivity. In vitro off-rate studies from rat brain tissue showed that the off-rate of FP-TZTP varied with the percentage of M 2 subtype in the tissue region. The slower dissociation kinetics of FP-TZTP from M 2 receptors compared with the four other muscarinic receptor subtypes may be a factor in its M 2 selectivity. (orig.)

  12. Distinct interneuron types express m2 muscarinic receptor immunoreactivity on their dendrites or axon terminals in the hippocampus.

    Science.gov (United States)

    Hájos, N; Papp, E C; Acsády, L; Levey, A I; Freund, T F

    1998-01-01

    In previous studies m2 muscarinic acetylcholine receptor-immunoreactive interneurons and various types of m2-positive axon terminals have been described in the hippocampal formation. The aim of the present study was to identify the types of interneurons expressing m2 receptor and to examine whether the somadendritic and axonal m2 immunostaining labels the same or distinct cell populations. In the CA1 subfield, neurons immunoreactive for m2 have horizontal dendrites, they are located at the stratum oriens/alveus border and have an axon that project to the dendritic region of pyramidal cells. In the CA3 subfield and the hilus, m2-positive neurons are multipolar and are scattered in all layers except stratum lacunosum-moleculare. In stratum pyramidale of the CA1 and CA3 regions, striking axon terminal staining for m2 was observed, surrounding the somata and axon initial segments of pyramidal cells in a basket-like manner. The co-localization of m2 with neurochemical markers and GABA was studied using the "mirror" technique and fluorescent double-immunostaining at the light microscopic level and with double-labelling using colloidal gold-conjugated antisera and immunoperoxidase reaction (diaminobenzidine) at the electron microscopic level. GABA was shown to be present in the somata of most m2-immunoreactive interneurons, as well as in the majority of m2-positive terminals in all layers. The calcium-binding protein parvalbumin was absent from practically all m2-immunoreactive cell bodies and dendrites. In contrast, many of the terminals synapsing on pyramidal cell somata and axon initial segments co-localized parvalbumin and m2, suggesting a differential distribution of m2 receptor immunoreactivity on the axonal and somadendritic membrane of parvalbumin-containing basket and axo-axonic cells. The co-existence of m2 receptors with the calcium-binding protein calbindin and the neuropeptides cholecystokinin and vasoactive intestinal polypeptide was rare throughout the

  13. Beta3 adrenoceptors substitute the role of M(2) muscarinic receptor in coping with cold stress in the heart: evidence from M(2)KO mice.

    Science.gov (United States)

    Benes, Jan; Novakova, Martina; Rotkova, Jana; Farar, Vladimir; Kvetnansky, Richard; Riljak, Vladimir; Myslivecek, Jaromir

    2012-07-01

    We investigated the role of beta3-adrenoceptors (AR) in cold stress (1 or 7 days in cold) in animals lacking main cardioinhibitive receptors-M2 muscarinic receptors (M(2)KO). There was no change in receptor number in the right ventricles. In the left ventricles, there was decrease in binding to all cardiostimulative receptors (beta1-, and beta2-AR) and increase in cardiodepressive receptors (beta3-AR) in unstressed KO in comparison to WT. The cold stress in WT animals resulted in decrease in binding to beta1- and beta2-AR (to 37%/35% after 1 day in cold and to 27%/28% after 7 days in cold) while beta3-AR were increased (to 216% of control) when 7 days cold was applied. MR were reduced to 46% and 58%, respectively. Gene expression of M2 MR in WT was not changed due to stress, while M3 was changed. The reaction of beta1- and beta2-AR (binding) to cold was similar in KO and WT animals, and beta3-AR in stressed KO animals did not change. Adenylyl cyclase activity was affected by beta3-agonist CL316243 in cold stressed WT animals but CL316243 had almost no effects on adenylyl cyclase activity in stressed KO. Nitric oxide activity (NOS) was not affected by BRL37344 (beta3-agonist) both in WT and KO animals. Similarly, the stress had no effects on NOS activity in WT animals and in KO animals. We conclude that the function of M2 MR is substituted by beta3-AR and that these effects are mediated via adenylyl cyclase rather than NOS.

  14. Muscarinic M2 receptors directly activate Gq/11 and Gs G-proteins

    Czech Academy of Sciences Publication Activity Database

    Michal, Pavel; El-Fakahany, E. E.; Doležal, Vladimír

    2007-01-01

    Roč. 320, č. 2 (2007), s. 607-614 ISSN 0022-3565 R&D Projects: GA ČR GP305/05/P209; GA ČR GA305/05/0452; GA MŠk(CZ) LC554 Grant - others:NIH(US) NS25743 Institutional research plan: CEZ:AV0Z50110509 Keywords : muscarinic * siRNA * G-proteins Subject RIV: CE - Biochemistry Impact factor: 4.003, year: 2007

  15. The detection of the non-M2 muscarinic receptor subtype in the rat heart atria and ventricles

    Czech Academy of Sciences Publication Activity Database

    Mysliveček, J.; Klein, M.; Nováková, M.; Říčný, Jan

    2008-01-01

    Roč. 378, č. 1 (2008), s. 103-116 ISSN 0028-1298 R&D Projects: GA MŠk(CZ) LC554; GA ČR(CZ) GA304/08/0256 Institutional research plan: CEZ:AV0Z50110509 Keywords : heart * muscarinic receptors * PLC activity Subject RIV: FH - Neuro logy Impact factor: 2.830, year: 2008

  16. A novel muscarinic receptor ligand which penetrates the blood brain barrier and displays in vivo selectivity for the m2 subtype

    International Nuclear Information System (INIS)

    Gitler, M.S.; Cohen, V.I.; De La Cruz, R.; Boulay, S.F.; Jin, B.; Zeeberg, B.R.; Reba, R.C.

    1993-01-01

    Alzheimer's disease (AD) involves selective loss of muscarinic m2, but not m1, subtype neuroreceptors in the posterior parietal cortex of the human brain. Emission tomographic study of the loss of m2 receptors in AD is limited by the fact that there is currently no available m2-selective radioligand which can penetrate the blood-brain barrier. In our efforts to prepare such a radioligand, the authors have used competition studies against currently existing muscarinic receptor radioligands to infer the in vitro and in vivo properties of a novel muscarinic receptor ligand, 5-[[4-[4-(diisobutylamino)butyl]-1-phenyl]acetyl]-10,11-dihydro-5H-dibenzo[b,e][1,4]diazepin-11-one (DIBD). In vitro competition studies against [ 3 H](R)-3-quinuclidinylbenzilate ([ 3 H]QNB) and [ 3 H]N-methylscopolamine ([ 3 H]NMS), using membranes derived from transfected cells expressing only m1, m2, m3, or m4 receptor subtypes, indicate that DIBD is selective for m2/m4 over m1/m3. In vivo competition studies against (R,R)-[ 125 I]IQNB indicate that DIBD crosses the blood brain barrier (BBB). The relationship of the regional percentage decrease in (R,R)-[ 125 I]IQNB versus the percentage of each of the receptor subtypes indicates that DIBD competes more effectively in those brain regions which are known to be enriched in the m2, relative to the m1, m3, and m4, receptor subtype; however, analysis of the data using a mathematical model shows that caution is required when interpreting the in vivo results. The authors conclude that a suitably radiolabeled derivative of DIBD may be of potential use in emission tomographic study of changes in m2 receptors in the central nervous system

  17. Membrane cholesterol content influences binding properties of muscarinic M2 receptors and differentially impacts activation of second messenger pathways

    Czech Academy of Sciences Publication Activity Database

    Michal, Pavel; Rudajev, Vladimír; El-Fakahany, E. E.; Doležal, Vladimír

    2009-01-01

    Roč. 606, 1-3 (2009), s. 50-60 ISSN 0014-2999 R&D Projects: GA ČR(CZ) GA305/05/0452; GA AV ČR(CZ) IAA500110703; GA MŠk(CZ) LC554 Grant - others:National Institutes of Health(US) NS25743; EC(XE) LipiDiDiet Institutional research plan: CEZ:AV0Z50110509 Keywords : muscarinic * cholesterol * receptors Subject RIV: ED - Physiology Impact factor: 2.585, year: 2009

  18. Dual effects of muscarinic M2 acetylcholine receptors on the synthesis of cyclic AMP in CHO cells: dependence on time, receptor density and receptor agonists

    Czech Academy of Sciences Publication Activity Database

    Michal, Pavel; Lysíková, Michaela; Tuček, Stanislav

    2001-01-01

    Roč. 132, č. 6 (2001), s. 1217-1228 ISSN 0007-1188 R&D Projects: GA ČR GA309/99/0214; GA AV ČR IAA7011910 Institutional research plan: CEZ:AV0Z5011922 Keywords : cyclic AMP * muscarinic receptors * CHO cells Subject RIV: ED - Physiology Impact factor: 3.502, year: 2001

  19. Autoradiography of H-3-pirenzepine and H-3-AFDX-384 in Mouse Brain Regions: Possible Insights into M-1, M-2, and M-4 Muscarinic Receptors Distribution

    Czech Academy of Sciences Publication Activity Database

    Valuskova, P.; Farar, V.; Forczek, Sándor; Křížová, I.; Mysliveček, J.

    2018-01-01

    Roč. 9, FEB 20 (2018), č. článku 124. ISSN 1663-9812 Institutional support: RVO:61389030 Keywords : 3 h-afdx-384 * 3 H-pirenzepine * 3 h-qnb * Autoradiography * M muscarinic receptor 1 * M muscarinic receptor 2 * M muscarinic receptor 4 Subject RIV: FH - Neurology OBOR OECD: Neurosciences (including psychophysiology Impact factor: 4.400, year: 2016

  20. Point mutation of a conserved aspartate, D69, in the muscarinic M2 receptor does not modify voltage-sensitive agonist potency.

    Science.gov (United States)

    Ågren, Richard; Sahlholm, Kristoffer; Nilsson, Johanna; Århem, Peter

    2018-01-29

    The muscarinic M 2 receptor (M 2 R) has been shown to display voltage-sensitive agonist binding, based on G protein-activated inward rectifier potassium channel (GIRK) opening and radioligand binding at different membrane voltages. A conserved aspartate in transmembrane segment (TM) II of M 2 R, D69, has been proposed as the voltage sensor. While a recent paper instead presented evidence of tyrosines in TMs III, VI, and VII acting as voltage sensors, these authors were not able to record GIRK channel activation by a D69N mutant M 2 R. In the present study, we succeeded in recording ACh-induced GIRK channel activation by this mutant at -80 and 0 mV. The acetylcholine EC 50 was about 2.5-fold higher at 0 mV, a potency shift very similar to that observed at wild-type M 2 R, indicating that voltage sensitivity persists at the D69N mutant. Thus, our present observations corroborate the notion that D69 is not responsible for voltage sensitivity of the M 2 R. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. CHARACTERIZATION OF MUSCARINIC RECEPTORS IN GUINEA-PIG UTERUS

    NARCIS (Netherlands)

    DOODS, HN; WILLIM, KD; BODDEKE, HWGM; ENTZEROTH, M

    1993-01-01

    To characterize the muscarinic receptor present in guinea-pig uterus smooth muscle the affinities of a series of 27 muscarinic receptor antagonists for M1 (rat cortex), M2 (rat heart), M3 (rat submandibular gland), m4 (transfected in CHO cells) and muscarinic binding sites in guinea-pig uterus

  2. Differential regulation by agonist and phorbol ester of cloned m1 and m2 muscarinic acetylcholine receptors in mouse Y1 adrenal cells and in Y1 cells deficient in cAMP-dependent protein kinase

    International Nuclear Information System (INIS)

    Scherer, N.M.; Nathanson, N.M.

    1990-01-01

    Cloned muscarinic acetylcholine m1 and m2 receptors were expressed in stably transfected mouse Y1 adrenal cells and in a variant Y1 line, Kin-8, which is deficient in cAMP-dependent protein kinase activity (PKA - ). m1 and m2 receptors were rapidly internalized following exposure of transfected PKA + or PKA - cells to the muscarinic agonist carbachol. Thus, agonist-dependent internalization of m1 and m2 did not require PKA activity. A differential effect of PKA on regulation by agonist of the m2 receptor, but not the m1 receptor, was unmasked in PKA - cells. These data indicate that the basal activity of PKA may modulate the agonist-dependent internalization of the m2 receptor, but not the m1 receptor. The internalization of the m1 and m2 receptors in both PKA + and PKA - cells was accompanied by desensitization of functional responses. Exposure of PKA + cells to 10 -7 M phorbol 12-myristate 13-acetate (PMA), an activator of protein kinase C, resulted in a 30 ± 9% decrease in the number of m1 receptors on the cell surface. The m2 receptor was not internalized following treatment of either PKA + or PKA - cells with PMA. Thus, the m1 and m2 receptors show differential sensitivity to internalization by PMA. Agonist-dependent internalization of the m1 receptor appeared to be independent of activation of PKC because (1) agonist-dependent internalization of m1 was not attenuated in PKA - cells, (2) the rate and extent of internalization of m1 in cells exposed to PMA were less than those in cells exposed to agonist, and (3) treatment of cells with concanavalin A selectivity blocked internalization of m1 in cells exposed to PMA, but not to agonist. The effects of agonist and PMA on receptor internalization were not additive. Exposure of PKA + or PKA - cells to PMA reduced the magnitude of pilocarpine-stimulated PI hydrolysis by about 25%

  3. Differences in kinetics of xanomeline binding and selectivity of activation of G proteins at M(1) and M(2) muscarinic acetylcholine receptors

    Czech Academy of Sciences Publication Activity Database

    Jakubík, Jan; El-Fakahany, E. E.; Doležal, Vladimír

    2006-01-01

    Roč. 70, č. 2 (2006), s. 656-666 ISSN 0026-895X R&D Projects: GA ČR(CZ) GA305/05/0452; GA MŠk(CZ) LC554 Grant - others:NIH(US) NS25743 Institutional research plan: CEZ:AV0Z5011922 Keywords : xanomeline * muscarinic receptors * G-protein activation Subject RIV: FR - Pharmacology ; Medidal Chemistry Impact factor: 4.469, year: 2006

  4. Wash-Resistantly Bound Xanomeline Inhibits Acetylcholine Release by Persistent Activation of Presynaptic M2 and M4 Muscarinic Receptors in Rat Brain

    Czech Academy of Sciences Publication Activity Database

    Machová, Eva; Jakubík, Jan; El-Fakahany, E. E.; Doležal, Vladimír

    2007-01-01

    Roč. 322, č. 1 (2007), s. 316-323 ISSN 0022-3565 R&D Projects: GA ČR(CZ) GA305/05/0452; GA MŠk(CZ) LC554 Grant - others:-(US) NS25743 Institutional research plan: CEZ:AV0Z50110509 Keywords : acetylcholine * xanomeline * muscarinic receptor Subject RIV: ED - Physiology Impact factor: 4.003, year: 2007

  5. Comparison of the pharmacokinetics of different analogs of 11C-labeled TZTP for imaging muscarinic M2 receptors with PET

    International Nuclear Information System (INIS)

    Reid, Alicia E.; Ding Yushin; Eckelman, William C.; Logan, Jean; Alexoff, David; Shea, Colleen; Xu Youwen; Fowler, Joanna S.

    2008-01-01

    Introduction: The only radiotracer available for the selective imaging of muscarinic M2 receptors in vivo is 3-(3-{3-[ 18 F]fluoropropyl)thio}-1,2,5-thiadiazol-4-yl) -1,2,5,6-tetrahydro-1-methylpyridine) ([ 18 F]FP-TZTP). We have prepared and labeled 3-(3-(3-fluoropropylthio)-1,2,5-thiadiazol-4-yl) -1,2,5,6-tetrahydro-1-methylpyridne (FP-TZTP, 3) and two other TZTP derivatives with 11 C at the methylpyridine moiety to explore the potential of using 11 C-labeled FP-TZTP for positron emission tomography imaging of M2 receptors and to compare the effect of small structural changes on tracer pharmacokinetics (PK) in brain and peripheral organs. Methods: 11 C-radiolabeled FP-TZTP, 3-(3-propylthio)-TZTP (6) and 3,3,3-(3-(3-trifluoropropyl)-TZTP (10) were prepared, and log D, plasma protein binding (PPB), affinity constants, time-activity curves (TACs), area under the curve (AUC) for arterial plasma, distribution volumes (DV) and pharmacological blockade in baboons were compared. Results: Values for log D, PPB and affinity constants were similar for 3, 6 and 10. The fraction of parent radiotracer in the plasma was higher and the AUC lower for 10 than for 3 and 6. TACs for brain regions were similar for 3 and 6, which showed PK similar to the 18 F tracer, while 10 showed slower uptake and little clearance over 90 min. DVs for 3 and 6 were similar to the 18 F tracer but higher for 10. Uptake of the three tracers was significantly reduced by coinjection of unlabeled 3 and 6. Conclusion: Small structural variations on the TZTP structure greatly altered the PK in brain and behavior in blood with little change in the log D, PPB or affinity. The study suggests that 11 C-radiolabeled 3 will be a suitable alternative to [ 18 F]FP-TZTP for translational studies in humans

  6. Comparison of the pharmacokinetics of different analogs of {sup 11}C-labeled TZTP for imaging muscarinic M2 receptors with PET

    Energy Technology Data Exchange (ETDEWEB)

    Reid, Alicia E. [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States)], E-mail: areid@bnl.gov; Ding Yushin [Radiology Department, Yale University School of Medicine, New Haven, CT 06510 (United States); Eckelman, William C. [Molecular Tracer LLC, Bethesda, MD 20892 (United States); Logan, Jean; Alexoff, David; Shea, Colleen; Xu Youwen; Fowler, Joanna S. [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2008-04-15

    Introduction: The only radiotracer available for the selective imaging of muscarinic M2 receptors in vivo is 3-(3-{l_brace}3-[{sup 18}F]fluoropropyl)thio{r_brace}-1,2,5-thiadiazol-4-yl) -1,2,5,6-tetrahydro-1-methylpyridine) ([{sup 18}F]FP-TZTP). We have prepared and labeled 3-(3-(3-fluoropropylthio)-1,2,5-thiadiazol-4-yl) -1,2,5,6-tetrahydro-1-methylpyridne (FP-TZTP, 3) and two other TZTP derivatives with {sup 11}C at the methylpyridine moiety to explore the potential of using {sup 11}C-labeled FP-TZTP for positron emission tomography imaging of M2 receptors and to compare the effect of small structural changes on tracer pharmacokinetics (PK) in brain and peripheral organs. Methods: {sup 11}C-radiolabeled FP-TZTP, 3-(3-propylthio)-TZTP (6) and 3,3,3-(3-(3-trifluoropropyl)-TZTP (10) were prepared, and log D, plasma protein binding (PPB), affinity constants, time-activity curves (TACs), area under the curve (AUC) for arterial plasma, distribution volumes (DV) and pharmacological blockade in baboons were compared. Results: Values for log D, PPB and affinity constants were similar for 3, 6 and 10. The fraction of parent radiotracer in the plasma was higher and the AUC lower for 10 than for 3 and 6. TACs for brain regions were similar for 3 and 6, which showed PK similar to the {sup 18}F tracer, while 10 showed slower uptake and little clearance over 90 min. DVs for 3 and 6 were similar to the {sup 18}F tracer but higher for 10. Uptake of the three tracers was significantly reduced by coinjection of unlabeled 3 and 6. Conclusion: Small structural variations on the TZTP structure greatly altered the PK in brain and behavior in blood with little change in the log D, PPB or affinity. The study suggests that {sup 11}C-radiolabeled 3 will be a suitable alternative to [{sup 18}F]FP-TZTP for translational studies in humans.

  7. Analysis of coupling of M2 muscarinic acetylcholine receptors to Gi/o, Gs and Gq heterotrimeric GTP-binding proteins

    Czech Academy of Sciences Publication Activity Database

    Jakubík, Jan; Doležal, Vladimír

    2006-01-01

    Roč. 27, č. S1 (2006), s. 361-361 ISSN 1671-4083. [World Congress of Pharmacology /15./. 02.07.2006-07.07.2006, Beijing] R&D Projects: GA ČR(CZ) GA305/05/0452; GA MŠk(CZ) LC554 Institutional research plan: CEZ:AV0Z50110509 Keywords : M2 receptor * heterotrimeric G-proteins * analysis of coupling Subject RIV: ED - Physiology

  8. Evaluation of stereoisomers of 4-fluoroalkyl analogues of 3-quinuclidinyl benzilate in in vivo competition studies for the M1, M2, and M3 muscarinic receptor subtypes in brain

    International Nuclear Information System (INIS)

    Kiesewetter, Dale O.; Eckelman, William C.; Jaetae, Lee; Paik, Chang H.; Park, Seok G.

    1995-01-01

    To develop a subtype selective muscarinic acetylcholine receptor (mAChR) antagonist for PET, fluorine-19 labeled alkyl analogues of quinuclidinyl benzilate (QNB) were synthesized by stereoselective reactions. To investigate these analogues for tissue subtype specificity, in vivo competitive binding studies were performed in rat brain using (R)-3-quinuclidinyl (R)-4-[ 125 I]Iodobenzilate (IQNB). Five, fifty, or five-hundred nmol of the non-radioactive ligands were coinjected intravenously with 8 pmol of the radioligand. Cold (R,R)-IQNB blocked (R,R)-[ 125 I]IQNB in a dose-dependent manner, without showing regional specificity. For the (R,S)-fluoromethyl, -fluoroethyl, and -fluoropropyl derivatives, a higher percent blockade was seen at 5 and 50 nmol levels in M2 predominant tissues (medulla, pons, and cerebellum) than in M1 predominant tissues (cortex, striatum and hippocampus). The blockade pattern of the radioligand also correlated qualitatively with the percentage of M2 receptors in the region. The S-quinuclidinyl analogues showed M2 selectivity but less efficient blockade of the radioligand, indicating lower affinities. Radioligand bound to the medulla was inversely correlated to the M2 relative binding affinity of the fluoroalkyl analogues. These results indicate that the nonradioactive ligand blocks the radioligand based on the affinity of the nonradioactive ligand for a particular receptor subtype compared to the affinity of the radioligand for the same receptor subtype. Of the seven compounds evaluated, (R,S)-fluoromethyl-QNB appears to show the most selectivity for the M2 subtypes in competition studies in vivo

  9. Presynaptic muscarinic acetylcholine autoreceptors (M1, M2 and M4 subtypes), adenosine receptors (A1 and A2A) and tropomyosin-related kinase B receptor (TrkB) modulate the developmental synapse elimination process at the neuromuscular junction.

    Science.gov (United States)

    Nadal, Laura; Garcia, Neus; Hurtado, Erica; Simó, Anna; Tomàs, Marta; Lanuza, Maria A; Santafé, Manel; Tomàs, Josep

    2016-06-23

    The development of the nervous system involves an initially exuberant production of neurons that make an excessive number of synaptic contacts. The initial overproduction of synapses promotes connectivity. Hebbian competition between axons with different activities (the least active are punished) leads to the loss of roughly half of the overproduced elements and this refines connectivity and increases specificity. The neuromuscular junction is innervated by a single axon at the end of the synapse elimination process and, because of its relative simplicity, has long been used as a model for studying the general principles of synapse development. The involvement of the presynaptic muscarinic ACh autoreceptors may allow for the direct competitive interaction between nerve endings through differential activity-dependent acetylcholine release in the synaptic cleft. Then, the most active ending may directly punish the less active ones. Our previous results indicate the existence in the weakest axons on the polyinnervated neonatal NMJ of an ACh release inhibition mechanism based on mAChR coupled to protein kinase C and voltage-dependent calcium channels. We suggest that this mechanism plays a role in the elimination of redundant neonatal synapses. Here we used confocal microscopy and quantitative morphological analysis to count the number of brightly fluorescent axons per endplate in P7, P9 and P15 transgenic B6.Cg-Tg (Thy1-YFP)16 Jrs/J mice. We investigate the involvement of individual mAChR M1-, M2- and M4-subtypes in the control of axonal elimination after the Levator auris longus muscle had been exposed to agonist and antagonist in vivo. We also analysed the role of adenosine receptor subtypes (A1 and A2A) and the tropomyosin-related kinase B receptor. The data show that postnatal axonal elimination is a regulated multireceptor mechanism that guaranteed the monoinnervation of the neuromuscular synapses. The three receptor sets considered (mAChR, AR and TrkB receptors

  10. Muscarinic Receptor Agonists and Antagonists

    Directory of Open Access Journals (Sweden)

    David R. Kelly

    2001-02-01

    Full Text Available A comprehensive review of pharmacological and medical aspects of the muscarinic class of acetylcholine agonists and antagonists is presented. The therapeutic benefits of achieving receptor subtype selectivity are outlined and applications in the treatment of Alzheimer’s disease are discussed. A selection of chemical routes are described, which illustrate contemporary methodology for the synthesis of chiral medicinal compounds (asymmetric synthesis, chiral pool, enzymes. Routes to bicyclic intrannular amines and intramolecular Diels-Alder reactions are highlighted.

  11. Voltage sensitivity of M2 muscarinic receptors underlies the delayed rectifier-like activation of ACh-gated K(+) current by choline in feline atrial myocytes.

    Science.gov (United States)

    Navarro-Polanco, Ricardo A; Aréchiga-Figueroa, Iván A; Salazar-Fajardo, Pedro D; Benavides-Haro, Dora E; Rodríguez-Elías, Julio C; Sachse, Frank B; Tristani-Firouzi, Martin; Sánchez-Chapula, José A; Moreno-Galindo, Eloy G

    2013-09-01

    Choline (Ch) is a precursor and metabolite of the neurotransmitter acetylcholine (ACh). In canine and guinea pig atrial myocytes, Ch was shown to activate an outward K(+) current in a delayed rectifier fashion. This current has been suggested to modulate cardiac electrical activity and to play a role in atrial fibrillation pathophysiology. However, the exact nature and identity of this current has not been convincingly established. We recently described the unique ligand- and voltage-dependent properties of muscarinic activation of ACh-activated K(+) current (IKACh) and showed that, in contrast to ACh, pilocarpine induces a current with delayed rectifier-like properties with membrane depolarization. Here, we tested the hypothesis that Ch activates IKACh in feline atrial myocytes in a voltage-dependent manner similar to pilocarpine. Single-channel recordings, biophysical profiles, specific pharmacological inhibition and computational data indicate that the current activated by Ch is IKACh. Moreover, we show that membrane depolarization increases the potency and efficacy of IKACh activation by Ch and thus gives the appearance of a delayed rectifier activating K(+) current at depolarized potentials. Our findings support the emerging concept that IKACh modulation is both voltage- and ligand-specific and reinforce the importance of these properties in understanding cardiac physiology.

  12. Characterization of muscarinic receptor subtypes in human tissues

    International Nuclear Information System (INIS)

    Giraldo, E.; Martos, F.; Gomez, A.; Garcia, A.; Vigano, M.A.; Ladinsky, H.; Sanchez de La Cuesta, F.

    1988-01-01

    The affinities of selective, pirenzepine and AF-DX 116, and classical, N-methylscopolamine and atropine, muscarinic cholinergic receptor antagonists were investigated in displacement binding experiments with [ 3 H]Pirenzepine and [ 3 H]N-methylscopolamine in membranes from human autoptic tissues (forebrain, cerebellum, atria, ventricle and submaxillary salivary glands). Affinity estimates of N-methylscopolamine and atropine indicated a non-selective profile. Pirenzepine showed differentiation between the M 1 neuronal receptor of the forebrain and the receptors in other tissues while AF-DX 116 clearly discriminated between muscarinic receptors of heart and glands. The results in human tissues confirm the previously described selectivity profiles of pirenzepine and AF-DX 116 in rat tissues. These findings thus reveal the presence also in man of three distinct muscarinic receptor subtypes: the neuronal M 1 , the cardiac M 2 and the glandular M 3

  13. Constitutive overexpression of muscarinic receptors leads to vagal hyperreactivity.

    Directory of Open Access Journals (Sweden)

    Angelo Livolsi

    Full Text Available BACKGROUND: Alterations in muscarinic receptor expression and acetylcholinesterase (AchE activity have been observed in tissues from Sudden Infant Death Syndrome (SIDS. Vagal overactivity has been proposed as a possible cause of SIDS as well as of vasovagal syncopes. The aim of the present study was to seek whether muscarinic receptor overexpression may be the underlying mechanism of vagal hyperreactivity. Rabbits with marked vagal pauses following injection of phenylephrine were selected and crossed to obtain a vagal hyperreactive strain. The density of cardiac muscarinic receptors and acetylcholinesterase (AchE gene expression were assessed. Blood markers of the observed cardiac abnormalities were also sought. METHODOLOGY/PRINCIPAL FINDINGS: Cardiac muscarinic M(2 and M(3 receptors were overexpressed in hyperreactive rabbits compared to control animals (2.3-fold and 2.5-fold, respectively and the severity of the phenylephrine-induced bradycardia was correlated with their densities. A similar overexpression of M(2 receptors was observed in peripheral mononuclear white blood cells, suggesting that cardiac M(2 receptor expression can be inferred with high confidence from measurements in blood cells. Sequencing of the coding fragment of the M(2 receptor gene revealed a single nucleotide mutation in 83% of hyperreactive animals, possibly contributing for the transcript overexpression. Significant increases in AchE expression and activity were also assessed (AchE mRNA amplification ratio of 3.6 versus normal rabbits. This phenomenon might represent a compensatory consequence of muscarinic receptors overexpression. Alterations in M(2 receptor and AchE expression occurred between the 5th and the 7th week of age, a critical period also characterized by a higher mortality rate of hyperreactive rabbits (52% in H rabbits versus 13% in normal rabbits and preceeded the appearance of functional disorders. CONCLUSIONS/SIGNIFICANCE: The results suggest that

  14. Muscarinic Receptor Signaling in Colon Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Rosenvinge, Erik C. von, E-mail: evonrose@medicine.umaryland.edu; Raufman, Jean-Pierre [University of Maryland School of Medicine, Division of Gastroenterology & Hepatology, 22 S. Greene Street, N3W62, Baltimore, MD 21201 (United States); Department of Veterans Affairs, VA Maryland Health Care System, 10 North Greene Street, Baltimore, MD 21201 (United States)

    2011-03-02

    According to the adenoma-carcinoma sequence, colon cancer results from accumulating somatic gene mutations; environmental growth factors accelerate and augment this process. For example, diets rich in meat and fat increase fecal bile acids and colon cancer risk. In rodent cancer models, increased fecal bile acids promote colon dysplasia. Conversely, in rodents and in persons with inflammatory bowel disease, low-dose ursodeoxycholic acid treatment alters fecal bile acid composition and attenuates colon neoplasia. In the course of elucidating the mechanism underlying these actions, we discovered that bile acids interact functionally with intestinal muscarinic receptors. The present communication reviews muscarinic receptor expression in normal and neoplastic colon epithelium, the role of autocrine signaling following synthesis and release of acetylcholine from colon cancer cells, post-muscarinic receptor signaling including the role of transactivation of epidermal growth factor receptors and activation of the ERK and PI3K/AKT signaling pathways, the structural biology and metabolism of bile acids and evidence for functional interaction of bile acids with muscarinic receptors on human colon cancer cells. In murine colon cancer models, deficiency of subtype 3 muscarinic receptors attenuates intestinal neoplasia; a proof-of-concept supporting muscarinic receptor signaling as a therapeutic target for colon cancer.

  15. Muscarinic Receptor Signaling in Colon Cancer

    International Nuclear Information System (INIS)

    Rosenvinge, Erik C. von; Raufman, Jean-Pierre

    2011-01-01

    According to the adenoma-carcinoma sequence, colon cancer results from accumulating somatic gene mutations; environmental growth factors accelerate and augment this process. For example, diets rich in meat and fat increase fecal bile acids and colon cancer risk. In rodent cancer models, increased fecal bile acids promote colon dysplasia. Conversely, in rodents and in persons with inflammatory bowel disease, low-dose ursodeoxycholic acid treatment alters fecal bile acid composition and attenuates colon neoplasia. In the course of elucidating the mechanism underlying these actions, we discovered that bile acids interact functionally with intestinal muscarinic receptors. The present communication reviews muscarinic receptor expression in normal and neoplastic colon epithelium, the role of autocrine signaling following synthesis and release of acetylcholine from colon cancer cells, post-muscarinic receptor signaling including the role of transactivation of epidermal growth factor receptors and activation of the ERK and PI3K/AKT signaling pathways, the structural biology and metabolism of bile acids and evidence for functional interaction of bile acids with muscarinic receptors on human colon cancer cells. In murine colon cancer models, deficiency of subtype 3 muscarinic receptors attenuates intestinal neoplasia; a proof-of-concept supporting muscarinic receptor signaling as a therapeutic target for colon cancer

  16. Muscarinic Receptor Signaling in Colon Cancer

    Directory of Open Access Journals (Sweden)

    Jean-Pierre Raufman

    2011-03-01

    Full Text Available According to the adenoma-carcinoma sequence, colon cancer results from accumulating somatic gene mutations; environmental growth factors accelerate and augment this process. For example, diets rich in meat and fat increase fecal bile acids and colon cancer risk. In rodent cancer models, increased fecal bile acids promote colon dysplasia. Conversely, in rodents and in persons with inflammatory bowel disease, low-dose ursodeoxycholic acid treatment alters fecal bile acid composition and attenuates colon neoplasia. In the course of elucidating the mechanism underlying these actions, we discovered that bile acids interact functionally with intestinal muscarinic receptors. The present communication reviews muscarinic receptor expression in normal and neoplastic colon epithelium, the role of autocrine signaling following synthesis and release of acetylcholine from colon cancer cells, post-muscarinic receptor signaling including the role of transactivation of epidermal growth factor receptors and activation of the ERK and PI3K/AKT signaling pathways, the structural biology and metabolism of bile acids and evidence for functional interaction of bile acids with muscarinic receptors on human colon cancer cells. In murine colon cancer models, deficiency of subtype 3 muscarinic receptors attenuates intestinal neoplasia; a proof-of-concept supporting muscarinic receptor signaling as a therapeutic target for colon cancer.

  17. Heterogeneity of muscarinic receptor subtypes in cerebral blood vessels

    International Nuclear Information System (INIS)

    Garcia-Villalon, A.L.; Krause, D.N.; Ehlert, F.J.; Duckles, S.P.

    1991-01-01

    The identity and distribution of muscarinic cholinergic receptor subtypes and associated signal transduction mechanisms was characterized for the cerebral circulation using correlated functional and biochemical investigations. Subtypes were distinguished by the relative affinities of a panel of muscarinic antagonists, pirenzepine, AF-DX 116 [11-2-[[2-[diethylaminomethyl]- 1-piperidinyl]acetyl]-5,11-dihydro-6H- pyrido[2,3-b][1,4]benzodiazepine-6-one], hexahydrosiladifenidol, methoctramine, 4-diphenylacetoxy-N-methylpiperidine methobromide, dicyclomine, para-fluoro-hexahydrosiladifenidol and atropine. Muscarinic receptors characterized by inhibition of [3H]quinuclidinylbenzilate binding in membranes of bovine pial arteries were of the M2 subtype. In contrast pharmacological analysis of [3H]-quinuclidinylbenzilate binding in bovine intracerebral microvessels suggests the presence of an M4 subtype. Receptors mediating endothelium-dependent vasodilation in rabbit pial arteries were of the M3 subtype, whereas muscarinic receptors stimulating endothelium-independent phosphoinositide hydrolysis in bovine pial arteries were of the M1 subtype. These findings suggest that characteristics of muscarinic receptors in cerebral blood vessels vary depending on the type of vessel, cellular location and function mediated

  18. Molecular alteration of a muscarinic acetylcholine receptor system during synaptogenesis

    International Nuclear Information System (INIS)

    Large, T.H.; Cho, N.J.; De Mello, F.G.; Klein, W.L.

    1985-01-01

    Biochemical properties of the muscarinic acetylcholine receptor system of the avian retina were found to change during the period when synapses form in ovo. Comparison of ligand binding to membranes obtained before and after synaptogenesis showed a significant increase in the affinity, but not proportion, of the high affinity agonist-binding state. There was no change in receptor sensitivity to antagonists during this period. Pirenzepine binding, which can discriminate muscarinic receptor subtypes, showed the presence of a single population of low affinity sites (M2) before and after synaptogenesis. The change in agonist binding was not due to the late development of receptor function. However, detergent-solubilization of membranes eliminated differences in agonist binding between receptors from embryos and hatched chicks, suggesting a developmental change in interactions of the receptor with functionally related membrane components. A possible basis for altered interactions was obtained from isoelectric point data showing that the muscarinic receptor population underwent a transition from a predominantly low pI form (4.25) in 13 day embryos to a predominantly high pI form (4.50) in newly hatched chicks. The possibility that biochemical changes in the muscarinic receptor play a role in differentiation of the system by controlling receptor position on the surface of nerve cells is discussed

  19. Characterization of muscarinic receptor subtypes in primary cultures of cerebellar granule cells using specific muscarinic receptor antagonists

    International Nuclear Information System (INIS)

    McLeskey, S.W.

    1989-01-01

    In cerebellar granule cell cultures, two muscarinic receptor mediated responses were observed: inhibition of adenylate cyclase (M-AC) and stimulation of phosphoinositide hydrolysis (M-PI). These responses were antagonized by three purported specific muscarinic antagonists: pirenzipine and (-)QNX (specific for M-PI) and methoctramine (specific for M-AC). However, the specificity for the three antagonists in blocking these responses is not comparable to the specificity observed in binding studies on these cells or to that quoted in the literature. Two peaks of molecular sizes were found in these cells corresponding to the two molecular sizes of muscarinic receptive proteins reported in the literature. Muscarinic receptive proteins were alkylated with 3 H-propylbenzilylcholine mustard followed by sodium dodecylsulfate polyacrylamide gel electrophoresis. Pirenzipine and (-)QNX were able to block alkylation of the high molecular size peak, which corresponds to the receptive protein m 3 reported in the literature. Methoctramine was able to block alkylation of a portion of the lower molecular size peak, possibly corresponding to the m 2 and/or m 4 receptive proteins reported in the literature. Studies attempting to show the presence of receptor reserve for either of the two biochemical responses present in these cells by alkylation of the receptive protein with nonradiolabeled propylbenzilylcholine mustard (PBCM) were confounded by specificity of this agent for the lower molecular weight peak of muscarinic receptive protein. Thus the muscarinic receptive proteins coupled to M-AC were alkylated preferentially over the ones coupled to M-PI

  20. An improved radiosynthesis of the muscarinic M2 radiopharmaceutical, [{sup 18}F]FP-TZTP

    Energy Technology Data Exchange (ETDEWEB)

    Oosten, Erik M. van [Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, M5S 3H6 (Canada); PET Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8 (Canada); Wilson, Alan A.; Stephenson, Karin A. [PET Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8 (Canada); Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario, M5T 1R8 (Canada); Mamo, David C. [PET Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8 (Canada); Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario, M5T 1R8 (Canada); Geriatric Mental Health Program, Centre for Addiction and Mental Health, 1001 Queen Street West, Toronto, Ontario, M6J 1H4 (Canada); Pollock, Bruce G.; Mulsant, Benoit H. [Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario, M5T 1R8 (Canada); Geriatric Mental Health Program, Centre for Addiction and Mental Health, 1001 Queen Street West, Toronto, Ontario, M6J 1H4 (Canada); Yudin, Andrei K. [Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, M5S 3H6 (Canada); Houle, Sylvain [PET Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8 (Canada); Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario, M5T 1R8 (Canada); Vasdev, Neil [PET Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8 (Canada); Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario, M5T 1R8 (Canada)], E-mail: neil.vasdev@camhpet.ca

    2009-04-15

    The radioligand 3-(4-(3-[{sup 18}F]fluoropropylthio)-1,2,5-thiadiazol-3-yl)-1-methyl-1,2,5, 6-tetrahydropyridine ([{sup 18}F]FP-TZTP) is an agonist with specificity towards subtype 2 of muscarinic acetylcholine (M2) receptors. It is currently the only radiotracer available for imaging M2 receptors in human subjects with positron emission tomography. The present study reports on an improved method for the synthesis of [{sup 18}F]FP-TZTP, automated using a GE TRACERlab{sup TM} FX{sub FN} radiosynthesis module. A key facet was the use of a new precursor, 3-(4-(1-methyl-1,2,5,6-tetrahydropyridin-3-yl)-1,2,5-thiadiazol-3-ylthio) propyl 4-methylbenzenesulfonate. The precursor was fluorinated via nucleophilic displacement of the tosyloxy group by potassium cryptand [{sup 18}F]fluoride (K[{sup 18}F]/K{sub 222}) in CH{sub 3}CN at 80 deg. C for 5 min, and purified by HPLC. Formulated [{sup 18}F]FP-TZTP was prepared in an uncorrected radiochemical yield of 29{+-}4%, with a specific activity of 138{+-}41 GBq/{mu}mol (3732{+-}1109 mCi/{mu}mol) at the end of synthesis (35 min; n=3). This methodology offers higher yields, faster synthesis times, an optimized precursor, and simpler automation than previously reported.

  1. An improved radiosynthesis of the muscarinic M2 radiopharmaceutical, [18F]FP-TZTP

    International Nuclear Information System (INIS)

    Oosten, Erik M. van; Wilson, Alan A.; Stephenson, Karin A.; Mamo, David C.; Pollock, Bruce G.; Mulsant, Benoit H.; Yudin, Andrei K.; Houle, Sylvain; Vasdev, Neil

    2009-01-01

    The radioligand 3-(4-(3-[ 18 F]fluoropropylthio)-1,2,5-thiadiazol-3-yl)-1-methyl-1,2,5, 6-tetrahydropyridine ([ 18 F]FP-TZTP) is an agonist with specificity towards subtype 2 of muscarinic acetylcholine (M2) receptors. It is currently the only radiotracer available for imaging M2 receptors in human subjects with positron emission tomography. The present study reports on an improved method for the synthesis of [ 18 F]FP-TZTP, automated using a GE TRACERlab TM FX FN radiosynthesis module. A key facet was the use of a new precursor, 3-(4-(1-methyl-1,2,5,6-tetrahydropyridin-3-yl)-1,2,5-thiadiazol-3-ylthio) propyl 4-methylbenzenesulfonate. The precursor was fluorinated via nucleophilic displacement of the tosyloxy group by potassium cryptand [ 18 F]fluoride (K[ 18 F]/K 222 ) in CH 3 CN at 80 deg. C for 5 min, and purified by HPLC. Formulated [ 18 F]FP-TZTP was prepared in an uncorrected radiochemical yield of 29±4%, with a specific activity of 138±41 GBq/μmol (3732±1109 mCi/μmol) at the end of synthesis (35 min; n=3). This methodology offers higher yields, faster synthesis times, an optimized precursor, and simpler automation than previously reported

  2. Convulsant bicuculline modifies CNS muscarinic receptor affinity

    Directory of Open Access Journals (Sweden)

    Rodríguez de Lores Arnaiz Georgina

    2006-04-01

    Full Text Available Abstract Background Previous work from this laboratory has shown that the administration of the convulsant drug 3-mercaptopropionic acid (MP, a GAD inhibitor, modifies not only GABA synthesis but also binding of the antagonist [3H]-quinuclidinyl benzilate ([3H]-QNB to central muscarinic receptors, an effect due to an increase in affinity without modifications in binding site number. The cholinergic system has been implicated in several experimental epilepsy models and the ability of acetylcholine to regulate neuronal excitability in the neocortex is well known. To study the potential relationship between GABAergic and cholinergic systems with seizure activity, we analyzed the muscarinic receptor after inducing seizure by bicuculline (BIC, known to antagonize the GABA-A postsynaptic receptor subtype. Results We analyzed binding of muscarinic antagonist [3H]-QNB to rat CNS membranes after i.p. administration of BIC at subconvulsant (1.0 mg/kg and convulsant (7.5 mg/kg doses. Subconvulsant BIC dose failed to develop seizures but produced binding alteration in the cerebellum and hippocampus with roughly 40% increase and 10% decrease, respectively. After convulsant BIC dose, which invariably led to generalized tonic-clonic seizures, binding increased 36% and 15% to cerebellar and striatal membranes respectively, but decreased 12% to hippocampal membranes. Kd value was accordingly modified: with the subconvulsant dose it decreased 27% in cerebellum whereas it increased 61% in hippocampus; with the convulsant dose, Kd value decreased 33% in cerebellum but increased 85% in hippocampus. No change in receptor number site was found, and Hill number was invariably close to unity. Conclusion Results indicate dissimilar central nervous system area susceptibility of muscarinic receptor to BIC. Ligand binding was modified not only by a convulsant BIC dose but also by a subconvulsant dose, indicating that changes are not attributable to the seizure process

  3. Allosteric Modulation of Muscarinic Acetylcholine Receptors

    Czech Academy of Sciences Publication Activity Database

    Jakubík, Jan; El-Fakahany, E. E.

    2010-01-01

    Roč. 3, č. 9 (2010), s. 2838-2860 ISSN 1424-8247 R&D Projects: GA ČR GA305/09/0681 Institutional research plan: CEZ:AV0Z50110509 Keywords : muscarinic acetylcholine receptors * allosteric modulation * Alzheimer´s disease Subject RIV: CE - Biochemistry

  4. Muscarinic acetylcholine receptor expression in aganglionic bowel.

    Science.gov (United States)

    Oue, T; Yoneda, A; Shima, H; Puri, P

    2000-01-01

    In Hirschsprung's disease (HD) there exists an overabundance of acetylcholine (ACh), which in turn stimulates excessive production of the enzyme acetylcholinesterase. Muscarinic ACh receptors (mAChRs) play an important role in smooth-muscle contraction. Recent studies have indicated five different subtypes of mAChRs encoded by five different genes, ml to m5. The purpose of this study was to investigate the expression of each mAChR subtype in aganglionic (AG) colon to further understand the pathophysiology of HD. Entire colon resected at the time of pull-through operation for HD was obtained from 14 patients. Specimens obtained at autopsy from 8 age-matched patients without gastrointestinal disease acted as controls. Frozen sections were used for indirect immunohistochemistry as well as in-situ hybridization. Immunohistochemistry was performed using specific antiserum against each mAChR subtype and in-situ hybridization was performed using specific oligonucleotide probes against ml to m5 subtypes. Messenger RNA (mRNA) was extracted from normoganglionic (NG) and AG bowel of HD patients and normal control bowel. Reverse transcription-polymerase chain reaction was performed to evaluate mRNA levels of each mAChR subtype. To adjust the levels of mRNA expression, a housekeeping gene G3PDH, known to be expressed normally, was used as an internal control. Strong m2 and m3 immunoreactivity was observed in the mucosal layer, smooth-muscle layers, and myenteric plexus of NG bowel, whereas ml immunoreactivity was only detected in the mucosal layer. The most striking finding was the abundance of m3-immunoreactive fibers in muscle layers of NG bowel while there was a total lack of m3 fibers in smooth-muscle of AG bowel. Intense mRNA signals encoding m2 and m3 and to a lesser degree ml were detected in NG bowel, and these signals were weak in AG bowel. Immunoreactivity and mRNA expression of m4 and m5 was not detected in NG or AG bowel. The lack of m3-immunoreactive fibers in the

  5. Autoradiographic visualization of muscarinic receptor subtypes in human and guinea pig lung

    International Nuclear Information System (INIS)

    Mak, J.C.; Barnes, P.J.

    1990-01-01

    Muscarinic receptor subtypes have been localized in human and guinea pig lung sections by an autoradiographic technique, using [3H](-)quinuclidinyl benzilate [( 3H]QNB) and selective muscarinic antagonists. [3H]QNB was incubated with tissue sections for 90 min at 25 degrees C, and nonspecific binding was determined by incubating adjacent serial sections in the presence of 1 microM atropine. Binding to lung sections had the characterization expected for muscarinic receptors. Autoradiography revealed that muscarinic receptors were widely distributed in human lung, with dense labeling over submucosal glands and airway ganglia, and moderate labeling over nerves in intrapulmonary bronchi and of airway smooth muscle of large and small airways. In addition, alveolar walls were uniformly labeled. In guinea pig lung, labeling of airway smooth muscle was similar, but in contrast to human airways, epithelium was labeled but alveolar walls were not. The muscarinic receptors of human airway smooth muscle from large to small airways were entirely of the M3-subtype, whereas in guinea pig airway smooth muscle, the majority were the M3-subtype with a very small population of the M2-subtype present. In human bronchial submucosal glands, M1- and M3-subtypes appeared to coexist in the proportions of 36 and 64%, respectively. In human alveolar walls the muscarinic receptors were entirely of the M1-subtype, which is absent from the guinea pig lung. No M2-receptors were demonstrated in human lung. The localization of M1-receptors was confirmed by direct labeling with [3H]pirenzepine. With the exception of the alveolar walls in human lung, the localization of muscarinic receptor subtypes on structures in the lung is consistent with known functional studies

  6. The binding of [3H]AF-DX 384 to rat ileal smooth muscle muscarinic receptors

    International Nuclear Information System (INIS)

    Entzeroth, M.; Mayer, N.

    1991-01-01

    The tritiated cardioselective muscarinic antagonist AF-DX 384 (5,11-dihydro-11-[2-[-(8-dipropylamino)methyl]-1-piperidinyl-ethyl-amino-carbonyl]-6H-pyrido [2,3-b] [1,4]benzodiazepin-6-one) was used to label muscarinic receptors in the rat ileum. Saturation binding to membrane suspensions revealed a high affinity binding site with a Kd of 9.2 nM. The maximal number of binding sites labeled in this tissue (Bmax) is 237 fmol/mg protein. The association and dissociation kinetics were well represented by single exponential reactions, and the dissociation constant obtained from the ratio of rate constants was in agreement with that derived from saturation experiments. Specific binding was inhibited by muscarinic antagonists with a rank order of potencies of atropine (pKi: 8.80) greater than 4-DAMP (pKi: 8.23) = AF-DX 384 (pKi: 8.20) greater than AF-DX 116 (pKi: 7.09) = hexahydro-sila-difenidol (pKi: 6.97) greater than pirenzepine (pKi: 6.49) and is consistent with the interaction of [3H]AF-DX 384 with muscarinic receptors of the M2 subtype. It can be concluded that [3H]AF-DX 384 can be used to selectively label M2 muscarinic receptors in heterogeneous receptor populations

  7. Activation of muscarinic acetylcholine receptors elicits pigment granule dispersion in retinal pigment epithelium isolated from bluegill.

    Science.gov (United States)

    González, Alfredo; Crittenden, Elizabeth L; García, Dana M

    2004-07-13

    In fish, melanin pigment granules in the retinal pigment epithelium disperse into apical projections as part of the suite of responses the eye makes to bright light conditions. This pigment granule dispersion serves to reduce photobleaching and occurs in response to neurochemicals secreted by the retina. Previous work has shown that acetylcholine may be involved in inducing light-adaptive pigment dispersion. Acetylcholine receptors are of two main types, nicotinic and muscarinic. Muscarinic receptors are in the G-protein coupled receptor superfamily, and five different muscarinic receptors have been molecularly cloned in human. These receptors are coupled to adenylyl cyclase, calcium mobilization and ion channel activation. To determine the receptor pathway involved in eliciting pigment granule migration, we isolated retinal pigment epithelium from bluegill and subjected it to a battery of cholinergic agents. The general cholinergic agonist carbachol induces pigment granule dispersion in isolated retinal pigment epithelium. Carbachol-induced pigment granule dispersion is blocked by the muscarinic antagonist atropine, by the M1 antagonist pirenzepine, and by the M3 antagonist 4-DAMP. Pigment granule dispersion was also induced by the M1 agonist 4-[N-(4-chlorophenyl) carbamoyloxy]-4-pent-2-ammonium iodide. In contrast the M2 antagonist AF-DX 116 and the M4 antagonist tropicamide failed to block carbachol-induced dispersion, and the M2 agonist arecaidine but-2-ynyl ester tosylate failed to elicit dispersion. Our results suggest that carbachol-mediated pigment granule dispersion occurs through the activation of Modd muscarinic receptors, which in other systems couple to phosphoinositide hydrolysis and elevation of intracellular calcium. This conclusion must be corroborated by molecular studies, but suggests Ca2+-dependent pathways may be involved in light-adaptive pigment dispersion.

  8. Activation of muscarinic acetylcholine receptors elicits pigment granule dispersion in retinal pigment epithelium isolated from bluegill

    Directory of Open Access Journals (Sweden)

    Crittenden Elizabeth L

    2004-07-01

    Full Text Available Abstract Background In fish, melanin pigment granules in the retinal pigment epithelium disperse into apical projections as part of the suite of responses the eye makes to bright light conditions. This pigment granule dispersion serves to reduce photobleaching and occurs in response to neurochemicals secreted by the retina. Previous work has shown that acetylcholine may be involved in inducing light-adaptive pigment dispersion. Acetylcholine receptors are of two main types, nicotinic and muscarinic. Muscarinic receptors are in the G-protein coupled receptor superfamily, and five different muscarinic receptors have been molecularly cloned in human. These receptors are coupled to adenylyl cyclase, calcium mobilization and ion channel activation. To determine the receptor pathway involved in eliciting pigment granule migration, we isolated retinal pigment epithelium from bluegill and subjected it to a battery of cholinergic agents. Results The general cholinergic agonist carbachol induces pigment granule dispersion in isolated retinal pigment epithelium. Carbachol-induced pigment granule dispersion is blocked by the muscarinic antagonist atropine, by the M1 antagonist pirenzepine, and by the M3 antagonist 4-DAMP. Pigment granule dispersion was also induced by the M1 agonist 4-[N-(4-chlorophenyl carbamoyloxy]-4-pent-2-ammonium iodide. In contrast the M2 antagonist AF-DX 116 and the M4 antagonist tropicamide failed to block carbachol-induced dispersion, and the M2 agonist arecaidine but-2-ynyl ester tosylate failed to elicit dispersion. Conclusions Our results suggest that carbachol-mediated pigment granule dispersion occurs through the activation of Modd muscarinic receptors, which in other systems couple to phosphoinositide hydrolysis and elevation of intracellular calcium. This conclusion must be corroborated by molecular studies, but suggests Ca2+-dependent pathways may be involved in light-adaptive pigment dispersion.

  9. Biochemical and immunological studies of the Muscarinic acetylcholine receptor

    International Nuclear Information System (INIS)

    Gainer, M.W.

    1985-01-01

    Muscarinic acetylcholine receptors were solubilized from bovine brain membranes with 3[3-cholamidopropyl)dimethylammonio]propanesulfonate (CHAPS). A combination of 10 mM CHAPS and 1 M NaCl solubilized 15-40% of the specific receptor binding sites from these membranes. The solubilized receptors displayed high affinity binding of the muscarinic antagonist, [ 3 H]quinuclidinyl benzilate with a K/sub D/ = 300 pM. In addition, the solubilized and retained guanyl nucleotide regulation of agonist binding characteristic of membrane bound receptors. Gel filtration experiments showed that solubilized receptors from cortex and cerebellum had different elution profiles. Analysis by sucrose density gradient centrifugation showed that receptors in the lower molecular weight peak sedimented with a coefficient of 5S. Receptors in the larger molecular weight peak sedimented to the bottom of the gradient. Attempts to purify receptors by chromatography on propylbenzilycholine Sepharose were unsuccessful. The technique used to attach the ligand to the solid support, however, was used to synthesize a PrBCM-BSA conjugate and the conjugate used as an antigen in the production of anti-ligand antibodies. Two anti-PrBCM monoclonal antibodies were isolated that recognize muscarinic but not nicotinic cholinergic ligands. The abilities of the antibodies to recognize other muscarinic ligands indicated the antibodies recognized a portion of PrBCM involved in binding to the receptor. Construction of an antibody affinity resin resulted in the purification of this fragment a minimum of 170 fold

  10. Muscarinic receptor compensation in hippocampus of alzheimer patients. [Autoradiography

    Energy Technology Data Exchange (ETDEWEB)

    Nordberg, A; Larsson, C; Adolfsson, R; Alafuzoff, I; Winblad, B [Uppsala Univ. (Sweden)

    1983-01-01

    The activity of the acetylcholine synthesizing enzyme choline acetyltransferase (ChAT) (presynaptic marker) and number of muscarine-like receptor binding sites have been measured in the hippocampus from eight individuals with senile dementia of Alzheimer type (SDAT) and ten controls. A negative correlation (r=0.80; p<0.05) was found between the ChAT activity and the number of muscarine-like receptors in the SDAT group but not in the controls. The findings might indicate an ongoing compensatory receptor mechanism as a response to changes in presynaptic cholinergic activity.

  11. Flavonoids with M1 Muscarinic Acetylcholine Receptor Binding Activity

    Directory of Open Access Journals (Sweden)

    Meyyammai Swaminathan

    2014-06-01

    Full Text Available Muscarinic acetylcholine receptor-active compounds have potential for the treatment of Alzheimer’s disease. In this study, a series of natural and synthetic flavones and flavonols was assayed in vitro for their ability to inhibit radioligand binding at human cloned M1 muscarinic receptors. Several compounds were found to possess competitive binding affinity (Ki = 40–110 µM, comparable to that of acetylcholine (Ki = 59 µM. Despite the fact that these compounds lack a positively-charged ammonium group under physiological conditions, molecular modelling studies suggested that they bind to the orthosteric site of the receptor, mainly through non-polar interactions.

  12. Muscarinic cholinergic receptor binding sites differentiated by their affinity for pirenzepine do not interconvert

    International Nuclear Information System (INIS)

    Gil, D.W.; Wolfe, B.B.

    1986-01-01

    Although it has been suggested by many investigators that subtypes of muscarinic cholinergic receptors exist, physical studies of solubilized receptors have indicated that only a single molecular species may exist. To test the hypothesis that the putative muscarinic receptor subtypes in rat forebrain are interconvertible states of the same receptor, the selective antagonist pirenzepine (PZ) was used to protect muscarinic receptors from blockade by the irreversible muscarinic receptor antagonist propylbenzilylcholine mustard (PBCM). If interconversion of high (M1) and low (M2) affinity binding sites for PZ occurs, incubation of cerebral cortical membranes with PBCM in the presence of PZ should not alter the proportions of M1 and M2 binding sites that are unalkylated (i.e., protected). If, on the other hand, the binding sites are not interconvertible, PZ should be able to selectively protect M1 sites and alter the proportions of unalkylated M1 and M2 binding sites. In the absence of PZ, treatment of cerebral cortical membranes with 20 nM PBCM at 4 degrees C for 50 min resulted in a 69% reduction in the density of M1 binding sites and a 55% reduction in the density of M2 binding sites with no change in the equilibrium dissociation constants of the radioligands [ 3 H]quinuclidinyl benzilate or [ 3 H]PZ. The reasons for this somewhat selective effect of PBCM are not apparent. In radioligand binding experiments using cerebral cortical membranes, PZ inhibited the binding of [ 3 H]quinuclidinyl benzilate in a biphasic manner

  13. Antipsychotic-like effect of the muscarinic acetylcholine receptor agonist BuTAC in non-human primates.

    Directory of Open Access Journals (Sweden)

    Maibritt B Andersen

    Full Text Available Cholinergic, muscarinic receptor agonists exhibit functional dopamine antagonism and muscarinic receptors have been suggested as possible future targets for the treatment of schizophrenia and drug abuse. The muscarinic ligand (5R,6R-6-(3-butylthio-1,2,5-thiadiazol-4-yl-1-azabicyclo[3.2.1]octane (BuTAC exhibits high affinity for muscarinic receptors with no or substantially less affinity for a large number of other receptors and binding sites, including the dopamine receptors and the dopamine transporter. In the present study, we wanted to examine the possible antipsychotic-like effects of BuTAC in primates. To this end, we investigated the effects of BuTAC on d-amphetamine-induced behaviour in antipsychotic-naive Cebus paella monkeys. Possible adverse events of BuTAC, were evaluated in the same monkeys as well as in monkeys sensitized to antipsychotic-induced extrapyramidal side effects. The present data suggests that, the muscarinic receptor ligand BuTAC exhibits antipsychotic-like behaviour in primates. The behavioural data of BuTAC as well as the new biochemical data further substantiate the rationale for the use of muscarinic M1/M2/M4-preferring receptor agonists as novel pharmacological tools in the treatment of schizophrenia.

  14. Quantitative autoradiographic analysis of muscarinic receptor subtypes and their role in representational memory

    International Nuclear Information System (INIS)

    Messer, W.S.

    1986-01-01

    Autoradiographic techniques were used to examine the distribution of muscarinic receptors in rat brain slices. Agonist and selective antagonist binding were examined by measuring the ability for unlabeled ligands to inhibit [ 3 H]-1-QNB labeling of muscarinic receptors. The distribution of high affinity pirenzepine binding sites (M 1 subtype) was distinct from the distribution of high affinity carbamylcholine sites, which corresponded to the M 2 subtype. In a separate assay, the binding profile for pirenzepine was shown to differ from the profile for scopolamine, a classical muscarinic antagonist. Muscarinic antagonists, when injected into the Hippocampus, impaired performance of a representational memory task. Pirenzepine, the M 1 selective antagonist, produced representational memory deficits. Scopolamine, a less selective muscarinic antagonist, caused increases in running times in some animals which prevented a definitive interpretation of the nature of the impairment. Pirenzepine displayed a higher affinity for the hippocampus and was more effective in producing a selective impairment of representational memory than scopolamine. The data indicated that cholinergic activity in the hippocampus was necessary for representation memory function

  15. Effects of dopamine D1-like and D2-like antagonists on cocaine discrimination in muscarinic receptor knockout mice.

    Science.gov (United States)

    Thomsen, Morgane; Caine, Simon Barak

    2016-04-05

    Muscarinic and dopamine brain systems interact intimately, and muscarinic receptor ligands, like dopamine ligands, can modulate the reinforcing and discriminative stimulus (S(D)) effects of cocaine. To enlighten the dopamine/muscarinic interactions as they pertain to the S(D) effects of cocaine, we evaluated whether muscarinic M1, M2 or M4 receptors are necessary for dopamine D1 and/or D2 antagonist mediated modulation of the S(D) effects of cocaine. Knockout mice lacking M1, M2, or M4 receptors, as well as control wild-type mice and outbred Swiss-Webster mice, were trained to discriminate 10mg/kg cocaine from saline in a food-reinforced drug discrimination procedure. Effects of pretreatments with the dopamine D1 antagonist SCH 23390 and the dopamine D2 antagonist eticlopride were evaluated. In intact mice, both SCH 23390 and eticlopride attenuated the cocaine discriminative stimulus effect, as expected. SCH 23390 similarly attenuated the cocaine discriminative stimulus effect in M1 knockout mice, but not in mice lacking M2 or M4 receptors. The effects of eticlopride were comparable in each knockout strain. These findings demonstrate differences in the way that D1 and D2 antagonists modulate the S(D) effects of cocaine, D1 modulation being at least partially dependent upon activity at the inhibitory M2/M4 muscarinic subtypes, while D2 modulation appeared independent of these systems. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Cardiac muscarinic receptor overexpression in sudden infant death syndrome.

    Directory of Open Access Journals (Sweden)

    Angelo Livolsi

    Full Text Available BACKGROUND: Sudden infant death syndrome (SIDS remains the leading cause of death among infants less than 1 year of age. Disturbed expression of some neurotransmitters and their receptors has been shown in the central nervous system of SIDS victims but no biological abnormality of the peripheral vago-cardiac system has been demonstrated to date. The present study aimed to seek vago-cardiac abnormalities in SIDS victims. The cardiac level of expression of muscarinic receptors, as well as acetylcholinesterase enzyme activity were investigated. METHODOLOGY/PRINCIPAL FINDINGS: Left ventricular samples and blood samples were obtained from autopsies of SIDS and children deceased from non cardiac causes. Binding experiments performed with [(3H]NMS, a selective muscarinic ligand, in cardiac membrane preparations showed that the density of cardiac muscarinic receptors was increased as shown by a more than doubled B(max value in SIDS (n = 9 SIDS versus 8 controls. On average, the erythrocyte acetylcholinesterase enzyme activity was also significantly increased (n = 9 SIDS versus 11 controls. CONCLUSIONS: In the present study, it has been shown for the first time that cardiac muscarinic receptor overexpression is associated with SIDS. The increase of acetylcholinesterase enzyme activity appears as a possible regulatory mechanism.

  17. Perirhinal Cortex Muscarinic Receptor Blockade Impairs Taste Recognition Memory Formation

    Science.gov (United States)

    Gutierrez, Ranier; De la Cruz, Vanesa; Rodriguez-Ortiz, Carlos J.; Bermudez-Rattoni, Federico

    2004-01-01

    The relevance of perirhinal cortical cholinergic and glutamatergic neurotransmission for taste recognition memory and learned taste aversion was assessed by microinfusions of muscarinic (scopolamine), NMDA (AP-5), and AMPA (NBQX) receptor antagonists. Infusions of scopolamine, but not AP5 or NBQX, prevented the consolidation of taste recognition…

  18. Muscarinic acetylcholine receptor subtypes: localization and structure/function

    DEFF Research Database (Denmark)

    Brann, M R; Ellis, J; Jørgensen, H

    1993-01-01

    Based on the sequence of the five cloned muscarinic receptor subtypes (m1-m5), subtype selective antibody and cDNA probes have been prepared. Use of these probes has demonstrated that each of the five subtypes has a markedly distinct distribution within the brain and among peripheral tissues...... are described, as well as the implied structures of these functional domains....

  19. Role of muscarinic receptor antagonists in urgency and nocturia

    NARCIS (Netherlands)

    Michel, Martin C.; de La Rosette, Jean J. M. C. H.

    2005-01-01

    The overactive bladder (OAB) syndrome is defined as urgency, with or without urgency incontinence, usually accompanied by frequency and nocturia. Muscarinic receptor antagonists are the most established form of treatment for OAB, but until recently their effectiveness was only confirmed for symptoms

  20. Adenosine receptors and muscarinic receptors cooperate in acetylcholine release modulation in the neuromuscular synapse.

    Science.gov (United States)

    Santafe, M M; Priego, M; Obis, T; Garcia, N; Tomàs, M; Lanuza, M A; Tomàs, J

    2015-07-01

    Adenosine receptors (ARs) are present in the motor terminals at the mouse neuromuscular junction. ARs and the presynaptic muscarinic acetylcholine receptors (mAChRs) share the functional control of the neuromuscular junction. We analysed their mutual interaction in transmitter release modulation. In electrophysiological experiments with unaltered synaptic transmission (muscles paralysed by blocking the voltage-dependent sodium channel of the muscle cells with μ-conotoxin GIIIB), we found that: (i) a collaborative action between different AR subtypes reduced synaptic depression at a moderate activity level (40 Hz); (ii) at high activity levels (100 Hz), endogenous adenosine production in the synaptic cleft was sufficient to reduce depression through A1 -type receptors (A1 Rs) and A2 A-type receptors (A2 A Rs); (iii) when the non-metabolizable 2-chloroadenosine (CADO) agonist was used, both the quantal content and depression were reduced; (iv) the protective effect of CADO on depression was mediated by A1 Rs, whereas A2 A Rs seemed to modulate A1 Rs; (v) ARs and mAChRs absolutely depended upon each other for the modulation of evoked and spontaneous acetylcholine release in basal conditions and in experimental conditions with CADO stimulation; (vi) the purinergic and muscarinic mechanisms cooperated in the control of depression by sharing a common pathway although the purinergic control was more powerful than the muscarinic control; and (vii) the imbalance of the ARs created by using subtype-selective and non-selective inhibitory and stimulatory agents uncoupled protein kinase C from evoked transmitter release. In summary, ARs (A1 Rs, A2 A Rs) and mAChRs (M1 , M2 ) cooperated in the control of activity-dependent synaptic depression and may share a common protein kinase C pathway. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  1. Muscarinic receptors mediate cold stress-induced detrusor overactivity in type 2 diabetes mellitus rats.

    Science.gov (United States)

    Imamura, Tetsuya; Ishizuka, Osamu; Ogawa, Teruyuki; Yamagishi, Takahiro; Yokoyama, Hitoshi; Minagawa, Tomonori; Nakazawa, Masaki; Gautam, Sudha Silwal; Nishizawa, Osamu

    2014-10-01

    This study determined if muscarinic receptors could mediate the cold stress-induced detrusor overactivity induced in type 2 diabetes mellitus rats. Ten-week-old female Goto-Kakizaki diabetic rats (n = 12) and Wister Kyoto non-diabetic rats (n = 12) were maintained on a high-fat diet for 4 weeks. Cystometric investigations of the unanesthetized rats were carried out at room temperature (27 ± 2°C) for 20 min. They were intravenously administered imidafenacin (0.3 mg/kg, n = 6) or vehicle (n = 6). After 5 min, the rats were transferred to a low temperature (4 ± 2°C) for 40 min where the cystometry was continued. The rats were then returned to room temperature for the final cystometric measurements. Afterwards, expressions of bladder muscarinic receptor M3 and M2 messenger ribonucleic acids and proteins were assessed by reverse transcription polymerase chain reaction and immunohistochemistry. In non-diabetic Wister Kyoto rats, imidafenacin did not reduce cold stress-induced detrusor overactivity. In diabetic Goto-Kakizaki rats, just after transfer to a low temperature, the cold stress-induced detrusor overactivity in imidafenacin-treated rats was reduced compared with vehicle-treated rats. Within the urinary bladders, the ratio of M3 to M2 receptor messenger ribonucleic acid in the diabetic Goto-Kakizaki rats was significantly higher than that of the non-diabetic Wister Kyoto rats. The proportion of muscarinic M3 receptor-positive area within the detrusor in diabetic Goto-Kakizaki rats was also significantly higher than that in non-diabetic Wister Kyoto rats. Imidafenacin partially inhibits cold stress-induced detrusor overactivity in diabetic Goto-Kakizaki rats. In this animal model, muscarinic M3 receptors partially mediate cold stress-induced detrusor overactivity. © 2014 The Japanese Urological Association.

  2. Alkylating derivative of oxotremorine interacts irreversibly with the muscarinic receptor

    International Nuclear Information System (INIS)

    Ehlert, F.J.; Jenden, D.J.; Ringdahl, B.

    1984-01-01

    A 2-chloroethylamine derivative of oxotremorine was studied in pharmacological experiments and muscarinic receptor binding assays. The compound, N-[4-(2-chloroethylmethylamino)-2-butynyl]-2-pyrrolidone (BM 123), forms an aziridinium ion in aqueous solution at neutral pH that stimulates contractions of guinea pig ileum with a potency similar to that of oxotremorine. Following the initial stimulation, there is a long lasting period of lack of sensitivity of the guinea pig ileum to muscarinic agonists. BM 123 also produces muscarinic effects in vivo. When homogenates of the rat cerebral cortex were incubated with BM 123 and assayed subsequently in muscarinic receptor binding assays, a loss of binding capacity for the muscarinic antagonist, [ 3 H]N-methylscopolamine ([ 3 H]NMS), was noted without a change in affinity. Similar observations were made in [ 3 H]1-3-quinuclidinyl benzilate ([ 3 H]-QNB) binding assays on the forebrains of mice that had been injected with BM 123 24 hr earlier. The loss in receptor capacity for both [ 3 H]NMS and [ 3 H]-QNB was prevented by atropine treatment. Kinetic studies of the interaction of BM 123 with homogenates of the rat cerebral cortex in vitro showed that the half-time for the loss of [ 3 H]-QNB binding sites increased from 10 to 45 min as the concentration of BM 123 decreased from 10 to 1 μM. In contrast to the aziridinium ion, the parent 2-chloroethylamine compound and the alcoholic hydrolysis product were largely devoid of pharmacological and binding activity

  3. Changes of muscarinic cholinergic receptors during aging process of primary cultured neutrons

    International Nuclear Information System (INIS)

    Fan Guohuang; Yi Ningyu; Xia Zongqin

    1996-01-01

    The dynamic changes of muscarinic receptor density and its reactivity during aging process in primary cultured neutrons were studied. Muscarinic receptor density was measured by 3 H-QNB binding assay, and muscarinic receptor reactivity was assessed by carbachol stimulation of cGMP formation, the latter was measured by RIA. After 2 weeks' incubation of neonatal rat brain cells, the nutrients began to rupture and the cell bodies shrank markedly showing senescent feature. The muscarinic receptor density reached peak at the 12th day in vitro (12 DIV), but the muscarinic receptor reactivity reached peak at 9 DIV and declined significantly at 12 DIV. The results demonstrated that during aging process of primary cultured neutrons, the decline of muscarinic receptor reactivity is likely prior to the decrease of receptor density

  4. Synergistic Action of Presynaptic Muscarinic Acetylcholine Receptors and Adenosine Receptors in Developmental Axonal Competition at the Neuromuscular Junction.

    Science.gov (United States)

    Nadal, Laura; Garcia, Neus; Hurtado, Erica; Simó, Anna; Tomàs, Marta; Lanuza, Maria Angel; Cilleros, Victor; Tomàs, Josep Maria

    2016-01-01

    The development of the nervous system involves the initial overproduction of synapses, which promotes connectivity. Hebbian competition between axons with different activities leads to the loss of roughly half of the overproduced elements and this refines connectivity. We used quantitative immunohistochemistry to investigate, in the postnatal day 7 (P7) to P9 neuromuscular junctions, the involvement of muscarinic receptors (muscarinic acetylcholine autoreceptors and the M1, M2, and M4 subtypes) and adenosine receptors (A1 and A2A subtypes) in the control of axonal elimination after the mouse levator auris longus muscle had been exposed to selective antagonists in vivo. In a previous study we analyzed the role of each of the individual receptors. Here we investigate the additive or occlusive effects of their inhibitors and thus the existence of synergistic activity between the receptors. The main results show that the A2A, M1, M4, and A1 receptors (in this order of ability) delayed axonal elimination at P7. M4 produces some occlusion of the M1 pathway and some addition to the A1 pathway, which suggests that they cooperate. M2 receptors may modulate (by allowing a permissive action) the other receptors, mainly M4 and A1. The continued action of these receptors (now including M2 but not M4) finally promotes axonal loss at P9. All 4 receptors (M2, M1, A1, and A2A, in this order of ability) are necessary. The M4 receptor (which in itself does not affect axon loss) seems to modulate the other receptors. We found a synergistic action between the M1, A1, and A2A receptors, which show an additive effect, whereas the potent M2 effect is largely independent of the other receptors (though can be modulated by M4). At P9, there is a full mutual dependence between the A1 and A2A receptors in regulating axon loss. In summary, postnatal axonal elimination is a regulated multireceptor mechanism that involves the cooperation of several muscarinic and adenosine receptor subtypes.

  5. Two types of muscarinic acetylcholine receptors in Drosophila and other arthropods.

    Science.gov (United States)

    Collin, Caitlin; Hauser, Frank; Gonzalez de Valdivia, Ernesto; de Valdivia, Ernesto Gonzalez; Li, Shizhong; Reisenberger, Julia; Carlsen, Eva M M; Khan, Zaid; Hansen, Niels O; Puhm, Florian; Søndergaard, Leif; Niemiec, Justyna; Heninger, Magdalena; Ren, Guilin R; Grimmelikhuijzen, Cornelis J P

    2013-09-01

    Muscarinic acetylcholine receptors (mAChRs) play a central role in the mammalian nervous system. These receptors are G protein-coupled receptors (GPCRs), which are activated by the agonists acetylcholine and muscarine, and blocked by a variety of antagonists. Mammals have five mAChRs (m1-m5). In this study, we cloned two structurally related GPCRs from the fruit fly Drosophila melanogaster, which, after expression in Chinese hamster ovary cells, proved to be muscarinic acetylcholine receptors. One mAChR (the A-type; encoded by gene CG4356) is activated by acetylcholine (EC50, 5 × 10(-8) M) and muscarine (EC50, 6 × 10(-8) M) and blocked by the classical mAChR antagonists atropine, scopolamine, and 3-quinuclidinyl-benzilate (QNB), while the other (the B-type; encoded by gene CG7918) is also activated by acetylcholine, but has a 1,000-fold lower sensitivity to muscarine, and is not blocked by the antagonists. A- and B-type mAChRs were also cloned and functionally characterized from the red flour beetle Tribolium castaneum. Recently, Haga et al. (Nature 2012, 482: 547-551) published the crystal structure of the human m2 mAChR, revealing 14 amino acid residues forming the binding pocket for QNB. These residues are identical between the human m2 and the D. melanogaster and T. castaneum A-type mAChRs, while many of them are different between the human m2 and the B-type receptors. Using bioinformatics, one orthologue of the A-type and one of the B-type mAChRs could also be found in all other arthropods with a sequenced genome. Protostomes, such as arthropods, and deuterostomes, such as mammals and other vertebrates, belong to two evolutionarily distinct lineages of animal evolution that split about 700 million years ago. We found that animals that originated before this split, such as cnidarians (Hydra), had two A-type mAChRs. From these data we propose a model for the evolution of mAChRs.

  6. Perirhinal Cortex Muscarinic Receptor Blockade Impairs Taste Recognition Memory Formation

    OpenAIRE

    Gutiérrez, Ranier; De la Cruz, Vanesa; Rodriguez-Ortiz, Carlos J.; Bermudez-Rattoni, Federico

    2004-01-01

    The relevance of perirhinal cortical cholinergic and glutamatergic neurotransmission for taste recognition memory and learned taste aversion was assessed by microinfusions of muscarinic (scopolamine), NMDA (AP-5), and AMPA (NBQX) receptor antagonists. Infusions of scopolamine, but not AP5 or NBQX, prevented the consolidation of taste recognition memory using attenuation of neophobia as an index. In addition, learned taste aversion in both short- and long-term memory tests was exclusively impa...

  7. Outline of therapeutic interventions with muscarinic receptor-mediated transmission

    Czech Academy of Sciences Publication Activity Database

    Jakubík, Jan; Šantrůčková, Eva; Randáková, Alena; Janíčková, Helena; Zimčík, Pavel; Rudajev, Vladimír; Michal, Pavel; El-Fakahany, E. E.; Doležal, Vladimír

    2014-01-01

    Roč. 63, Suppl.1 (2014), S177-S189 ISSN 0862-8408 R&D Projects: GA ČR(CZ) GA305/09/0681; GA ČR(CZ) GAP304/12/0259; GA MŠk(CZ) 7E10060 Institutional support: RVO:67985823 Keywords : cholinergic transmission * muscarinic receptors * therapy * Alzheimer's disease, * schizophrenia Subject RIV: ED - Physiology Impact factor: 1.293, year: 2014

  8. Role of dopamine receptor and muscarinic acetylcholine receptor blockade in the antiapomorphine action of neuroleptics

    Energy Technology Data Exchange (ETDEWEB)

    Zharkovskii, A.M.; Langel, Yu.L.; Chereshka, K.S.; Zharkovskaya, T.A.

    1987-08-01

    The authors analyze the role of dopamine and muscarinic acetylcholine receptor blocking components in the antistereotypic action of neuroleptics with different chemical structure. To determine dopamine-blocking activity in vitro, binding of /sup 3/H-spiperone with membranes of the rat striatum was measured. To study the blocking action of the substances on muscarinic acetylcholine receptors, binding of /sup 3/H-quinuclidinyl benzylate with brain membranes was chosen.

  9. COLOCALIZATION OF MUSCARINIC AND NICOTINIC RECEPTORS IN CHOLINOCEPTIVE NEURONS OF THE SUPRACHIASMATIC REGION IN YOUNG AND AGED RATS

    NARCIS (Netherlands)

    VANDERZEE, EA; STREEFLAND, C; STROSBERG, AD; SCHRODER, H; LUITEN, PGM; Schröder, H.

    1991-01-01

    In the present study muscarinic and nicotinic cholinergic receptors in the SCN region were demonstrated and analyzed, employing monoclonal antibodies to purified muscarinic and nicotinic cholinergic receptor proteins. A near-total colocalization of the two acetylcholine receptor subclasses in

  10. Muscarinic receptor subtype mRNA expression in the human prostate: association with age, pathological diagnosis, prostate size, or potentially interfering medications?

    NARCIS (Netherlands)

    Witte, Lambertus P. W.; Teitsma, Christine A.; de La Rosette, Jean J. M. C. H.; Michel, Martin C.

    2014-01-01

    As the prostate abundantly expresses muscarinic receptors and antagonists for such receptors are increasingly used in the treatment of men with voiding function and large prostates, we have explored an association of the mRNA expression of human M1, M2, M3, M4, and M5 receptors in human prostate

  11. Muscarinic receptor M4 positive allosteric modulators attenuate central effects of cocaine

    DEFF Research Database (Denmark)

    Dall, Camilla; Weikop, Pia; Dencker, Ditte

    2017-01-01

    BACKGROUND: Cocaine addiction is a chronic brain disease affecting neurotransmission. Muscarinic cholinergic receptors modulate dopaminergic signaling in the reward system, and muscarinic receptor stimulation can block direct reinforcing effects of cocaine. Here, we tested the hypothesis...... that specific muscarinic M4receptor stimulation can attenuate the discriminative stimulus effects and conditioned rewarding effects of cocaine, measures believed to predict the ability of cocaine and cocaine-associated cues to elicit relapse to drug taking. METHODS: We tested the M4-selective positive...

  12. Muscarinic receptor subtypes in porcine detrusor: comparison with humans and regulation by bladder augmentation

    NARCIS (Netherlands)

    Goepel, M.; Gronewald, A.; Krege, S.; Michel, M. C.

    1998-01-01

    The properties of muscarinic acetylcholine receptors of porcine and human bladder detrusor were compared in radioligand binding studies using [3H]quinuclidinylbenzylate as the radioligand. The receptor affinity for the radioligand and the density of muscarinic receptors was similar in male and

  13. Soman- or kainic acid-induced convulsions decrease muscarinic receptors but not benzodiazepine receptors

    International Nuclear Information System (INIS)

    Churchill, L.; Pazdernik, T.L.; Cross, R.S.; Nelson, S.R.; Samson, F.E.

    1990-01-01

    [3H]Quinuclidinyl benzilate (QNB) binding to muscarinic receptors decreased in the rat forebrain after convulsions induced by a single dose of either soman, a potent inhibitor of acetylcholinesterase, or kainic acid, an excitotoxin. A Rosenthal plot revealed that the receptors decreased in number rather than affinity. When the soman-induced convulsions were blocked, the decrease in muscarinic receptors at 3 days was less extensive than when convulsions occurred and at 10 days they approached control levels in most of the brain areas. The most prominent decrements in QNB binding were in the piriform cortex where the decline in QNB binding is probably related to the extensive convulsion-associated neuropathology. The decrements in QNB binding after convulsions suggest that the convulsive state leads to a down-regulation of muscarinic receptors in some brain areas. In contrast to the decrease in QNB binding after convulsions, [3H]flunitrazepam binding to benzodiazepine receptors did not change even in the piriform cortex where the loss in muscarinic receptors was most prominent. Thus, it appears that those neuronal processes that bear muscarinic receptors are more vulnerable to convulsion-induced change than those with benzodiazepine receptors

  14. Visualization of cholinoceptive neurons in the rat neocortex : colocalization of muscarinic and nicotinic acetylcholine receptors

    NARCIS (Netherlands)

    Zee, E.A. van der; Streefland, C.; Strosberg, A.D.; Schröder, H.; Luiten, P.G.M.

    The present investigation analyzes the cellular distribution of muscarinic and nicotinic acetylcholine receptors in rat neocortex, by use of monoclonal antibodies raised against purified receptor proteins. The degree of colocalization of both types of receptors was determined by way of

  15. Effect of aging on airway remodeling and muscarinic receptors in a murine acute asthma model

    Directory of Open Access Journals (Sweden)

    Kang JY

    2013-10-01

    Full Text Available Ji Young Kang, Sook Young Lee, Chin Kook Rhee, Seung Joon Kim, Soon Seog Kwon, Young Kyoon KimDepartment of Internal Medicine, College of Medicine, Catholic University of Korea, Seoul, KoreaBackground and objectives: The influence of aging on the development of asthma has not been studied thoroughly. The aim of this study was to investigate age-related airway responses involving lung histology and expression of muscarinic receptors in a murine model of acute asthma. Methods: Female BALB/c mice at the ages of 6 weeks and 6, 9, and 12 months were sensitized and challenged with ovalbumin (OVA for 1 month (n = 8–12 per group. We analyzed inflammatory cells and T-helper (Th2 cytokines in bronchoalveolar lavage (BAL fluid and parameters of airway remodeling and expression of muscarinic receptors in lung tissue. Results: Among the OVA groups, total cell and eosinophil numbers in BAL fluid were significantly higher in the older (6-, 9-, and 12-month-old mice than in the young (6-week-old mice. Interleukin (IL 4 (IL-4 concentration increased, but IL-5 and IL-13 concentrations showed a decreased tendency, with age. IL-17 concentration tended to increase with age, which did not reach statistical significance. periodic acid-Schiff (PAS staining area, peribronchial collagen deposition, and area of α-smooth muscle staining were significantly higher in the 6-month older OVA group than in the young OVA group. The expression of the M3 and M2 muscarinic receptors tended to increase and decrease, respectively, with age. Conclusion: The aged mice showed an active and unique pattern not only on airway inflammation, but also on airway remodeling and expression of the muscarinic receptors during the development of acute asthma compared with the young mice. These findings suggest that the aging process affects the pathogenesis of acute asthma and age-specific approach might be more appropriate for better asthma control in a clinical practice.Keywords: aging, asthma

  16. Muscarinic supersensitivity and impaired receptor desensitization in G protein-coupled receptor kinase 5-deficient mice.

    Science.gov (United States)

    Gainetdinov, R R; Bohn, L M; Walker, J K; Laporte, S A; Macrae, A D; Caron, M G; Lefkowitz, R J; Premont, R T

    1999-12-01

    G protein-coupled receptor kinase 5 (GRK5) is a member of a family of enzymes that phosphorylate activated G protein-coupled receptors (GPCR). To address the physiological importance of GRK5-mediated regulation of GPCRs, mice bearing targeted deletion of the GRK5 gene (GRK5-KO) were generated. GRK5-KO mice exhibited mild spontaneous hypothermia as well as pronounced behavioral supersensitivity upon challenge with the nonselective muscarinic agonist oxotremorine. Classical cholinergic responses such as hypothermia, hypoactivity, tremor, and salivation were enhanced in GRK5-KO animals. The antinociceptive effect of oxotremorine was also potentiated and prolonged. Muscarinic receptors in brains from GRK5-KO mice resisted oxotremorine-induced desensitization, as assessed by oxotremorine-stimulated [5S]GTPgammaS binding. These data demonstrate that elimination of GRK5 results in cholinergic supersensitivity and impaired muscarinic receptor desensitization and suggest that a deficit of GPCR desensitization may be an underlying cause of behavioral supersensitivity.

  17. Hypoxia increases exercise heart rate despite combined inhibition of β-adrenergic and muscarinic receptors

    DEFF Research Database (Denmark)

    Siebenmann, Christoph; Rasmussen, Peter; Sørensen, Henrik

    2015-01-01

    Hypoxia increases the heart rate (HR) response to exercise but the mechanism(s) remain unclear. We tested the hypothesis that the tachycardic effect of hypoxia persists during separate but not combined inhibition of β-adrenergic and muscarinic receptors. Nine subjects performed incremental exercise...... combined β-adrenergic and muscarinic receptor inhibition....

  18. Antipsychotic-induced catalepsy is attenuated in mice lacking the M4 muscarinic acetylcholine receptor

    DEFF Research Database (Denmark)

    Fink-Jensen, Anders; Schmidt, Lene S; Dencker, Ditte

    2011-01-01

    of the striatum, suggesting a role for muscarinic M4 receptors in the motor side effects of antipsychotics, and in the alleviation of these side effects by anticholinergics. Here we investigated the potential role of the muscarinic M4 receptor in catalepsy induced by antipsychotics (haloperidol and risperidone...

  19. Attenuation of cocaine's reinforcing and discriminative stimulus effects via muscarinic M1 acetylcholine receptor stimulation

    DEFF Research Database (Denmark)

    Thomsen, Morgane; Conn, P Jeffrey; Lindsley, Craig

    2010-01-01

    Muscarinic cholinergic receptors modulate dopaminergic function in brain pathways thought to mediate cocaine's abuse-related effects. Here, we sought to confirm and extend in the mouse species findings that nonselective muscarinic receptor antagonists can enhance cocaine's discriminative stimulus...... for cocaine addiction....

  20. Decrease in the number of rat brain dopamine and muscarinic receptors after chronic alcohol intake

    International Nuclear Information System (INIS)

    Syvaelahti, E.K.G.; Hietala, J.; Roeyttae, M.; Groenroos, J.

    1988-01-01

    The effect of 32 weeks' alcohol treatment on the number and affinity of dopamine and muscarinic receptor sites in rat striatum were measured using 3 H-spiperone and 3 H-quinuclidinylbenzilate ( 3 H-QNB) as radioligans. The number of dopamine receptor sites was 38 per cent and the number of muscarinic receptor sites 36 per cent lower in the alcohol group than in control rats. The differences in receptor affinities were less marked. In conclusion, a long-term alcohol intake with rather moderate doses seems to induce a pronounced down-regulation in dopamine and muscarinic receptor systems in rat striatum. (author)

  1. Differential effects of m1 and m2 receptor antagonists in perirhinal cortex on visual recognition memory in monkeys.

    Science.gov (United States)

    Wu, Wei; Saunders, Richard C; Mishkin, Mortimer; Turchi, Janita

    2012-07-01

    Microinfusions of the nonselective muscarinic antagonist scopolamine into perirhinal cortex impairs performance on visual recognition tasks, indicating that muscarinic receptors in this region play a pivotal role in recognition memory. To assess the mnemonic effects of selective blockade in perirhinal cortex of muscarinic receptor subtypes, we locally infused either the m1-selective antagonist pirenzepine or the m2-selective antagonist methoctramine in animals performing one-trial visual recognition, and compared these scores with those following infusions of equivalent volumes of saline. Compared to these control infusions, injections of pirenzepine, but not of methoctramine, significantly impaired recognition accuracy. Further, similar doses of scopolamine and pirenzepine yielded similar deficits, suggesting that the deficits obtained earlier with scopolamine were due mainly, if not exclusively, to blockade of m1 receptors. The present findings indicate that m1 and m2 receptors have functionally dissociable roles, and that the formation of new visual memories is critically dependent on the cholinergic activation of m1 receptors located on perirhinal cells. Published by Elsevier Inc.

  2. Current status of muscarinic M1 and M4 receptors as drug targets for neurodegenerative diseases.

    Science.gov (United States)

    Felder, Christian C; Goldsmith, Paul J; Jackson, Kimberley; Sanger, Helen E; Evans, David A; Mogg, Adrian J; Broad, Lisa M

    2018-01-25

    The cholinergic signalling system has been an attractive pathway to seek targets for modulation of arousal, cognition, and attention which are compromised in neurodegenerative and neuropsychiatric diseases. The acetylcholine muscarinic receptor M1 and M4 subtypes which are highly expressed in the central nervous system, in cortex, hippocampus and striatum, key areas of cognitive and neuropsychiatric control, have received particular attention. Historical muscarinic drug development yielded first generation agonists with modest selectivity for these two receptor targets over M2 and M3 receptors, the major peripheral sub-types hypothesised to underlie the dose-limiting clinical side effects. More recent compound screening and medicinal chemistry optimization of orthosteric and allosteric agonists, and positive allosteric modulators binding to sites distinct from the highly homologous acetylcholine binding pocket have yielded a collection of highly selective tool compounds for preclinical validation studies. Several M1 selective ligands have progressed to early clinical development and in time will hopefully lead to useful therapeutics for treating symptoms of Alzheimer's disease and related disorders. Copyright © 2018. Published by Elsevier Ltd.

  3. Comparative Effects of Oral Chlorpyrifos Exposure on Cholinesterase Activity and Muscarinic Receptor Binding in Neonatal and Adult Rat Heart

    Science.gov (United States)

    Howard, Marcia D.; Mirajkar, Nikita; Karanth, Subramanya; Pope, Carey N.

    2010-01-01

    Organophosphorus (OP) pesticides elicit acute toxicity by inhibiting acetylcholinesterase (AChE), the enzyme responsible for inactivating acetylcholine (ACh) at cholinergic synapses. A number of OP toxicants have also been reported to interact directly with muscarinic receptors, in particular the M2 muscarinic subtype. Parasympathetic innervation to the heart primarily regulates cardiac function by activating M2 receptors in the sinus node, atrial-ventricular node and conducting tissues. Thus, OP insecticides can potentially influence cardiac function in a receptor–mediated manner indirectly by inhibiting acetylcholinesterase and directly by binding to muscarinic M2 receptors. Young animals are generally more sensitive than adults to the acute toxicity of OP insecticides and age related differences in potency of direct binding to muscarinic receptors by some OP toxicants have been reported. We thus compared the effects of the common OP insecticide chlorpyrifos (CPF) on functional signs of toxicity and cardiac ChE activity and muscarinic receptor binding in neonatal and adult rats. Dosages were based on acute lethality (i.e., 0.5 and 1 × LD10: neonates, 7.5 and 15 mg/kg; adults, 68 and 136 mg/kg). Dose- and time-related changes in body weight and cholinergic signs of toxicity (involuntary movements) were noted in both age groups. With 1 × LD10, relatively similar maximal reductions in ChE activity (95%) and muscarinic receptor binding (≈ 30%) were noted, but receptor binding reductions appeared earlier in adults and were more prolonged in neonates. In vitro inhibition studies indicated that ChE in neonatal tissues was markedly more sensitive to inhibition by the active metabolite of chlorpyrifos (i.e., chlorpyrifos oxon, CPO) than enzyme in adult tissues (IC50 values: neonates, 17 nM; adults, 200 nM). Chelation of free calcium with EDTA had relatively little effect on in vitro cholinesterase inhibition, suggesting that differential A-esterase activity was not

  4. Molecular basis of the functional heterogeneity of the muscarinic acetylcholine receptor

    International Nuclear Information System (INIS)

    Numa, S.; Fukuda, K.; Kubo, T.; Maeda, A.; Akiba, I.; Bujo, H.; Nakai, J.; Mishina, M.; Higashida, H.

    1988-01-01

    The muscarinic acetylcholine receptor (mAChR) mediates a variety of cellular responses, including inhibition of adenylate cyclase, breakdown of phosphoinositides, and modulation of potassium channels, through the action of guanine-nucleotide-binding regulatory proteins (G proteins). The question then arises as to whether multiple mAChR species exist that are responsible for the various biochemical and physiological effects. In fact, pharmacologically distinguishable forms of the mAChR occur in different tissues and have been provisionally classified into M 1 (I), M 2 cardiac (II), and M 2 glandular (III) subtypes on the basis of their difference in apparent affinity for antagonists. Here, the authors have made attempts to understand the molecular basis of the functional heterogeneity of the mAChR, using recombinant DNA technology

  5. Muscarinic receptors as targets for anti-inflammatory therapy.

    Science.gov (United States)

    Sales, María Elena

    2010-11-01

    ACh, the main neurotransmitter in the neuronal cholinergic system, is synthesized by pre-ganglionic fibers of the sympathetic and parasympathetic autonomic nervous system and by post-ganglionic parasympathetic fibers. There is increasing experimental evidence that ACh is widely expressed in prokaryotic and eukaryotic non-neuronal cells. The neuronal and non-neuronal cholinergic systems comprise ACh, choline acetyltransferase and cholinesterase, enzymes that synthesize and catabolize ACh, and the nicotinic and muscarinic ACh receptors (nAChRs and mAChRs, respectively), which are the targets for ACh action. This review analyzes the participation of the cholinergic system, particularly through mAChRs, in inflammation, and discusses the role of the different mAChR antagonists that have been used to treat skin inflammatory disorders, asthma and COPD, as well as intestinal inflammation and systemic inflammatory diseases, to assess the potential application of these compounds as therapeutic tools.

  6. The allosteric site regulates the voltage sensitivity of muscarinic receptors.

    Science.gov (United States)

    Hoppe, Anika; Marti-Solano, Maria; Drabek, Matthäus; Bünemann, Moritz; Kolb, Peter; Rinne, Andreas

    2018-01-01

    Muscarinic receptors (M-Rs) for acetylcholine (ACh) belong to the class A of G protein-coupled receptors. M-Rs are activated by orthosteric agonists that bind to a specific site buried in the M-R transmembrane helix bundle. In the active conformation, receptor function can be modulated either by allosteric modulators, which bind to the extracellular receptor surface or by the membrane potential via an unknown mechanism. Here, we compared the modulation of M 1 -Rs and M 3 -Rs induced by changes in voltage to their allosteric modulation by chemical compounds. We quantified changes in receptor signaling in single HEK 293 cells with a FRET biosensor for the G q protein cycle. In the presence of ACh, M 1 -R signaling was potentiated by voltage, similarly to positive allosteric modulation by benzyl quinolone carboxylic acid. Conversely, signaling of M 3 -R was attenuated by voltage or the negative allosteric modulator gallamine. Because the orthosteric site is highly conserved among M-Rs, but allosteric sites vary, we constructed "allosteric site" M 3 /M 1 -R chimeras and analyzed their voltage dependencies. Exchanging the entire allosteric sites eliminated the voltage sensitivity of ACh responses for both receptors, but did not affect their modulation by allosteric compounds. Furthermore, a point mutation in M 3 -Rs caused functional uncoupling of the allosteric and orthosteric sites and abolished voltage dependence. Molecular dynamics simulations of the receptor variants indicated a subtype-specific crosstalk between both sites, involving the conserved tyrosine lid structure of the orthosteric site. This molecular crosstalk leads to receptor subtype-specific voltage effects. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Presynaptic Muscarinic Acetylcholine Receptors and TrkB Receptor Cooperate in the Elimination of Redundant Motor Nerve Terminals during Development.

    Science.gov (United States)

    Nadal, Laura; Garcia, Neus; Hurtado, Erica; Simó, Anna; Tomàs, Marta; Lanuza, Maria A; Cilleros, Victor; Tomàs, Josep

    2017-01-01

    The development of the nervous system involves the overproduction of synapses but connectivity is refined by Hebbian activity-dependent axonal competition. The newborn skeletal muscle fibers are polyinnervated but, at the end of the competition process, some days later, become innervated by a single axon. We used quantitative confocal imaging of the autofluorescent axons from transgenic B6.Cg-Tg (Thy1-YFP)16 Jrs/J mice to investigate the possible cooperation of the muscarinic autoreceptors (mAChR, M 1 -, M 2 - and M 4 -subtypes) and the tyrosine kinase B (TrkB) receptor in the control of axonal elimination after the mice Levator auris longus (LAL) muscle had been exposed to several selective antagonist of the corresponding receptor pathways in vivo . Our previous results show that M 1 , M 2 and TrkB signaling individually increase axonal loss rate around P9. Here we show that although the M 1 and TrkB receptors cooperate and add their respective individual effects to increase axonal elimination rate even more, the effect of the M 2 receptor is largely independent of both M 1 and TrkB receptors. Thus both, cooperative and non-cooperative signaling mechanisms contribute to developmental synapse elimination.

  8. Muscarinic receptor antagonists for overactive bladder treatment: does one fit all?

    NARCIS (Netherlands)

    Witte, Lambertus P. W.; Mulder, Wilhelmina M. C.; de La Rosette, Jean J. M. C. H.; Michel, Martin C.

    2009-01-01

    Purpose of review To review evidence and regulatory dosing recommendations for muscarinic receptor antagonists used in the treatment of overactive bladder symptom complex (darifenacin, fesoterodine oxybutynin propiverine solifenacin tolterodine trospium) in special patient populations. Recent

  9. Effects of muscarinic receptor antagonists on cocaine discrimination in wild-type mice and in muscarinic receptor M1, M2, and M4 receptor knockout mice

    DEFF Research Database (Denmark)

    Joseph, Lauren; Thomsen, Morgane

    2017-01-01

    Muscarinic M1/M4 receptor stimulation can reduce abuse-related effects of cocaine and may represent avenues for treating cocaine addiction. Muscarinic antagonists can mimic and enhance effects of cocaine, including discriminative stimulus (SD) effects, but the receptor subtypes mediating those...

  10. Bovine pancreatic polypeptide as an antagonist of muscarinic cholinergic receptors

    International Nuclear Information System (INIS)

    Pan, G.Z.; Lu, L.; Qian, J.; Xue, B.G.

    1987-01-01

    In dispersed acini from rat pancreas, it was found that bovine pancreatic polypeptide (BPP) and its C-fragment hexapeptide amide (PP-6), at concentrations of 0.1 and 30 μM, respectively, could significantly inhibit amylase secretion stimulated by carbachol, and this inhibition by BPP was dose dependent. 45 Ca outflux induced by carbachol was also inhibited by BPP or PP-6, but they had no effect on cholecystokinin octapeptide- (CCK-8) or A23187-stimulated 45 Ca outflux. BPP was also capable of displacing the specific binding of [ 3 H]-quinuclidinyl benzilate to its receptors, and it possessed a higher affinity (K/sub i/35nM) than carbachol (K/sub i/ 1.8 μM) in binding with M-receptors. It is concluded from this study that BPP acts as an antagonist of muscarinic cholinergic receptors in rat pancreatic acini. In addition, BPP inhibited the potentiation of amylase secretion caused by the combination of carbachol plus secretin or vasoactive intestinal peptide. This may be a possible explanation of the inhibitory effect of BPP on secretin-induced pancreatic enzyme secretion shown in vivo, since pancreatic enzyme secretion stimulated by secretin under experimental conditions may be the result of potentiation of enzyme release produced by the peptide in combination with a cholinergic stimulant

  11. Characterization of muscarinic and P2X receptors in the urothelium and detrusor muscle of the rat bladder

    Directory of Open Access Journals (Sweden)

    Masaki Ogoda

    2016-05-01

    Full Text Available Muscarinic and purinergic (P2X receptors play critical roles in bladder urothelium under physiological and pathological conditions. Aim of present study was to characterize these receptors in rat bladder urothelium and detrusor muscle using selective radioligands of [N-methyl-3H]scopolamine methyl chloride ([3H]NMS and αβ-methylene ATP [2,8-3H]tetrasodium salt ([3H]αβ-MeATP. Similar binding parameters for each radioligand were observed in urothelium and detrusor muscle. Pretreatment with N-(2-chloroethyl-4-piperidinyl diphenylacetate (4-DAMP mustard mustard revealed co-existence of M2 and M3 receptors, with the number of M2 receptors being larger in the urothelium and detrusor muscle. Intravesical administration of imidafenacin and Dpr-P-4 (N → O (active metabolite of propiverine displayed significant binding of muscarinic receptors in the urothelium and detrusor muscle. The treatment with cyclophosphamide (CYP or resiniferatoxin (RTX resulted in a significant decrease in maximal number of binding sites (Bmax for [3H]NMS and/or [3H]αβ-MeATP in the urothelium and detrusor muscle. These results demonstrated that 1 pharmacological characteristics of muscarinic and P2X receptors in rat bladder urothelium were similar to those in the detrusor muscle, 2 that densities of these receptors were significantly altered by pretreatments with CYP and RTX, and 3 that these receptors may be pharmacologically affected by imidafenacin and Dpr-P-4 (N → O which are excreted in the urine.

  12. Antipsychotic-like effect of the muscarinic acetylcholine receptor agonist BuTAC in non-human primates

    DEFF Research Database (Denmark)

    Andersen, Maibritt B; Croy, Carrie Hughes; Dencker, Ditte

    2015-01-01

    Cholinergic, muscarinic receptor agonists exhibit functional dopamine antagonism and muscarinic receptors have been suggested as possible future targets for the treatment of schizophrenia and drug abuse. The muscarinic ligand (5R,6R)-6-(3-butylthio-1,2,5-thiadiazol-4-yl)-1-azabicyclo[3.2.1]octane...... (BuTAC) exhibits high affinity for muscarinic receptors with no or substantially less affinity for a large number of other receptors and binding sites, including the dopamine receptors and the dopamine transporter. In the present study, we wanted to examine the possible antipsychotic-like effects...

  13. Muscarinic acetylcholine receptors: location of the ligand binding site

    International Nuclear Information System (INIS)

    Hulme, E.; Wheatley, M.; Curtis, C.; Birdsall, N.

    1987-01-01

    The key to understanding the pharmacological specificity of muscarinic acetylcholine receptors (mAChR's) is the location within the receptor sequence of the amino acid residues responsible for ligand binding. To approach this problem, they have purified mAChR's from rat brain to homogeneity by sequential ion-exchange chromatography, affinity chromatography and molecular weight fractionation. Following labelling of the binding site with an alkylating affinity label, 3 H-propylbenzilycholine mustard aziridinium ion ( 3 H-PrBCM), the mAChR was digested with a lysine-specific endoproteinase, and a ladder of peptides of increasing molecular weight, each containing the glycosylated N-terminus, isolated by chromatography on wheat-germ agglutinin sepharose. The pattern of labelling showed that a residue in the peptides containing transmembrane helices 2 and/or 3 of the mAChR was alkylated. The linkage was cleaved by 1 M hydroxylamine, showing that 3 H-PrBCM was attached to an acidic residue, whose properties strongly suggested it to be embedded in a hydrophobic intramembrane region of the mAChR. Examination of the cloned sequence of the mAChR reveals several candidate residues, the most likely of which is homologous to an aspartic acid residue thought to protonate the retinal Schiff's base in the congeneric protein rhodopsin

  14. Muscarinic receptors modulate dendrodendritic inhibitory synapses to sculpt glomerular output.

    Science.gov (United States)

    Liu, Shaolin; Shao, Zuoyi; Puche, Adam; Wachowiak, Matt; Rothermel, Markus; Shipley, Michael T

    2015-04-08

    Cholinergic [acetylcholine (ACh)] axons from the basal forebrain innervate olfactory bulb glomeruli, the initial site of synaptic integration in the olfactory system. Both nicotinic acetylcholine receptors (nAChRs) and muscarinic acetylcholine receptors (mAChRs) are expressed in glomeruli. The activation of nAChRs directly excites both mitral/tufted cells (MTCs) and external tufted cells (ETCs), the two major excitatory neurons that transmit glomerular output. The functional roles of mAChRs in glomerular circuits are unknown. We show that the restricted glomerular application of ACh causes rapid, brief nAChR-mediated excitation of both MTCs and ETCs in the mouse olfactory bulb. This excitation is followed by mAChR-mediated inhibition, which is blocked by GABAA receptor antagonists, indicating the engagement of periglomerular cells (PGCs) and/or short axon cells (SACs), the two major glomerular inhibitory neurons. Indeed, selective activation of glomerular mAChRs, with ionotropic GluRs and nAChRs blocked, increased IPSCs in MTCs and ETCs, indicating that mAChRs recruit glomerular inhibitory circuits. Selective activation of glomerular mAChRs in the presence of tetrodotoxin increased IPSCs in all glomerular neurons, indicating action potential-independent enhancement of GABA release from PGC and/or SAC dendrodendritic synapses. mAChR-mediated enhancement of GABA release also presynaptically suppressed the first synapse of the olfactory system via GABAB receptors on sensory terminals. Together, these results indicate that cholinergic modulation of glomerular circuits is biphasic, involving an initial excitation of MTC/ETCs mediated by nAChRs followed by inhibition mediated directly by mAChRs on PGCs/SACs. This may phasically enhance the sensitivity of glomerular outputs to odorants, an action that is consistent with recent in vivo findings. Copyright © 2015 the authors 0270-6474/15/355680-13$15.00/0.

  15. M3 muscarinic receptor interaction with phospholipase C beta3 determines its signaling efficiency

    NARCIS (Netherlands)

    Kan, W.; Adjobo-Hermans, M.J.; Burroughs, M.; Faibis, G.; Malik, S.; Tall, G.G.; Smrcka, A.V.

    2014-01-01

    Phospholipase Cbeta (PLCbeta) enzymes are activated by G protein-coupled receptors through receptor-catalyzed guanine nucleotide exchange on Galphabetagamma heterotrimers containing Gq family G proteins. Here we report evidence for a direct interaction between M3 muscarinic receptor (M3R) and

  16. Muscarinic receptors in amygdala control trace fear conditioning.

    Directory of Open Access Journals (Sweden)

    Amber N Baysinger

    Full Text Available Intelligent behavior requires transient memory, which entails the ability to retain information over short time periods. A newly-emerging hypothesis posits that endogenous persistent firing (EPF is the neurophysiological foundation for aspects or types of transient memory. EPF is enabled by the activation of muscarinic acetylcholine receptors (mAChRs and is triggered by suprathreshold stimulation. EPF occurs in several brain regions, including the lateral amygdala (LA. The present study examined the role of amygdalar mAChRs in trace fear conditioning, a paradigm that requires transient memory. If mAChR-dependent EPF selectively supports transient memory, then blocking amygdalar mAChRs should impair trace conditioning, while sparing delay and context conditioning, which presumably do not rely upon transient memory. To test the EPF hypothesis, LA was bilaterally infused, prior to trace or delay conditioning, with either a mAChR antagonist (scopolamine or saline. Computerized video analysis quantified the amount of freezing elicited by the cue and by the training context. Scopolamine infusion profoundly reduced freezing in the trace conditioning group but had no significant effect on delay or context conditioning. This pattern of results was uniquely anticipated by the EPF hypothesis. The present findings are discussed in terms of a systems-level theory of how EPF in LA and several other brain regions might help support trace fear conditioning.

  17. Muscarinic receptors in amygdala control trace fear conditioning.

    Science.gov (United States)

    Baysinger, Amber N; Kent, Brianne A; Brown, Thomas H

    2012-01-01

    Intelligent behavior requires transient memory, which entails the ability to retain information over short time periods. A newly-emerging hypothesis posits that endogenous persistent firing (EPF) is the neurophysiological foundation for aspects or types of transient memory. EPF is enabled by the activation of muscarinic acetylcholine receptors (mAChRs) and is triggered by suprathreshold stimulation. EPF occurs in several brain regions, including the lateral amygdala (LA). The present study examined the role of amygdalar mAChRs in trace fear conditioning, a paradigm that requires transient memory. If mAChR-dependent EPF selectively supports transient memory, then blocking amygdalar mAChRs should impair trace conditioning, while sparing delay and context conditioning, which presumably do not rely upon transient memory. To test the EPF hypothesis, LA was bilaterally infused, prior to trace or delay conditioning, with either a mAChR antagonist (scopolamine) or saline. Computerized video analysis quantified the amount of freezing elicited by the cue and by the training context. Scopolamine infusion profoundly reduced freezing in the trace conditioning group but had no significant effect on delay or context conditioning. This pattern of results was uniquely anticipated by the EPF hypothesis. The present findings are discussed in terms of a systems-level theory of how EPF in LA and several other brain regions might help support trace fear conditioning.

  18. New pharmacological approaches to the cholinergic system: an overview on muscarinic receptor ligands and cholinesterase inhibitors.

    Science.gov (United States)

    Greig, Nigel H; Reale, Marcella; Tata, Ada M

    2013-08-01

    The cholinergic system is expressed in neuronal and in non-neuronal tissues. Acetylcholine (ACh), synthesized in and out of the nervous system can locally contribute to modulation of various cell functions (e.g. survival, proliferation). Considering that the cholinergic system and its functions are impaired in a number of disorders, the identification of new pharmacological approaches to regulate cholinergic system components appears of great relevance. The present review focuses on recent pharmacological drugs able to modulate the activity of cholinergic receptors and thereby, cholinergic function, with an emphasis on the muscarinic receptor subtype, and additionally covers the cholinesterases, the main enzymes involved in ACh hydrolysis. The presence and function of muscarinic receptor subtypes both in neuronal and non-neuronal cells has been demonstrated using extensive pharmacological data emerging from studies on transgenic mice. The possible involvement of ACh in different pathologies has been proposed in recent years and is becoming an important area of study. Although the lack of selective muscarinic receptor ligands has for a long time limited the definition of therapeutic treatment based on muscarinic receptors as targets, some muscarinic ligands such as cevimeline (patents US4855290; US5571918) or xanomeline (patent, US5980933) have been developed and used in pre-clinical or in clinical studies for the treatment of nervous system diseases (Alzheimer' and Sjogren's diseases). The present review focuses on the potential implications of muscarinic receptors in different pathologies, including tumors. Moreover, the future use of muscarinic ligands in therapeutic protocols in cancer therapy will be discussed, considering that some muscarinic antagonists currently used in the treatment of genitourinary disease (e.g. darifenacin, patent, US5096890; US6106864) have also been demonstrated to arrest tumor progression in nude mice. The involvement of muscarinic

  19. Muscarinic receptor agonists stimulate matrix metalloproteinase 1-dependent invasion of human colon cancer cells

    International Nuclear Information System (INIS)

    Raufman, Jean-Pierre; Cheng, Kunrong; Saxena, Neeraj; Chahdi, Ahmed; Belo, Angelica; Khurana, Sandeep; Xie, Guofeng

    2011-01-01

    Highlights: ► Muscarinic receptor agonists stimulated robust human colon cancer cell invasion. ► Anti-matrix metalloproteinase1 antibody pre-treatment blocks cell invasion. ► Bile acids stimulate MMP1 expression, cell migration and MMP1-dependent invasion. -- Abstract: Mammalian matrix metalloproteinases (MMPs) which degrade extracellular matrix facilitate colon cancer cell invasion into the bloodstream and extra-colonic tissues; in particular, MMP1 expression correlates strongly with advanced colon cancer stage, hematogenous metastasis and poor prognosis. Likewise, muscarinic receptor signaling plays an important role in colon cancer; muscarinic receptors are over-expressed in colon cancer compared to normal colon epithelial cells. Muscarinic receptor activation stimulates proliferation, migration and invasion of human colon cancer cells. In mouse intestinal neoplasia models genetic ablation of muscarinic receptors attenuates carcinogenesis. In the present work, we sought to link these observations by showing that MMP1 expression and activation plays a mechanistic role in muscarinic receptor agonist-induced colon cancer cell invasion. We show that acetylcholine, which robustly increases MMP1 expression, stimulates invasion of HT29 and H508 human colon cancer cells into human umbilical vein endothelial cell monolayers – this was abolished by pre-incubation with atropine, a non-selective muscarinic receptor inhibitor, and by pre-incubation with anti-MMP1 neutralizing antibody. Similar results were obtained using a Matrigel chamber assay and deoxycholyltaurine (DCT), an amidated dihydroxy bile acid associated with colon neoplasia in animal models and humans, and previously shown to interact functionally with muscarinic receptors. DCT treatment of human colon cancer cells resulted in time-dependent, 10-fold increased MMP1 expression, and DCT-induced cell invasion was also blocked by pre-treatment with anti-MMP1 antibody. This study contributes to understanding

  20. Muscarinic receptor agonists stimulate matrix metalloproteinase 1-dependent invasion of human colon cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Raufman, Jean-Pierre, E-mail: jraufman@medicine.umaryland.edu [Division of Gastroenterology and Hepatology, University of Maryland School of Medicine, Baltimore, MD (United States); Cheng, Kunrong; Saxena, Neeraj; Chahdi, Ahmed; Belo, Angelica; Khurana, Sandeep; Xie, Guofeng [Division of Gastroenterology and Hepatology, University of Maryland School of Medicine, Baltimore, MD (United States)

    2011-11-18

    Highlights: Black-Right-Pointing-Pointer Muscarinic receptor agonists stimulated robust human colon cancer cell invasion. Black-Right-Pointing-Pointer Anti-matrix metalloproteinase1 antibody pre-treatment blocks cell invasion. Black-Right-Pointing-Pointer Bile acids stimulate MMP1 expression, cell migration and MMP1-dependent invasion. -- Abstract: Mammalian matrix metalloproteinases (MMPs) which degrade extracellular matrix facilitate colon cancer cell invasion into the bloodstream and extra-colonic tissues; in particular, MMP1 expression correlates strongly with advanced colon cancer stage, hematogenous metastasis and poor prognosis. Likewise, muscarinic receptor signaling plays an important role in colon cancer; muscarinic receptors are over-expressed in colon cancer compared to normal colon epithelial cells. Muscarinic receptor activation stimulates proliferation, migration and invasion of human colon cancer cells. In mouse intestinal neoplasia models genetic ablation of muscarinic receptors attenuates carcinogenesis. In the present work, we sought to link these observations by showing that MMP1 expression and activation plays a mechanistic role in muscarinic receptor agonist-induced colon cancer cell invasion. We show that acetylcholine, which robustly increases MMP1 expression, stimulates invasion of HT29 and H508 human colon cancer cells into human umbilical vein endothelial cell monolayers - this was abolished by pre-incubation with atropine, a non-selective muscarinic receptor inhibitor, and by pre-incubation with anti-MMP1 neutralizing antibody. Similar results were obtained using a Matrigel chamber assay and deoxycholyltaurine (DCT), an amidated dihydroxy bile acid associated with colon neoplasia in animal models and humans, and previously shown to interact functionally with muscarinic receptors. DCT treatment of human colon cancer cells resulted in time-dependent, 10-fold increased MMP1 expression, and DCT-induced cell invasion was also blocked by pre

  1. The pharmacological rationale for combining muscarinic receptor antagonists and beta-adrenoceptor agonists in the treatment of airway and bladder disease

    NARCIS (Netherlands)

    Dale, Philippa R.; Cernecka, Hana; Schmidt, Martina; Dowling, Mark R.; Charlton, Steven J.; Pieper, Michael P.; Michel, Martin C.

    Muscarinic receptor antagonists and beta-adrenoceptor agonists are used in the treatment of obstructive airway disease and overactive bladder syndrome. Here we review the pharmacological rationale for their combination. Muscarinic receptors and beta-adrenoceptors are physiological antagonists for

  2. G-protein mediates voltage regulation of agonist binding to muscarinic receptors: effects on receptor-Na+ channel interaction

    International Nuclear Information System (INIS)

    Cohen-Armon, M.; Garty, H.; Sokolovsky, M.

    1988-01-01

    The authors previous experiments in membranes prepared from rat heart and brain led them to suggest that the binding of agonist to the muscarinic receptors and to the Na + channels is a coupled event mediated by guanine nucleotide binding protein(s) [G-protein(s)]. These in vitro findings prompted us to employ synaptoneurosomes from brain stem tissue to examine (i) the binding properties of [ 3 H] acetylcholine at resting potential and under depolarization conditions in the absence and presence of pertussis toxin; (ii) the binding of [ 3 H]batrachotoxin to Na + channel(s) in the presence of the muscarinic agonists; and (iii) muscarinically induced 22 Na + uptake in the presence and absence of tetrodotoxin, which blocks Na + channels. The findings indicate that agonist binding to muscarinic receptors is voltage dependent, that this process is mediated by G-protein(s), and that muscarinic agonists induce opening of Na + channels. The latter process persists even after pertussis toxin treatment, indicating that it is not likely to be mediated by pertussis toxin sensitive G-protein(s). The system with its three interacting components-receptor, G-protein, and Na + channel-is such that at resting potential the muscarinic receptor induces opening of Na + channels; this property may provide a possible physiological mechanism for the depolarization stimulus necessary for autoexcitation or repetitive firing in heart or brain tissues

  3. Two types of muscarinic acetylcholine receptors in Drosophila and other arthropods

    DEFF Research Database (Denmark)

    Collin, Caitlin Alexis; Hauser, Frank; Gonzalez de Valdivia, Ernesto I

    2013-01-01

    Muscarinic acetylcholine receptors (mAChRs) play a central role in the mammalian nervous system. These receptors are G protein-coupled receptors (GPCRs), which are activated by the agonists acetylcholine and muscarine, and blocked by a variety of antagonists. Mammals have five mAChRs (m1-m5......). In this study, we cloned two structurally related GPCRs from the fruit fly Drosophila melanogaster, which, after expression in Chinese hamster ovary cells, proved to be muscarinic acetylcholine receptors. One mAChR (the A-type; encoded by gene CG4356) is activated by acetylcholine (EC50, 5 × 10(-8) M......) and muscarine (EC50, 6 × 10(-8) M) and blocked by the classical mAChR antagonists atropine, scopolamine, and 3-quinuclidinyl-benzilate (QNB), while the other (the B-type; encoded by gene CG7918) is also activated by acetylcholine, but has a 1,000-fold lower sensitivity to muscarine, and is not blocked...

  4. Prediction of consensus binding mode geometries for related chemical series of positive allosteric modulators of adenosine and muscarinic acetylcholine receptors.

    Science.gov (United States)

    Sakkal, Leon A; Rajkowski, Kyle Z; Armen, Roger S

    2017-06-05

    Following insights from recent crystal structures of the muscarinic acetylcholine receptor, binding modes of Positive Allosteric Modulators (PAMs) were predicted under the assumption that PAMs should bind to the extracellular surface of the active state. A series of well-characterized PAMs for adenosine (A 1 R, A 2A R, A 3 R) and muscarinic acetylcholine (M 1 R, M 5 R) receptors were modeled using both rigid and flexible receptor CHARMM-based molecular docking. Studies of adenosine receptors investigated the molecular basis of the probe-dependence of PAM activity by modeling in complex with specific agonist radioligands. Consensus binding modes map common pharmacophore features of several chemical series to specific binding interactions. These models provide a rationalization of how PAM binding slows agonist radioligand dissociation kinetics. M 1 R PAMs were predicted to bind in the analogous M 2 R PAM LY2119620 binding site. The M 5 R NAM (ML-375) was predicted to bind in the PAM (ML-380) binding site with a unique induced-fit receptor conformation. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  5. Effect of paraoxon on muscarinic, dopamine and γ-aminobutyric acid receptors of brain and sensitivity to muscarinic antagonists

    International Nuclear Information System (INIS)

    Fernando, J.C.R.; Hoskins, B.; Ho, I.K.

    1986-01-01

    Several acetylcholinesterase (AChE) inhibitors decrease muscarinic cholinergic (mACh) receptors in the brain, alteration of dopamine (DA) and γ-aminobutyric acid (GABA) receptors after AChE inhibition was also reported. In view of the important interactions among DA, GABA and ACh systems, whether this is a common effect of AChE inhibitors should be established. They report the effect of the AChE inhibitor, paraoxon, on DA, GABA and mACh receptors in the rat. The binding of 3 H-QNB (for mACh), 3 H-spiperone (for DA) and 3 H-muscimol (for GABA) to striatal and hippocampal membranes was analyzed. Also, behavioral sensitivity to atropine was studied. Twenty-four hr after a single dose (0.75 mg/kg, s.c.) of paraoxon, the density of mACh receptors in the striatum was decreased but, at 3 days, no change was seen. In the hippocampus, the mACh receptors were not affected. Repeated treatment with paraoxon (0.3 mg/kg, 48 hourly) for 2 weeks reduced the mACh receptor density in both regions. Neither single nor repeated paraoxon treatment had an effect on DA or GABA receptors. After single or repeated dosing with paraoxon, myoclonus induced by atropine (10 mg/kg, i.p.) was enhanced. The results show rapid downregulation of mACh receptors by paraoxon. DA or GABA, however, appear not to be affected under these treatment regimens

  6. Comparative study of muscarinic acetylcholine receptors of human and rat cortical glial cells

    International Nuclear Information System (INIS)

    Demushkin, V.P.; Burbaeva, G.S.; Dzhaliashvili, T.A.; Plyashkevich, Y.G.

    1985-01-01

    The aim of the present investigation was a comparative studyof muscarinic acetylcholine receptors in human and rat glial cells. ( 3 H)Quinuclidinyl-benzylate (( 3 H)-QB), atropine, platiphylline, decamethonium, carbamylcholine, tubocurarine, and nicotine were used. The glial cell fraction was obtained from the cerebral cortex of rats weighing 130-140 g and from the frontal pole of the postmortem brain from men aged 60-70 years. The use of the method of radioimmune binding of ( 3 H)-QB with human and rat glial cell membranes demonstrated the presence of a muscarinic acetylcholine receptor in the glial cells

  7. Attenuation of cocaine's reinforcing and discriminative stimulus effects via muscarinic M1 acetylcholine receptor stimulation

    DEFF Research Database (Denmark)

    Thomsen, Morgane; Conn, P Jeffrey; Lindsley, Craig

    2010-01-01

    substituted for cocaine and enhanced its discriminative stimulus. Conversely, muscarinic agonists blunted cocaine discrimination and abolished cocaine self-administration with varying effects on food-maintained behavior. Specifically, increasing selectivity for the M(1) subtype (oxotremorine ...'s abuse-related effects, whereas non-M(1)/M(4) receptors probably contribute to undesirable effects of muscarinic stimulation. These data provide the first demonstration of anticocaine effects of systemically applied, M(1) receptor agonists and suggest the possibility of a new approach to pharmacotherapy...

  8. In vivo binding, pharmacokinetics and metabolism of the selective M2 muscarinic antagonists [3H]AF-DX 116 and [3H]AF-DX 384 in the anesthetized rat

    International Nuclear Information System (INIS)

    Mickala, Patrick; Boutin, Herve; Bellanger, Cecile; Chevalier, Cyril; MacKenzie, Eric T.; Dauphin, Francois

    1996-01-01

    The pharmacokinetics, in vivo binding and metabolism of two M 2 muscarinic receptor antagonists, [ 3 H]AF-DX 116 and [ 3 H]AF-DX 384, were studied in anesthetized rats, which received either the tracer alone or following a saturating injection of atropine. Both radioligands were cleared from the circulation with distribution half-lives of 17 and 14 sec and elimination half-lives of 17 and 40 min for [ 3 H]AF-DX 116 and [ 3 H]AF-DX 384, respectively. A radioactive distribution, predominant in peripheral organs when compared to brain, was found at each time studied after tracer injection. Atropine-displaceable tracer uptake was evidenced at 20-40 min in brain (31%), submandibular glands (26%), spleen (37%) and notably heart (55%) for [ 3 H]AF-DX 116 but only in heart (50%) for [ 3 H]AF-DX 384 at 10-20 min. Regional brain sampling revealed a relatively uniform distribution of [ 3 H]AF-DX 384 and a -45% atropine saturation effect (i.e., specific binding) in the thalamus 20 min after injection. Sequential thin-layer chromatographic studies performed on tissue extracts demonstrated the rapid appearance of labeled metabolites of both radiotracers in brain (but less so in liver) and especially in cardiac tissues, where almost 70% of total radioactivity still corresponded to authentic tracer 40 min after injection. Thus, based on their low blood-brain barrier permeability and the high presence of labeled metabolites in the central nervous system, AF-DX 116 and AF-DX 384 might be more helpful in the study of M 2 muscarinic receptors present in heart rather than brain. Labeled with positron emittors, these M 2 antagonists might be applicable to the pathophysiological study of disease states, such as cardiomyopathies

  9. Drugs Interfering with Muscarinic Acetylcholine Receptors and Their Effects on Place Navigation

    Directory of Open Access Journals (Sweden)

    Jan Svoboda

    2017-11-01

    Full Text Available Muscarinic acetylcholine receptors (mAChRs have been found to regulate many diverse functions, ranging from motivation and feeding to spatial navigation, an important and widely studied type of cognitive behavior. Systemic administration of non-selective antagonists of mAChRs, such as scopolamine or atropine, have been found to have adverse effects on a vast majority of place navigation tasks. However, many of these results may be potentially confounded by disruptions of functions other than spatial learning and memory. Although studies with selective antimuscarinics point to mutually opposite effects of M1 and M2 receptors, their particular contribution to spatial cognition is still poorly understood, partly due to a lack of truly selective agents. Furthermore, constitutive knock-outs do not always support results from selective antagonists. For modeling impaired spatial cognition, the scopolamine-induced amnesia model still maintains some limited validity, but there is an apparent need for more targeted approaches such as local intracerebral administration of antagonists, as well as novel techniques such as optogenetics focused on cholinergic neurons and chemogenetics aimed at cells expressing metabotropic mAChRs.

  10. Enhanced muscarinic M1 receptor gene expression in the corpus striatum of streptozotocin-induced diabetic rats

    Directory of Open Access Journals (Sweden)

    Mathew Jobin

    2009-04-01

    Full Text Available Abstract Acetylcholine (ACh, the first neurotransmitter to be identified, regulate the activities of central and peripheral functions through interactions with muscarinic receptors. Changes in muscarinic acetylcholine receptor (mAChR have been implicated in the pathophysiology of many major diseases of the central nervous system (CNS. Previous reports from our laboratory on streptozotocin (STZ induced diabetic rats showed down regulation of muscarinic M1 receptors in the brainstem, hypothalamus, cerebral cortex and pancreatic islets. In this study, we have investigated the changes of acetylcholine esterase (AChE enzyme activity, total muscarinic and muscarinic M1 receptor binding and gene expression in the corpus striatum of STZ – diabetic rats and the insulin treated diabetic rats. The striatum, a neuronal nucleus intimately involved in motor behaviour, is one of the brain regions with the highest acetylcholine content. ACh has complex and clinically important actions in the striatum that are mediated predominantly by muscarinic receptors. We observed that insulin treatment brought back the decreased maximal velocity (Vmax of acetylcholine esterase in the corpus striatum during diabetes to near control state. In diabetic rats there was a decrease in maximal number (Bmax and affinity (Kd of total muscarinic receptors whereas muscarinic M1 receptors were increased with decrease in affinity in diabetic rats. We observed that, in all cases, the binding parameters were reversed to near control by the treatment of diabetic rats with insulin. Real-time PCR experiment confirmed the increase in muscarinic M1 receptor gene expression and a similar reversal with insulin treatment. These results suggest the diabetes-induced changes of the cholinergic activity in the corpus striatum and the regulatory role of insulin on binding parameters and gene expression of total and muscarinic M1 receptors.

  11. Cholinergic nicotinic and muscarinic receptors in dementia of Alzheimer, Parkinson and Lewy body types.

    Science.gov (United States)

    Perry, E K; Smith, C J; Court, J A; Perry, R H

    1990-01-01

    Cholinergic nicotinic and muscarinic receptor binding were measured in post mortem human brain tissue, using low (nM) concentrations of (3H)-nicotine to detect predominately the high affinity nicotinic site and (3H)-N-methylscopolamine in the presence and absence of 3 x 10(-4) M carbachol to measure both the low and high affinity agonist subtypes of the muscarinic receptor group. Consistent with most previous reports, the nicotinic but not muscarinic binding was reduced in the different forms of dementia associated with cortical cholinergic deficits, including Alzheimer's and Parkinson's disease, senile dementia of Lewy body type (SDLT) and Down's syndrome (over 50 years). Analysis of (3H)-nicotine binding displaced by a range of carbachol concentrations (10(-9)-10(-3) M) indicated 2 binding sites for nicotine and that the high affinity rather than low affinity site was reduced in Alzheimer's disease. In all 3 cortical areas investigated (temporal, parietal and occipital) there were increases in the low affinity muscarinic site in Parkinson's disease and SDLT but not Alzheimer's disease or middle-aged Down's syndrome. This observation raised the question of whether the presence of neurofibrillary tangles (evident in the latter but not former 2 disorders) is incompatible with denervation-induced muscarinic supersensitivity in cholinoceptive neurons which include cortical pyramids generally affeted by tangle formation.

  12. Pet measurements of postsynaptic muscarinic and beta adrenergic receptors in the heart

    International Nuclear Information System (INIS)

    Syrota, A.

    1991-01-01

    There is ample evidence from both experimental and clinical studies that changes in β-adrenergic and muscarinic receptor density can be associated with such cardiac diseases as congestive heart failure, myocardial ischemia and infarction, cardiomyopathy, diabetes, or thyroid-induced muscle disease. Changes in B-adrenergic density also have been shown in the denervated transplanted heart. These alterations of cardiac receptors have been demonstrated in vitro on homogenates from samples collected mainly during surgery or post mortem. Recent developments of Positron Emission Tomography (PET) techniques and of radioligands suitable for cardiac receptor binding studies in vivo have made possible both the imaging and the measurement of receptor density. From these studies, important information is now available concerning physiologic and pathologic conditions, as well as alterations induced by treatment. For the investigation of myocardial B-adrenergic receptors we have used [ 11 C] CGP 12177, a potent hydrophilic antagonist of the 3-adrenergic receptor. The quantification of myocardial muscarinic receptors in vivo has been obtained with [ 11 C] MQNB, a nonmetabolized hydrophilic antagonist of the muscarinic receptor. Receptor density and affinity have been measured by a kinetic, nonequilibrium approach in an experimental protocol that provides sufficient data to determine values for all parameters from a single experiment

  13. Characterization of the effect of penehyclidine hydrochloride on muscarinic receptor subtypes mediating the contraction of guinea-pig isolated gastrointestinal smooth muscle.

    Science.gov (United States)

    Xiao, Hong-Tao; Liao, Zhi; Meng, Xian-Min; Yan, Xiao-Yan; Chen, Shu-Jie; Mo, Zheng-Ji

    2009-07-01

    The aim was to characterize the effect of penehyclidine hydrochloride, which mediates the relaxation of guinea-pig isolated gastrointestinal smooth muscle, on muscarinic receptor subtypes. Radioimmune assay was used to determine cAMP levels in isolated guinea-pig gastrointestinal smooth muscle to compare the selective effects of penehyclidine hydrochloride on muscarinic receptor subtypes. The results indicated that the relaxing effect of penehyclidine hydrochloride on isolated gastrointestinal smooth muscle contraction induced by acetylcholine was stronger than that of atropine (based on PA2 values). In the radioimmune assay, penehyclidine hydrochloride increased the cAMP content in isolated guinea-pig stomach smooth muscle and decreased the cAMP content in isolated guinea-pig intestinal smooth muscle, but the difference was not statistically significant at a dose of 10 mumol/l. The results suggest that penehyclidine hydrochloride has little or no effect on M2 receptor subtypes in guinea-pig gastrointestinal smooth muscle.

  14. Increased cocaine self-administration in M4 muscarinic acetylcholine receptor knockout mice

    DEFF Research Database (Denmark)

    Schmidt, Lene Sørensen; Thomsen, Morgane; Weikop, Pia

    2011-01-01

    Rationale The reinforcing effects of cocaine are mediated by the mesolimbic dopamine system. Behavioral and neurochemical studies have shown that the cholinergic muscarinic M4 receptor subtype plays an important role in regulation of dopaminergic neurotransmission. Objectives Here we investigated...... of drug addiction...

  15. MUSCARINIC ACETYLCHOLINE RECEPTOR-EXPRESSION IN ASTROCYTES IN THE CORTEX OF YOUNG AND AGED RATS

    NARCIS (Netherlands)

    VANDERZEE, EA; DEJONG, GI; STROSBERG, AD; LUITEN, PGM

    The present report describes the cellular and subcellular distribution pattern of immunoreactivity to M35, a monoclonal antibody raised against purified muscarinic acetylcholine receptor protein, in astrocytes in the cerebral cortex of young and aged rats. Most M35-positive astrocytes were localized

  16. Quantitative autoradiography of muscarinic and benzodiazepine receptors in the forebrain of the turtle, Pseudemys scripta

    International Nuclear Information System (INIS)

    Schlegel, J.R.; Kriegstein, A.R.

    1987-01-01

    The distribution of muscarinic and benzodiazepine receptors was investigated in the turtle forebrain by the technique of in vitro receptor autoradiography. Muscarinic binding sites were labeled with 1 nM 3 H-quinuclidinyl benzilate ( 3 H-QNB), and benzodiazepine sites were demonstrated with the aid of 1 nM 3 H-flunitrazepam ( 3 H-FLU). Autoradiograms generated on 3 H-Ultrofilm apposed to tissue slices revealed regionally specific distributions of muscarinic and benzodiazepine binding sites that are comparable with those for mammalian brain. Dense benzodiazepine binding was found in the anterior olfactory nucleus, the lateral and dorsal cortices, and the dorsal ventricular ridge (DVR), a structure with no clear mammalian homologue. Muscarinic binding sites were most dense in the striatum, accumbens, DVR, lateral geniculate, and the anterior olfactory nucleus. Cortical binding sites were studied in greater detail by quantitative analysis of autoradiograms generated by using emulsion-coated coverslips. Laminar gradients of binding were observed that were specific for each radioligand; 3 H-QNB sites were most dense in the inner molecular layer in all cortical regions, whereas 3 H-FLU binding was generally most concentrated in the outer molecular layer and was least dense through all layers in the dorsomedial cortex. Because pyramidal cells are arranged in register in turtle cortex, the laminar patterns of receptor binding may reflect different receptor density gradients along pyramidal cell dendrites

  17. Divergence of allosteric effects of rapacuronium on binding and function of muscarinic receptors

    Czech Academy of Sciences Publication Activity Database

    Jakubík, Jan; Randáková, Alena; El-Fakahany, E. E.; Doležal, Vladimír

    2009-01-01

    Roč. 9, č. 15 (2009), s. 1-20 ISSN 1471-2210 R&D Projects: GA ČR GA305/09/0681; GA MŠk(CZ) LC554; GA AV ČR(CZ) IAA500110703 Institutional research plan: CEZ:AV0Z50110509 Keywords : muscarinic receptors * allosteric modulation * rapacuronium Subject RIV: ED - Physiology

  18. Muscarinic Acetylcholine Receptors Act in Synergy to Facilitate Learning and Memory

    Science.gov (United States)

    Leaderbrand, Katherine; Chen, Helen J.; Corcoran, Kevin A.; Guedea, Anita L.; Jovasevic, Vladimir; Wess, Jurgen; Radulovic, Jelena

    2016-01-01

    Understanding how episodic memories are formed and retrieved is necessary if we are to treat disorders in which they malfunction. Muscarinic acetylcholine receptors (mAChR) in the hippocampus and cortex underlie memory formation, but there is conflicting evidence regarding their role in memory retrieval. Additionally, there is no consensus on…

  19. Binding of N-methylscopolamine to the extracellular domain of muscarinic acetylcholine receptors

    Czech Academy of Sciences Publication Activity Database

    Jakubík, Jan; Randáková, Alena; Zimčík, Pavel; El-Fakahany, E. E.; Doležal, Vladimír

    2017-01-01

    Roč. 7, Jan 16 (2017), č. článku 40381. ISSN 2045-2322 R&D Projects: GA ČR(CZ) GBP304/12/G069 Institutional support: RVO:67985823 Keywords : muscarinic acetylcholine receptors * N-methylscopolamine * ligand binding * molecular dynamics Subject RIV: ED - Physiology OBOR OECD: Physiology (including cytology) Impact factor: 4.259, year: 2016

  20. GABAergic Neurons of the Rat Dorsal Hippocampus Express Muscarinic Acetylcholine Receptors

    NARCIS (Netherlands)

    van der Zee, E.A.; Luiten, P.G.M.

    1993-01-01

    The expression of muscarinic acetylcholine receptors (mAChRs) in glutamic acid decarboxylase (GAD)-positive cells in the different strata of CA1, CA3, and the dentate gyrus (DG) of the dorsal hippocampus is examined by way of quantitative immunofluorescent double labeling employing M35, the

  1. Evidence for inhibitory nicotinic and facilitatory muscarinic receptors in cholinergic nerve terminals of the rat urinary bladder.

    Science.gov (United States)

    Somogyi, G T; de Groat, W C

    1992-02-01

    Cholinergic prejunctional modulatory receptors on parasympathetic nerves in the rat urinary bladder were studied by measuring 3H-acetylcholine (ACh) release in muscle strips from the bladder body. Electrical field stimulation markedly increased 3H-ACh overflow in strips preloaded with 3H-choline. Oxotremorine (1 microM), an M2 receptor agonist and DMPP (10 microM) a nicotinic (N) receptor agonist decreased the release of ACh (50% and 55% respectively); whereas McN-A 343 (50 microM) an M1 receptor agonist increased the release (33%), indicating the presence of three types of modulatory receptors. The anticholinesterase agent, physostigmine in concentrations of 1, 5 and 25 microM and neostigmine (5 microM) increased ACh release (44-710%). However a low concentration of physostigmine (0.05 microM) decreased release. Pirenzepine, an M1 muscarinic antagonist or atropine blocked the increased ACh release in physostigmine-treated strips, but in normal strips pirenzepine did not change release and atropine increased release. McN-A 343 or prolonged application (15 min) of DMPP increased ACh release (376% and 391% respectively) in physostigmine-treated strips. The response to McN-A 343 was blocked by pirenzepine. d-Tubocurarine (DTC), a nicotinic receptor blocker, enhanced ACh release in the presence of physostigmine but proved to be ineffective in normal preparations. These findings suggest that all three cholinergic receptors (M1 facilitatory, N inhibitory and M2 inhibitory) are activated by endogenous ACh in physostigmine treated preparations whereas only M2-inhibitory receptors are activated in normal preparations. It will be important in future studies to determine whether M1 and M2 mechanisms can also be activated under more physiological conditions in the bladder and whether they are present at other cholinergic synapses.

  2. Loss of muscarinic receptors and of stimulated phospholipid labeling in ibotenate-treated hippocampus

    International Nuclear Information System (INIS)

    Fisher, S.K.; Frey, K.A.; Agranoff, B.W.

    1981-01-01

    The stimulation of phospholipid labeling by muscarinic agonists has been examined in nerve ending preparations from lesioned hippocampus in order to investigate the synaptic locus of the effect. Unilateral injections of the neurotoxin, ibotenic acid, into the hippocampus resulted in an extensive loss of nerve cells from both the dentate gyrus and hippocampus on the lesioned side and a parallel loss of muscarinic receptors as revealed by [ 3 H]quinuclidinyl benzilate autoradiography. Homogenates and nerve ending fractions prepared from the lesioned side of the hippocampus possessed a reduced specific activity (expressed per milligram of protein) of glutamic acid decarboxylase as well as a reduced number of muscarinic receptors compared with the control side. By contrast, choline acetyltransferase activity was either unchanged or slightly increased on the lesioned side. Although there was a reduced yield (25%) of nerve endings from the lesioned side, the specific activity of 32 Pi incorporation into phospholipids in the absence of added carbachol was comparable to that of the control side. There was, however, a marked reduction in the carbachol stimulation of phosphatidic acid and phosphatidylinositol labeling in nerve ending fractions obtained from he lesioned hippocampus. These results indicate that the muscarinic receptors present in nerve ending fractions from hippocampus and implicated in stimulated phospholipid turnover are derived from cholinoceptive intrinsic neurons

  3. Muscarinic receptor blockade in ventral hippocampus and prelimbic cortex impairs memory for socially transmitted food preference.

    Science.gov (United States)

    Carballo-Márquez, Anna; Vale-Martínez, Anna; Guillazo-Blanch, Gemma; Martí-Nicolovius, Margarita

    2009-05-01

    Acetylcholine is involved in learning and memory and, particularly, in olfactory tasks, but reports on its specific role in consolidation processes are somewhat controversial. The present experiment sought to determine the effects of blocking muscarinic cholinergic receptors in the ventral hippocampus (vHPC) and the prelimbic cortex (PLC) on the consolidation of social transmission of food preference, an odor-guided relational task that depends on such brain areas. Adult male Wistar rats were bilaterally infused with scopolamine (20 microg/site) immediately after social training and showed impairment, relative to vehicle-injected controls, in the expression of the task measured 24 h after learning. Results indicated that scopolamine in the PLC completely abolished memory, suggesting that muscarinic transmission in this cortical region is crucial for consolidation of recent socially acquired information. Muscarinic receptors in the vHPC contribute in some way to task consolidation, as the rats injected with scopolamine in the vHPC showed significantly lower trained food preference than control rats, but higher than both chance level and that of the PLC-injected rats. Behavioral measures such as social interaction, motivation to eat, neophobia, or exploration did not differ between rats infused with scopolamine or vehicle. Such data suggest a possible differential role of muscarinic receptors in the PLC and the vHPC in the initial consolidation of a naturalistic form of nonspatial relational memory. Copyright 2008 Wiley-Liss, Inc.

  4. Agonist and antagonist binding to rat brain muscarinic receptors: influence of aging

    International Nuclear Information System (INIS)

    Gurwitz, D.; Egozi, Y.; Henis, Y.I.; Kloog, Y.; Sokolovsky, M.

    1987-01-01

    The objective of the present study was to determine the binding properties of muscarinic receptors in six brain regions in mature and old rats of both sexes by employing direct binding of [ 3 H]-antagonist as well as of the labeled natural neurotransmitter, [ 3 H]-acetylcholine [( 3 H]-AcCh). In addition, age-related factors were evaluated in the modulation processes involved in agonist binding. The results indicate that as the rat ages the density of the muscarinic receptors is altered differently in the various brain regions: it is decreased in the cerebral cortex, hippocampus, striatum and olfactory bulb of both male and female rats, but is increased (58%) in the brain stem of senescent males while no significant change is observed for females. The use of the highly sensitive technique measuring direct binding of [ 3 H]-AcCh facilitated the separate detection of age-related changes in the two classes (high- and low-affinity) of muscarinic agonist binding sites. In old female rats the density of high-affinity [ 3 H]-AcCh binding sites was preserved in all tissues studied, indicating that the decreases in muscarinic receptor density observed with [ 3 H]-antagonist represent a loss of low-affinity agonist binding sites. In contrast, [ 3 H]-AcCh binding is decreased in the hypothalamus and increased in the brain stem of old male rats. These data imply sexual dimorphism of the aging process in central cholinergic mechanisms

  5. Role of membrane cholesterol in differential sensitivity of muscarinic receptor subtypes to persistently bound xanomeline

    Czech Academy of Sciences Publication Activity Database

    Randáková, Alena; Dolejší, Eva; Rudajev, Vladimír; Zimčík, Pavel; Doležal, Vladimír; El-Fakahany, E. E.; Jakubík, Jan

    2018-01-01

    Roč. 133, May 1 (2018), s. 129-144 ISSN 0028-3908 R&D Projects: GA ČR(CZ) GA14-05696S; GA ČR(CZ) GA17-16182S Institutional support: RVO:67985823 Keywords : muscarinic acetylcholine receptors * membrane cholesterol * xanomeline * receptor activation * molecular dynamics Subject RIV: ED - Physiology OBOR OECD: Physiology (including cytology) Impact factor: 5.012, year: 2016

  6. Autoantibodies Enhance Agonist Action and Binding to Cardiac Muscarinic Receptors in Chronic Chagas’ Disease

    Science.gov (United States)

    Hernández, Ciria C.; Nascimento, José H.; Chaves, Elen A.; Costa, Patrícia C.; Masuda, Masako O.; Kurtenbach, Eleonora; Campos de Carvalho, Antônio C.; Giménez, Luis E.

    2009-01-01

    Chronic Chagasic patient immunoglobulins (CChP-IgGs) recognize an acidic amino acid cluster at the second extracellular loop (el2) of cardiac M2-muscarinic acetylcholine receptors (M2AChRs). These residues correspond to a common binding site for various allosteric agents. We characterized the nature of the M2AChR/CChP-IgG interaction in functional and radioligand binding experiments applying the same mainstream strategies previously used for the characterization of other allosteric agents. Dose-response curves of acetylcholine effect on heart rate were constructed with data from isolated heart experiments in the presence of CChP or normal blood donor (NBD) sera. In these experiments, CChP sera but not NBD sera increased the efficacy of agonist action by augmenting the onset of bradyarrhythmias and inducing a Hill slope of 2.5. This effect was blocked by gallamine, an M2AChR allosteric antagonist. Correspondingly, CChP-IgGs increased acetylcholine affinity twofold and showed negative cooperativity for [3H]-N-methyl scopolamine ([3H]-NMS) in allosterism binding assays. A peptide corresponding to the M2AChR-el2 blocked this effect. Furthermore, dissociation assays showed that the effect of gallamine on the [3H]-NMS off-rate was reverted by CChP-IgGs. Finally, concentration-effect curves for the allosteric delay of W84 on [3H]-NMS dissociation right shifted from an IC50 of 33 nmol/L to 78 nmol/L, 992 nmol/L, and 1670 nmol/L in the presence of 6.7 × 10−8, 1.33 × 10−7, and 2.0 × 10−7 mol/L of anti-el2 affinity-purified CChP-IgGs. Taken together, these findings confirmed a competitive interplay of these ligands at the common allosteric site and revealed the novel allosteric nature of the interaction of CChP-IgGs at the M2AChRs as a positive cooperativity effect on acetylcholine action. PMID:18702010

  7. Mechanism of the G-protein mimetic nanobody binding to a muscarinic G-protein-coupled receptor.

    Science.gov (United States)

    Miao, Yinglong; McCammon, J Andrew

    2018-03-20

    Protein-protein binding is key in cellular signaling processes. Molecular dynamics (MD) simulations of protein-protein binding, however, are challenging due to limited timescales. In particular, binding of the medically important G-protein-coupled receptors (GPCRs) with intracellular signaling proteins has not been simulated with MD to date. Here, we report a successful simulation of the binding of a G-protein mimetic nanobody to the M 2 muscarinic GPCR using the robust Gaussian accelerated MD (GaMD) method. Through long-timescale GaMD simulations over 4,500 ns, the nanobody was observed to bind the receptor intracellular G-protein-coupling site, with a minimum rmsd of 2.48 Å in the nanobody core domain compared with the X-ray structure. Binding of the nanobody allosterically closed the orthosteric ligand-binding pocket, being consistent with the recent experimental finding. In the absence of nanobody binding, the receptor orthosteric pocket sampled open and fully open conformations. The GaMD simulations revealed two low-energy intermediate states during nanobody binding to the M 2 receptor. The flexible receptor intracellular loops contribute remarkable electrostatic, polar, and hydrophobic residue interactions in recognition and binding of the nanobody. These simulations provided important insights into the mechanism of GPCR-nanobody binding and demonstrated the applicability of GaMD in modeling dynamic protein-protein interactions.

  8. Long-term activation upon brief exposure to xanomleline is unique to M1 and M4 subtypes of muscarinic acetylcholine receptors.

    Directory of Open Access Journals (Sweden)

    Eva Šantrůčková

    Full Text Available Xanomeline is an agonist endowed with functional preference for M1/M4 muscarinic acetylcholine receptors. It also exhibits both reversible and wash-resistant binding to and activation of these receptors. So far the mechanisms of xanomeline selectivity remain unknown. To address this question we employed microfluorometric measurements of intracellular calcium levels and radioligand binding to investigate differences in the short- and long-term effects of xanomeline among muscarinic receptors expressed individually in Chinese hamster ovary cells. 1/One-min exposure of cells to xanomeline markedly increased intracellular calcium at hM1 and hM4, and to a lesser extent at hM2 and hM3 muscarinic receptors for more than 1 hour. 2/Unlike the classic agonists carbachol, oxotremorine, and pilocarpine 10-min exposure to xanomeline did not cause internalization of any receptor subtype. 3/Wash-resistant xanomeline selectively prevented further increase in intracellular calcium by carbachol at hM1 and hM4 receptors. 4/After transient activation xanomeline behaved as a long-term antagonist at hM5 receptors. 5/The antagonist N-methylscopolamine (NMS reversibly blocked activation of hM1 through hM4 receptors by xanomeline. 6/NMS prevented formation of xanomeline wash-resistant binding and activation at hM2 and hM4 receptors and slowed them at hM1, hM3 and hM5 receptors. Our results show commonalities of xanomeline reversible and wash-resistant binding and short-time activation among the five muscarinic receptor subtypes. However long-term receptor activation takes place in full only at hM1 and hM4 receptors. Moreover xanomeline displays higher efficacy at hM1 and hM4 receptors in primary phasic intracellular calcium release. These findings suggest the existence of particular activation mechanisms specific to these two receptors.

  9. Blocking muscarinic receptors in the olfactory bulb impairs performance on an olfactory short term memory task

    Directory of Open Access Journals (Sweden)

    Sasha eDevore

    2012-09-01

    Full Text Available Cholinergic inputs to cortical processing networks have long been associated with attentional and top-down processing. Experimental and theoretical studies suggest that cholinergic inputs to the main olfactory bulb (OB can modulate both neural and behavioral odor discrimination. Previous experiments from our laboratory and others demonstrate that blockade of nicotinic receptors directly impairs olfactory discrimination, whereas blockade of muscarinic receptors only measurably impairs olfactory perception when task demands are made more challenging, such as when very low-concentration odors are used or rats are required to maintain sensory memory over long durations. To further investigate the role of muscarinic signaling in the OB, we developed an olfactory delayed match-to-sample task using a digging-based behavioral paradigm. We find that rats are able to maintain robust short-term odor memory for tens to hundreds of seconds. To investigate the role of muscarinic signaling in task performance, we bilaterally infused scopolamine into the OB. We find that high dosages of scopolamine (38 mM impair performance on the task across all delays tested, including the baseline condition with no delay, whereas lower dosages (7.6 mM and 22.8 mM had no measureable effects. These results indicate that general execution of the match-to-sample task, even with no delay, is at least partially dependent on muscarinic signaling in the OB.

  10. Regional distribution of muscarinic acetylcholine receptors in the telencephalon of the pigeon (Columba livia f. domestica)

    International Nuclear Information System (INIS)

    Waechtler, K.

    1985-01-01

    The distribution of muscarinic acetylcholine receptors was studied autoradiographically in croystat sections of the pigeon telencephalon using 3 H-quinuclidinylbenzylate as a ligand. Highest receptor density was observed in the hyperstriatum ventrale, palaeostriatum augmentatum, septum, and parts of the archistriatum. In sites of known sensory input of neostriatum (field L) and ectostriatum low receptor binding was observed. Acetylcholinesterase distribution is in good agreement with the receptor picture only in the basal telencephalon. In the pallium differences in the pattern of these two components can be seen. (author)

  11. Investigation of the presence and antinociceptive function of muscarinic acetylcholine receptors in the African naked mole-rat (Heterocephalus glaber).

    Science.gov (United States)

    Jørgensen, Kristine B; Krogh-Jensen, Karen; Pickering, Darryl S; Kanui, Titus I; Abelson, Klas S P

    2016-01-01

    The present study investigated the cholinergic system in the African naked mole-rat (Heterocephalus glaber) with focus on the muscarinic acetylcholine receptor subtypes M1 and M4. The protein sequences for the subtypes m 1-5 of the naked mole-rat were compared to that of the house mouse (Mus musculus) using basic local alignment search tool (BLAST). The presence and function of M1 and M4 was investigated in vivo, using the formalin test with the muscarinic receptor agonists xanomeline and VU0152100. Spinal cord tissue from the naked mole-rat was used for receptor saturation binding studies with [(3)H]-N-methylscopolamine. The BLAST test revealed 95 % protein sequence homology showing the naked mole-rat to have the genetic potential to express all five muscarinic acetylcholine receptor subtypes. A significant reduction in pain behavior was demonstrated after administration of 8.4 mg/kg in the formalin test. Administration of 50 mg/kg VU0152100 resulted in a non-significant tendency towards antinociception. The antinociceptive effects were reversed by the muscarinic acetylcholine receptor antagonist atropine. Binding studies indicated presence of muscarinic acetylcholine receptors with a radioligand affinity comparable to that reported in mice. In conclusion, muscarinic acetylcholine receptor subtypes are present in the naked mole-rat and contribute to antinociception in the naked mole-rat.

  12. Decreased ipsilateral [123I]iododexetimide binding to cortical muscarinic receptors in unilaterally 6-hydroxydopamine lesioned rats

    International Nuclear Information System (INIS)

    Knol, Remco J.J.; Bruin, Kora de; Opmeer, Brent; Voorn, Pieter; Jonker, Allert J.; Eck-Smit, Berthe L.F. van; Booij, Jan

    2014-01-01

    Introduction: Dysfunction of the cholinergic neurotransmitter system is present in Parkinson’s disease, Parkinson’s disease related dementia and dementia with Lewy bodies, and is thought to contribute to cognitive deficits in these patients. In vivo imaging of the cholinergic system in these diseases may be of value to monitor central cholinergic disturbances and to select cases in which treatment with cholinesterase inhibitors could be beneficial. The muscarinic receptor tracer [ 123 I]iododexetimide, predominantly reflecting M 1 receptor binding, may be an appropriate tool for imaging of the cholinergic system by means of SPECT. In this study, we used [ 123 I]iododexetimide to study the effects of a 6-hydroxydopamine lesion (an animal model of Parkinson’s disease) on the muscarinic receptor availability in the rat brain. Methods: Rats (n = 5) were injected in vivo at 10–13 days after a confirmed unilateral 6-hydroxydopamine lesion. Muscarinic receptor availability was measured bilaterally in multiple brain areas on storage phosphor images by region of interest analysis. Results: Autoradiography revealed a consistent and statistically significant lower [ 123 I]iododexetimide binding in all examined neocortical areas on the ipsilateral side of the lesion as compared to the contralateral side. In hippocampal and subcortical areas, such asymmetry was not detected. Conclusions: This study suggests that evaluation of muscarinic receptor availability in dopamine depleted brains using [ 123 I]iododexetimide is feasible. We conclude that 6-hydroxydopamine lesions induce a decrease of neocortical muscarinic receptor availability. We hypothesize that this arises from down regulation of muscarinic postsynaptic M 1 receptors due to hyperactivation of the cortical cholinergic system in response to dopamine depletion. Advances in knowledge: In rats, dopamine depletion provokes a decrease in neocortical muscarinic receptor availability, which is evaluable by [ 123 I

  13. Muscarinic Acetylcholine Receptor Subtypes as Potential Drug Targets for the Treatment of Schizophrenia, Drug Abuse and Parkinson's Disease

    DEFF Research Database (Denmark)

    Dencker, Ditte; Thomsen, Morgane; Wörtwein, Gitta

    2011-01-01

    's disease and drug abuse. Dopaminergic systems are regulated by cholinergic, especially muscarinic, input. Not surprisingly, increasing evidence implicates muscarinic acetylcholine receptor-mediated pathways as potential targets for the treatment of these disorders classically viewed as "dopamine based...... site. Such agents may lead to the development of novel classes of drugs useful for the treatment of psychosis, drug abuse and Parkinson's disease. The present review highlights recent studies carried out using muscarinic receptor knock-out mice and new subtype-selective allosteric ligands to assess...... the roles of M(1), M(4), and M(5) receptors in various central processes that are under strong dopaminergic control. The outcome of these studies opens new perspectives for the use of novel muscarinic drugs for several severe disorders of the CNS....

  14. Muscarinic receptors in separate populations of noradrenaline- and adrenaline-containing chromaffin cells

    International Nuclear Information System (INIS)

    Michelena, P.; Moro, M.A.; Castillo, C.J.; Garcia, A.G.

    1991-01-01

    We have performed binding experiments of (a)[3H]quinuclidinyl benzilate to partially purified membranes from noradrenaline- and adrenaline-containing chromaffin cells and (b) [3H]N-methyl-quinuclidinyl benzilate to acutely isolated, or 48-h cultured, chromaffin cells subpopulations. Using this approach, we obtained enough evidence to conclude (1st) that muscarinic receptors are present in both noradrenaline- and adrenaline containing cells; (2nd) that noradrenaline cells contain in fact 2-3 fold higher density of those receptors; and (3rd) that those receptors undergo plastic changes upon chronic culturing of the cells

  15. Uncoupling of M1 muscarinic receptor/G-protein interaction by amyloid beta(1-42)

    Czech Academy of Sciences Publication Activity Database

    Janíčková, Helena; Rudajev, Vladimír; Zimčík, Pavel; Jakubík, Jan; Tanila, H.; El-Fakahany, E. E.; Doležal, Vladimír

    2013-01-01

    Roč. 67, April (2013), s. 272-283 ISSN 0028-3908 R&D Projects: GA ČR(CZ) GA305/09/0681; GA ČR(CZ) GBP304/12/G069; GA MŠk(CZ) 7E10060 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : Alzheimer ´s Disease * muscarinic receptors * G-proteins Subject RIV: ED - Physiology Impact factor: 4.819, year: 2013

  16. Classical and atypical agonists activate M1 muscarinic acetylcholine receptors through common mechanisms

    Czech Academy of Sciences Publication Activity Database

    Randáková, Alena; Dolejší, Eva; Rudajev, Vladimír; Zimčík, Pavel; Doležal, Vladimír; El-Fakahany, E. E.; Jakubík, Jan

    2015-01-01

    Roč. 97, Jul 2015 (2015), s. 27-39 ISSN 1043-6618 R&D Projects: GA ČR(CZ) GA305/09/0681; GA ČR(CZ) GBP304/12/G069; GA MŠk(CZ) EE2.3.30.0025 Institutional support: RVO:67985823 Keywords : muscarinic acetylcholine receptors * atypical agonists * xanomeline * activation mechanism Subject RIV: ED - Physiology Impact factor: 4.816, year: 2015

  17. Distinct muscarinic acetylcholine receptor subtypes mediate pre- and postsynaptic effects in rat neocortex

    Directory of Open Access Journals (Sweden)

    Gigout Sylvain

    2012-04-01

    Full Text Available Abstract Background Cholinergic transmission has been implicated in learning, memory and cognition. However, the cellular effects induced by muscarinic acetylcholine receptors (mAChRs activation are poorly understood in the neocortex. We investigated the effects of the cholinergic agonist carbachol (CCh and various agonists and antagonists on neuronal activity in rat neocortical slices using intracellular (sharp microelectrode and field potential recordings. Results CCh increased neuronal firing but reduced synaptic transmission. The increase of neuronal firing was antagonized by pirenzepine (M1/M4 mAChRs antagonist but not by AF-DX 116 (M2/M4 mAChRs antagonist. Pirenzepine reversed the depressant effect of CCh on excitatory postsynaptic potential (EPSP but had marginal effects when applied before CCh. AF-DX 116 antagonized the depression of EPSP when applied before or during CCh. CCh also decreased the paired-pulse inhibition of field potentials and the inhibitory conductances mediated by GABAA and GABAB receptors. The depression of paired-pulse inhibition was antagonized or prevented by AF-DX 116 or atropine but only marginally by pirenzepine. The inhibitory conductances were unaltered by xanomeline (M1/M4 mAChRs agonist, yet the CCh-induced depression was antagonized by AF-DX 116. Linopirdine, a selective M-current blocker, mimicked the effect of CCh on neuronal firing. However, linopirdine had no effect on the amplitude of EPSP or on the paired-pulse inhibition, indicating that M-current is involved in the increase of neuronal excitability but neither in the depression of EPSP nor paired-pulse inhibition. Conclusions These data indicate that the three effects are mediated by different mAChRs, the increase in firing being mediated by M1 mAChR, decrease of inhibition by M2 mAChR and depression of excitatory transmission by M4 mAChR. The depression of EPSP and increase of neuronal firing might enhance the signal-to-noise ratio, whereas the

  18. Eosinophils express muscarinic receptors and corticotropin-releasing factor to disrupt the mucosal barrier in ulcerative colitis.

    Science.gov (United States)

    Wallon, Conny; Persborn, Mats; Jönsson, Maria; Wang, Arthur; Phan, Van; Lampinen, Maria; Vicario, Maria; Santos, Javier; Sherman, Philip M; Carlson, Marie; Ericson, Ann-Charlott; McKay, Derek M; Söderholm, Johan D

    2011-05-01

    Altered intestinal barrier function has been implicated in the pathophysiology of ulcerative colitis (UC) in genetic, functional, and epidemiological studies. Mast cells and corticotropin-releasing factor (CRF) regulate the mucosal barrier in human colon. Because eosinophils are often increased in colon tissues of patients with UC, we assessed interactions among mast cells, CRF, and eosinophils in the mucosal barrier of these patients. Transmucosal fluxes of protein antigens (horseradish peroxidase) and paracellular markers ((51)Cr-EDTA, fluorescein isothiocyanate-dextran 4000) were studied in noninflamed, colonic mucosal biopsy samples collected from 26 patients with UC and 53 healthy volunteers (controls); samples were mounted in Ussing chambers. We also performed fluorescence and electron microscopy of human tissue samples, assessed isolated eosinophils, and performed mechanistic studies using in vitro cocultured eosinophils (15HL-60), mast cells (HMC-1), and a colonic epithelial cell line (T84). Colon tissues from patients with UC had significant increases in permeability to protein antigens compared with controls. Permeability was blocked by atropine (a muscarinic receptor antagonist), α-helical CRF(9-41) (a CRF receptor antagonist), and lodoxamide (a mast-cell stabilizer). Eosinophils were increased in number in UC tissues (compared with controls), expressed the most M2 and M3 muscarinic receptors of any mucosal cell type, and had immunoreactivity to CRF. In coculture studies, carbachol activation of eosinophils caused production of CRF and activation of mast cells, which increased permeability of T84 epithelial cells to macromolecules. We identified a neuroimmune intercellular circuit (from cholinergic nerves, via eosinophils to mast cells) that mediates colonic mucosal barrier dysfunction in patients with UC. This circuit might exacerbate mucosal inflammation. Copyright © 2011 AGA Institute. Published by Elsevier Inc. All rights reserved.

  19. The effects of abnormalities of glucose homeostasis on the expression and binding of muscarinic receptors in cerebral cortex of rats.

    Science.gov (United States)

    Sherin, Antony; Peeyush, Kumar T; Naijil, George; Nandhu, Mohan Sobhana; Jayanarayanan, Sadanandan; Jes, Paul; Paulose, Cheramadathikudiyil Skaria

    2011-01-25

    Glucose homeostasis in humans is an important factor for the functioning of nervous system. Both hypo and hyperglycemia contributes to neuronal functional deficit. In the present study, effect of insulin induced hypoglycemia and streptozotocin induced diabetes on muscarinic receptor binding, cholinergic enzymes; AChE, ChAT expression and GLUT3 in the cerebral cortex of experimental rats were analysed. Total muscarinic, muscarinic M(1) receptor showed a significant decrease and muscarinic M(3) receptor subtype showed a significant increased binding in the cerebral cortex of hypoglycemic rats compared to diabetic and control. Real-Time PCR analysis of muscarinic M(1), M(3) receptor subtypes confirmed the receptor binding studies. Immunohistochemistry of muscarinic M(1), M(3) receptors using specific antibodies were also carried out. AChE and GLUT3 expression up regulated and ChAT expression down regulated in hypoglycemic rats compared to diabetic and control rats. Our results showed that hypo/hyperglycemia caused impaired glucose transport in neuronal cells as shown by altered expression of GLUT3. Increased AChE and decreased ChAT expression is suggested to alter cortical acetylcholine metabolism in experimental rats along with altered muscarinic receptor binding in hypo/hyperglycemic rats, impair cholinergic transmission, which subsequently lead to cholinergic dysfunction thereby causing learning and memory deficits. We observed a prominent cholinergic functional disturbance in hypoglycemic condition than in hyperglycemia. Hypoglycemia exacerbated the neurochemical changes in cerebral cortex induced by hyperglycemia. These findings have implications for both therapy and identification of causes contributing to neuronal dysfunction in diabetes. Copyright © 2010 Elsevier B.V. All rights reserved.

  20. Tuning the allosteric regulation of artificial muscarinic and dopaminergic ligand-gated potassium channels by protein engineering of G protein-coupled receptors

    Science.gov (United States)

    Moreau, Christophe J.; Revilloud, Jean; Caro, Lydia N.; Dupuis, Julien P.; Trouchet, Amandine; Estrada-Mondragón, Argel; Nieścierowicz, Katarzyna; Sapay, Nicolas; Crouzy, Serge; Vivaudou, Michel

    2017-01-01

    Ligand-gated ion channels enable intercellular transmission of action potential through synapses by transducing biochemical messengers into electrical signal. We designed artificial ligand-gated ion channels by coupling G protein-coupled receptors to the Kir6.2 potassium channel. These artificial channels called ion channel-coupled receptors offer complementary properties to natural channels by extending the repertoire of ligands to those recognized by the fused receptors, by generating more sustained signals and by conferring potassium selectivity. The first artificial channels based on the muscarinic M2 and the dopaminergic D2L receptors were opened and closed by acetylcholine and dopamine, respectively. We find here that this opposite regulation of the gating is linked to the length of the receptor C-termini, and that C-terminus engineering can precisely control the extent and direction of ligand gating. These findings establish the design rules to produce customized ligand-gated channels for synthetic biology applications. PMID:28145461

  1. New advances in pharmacological approaches to the cholinergic system: an overview on muscarinic receptor ligands and cholinesterase inhibitors

    Science.gov (United States)

    Greig, Nigel H.; Reale, Marcella; Tata, Ada Maria

    2016-01-01

    The cholinergic system is expressed in neuronal and in non-neuronal tissues. Acetylcholine (ACh), synthesized in and out of the nervous system can locally contribute to modulation of various cell functions (e.g. survival, proliferation). Considering that the cholinergic system and its functions are impaired in a number of disorders, the identification of new pharmacological approaches to regulate cholinergic system components appears of great relevance. The present review focuses on recent pharmacological drugs able to modulate the activity of cholinergic receptors and thereby, cholinergic function, with an emphasis on the muscarinic receptor subtype, and additionally covers the cholinesterases, the main enzymes involved in ACh hydrolysis. The presence and function of muscarinic receptor subtypes both in neuronal and non-neuronal cells has been demonstrated using extensive pharmacological data emerging from studies on transgenic mice. The possible involvement of ACh in different pathologies has been proposed in recent years and is becoming an important area of study. Although the lack of selective muscarinic receptor ligands has for a long time limited the definition of therapeutic treatment based on muscarinic receptors as targets, some muscarinic ligands such as cevimeline (patents US4855290; US5571918) or xanomeline (patent, US5980933) have been developed and used in pre-clinical or in clinical studies for the treatment of nervous system diseases (Alzheimer’ and Sjogren’s diseases). The present review focuses on the potential implications of muscarinic receptors in different pathologies, including tumors. Moreover, the future use of muscarinic ligands in therapeutic protocols in cancer therapy will be discussed, considering that some muscarinic antagonists currently used in the treatment of genitourinary disease (e.g. darifenacin, patent, US5096890; US6106864) have also been demonstrated to arrest tumor progression in nude mice. The involvement of muscarinic

  2. Neuronal M3 muscarinic acetylcholine receptors are essential for somatotroph proliferation and normal somatic growth.

    Science.gov (United States)

    Gautam, Dinesh; Jeon, Jongrye; Starost, Matthew F; Han, Sung-Jun; Hamdan, Fadi F; Cui, Yinghong; Parlow, Albert F; Gavrilova, Oksana; Szalayova, Ildiko; Mezey, Eva; Wess, Jürgen

    2009-04-14

    The molecular pathways that promote the proliferation and maintenance of pituitary somatotrophs and other cell types of the anterior pituitary gland are not well understood at present. However, such knowledge is likely to lead to the development of novel drugs useful for the treatment of various human growth disorders. Although muscarinic cholinergic pathways have been implicated in regulating somatotroph function, the physiological relevance of this effect and the localization and nature of the receptor subtypes involved in this activity remain unclear. We report the surprising observation that mutant mice that selectively lack the M(3) muscarinic acetylcholine receptor subtype in the brain (neurons and glial cells; Br-M3-KO mice) showed a dwarf phenotype associated with a pronounced hypoplasia of the anterior pituitary gland and a marked decrease in pituitary and serum growth hormone (GH) and prolactin. Remarkably, treatment of Br-M3-KO mice with CJC-1295, a synthetic GH-releasing hormone (GHRH) analog, rescued the growth deficit displayed by Br-M3-KO mice by restoring normal pituitary size and normal serum GH and IGF-1 levels. These findings, together with results from M(3) receptor/GHRH colocalization studies and hypothalamic hormone measurements, support a model in which central (hypothalamic) M(3) receptors are required for the proper function of hypothalamic GHRH neurons. Our data reveal an unexpected and critical role for central M(3) receptors in regulating longitudinal growth by promoting the proliferation of pituitary somatotroph cells.

  3. Investigation of the presence and antinociceptive function of muscarinic acetylcholine receptors in the African naked mole-rat (Heterocephalus glaber)

    DEFF Research Database (Denmark)

    Jørgensen, Kristine B.; Krogh-Jensen, Karen; Pickering, Darryl S

    2016-01-01

    The present study investigated the cholinergic system in the African naked mole-rat (Heterocephalus glaber) with focus on the muscarinic acetylcholine receptor subtypes M1 and M4. The protein sequences for the subtypes m 1–5 of the naked mole-rat were compared to that of the house mouse (Mus...... musculus) using basic local alignment search tool (BLAST). The presence and function of M1 and M4 was investigated in vivo, using the formalin test with the muscarinic receptor agonists xanomeline and VU0152100. Spinal cord tissue from the naked mole-rat was used for receptor saturation binding studies...

  4. The muscarinic M1/M4 receptor agonist xanomeline exhibits antipsychotic-like activity in Cebus apella monkeys

    DEFF Research Database (Denmark)

    Andersen, Maibritt B; Fink-Jensen, Anders; Peacock, Linda

    2003-01-01

    Xanomeline is a muscarinic M(1)/M(4) preferring receptor agonist with little or no affinity for dopamine receptors. The compound reduces psychotic-like symptoms in patients with Alzheimer's disease and exhibits an antipsychotic-like profile in rodents without inducing extrapyramidal side effects ...

  5. An allosteric enhancer of M4muscarinic acetylcholine receptor function inhibits behavioral and neurochemical effects of cocaine

    DEFF Research Database (Denmark)

    Dencker, Ditte; Weikop, Pia; Sørensen, Gunnar

    2012-01-01

    The mesostriatal dopamine system plays a key role in mediating the reinforcing effects of psychostimulant drugs like cocaine. The muscarinic M4 acetylcholine receptor subtype is centrally involved in the regulation of dopamine release in striatal areas. Consequently, striatal M4 receptors could...

  6. Physiological roles of CNS muscarinic receptors gained from knockout mice

    DEFF Research Database (Denmark)

    Thomsen, Morgane; Sørensen, Gunnar; Dencker, Ditte

    2017-01-01

    receptors modulating neuronal activity and neurotransmitter release in many brain regions, shaping neuronal plasticity, and affecting functions ranging from motor and sensory function to cognitive processes. As gene targeting technology evolves including the use of conditional, cell type specific strains......, knockout mice are likely to continue to provide valuable insights into brain physiology and pathophysiology, and advance the development of new medications for a range of conditions such as Alzheimer's disease, Parkinson's disease, schizophrenia, and addictions, as well as non-opioid analgesics...

  7. Vitamin C Deficiency Reduces Muscarinic Receptor Coronary Artery Vasoconstriction and Plasma Tetrahydrobiopterin Concentration in Guinea Pigs

    Directory of Open Access Journals (Sweden)

    Gry Freja Skovsted

    2017-07-01

    Full Text Available Vitamin C (vitC deficiency is associated with increased cardiovascular disease risk, but its specific interplay with arteriolar function is unclear. This study investigates the effect of vitC deficiency in guinea pigs on plasma biopterin status and the vasomotor responses in coronary arteries exposed to vasoconstrictor/-dilator agents. Dunkin Hartley female guinea pigs (n = 32 were randomized to high (1500 mg/kg diet or low (0 to 50 mg/kg diet vitC for 10–12 weeks. At euthanasia, coronary artery segments were dissected and mounted in a wire-myograph. Vasomotor responses to potassium, carbachol, sodium nitroprusside (SNP, U46619, sarafotoxin 6c (S6c and endothelin-1 (ET-1 were recorded. Plasma vitC and tetrahydrobiopterin were measured by HPLC. Plasma vitC status reflected the diets with deficient animals displaying reduced tetrahydrobiopterin. Vasoconstrictor responses to carbachol were significantly decreased in vitC deficient coronary arteries independent of their general vasoconstrictor/vasodilator capacity (p < 0.001. Moreover, in vitC deficient animals, carbachol-induced vasodilator responses correlated with coronary artery diameter (p < 0.001. Inhibition of cyclooxygenases with indomethacin increased carbachol-induced vasoconstriction, suggesting an augmented carbachol-induced release of vasodilator prostanoids. Atropine abolished carbachol-induced vasomotion, supporting a specific muscarinic receptor effect. Arterial responses to SNP, potassium, S6c, U46619 and ET-1 were unaffected by vitC status. The study shows that vitC deficiency decreases tetrahydrobiopterin concentrations and muscarinic receptor mediated contraction in coronary arteries. This attenuated vasoconstrictor response may be linked to altered production of vasoactive arachidonic acid metabolites and reduced muscarinic receptor expression/signaling.

  8. M1 muscarinic receptor facilitates cognitive function by interplay with AMPA receptor GluA1 subunit.

    Science.gov (United States)

    Zhao, Lan-Xue; Ge, Yan-Hui; Xiong, Cai-Hong; Tang, Ling; Yan, Ying-Hui; Law, Ping-Yee; Qiu, Yu; Chen, Hong-Zhuan

    2018-03-06

    M1 muscarinic acetylcholine receptors (M1 mAChRs) are the most abundant muscarinic receptors in the hippocampus and have been shown to have procognitive effects. AMPA receptors (AMPARs), an important subtype of ionotropic glutamate receptors, are key components in neurocognitive networks. However, the role of AMPARs in procognitive effects of M1 mAChRs and how M1 mAChRs affect the function of AMPARs remain poorly understood. Here, we found that basal expression of GluA1, a subunit of AMPARs, and its phosphorylation at Ser845 were maintained by M1 mAChR activity. Activation of M1 mAChRs promoted membrane insertion of GluA1, especially to postsynaptic densities. Impairment of hippocampus-dependent learning and memory by antagonism of M1 mAChRs paralleled the reduction of GluA1 expression, and improvement of learning and memory by activation of M1 mAChRs was accompanied by the synaptic insertion of GluA1 and its increased phosphorylation at Ser845. Furthermore, abrogation of phosphorylation of Ser845 residue of GluA1 ablated M1 mAChR-mediated improvement of learning and memory. Taken together, these results show a functional correlation of M1 mAChRs and GluA1 and the essential role of GluA1 in M1 mAChR-mediated cognitive improvement.-Zhao, L.-X., Ge, Y.-H., Xiong, C.-H., Tang, L., Yan, Y.-H., Law, P.-Y., Qiu, Y., Chen, H.-Z. M1 muscarinic receptor facilitates cognitive function by interplay with AMPA receptor GluA1 subunit.

  9. The A- and B-type muscarinic acetylcholine receptors from Drosophila melanogaster couple to different second messenger pathways

    DEFF Research Database (Denmark)

    Ren, Guilin Robin; Folke, Jonas; Hauser, Frank

    2015-01-01

    Muscarinic acetylcholine receptors (mAChRs) are G protein-coupled receptors (GPCRs) that are activated by the agonists acetylcholine and muscarine and blocked by several antagonists, among them atropine. In mammals five mAChRs (m1-m5) exist of which m1, m3, and m5 are coupled to members of the Gq...

  10. Muscarinic Acetylcholine Receptor M3 Mutation Causes Urinary Bladder Disease and a Prune-Belly-like Syndrome.

    Science.gov (United States)

    Weber, Stefanie; Thiele, Holger; Mir, Sevgi; Toliat, Mohammad Reza; Sozeri, Betül; Reutter, Heiko; Draaken, Markus; Ludwig, Michael; Altmüller, Janine; Frommolt, Peter; Stuart, Helen M; Ranjzad, Parisa; Hanley, Neil A; Jennings, Rachel; Newman, William G; Wilcox, Duncan T; Thiel, Uwe; Schlingmann, Karl Peter; Beetz, Rolf; Hoyer, Peter F; Konrad, Martin; Schaefer, Franz; Nürnberg, Peter; Woolf, Adrian S

    2011-11-11

    Urinary bladder malformations associated with bladder outlet obstruction are a frequent cause of progressive renal failure in children. We here describe a muscarinic acetylcholine receptor M3 (CHRM3) (1q41-q44) homozygous frameshift mutation in familial congenital bladder malformation associated with a prune-belly-like syndrome, defining an isolated gene defect underlying this sometimes devastating disease. CHRM3 encodes the M3 muscarinic acetylcholine receptor, which we show is present in developing renal epithelia and bladder muscle. These observations may imply that M3 has a role beyond its known contribution to detrusor contractions. This Mendelian disease caused by a muscarinic acetylcholine receptor mutation strikingly phenocopies Chrm3 null mutant mice. Copyright © 2011 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  11. Differentiation-associated decrease in muscarinic receptor sensitivity in human neuroblastoma cells

    International Nuclear Information System (INIS)

    Heikkilae, J.E.; Scott, J.G.; Suominen, L.A.; Akerman, K.E.O.

    1987-01-01

    Muscarinic receptor-linked increases in intracellular free Ca 2+ as measured with quin-2 and Ca 2+ release from monolayers of cells have been measured in the human neuroblastoma cell line SH-SY5Y. Induction of differentiation with the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) leads to a decrease in the sensitivity of the cells to low concentrations of agonists with respect to the induced increase in cytosolic free Ca 2+ and stimulation of Ca 2+ efflux. No decrease in agonist binding affinity was observed when the displacement of a labelled antagonist, 3 H-NMS, by a non-labelled agonist was studied

  12. Presynaptic muscarinic receptors: Change of sensitivity during long-term drug treatment

    International Nuclear Information System (INIS)

    Marchi, M.; Raiteri, M.

    1986-01-01

    The authors investigate some of the characteristics of auto- and heteroreceptors from different brain areas in male rats; their alteration in sensitivity following chronic drug treatment is monitored. The synaptosomes were prelabeled with tritium-choline or tritium-dopamine and the release of tritium-acetylcholine and tritium-DA was studied in superfusion. It is shown that the difference in susceptibility between auto- and heteroreceptors with respect to changes of sensitivity may represent a further criterion to discriminate between muscarinic receptor subtypes

  13. Connexins and M3 Muscarinic Receptors Contribute to Heterogeneous Ca2+ Signaling in Mouse Aortic Endothelium

    Directory of Open Access Journals (Sweden)

    François-Xavier Boittin

    2013-02-01

    Full Text Available Background/Aims: Smooth muscle tone is controlled by Ca2+ signaling in the endothelial layer. Mouse endothelial cells are interconnected by gap junctions made of Connexin40 (Cx40 and Cx37, which allow the exchange of signaling molecules to coordinate their activity. Here, we investigated the role of Cx40 in the endothelial Ca2+ signaling of the mouse aorta. Methods: Ca2+ imaging was performed on intact aortic endothelium from both wild type (Cx40+/+ and Connexin40-deficient (Cx40 -/- mice. Results: Acetylcholine (ACh induced early fast and high amplitude Ca2+ transients in a fraction of endothelial cells expressing the M3 muscarinic receptors. Inhibition of intercellular communication using carbenoxolone or octanol fully blocked the propagation of ACh-induced Ca2+ transients toward adjacent cells in WT and Cx40-/- mice. As compared to WT, Cx40-/- mice displayed a reduced propagation of ACh-induced Ca2+ waves, indicating that Cx40 contributes to the spreading of Ca2+ signals. The propagation of those Ca2+ responses was not blocked by suramin, a blocker of purinergic ATP receptors, indicating that there is no paracrine effect of ATP release on the Ca2+ waves. Conclusions: Altogether our data show that Cx40 and Cx37 contribute to the propagation and amplification of the Ca2+ signaling triggered by ACh in endothelial cells expressing the M3 muscarinic receptors.

  14. SELECTIVITY PROFILE OF SOME RECENT MUSCARINIC ANTAGONISTS IN BOVINE AND GUINEA-PIG TRACHEA AND HEART

    NARCIS (Netherlands)

    ROFFEL, AF; HAMSTRA, JJ; ELZINGA, CRS; ZAAGSMA, J

    1994-01-01

    The functional affinities of some recently developed subtype-selective muscarinic antagonists towards bovine tracheal smooth muscle muscarinic M(3) receptors were established and compared to binding affinities for bovine cardiac M(2) and functional affinities for guinea-pig tracheal smooth muscle

  15. Effects of selective activation of M1 and M4 muscarinic receptors on object recognition memory performance in rats.

    Science.gov (United States)

    Galloway, Claire R; Lebois, Evan P; Shagarabi, Shezza L; Hernandez, Norma A; Manns, Joseph R

    2014-01-01

    Acetylcholine signaling through muscarinic receptors has been shown to benefit memory performance in some conditions, but pan-muscarinic activation also frequently leads to peripheral side effects. Drug therapies that selectively target M1 or M4 muscarinic receptors could potentially improve memory while minimizing side effects mediated by the other muscarinic receptor subtypes. The ability of three recently developed drugs that selectively activate M1 or M4 receptors to improve recognition memory was tested by giving Long-Evans rats subcutaneous injections of three different doses of the M1 agonist VU0364572, the M1 positive allosteric modulator BQCA or the M4 positive allosteric modulator VU0152100 before performing an object recognition memory task. VU0364572 at 0.1 mg/kg, BQCA at 1.0 mg/kg and VU0152100 at 3.0 and 30.0 mg/kg improved the memory performance of rats that performed poorly at baseline, yet the improvements in memory performance were the most statistically robust for VU0152100 at 3.0 mg/kg. The results suggested that selective M1 and M4 receptor activation each improved memory but that the likelihood of obtaining behavioral efficacy at a given dose might vary between subjects even in healthy groups depending on baseline performance. These results also highlighted the potential of drug therapies that selectively target M1 or M4 receptors to improve memory performance in individuals with impaired memory.

  16. Permanent alterations in muscarinic receptors and pupil size produced by chronic atropinization in kittens

    International Nuclear Information System (INIS)

    Smith, E.L.; Redburn, D.A.; Harwerth, R.S.; Maguire, G.W.

    1984-01-01

    Chronic mydriasis was induced in six kittens (four monocular, two binocular) and two adult cats (both monocular) by the daily topical application of atropine. Both the kittens and the adult cats were atropinized for a 13-week period with the treatment regimen beginning at the time of eye opening for the kittens. Pupil size measurements, obtained 1 year after the atropinization were discontinued, revealed that, although the pupils of the adult cats were normal, the pupils of the kittens' treated eyes were consistently smaller than pupils in control eyes. The status of the muscarinic receptors in the kittens' irides was investigated using 3 H-QNB binding assays. In comparison with iris muscle homogenates from the control eyes, those from the treated eyes demonstrated an eightfold increase in the number of receptor binding sites. The results indicate that pupil size can be altered permanently by chronic mydriasis initiated early in the life of a kitten and that the permanent change in pupil size may result, in part, from a type of permanent supersensitivity response in the muscle following chronic blockade of muscarinic transmission by atropine

  17. The M3 muscarinic receptor is required for optimal adaptive immunity to helminth and bacterial infection.

    Directory of Open Access Journals (Sweden)

    Matthew Darby

    2015-01-01

    Full Text Available Innate immunity is regulated by cholinergic signalling through nicotinic acetylcholine receptors. We show here that signalling through the M3 muscarinic acetylcholine receptor (M3R plays an important role in adaptive immunity to both Nippostrongylus brasiliensis and Salmonella enterica serovar Typhimurium, as M3R-/- mice were impaired in their ability to resolve infection with either pathogen. CD4 T cell activation and cytokine production were reduced in M3R-/- mice. Immunity to secondary infection with N. brasiliensis was severely impaired, with reduced cytokine responses in M3R-/- mice accompanied by lower numbers of mucus-producing goblet cells and alternatively activated macrophages in the lungs. Ex vivo lymphocyte stimulation of cells from intact BALB/c mice infected with N. brasiliensis and S. typhimurium with muscarinic agonists resulted in enhanced production of IL-13 and IFN-γ respectively, which was blocked by an M3R-selective antagonist. Our data therefore indicate that cholinergic signalling via the M3R is essential for optimal Th1 and Th2 adaptive immunity to infection.

  18. Negative cooperativity in binding of muscarinic receptor agonists and GDP as a measure of agonist efficacy.

    Science.gov (United States)

    Jakubík, J; Janíčková, H; El-Fakahany, E E; Doležal, V

    2011-03-01

    Conventional determination of agonist efficacy at G-protein coupled receptors is measured by stimulation of guanosine-5'-γ-thiotriphosphate (GTPγS) binding. We analysed the role of guanosine diphosphate (GDP) in the process of activation of the M₂ muscarinic acetylcholine receptor and provide evidence that negative cooperativity between agonist and GDP binding is an alternative measure of agonist efficacy. Filtration and scintillation proximity assays measured equilibrium binding as well as binding kinetics of [³⁵S]GTPγS and [³H]GDP to a mixture of G-proteins as well as individual classes of G-proteins upon binding of structurally different agonists to the M₂ muscarinic acetylcholine receptor. Agonists displayed biphasic competition curves with the antagonist [³H]-N-methylscopolamine. GTPγS (1 µM) changed the competition curves to monophasic with low affinity and 50 µM GDP produced a similar effect. Depletion of membrane-bound GDP increased the proportion of agonist high-affinity sites. Carbachol accelerated the dissociation of [³H]GDP from membranes. The inverse agonist N-methylscopolamine slowed GDP dissociation and GTPγS binding without changing affinity for GDP. Carbachol affected both GDP association with and dissociation from G(i/o) G-proteins but only its dissociation from G(s/olf) G-proteins. These findings suggest the existence of a low-affinity agonist-receptor conformation complexed with GDP-liganded G-protein. Also the negative cooperativity between GDP and agonist binding at the receptor/G-protein complex determines agonist efficacy. GDP binding reveals differences in action of agonists versus inverse agonists as well as differences in activation of G(i/o) versus G(s/olf) G-proteins that are not identified by conventional GTPγS binding. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.

  19. Hyperfunction of muscarinic receptor maintains long-term memory in 5-HT4 receptor knock-out mice.

    Directory of Open Access Journals (Sweden)

    Luis Segu

    Full Text Available Patients suffering from dementia of Alzheimer's type express less serotonin 4 receptors (5-HTR(4, but whether an absence of these receptors modifies learning and memory is unexplored. In the spatial version of the Morris water maze, we show that 5-HTR(4 knock-out (KO and wild-type (WT mice performed similarly for spatial learning, short- and long-term retention. Since 5-HTR(4 control mnesic abilities, we tested whether cholinergic system had circumvented the absence of 5-HTR(4. Inactivating muscarinic receptor with scopolamine, at an ineffective dose (0.8 mg/kg to alter memory in WT mice, decreased long-term but not short-term memory of 5-HTR(4 KO mice. Other changes included decreases in the activity of choline acetyltransferase (ChAT, the required enzyme for acetylcholine synthesis, in the septum and the dorsal hippocampus in 5-HTR(4 KO under baseline conditions. Training- and scopolamine-induced increase and decrease, respectively in ChAT activity in the septum in WT mice were not detected in the 5-HTR(4 KO animals. Findings suggest that adaptive changes in cholinergic systems may circumvent the absence of 5-HTR(4 to maintain long-term memory under baseline conditions. In contrast, despite adaptive mechanisms, the absence of 5-HTR(4 aggravates scopolamine-induced memory impairments. The mechanisms whereby 5-HTR(4 mediate a tonic influence on ChAT activity and muscarinic receptors remain to be determined.

  20. SPET imaging of central muscarinic receptors with (R,R)[123I]-I-QNB: methodological considerations

    International Nuclear Information System (INIS)

    Norbury, R.; Travis, M.J.; Erlandsson, K.; Waddington, W.; Owens, J.; Ell, P.J.; Murphy, D.G.

    2004-01-01

    Investigations on the effect of normal healthy ageing on the muscarinic system have shown conflicting results. Also, in vivo determination of muscarinic receptor binding has been hampered by a lack of subtype selective ligands and differences in methods used for quantification of receptor densities. Recent in vitro and in vivo work with the muscarinic antagonist (R,R)-I-QNB indicates this ligand has selectivity for m 1 and m 4 muscarinic receptor subtypes. Therefore, we used (R,R)[ 123 I]-I-QNB and single photon emission tomography to study brain m 1 and m 4 muscarinic receptors in 25 healthy female subjects (11 younger subjects, age range 26-32 years and 14 older subjects, age range 57-82 years). Our aims were to ascertain the viability of tracer administration and imaging within the same day, and to evaluate whether normalization to whole brain, compared to normalization to cerebellum, could alter the clinical interpretation of results. Images were analyzed using the simplified reference tissue model and by two ratio methods: normalization to whole brain and normalization to cerebellum. Significant correlations were observed between kinetic analysis and normalization to cerebellum, but not to whole brain. Both the kinetic analysis and normalization to cerebellum showed age-related reductions in muscarinic binding in frontal, orbitofrontal, and parietal regions. Normalization to whole brain, however, failed to detect age-related changes in any region. Here we show that, for this radiotracer, normalizing to a region of negligible specific binding (cerebellum) significantly improves sensitivity when compared to global normalization

  1. Costimulation of N-methyl-d-aspartate and muscarinic neuronal receptors modulates gap junctional communication in striatal astrocytes

    OpenAIRE

    Rouach, N.; Tencé, M.; Glowinski, J.; Giaume, C.

    2002-01-01

    Cocultures of neurons and astrocytes from the rat striatum were used to determine whether the stimulation of neuronal receptors could affect the level of intercellular communication mediated by gap junctions in astrocytes. The costimulation of N-methyl-D-asparte (NMDA) and muscarinic receptors led to a prominent reduction of astrocyte gap junctional communication (GJC) in coculture. This treatment was not effective in astrocyte cultures, these cells being devoid of NMDA receptors. Both types ...

  2. Synthesis of dibenzodioxazocines and their effects on cholinesterases and muscarinic cholinergic receptors.

    Science.gov (United States)

    Gaál, J; Batke, J; Borsodi, A; Rózsa, L; Somogyi, G

    1989-01-01

    A new family of tricyclic compounds, the dibenzodioxazocines were synthesized. These compounds were the following: 2-chloro-12-(2-piperidino-ethyl)-dibenzo d,g 1,3,6 dioxazocine hydrochloride: EGYT-2347, 2-chloro-12-(3-dimethylamino-2-methyl-propyl)-dibenzo [d,g] [1,3,6]-dibenzodioxazocine hydrochloride: EGYT-2509, 2-chloro-12-(3-dimethylamino-propyl)-dibenzo [d,g] [1,3,6] dioxazocine-maleate: EGYT-2474 and 2-chloro-12-2-(4-methyl-piperazino)-ethyl-dibenzo [d,g] [1,3,6]-dioxazocine-dihydrochloride: EGYT-2541. These compounds are inhibitors of both butyryl- and acetylcholinesterase to and they exhibited relatively good anticholinergic properties in receptor binding experiments. The most selective inhibitor of butyrylcholinesterase is the compound EGYT-2347 (Ki = 1.5 x 10(-7) M) which strongly binds to rat brain muscarinic cholinergic receptor (KD = 4.1 x 10(-8) M).

  3. Differential receptor dependencies: expression and significance of muscarinic M1 receptors in the biology of prostate cancer.

    Science.gov (United States)

    Mannan Baig, Abdul; Khan, Naveed A; Effendi, Vardah; Rana, Zohaib; Ahmad, H R; Abbas, Farhat

    2017-01-01

    Recent reports on acetylcholine muscarinic receptor subtype 3 (CHRM3) have shown its growth-promoting role in prostate cancer. Additional studies report the proliferative effect of the cholinergic agonist carbachol on prostate cancer by its agonistic action on CHRM3. This study shows that the type 1 acetylcholine muscarinic receptor (CHRM1) contributes toward the proliferation and growth of prostate cancer. We used growth and cytotoxic assays, the prostate cancer microarray database and CHRM downstream pathways' homology of CHRM subtypes to uncover multiple signals leading to the growth of prostate cancer. Growth assays showed that pilocarpine stimulates the proliferation of prostate cancer. Moreover, it shows that carbachol exerts an additional agonistic action on nicotinic cholinergic receptor of prostate cancer cells that can be blocked by tubocurarine. With the use of selective CHRM1 antagonists such as pirenzepine and dicyclomine, a considerable inhibition of proliferation of prostate cancer cell lines was observed in dose ranging from 15-60 µg/ml of dicyclomine. The microarray database of prostate cancer shows a dominant expression of CHRM1 in prostate cancer compared with other cholinergic subtypes. The bioinformatics of prostate cancer and CHRM pathways show that the downstream signalling include PIP3-AKT-CaM-mediated growth in LNCaP and PC3 cells. Our study suggests that antagonism of CHRM1 may be a potential therapeutic target against prostate cancer.

  4. Immunocytochemical demonstration of M1 muscarinic acetylcholine receptors at the presynaptic and postsynaptic membranes of rat diaphragm endplates

    Czech Academy of Sciences Publication Activity Database

    Malomouzh, A. I.; Arkhipova, S. S.; Nikolsky, E. E.; Vyskočil, František

    2011-01-01

    Roč. 60, č. 1 (2011), s. 185-188 ISSN 0862-8408 R&D Projects: GA AV ČR(CZ) IAA500110905; GA ČR GA202/09/0806 Institutional research plan: CEZ:AV0Z50110509 Keywords : skeletal muscle * M1 muscarinic receptor Subject RIV: ED - Physiology Impact factor: 1.555, year: 2011

  5. Allosteric modulation by persistent binding of xanomeline of the interaction of competitive ligands with the M1 muscarinic acetylcholine receptor

    Czech Academy of Sciences Publication Activity Database

    Jakubík, Jan; Tuček, Stanislav; El-Fakahany, E. E.

    2002-01-01

    Roč. 301, č. 3 (2002), s. 1033-1041 ISSN 0022-3565 R&D Projects: GA ČR GP305/01/D119 Grant - others:NIH(US) NS25743 Institutional research plan: CEZ:AV0Z5011922 Keywords : xanomeline * M(1) muscarinic acetylcholine receptor Subject RIV: FH - Neurology Impact factor: 3.991, year: 2002

  6. Identification, expression and functional characterization of M4L, a muscarinic acetylcholine M4 receptor splice variant.

    Directory of Open Access Journals (Sweden)

    Douglas A Schober

    Full Text Available Rodent genomic alignment sequences support a 2-exon model for muscarinic M4 receptor. Using this model a novel N-terminal extension was discovered in the human muscarinic acetylcholine M4 receptor. An open reading frame was discovered in the human, mouse and rat with a common ATG (methionine start codon that extended the N-terminus of the muscarinic acetylcholine M4 receptor subtype by 155 amino acids resulting in a longer variant. Transcriptional evidence for this splice variant was confirmed by RNA-Seq and RT-PCR experiments performed from human donor brain prefrontal cortices. We detected a human upstream exon indicating the translation of the mature longer M4 receptor transcript. The predicted size for the longer two-exon M4 receptor splice variant with the additional 155 amino acid N-terminal extension, designated M4L is 69.7 kDa compared to the 53 kDa canonical single exon M4 receptor (M4S. Western blot analysis from a mammalian overexpression system, and saturation radioligand binding with [3H]-NMS (N-methyl-scopolamine demonstrated the expression of this new splice variant. Comparative pharmacological characterization between the M4L and M4S receptors revealed that both the orthosteric and allosteric binding sites for both receptors were very similar despite the addition of an N-terminal extension.

  7. Identification, expression and functional characterization of M4L, a muscarinic acetylcholine M4 receptor splice variant.

    Science.gov (United States)

    Schober, Douglas A; Croy, Carrie H; Ruble, Cara L; Tao, Ran; Felder, Christian C

    2017-01-01

    Rodent genomic alignment sequences support a 2-exon model for muscarinic M4 receptor. Using this model a novel N-terminal extension was discovered in the human muscarinic acetylcholine M4 receptor. An open reading frame was discovered in the human, mouse and rat with a common ATG (methionine start codon) that extended the N-terminus of the muscarinic acetylcholine M4 receptor subtype by 155 amino acids resulting in a longer variant. Transcriptional evidence for this splice variant was confirmed by RNA-Seq and RT-PCR experiments performed from human donor brain prefrontal cortices. We detected a human upstream exon indicating the translation of the mature longer M4 receptor transcript. The predicted size for the longer two-exon M4 receptor splice variant with the additional 155 amino acid N-terminal extension, designated M4L is 69.7 kDa compared to the 53 kDa canonical single exon M4 receptor (M4S). Western blot analysis from a mammalian overexpression system, and saturation radioligand binding with [3H]-NMS (N-methyl-scopolamine) demonstrated the expression of this new splice variant. Comparative pharmacological characterization between the M4L and M4S receptors revealed that both the orthosteric and allosteric binding sites for both receptors were very similar despite the addition of an N-terminal extension.

  8. Altered trafficking and unfolded protein response induction as a result of M3 muscarinic receptor impaired N-glycosylation.

    Science.gov (United States)

    Romero-Fernandez, Wilber; Borroto-Escuela, Dasiel O; Alea, Mileidys Perez; Garcia-Mesa, Yoelvis; Garriga, Pere

    2011-12-01

    The human M(3) muscarinic acetylcholine receptor is present in both the central and peripheral nervous system, and it is involved in the pathophysiology of several neurodegenerative and autoimmune diseases. We suggested a possible N-glycosylation map for the M(3) muscarinic receptor expressed in COS-7 cells. Here, we examined the role that N-linked glycans play in the folding and in the cell surface trafficking of this receptor. The five potential asparagine-linked glycosylation sites in the muscarinic receptor were mutated and transiently expressed in COS-7 cells. The elimination of N-glycan attachment sites did not affect the cellular expression levels of the receptor. However, proper receptor localization to the plasma membrane was affected as suggested by reduced [(3)H]-N-methylscopolamine binding. Confocal microscopy confirmed this observation and showed that the nonglycosylated receptor was primarily localized in the intracellular compartments. The mutant variant showed an increase in phosphorylation of the α-subunit of eukaryote initiation factor 2, and other well-known endoplasmic reticulum stress markers of the unfolded protein response pathway, which further supports the proposal of the improper intracellular accumulation of the nonglycosylated receptor. The receptor devoid of glycans showed more susceptibility to events that culminate in apoptosis reducing cell viability. Our findings suggest up-regulation of pro-apoptotic Bax protein, down-regulation of anti-apoptotic Bcl-2, and cleavage of caspase-3 effectors. Collectively, our data provide experimental evidence of the critical role that N-glycan chains play in determining muscarinic receptor distribution, localization, as well as cell integrity. © The Author 2011. Published by Oxford University Press. All rights reserved.

  9. Muscarinic receptor-mediated inositol tetrakisphosphate response in bovine adrenal chromaffin cells

    International Nuclear Information System (INIS)

    Sanborn, B.B.; Schneider, A.S.

    1990-01-01

    Inositol trisphosphate (IP 3 ), a product of the phosphoinositide cycle, mobilizes intracellular Ca 2+ in many cell types. New evidence suggests that inositol tetrakisphosphate (IP 4 ), an IP 3 derivative, may act as another second messenger to further alter calcium homeostasis. However, the function and mechanism of action of IP 4 are presently unresolved. We now report evidence of muscarinic receptor-mediated accumulation of IP 4 in bovine adrenal chromaffin cells, a classic neurosecretory system in which calcium movements have been well studied. Muscarine stimulated an increase in [ 3 H]IP 4 and [ 3 H]IP 3 accumulation in chromaffin cells and this effect was completely blocked by atropine. [ 3 H]IP 4 accumulation was detectable within 15 sec, increased to a maximum by 30 sec and thereafter declined. 2,3-diphosphoglycerate, an inhibitor of IP 3 and IP 4 hydrolysis, enhanced accumulation of these inositol polyphosphates. The results provide the first evidence of a rapid inositol tetrakisphosphate response in adrenal chromaffin cells, which should facilitate the future resolution of the relationship between IP 4 and calcium homeostasis

  10. Activation of muscarinic receptors protects against retinal neurons damage and optic nerve degeneration in vitro and in vivo models.

    Science.gov (United States)

    Tan, Pan-Pan; Yuan, Hai-Hong; Zhu, Xu; Cui, Yong-Yao; Li, Hui; Feng, Xue-Mei; Qiu, Yu; Chen, Hong-Zhuan; Zhou, Wei

    2014-03-01

    Muscarinic acetylcholine receptor agonist pilocarpine reduces intraocular pressure (IOP) of glaucoma mainly by stimulating ciliary muscle contraction and then increasing aqueous outflow. It is of our great interest to know whether pilocarpine has the additional properties of retinal neuroprotection independent of IOP lowering in vitro and in vivo models. In rat primary retinal cultures, cell viability was measured using an MTT assay and the trypan blue exclusion method, respectively. Retinal ganglion cells (RGCs) were identified by immunofluorescence and quantified by flow cytometry. For the in vivo study, the retinal damage after retinal ischemia/reperfusion injury in rats was evaluated by histopathological study using hematoxylin and eosin staining, transmission electron microscopy, and immunohistochemical study on cleaved caspase-3, caspase-3, and ChAT. Pretreatment of pilocarpine attenuated glutamate-induced neurotoxicity of primary retinal neurons in a dose-dependent manner. Protection of pilocarpine in both retinal neurons and RGCs was largely abolished by the nonselective muscarinic receptor antagonist atropine and the M1-selective muscarinic receptor antagonist pirenzepine. After ischemia/reperfusion injury in retina, the inner retinal degeneration occurred including ganglion cell layer thinning and neuron lost, and the optic nerve underwent vacuolar changes. These degenerative changes were significantly lessened by topical application of 2% pilocarpine. In addition, the protective effect of pilocarpine on the ischemic rat retina was favorably reflected by downregulating the expression of activated apoptosis marker cleaved caspase-3 and caspase-3 and upregulating the expression of cholinergic cell marker ChAT. Taken together, this highlights pilocarpine through the activation of muscarinic receptors appear to afford significant protection against retinal neurons damage and optic nerve degeneration at clinically relevant concentrations. These data also

  11. Identification of four areas each enriched in a unique muscarinic receptor subtype

    International Nuclear Information System (INIS)

    Hoss, W.; Ellerbrock, B.R.; Goldman, P.S.; Collins, D.A.; Messer, W.S. Jr.

    1990-01-01

    The affinities of muscarinic agonists and antagonists were determined by autoradiography and image analysis in selected areas of the rat brain. IC 50 values and Hill coefficients for the inhibition of the binding of 0.2 nM [ 3 H]-QNB to dentate gyrus, superior colliculus, rhomboid thalamus and substantia nigra were measured in coronal sections. Pirenzepine displayed a high affinity for receptors in the dentate gyrus and AF-DX 116, the superior colliculus. Both pirenzepine and AF-DX 116 had high affinities for the substantia nigra and low affinities for the rhomboid thalamus. Gallamine displayed a 50-fold preference for superior colliculus over dentate gyrus receptors. Amitriptyline was less selective, showing a modest preference for substantia nigra receptors and 4-DAMP was essentially nonselective. Carbachol was the most selective agonist with a 4000-fold preference for superior colliculus over dentate gyrus receptors. Other agonists except RS 86 were also selective for superior colliculus receptors in the order carbachol >> arecoline > bethanechol > McN A343 = oxotremorine = pilocarpine

  12. Muscarinic and alpha 1-adrenergic receptor binding characteristics of saw palmetto extract in rat lower urinary tract.

    Science.gov (United States)

    Suzuki, Mayumi; Oki, Tomomi; Sugiyama, Tomomi; Umegaki, Keizo; Uchida, Shinya; Yamada, Shizuo

    2007-06-01

    To elucidate the in vitro and ex vivo effects of saw palmetto extract (SPE) on autonomic receptors in the rat lower urinary tract. The in vitro binding affinities for alpha 1-adrenergic, muscarinic, and purinergic receptors in the rat prostate and bladder were measured by radioligand binding assays. Rats received vehicle or SPE (0.6 to 60 mg/kg/day) orally for 4 weeks, and alpha 1-adrenergic and muscarinic receptor binding in tissues of these rats were measured. Saw palmetto extract inhibited specific binding of [3H]prazosin and [N-methyl-3H]scopolamine methyl chloride (NMS) but not alpha, beta-methylene adenosine triphosphate [2,8-(3)H]tetrasodium salt in the rat prostate and bladder. The binding activity of SPE for muscarinic receptors was four times greater than that for alpha 1-adrenergic receptors. Scatchard analysis revealed that SPE significantly reduced the maximal number of binding sites (Bmax) for each radioligand in the prostate and bladder under in vitro condition. Repeated oral administration of SPE to rats brought about significant alteration in Bmax for prostatic [3H]prazosin binding and for bladder [3H]NMS binding. Such alteration by SPE was selective to the receptors in the lower urinary tract. Saw palmetto extract exerts significant binding activity on autonomic receptors in the lower urinary tract under in vitro and in vivo conditions.

  13. Involvement of a subpopulation of neuronal M4 muscarinic acetylcholine receptors in the antipsychotic-like effects of the M1/M4 preferring muscarinic receptor agonist xanomeline

    DEFF Research Database (Denmark)

    Dencker, Ditte; Wörtwein, Gitta; Weikop, Pia

    2011-01-01

    Disturbances in central dopaminergic neurotransmission are believed to be centrally involved in the pathogenesis of schizophrenia. Central dopaminergic and cholinergic systems interact and the cholinergic muscarinic agonist xanomeline has shown antipsychotic effects in clinical studies. Preclinic...

  14. Differences in muscarinic acetylcholine receptor subtypes in the central nervous system of long sleep and short sleep mice

    International Nuclear Information System (INIS)

    Watson, M.; Ming, X.; McArdle, J.J.

    1989-01-01

    Differences in voluntary ethanol consumption have been noted in various inbred strains of mice and pharmacogenetic approaches have been used to study the mechanisms of action of many drugs such as ethanol. Long-sleep (LS) and short-sleep (SS) mice, selectively bred for differences in ethanol induced narcosis, provide a method by which a relationship between the differential responsiveness of these geno-types and muscarinic acetylcholine receptors (mAChR) may be evaluated. Sleep times after injection of 3ml ethanol/kg (i.p.) verified the higher sensitivity of LS vs. SS. Mean body weights of LS (26.5g) vs. SS (22g) were also significantly (p 3 H](-) quinuclidinylbenzilate ([ 3 H](-)QNB), a specific but nonsubtype selective mAChR antagonist, [ 3 H]pirenzepine ([ 3 H]PZ), a specific M1 mAChR antagonist and [ 3 H]11-2-[[2-[(diethylamino) methyl]-1-piperidinyl] acetyl]-5,11-dihydro-6H-pyrido (2,3-b) (1,4) benzodiazepine-6-one, ([ 3 H]AF-DX 116), an M2 selective antagonist were performed to determine mAChR affinity (K d ) and density (B max ) in CNS regions such as the cerebral cortex, hippocampus, corpus striatum and other areas. Significantly lower (30-40%) [ 3 H](-)QNB binding suggests that SS have fewer mAChR's than LS in many areas. These differences may relate to their differential ethanol sensitivity

  15. The Effects of Nicotinic and Muscarinic Receptor Activation on Patch-Clamped Cells in the Optic Tectum of Rana Pipiens

    OpenAIRE

    Yu, C.-J.; Debski, E. A.

    2003-01-01

    Both nicotinic and muscarinic cholinergic receptors are present in the optic tectum. To begin to understand how the activation of these receptors affects visual activity patterns, we have determined the types of physiological responses induced by their activation. Using tectal brain slices from the leopard frog, we found that application of nicotine (100 μM) evoked long-lasting responses in 60% of patch-clamped tectal cells. Thirty percent of these responses consisted of an increase in sponta...

  16. Differential expression of muscarinic acetylcholine receptor subtypes in Jurkat cells and their signaling.

    Science.gov (United States)

    Alea, Mileidys Perez; Borroto-Escuela, Dasiel O; Romero-Fernandez, Wilber; Fuxe, Kjell; Garriga, Pere

    2011-08-15

    Muscarinic acetylcholine receptors expression and signaling in the human Jurkat T cell line were investigated. Semiquantitative real-time PCR and radioligand binding studies, using a wide set of antagonist compounds, showed the co-existence of M(3), M(4), and M(5) subtypes. Stimulation of these subpopulations caused a concentration and time- dependent activation of second messengers and ERK signaling pathways, with a major contribution of the M(3) subtype in a G(q/11)-mediated response. In addition, we found that T-cell stimulation leads to increased expression of M(3) and M(5) both at transcriptional and protein levels in a PLC/PKCθ dependent manner. Our data clarifies the functional role of AChR subtypes in Jurkat cells and pave the way to future studies on the potential cross-talk among these subpopulations and their regulation of T lymphocytes immune function. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Changes in acetylcholine content, release and muscarinic receptors in rat hippocampus under cold stress

    International Nuclear Information System (INIS)

    Fatranska, M.; Budai, D.; Gulya, K; Kvetnansky, R.

    1989-01-01

    The aim was to study the mechanism of the previously established decrease in acetylcholine (ACh) concentration in the rat hippocampus under cold stress. Male rats were exposed for 14 days to cold (5 degree C) or kept (controls) at room temperature (24 degree C). Acetylcholine content, release and muscarinic receptor binding were investigated in the hippocampus. Cold exposure resulted in a decrease of ACh concentration in the dorsal hippocampus. Moreover, the potassium-evoked release of ACh from hippocampal slices was increased and an increase of maximal binding capacity of [ 3 H](-) quinuclidinyl benzilate in the dorsal hippocampus of cold exposed animals was also observed. Thus the decrease of hippocampal ACh concentration under cold exposure is probably due to its increased release. On balance then, our results demonstrate that cold stress in the rat induces significant activation of the hippocampal cholinergic system

  18. Vitamin C deficiency reduces muscarinic receptor coronary artery vasoconstriction and plasma tetrahydrobiopterin concentration in guinea pigs

    DEFF Research Database (Denmark)

    Skovsted, Gry Freja; Tveden-Nyborg, Pernille; Lindblad, Maiken Marie

    2017-01-01

    Vitamin C (vitC) deficiency is associated with increased cardiovascular disease risk, but its specific interplay with arteriolar function is unclear. This study investigates the effect of vitC deficiency in guinea pigs on plasma biopterin status and the vasomotor responses in coronary arteries...... exposed to vasoconstrictor/-dilator agents. Dunkin Hartley female guinea pigs (n = 32) were randomized to high (1500 mg/kg diet) or low (0 to 50 mg/kg diet) vitC for 10-12 weeks. At euthanasia, coronary artery segments were dissected and mounted in a wire-myograph. Vasomotor responses to potassium......-1 were unaffected by vitC status. The study shows that vitC deficiency decreases tetrahydrobiopterin concentrations and muscarinic receptor mediated contraction in coronary arteries. This attenuated vasoconstrictor response may be linked to altered production of vasoactive arachidonic acid...

  19. Functional Characterization of CCHamide and Muscarinic Acetylcholine Receptor Signalling in Drosophila melanogaster

    DEFF Research Database (Denmark)

    Ren, Guilin Robin

    G-protein coupled receptors (GPCRs) constitute a large and ancient superfamily of membraneproteins responsible for the transduction of extracellular signals to the inside of the cells. In thisPh.D. thesis, Drosophila melanogaster (Dm) was used as a model organism to investigate a numberof topics...... is a newly discovered insect peptide hormone. The function of this novel peptide hasnot been well characterised. In this Ph.D. thesis, I identified CCHamide-2 peptides in endocrinecells of the gut and neurones of the brain of larvae and endocrine cells of the gut of adultDrosophila. Behavioural assays...... little is known about muscarinic acetylcholine receptorsignalling in insects. In this study, I found that two types of mAChRs occur in D. melanogaster, onecoupling to Gq (A-type) and the other to Gi (B-type). Both A- and B-type Dm-mAChRs can beactivated by acetylcholine (ACh), but the classical...

  20. Noninvasive quantification of muscarinic receptors in vivo with positron emission tomography in the dog heart

    International Nuclear Information System (INIS)

    Delforge, J.; Janier, M.; Syrota, A.; Crouzel, C.; Vallois, J.M.; Cayla, J.; Lancon, J.P.; Mazoyer, B.M.

    1990-01-01

    The in vivo quantification of myocardial muscarinic receptors has been obtained in six closed-chest dogs by using positron emission tomography. The dogs were injected with a trace amount of 11C-labeled methylquinuclidinyl benzilate (MQNB), a nonmetabolized antagonist of the muscarinic receptor. This was followed 30 minutes later by an injection of an excess of unlabeled MQNB (displacement experiment). Two additional injections of unlabeled MQNB with [11C]MQNB and without [11C]MQNB (second displacement experiment) were administered after 70 and 120 minutes, respectively. This protocol allowed a separate evaluation of the quantity of available receptors (B'max) as well as the association and dissociation rate constants (k+1 and k-1) in each dog. The parameters were calculated by using a nonlinear mathematical model in regions of interest over the left ventricle and the interventricular septum. The average value of B'max was 42 +/- 11 pmol/ml tissue, the rate constants k+1, k-1, and Kd were 0.6 +/- 0.1 ml.pmol-1.min-1, 0.27 +/- 0.03 ml.pmol-1.min-1, and 0.49 +/- 0.14 pmol.ml-1, respectively, taking into account the MQNB reaction volume estimated to 0.15 ml/ml tissue. Although [11C]MQNB binding would appear irreversible, our findings indicate that the association of the antagonist is very rapid and that the dissociation is far from negligible. The dissociated ligand, however, has a high probability of rebinding to a free receptor site instead of escaping into the microcirculation. We deduce that the positron emission tomographic images obtained after injecting a trace amount of [11C]MQNB are more representative of blood flow than of receptor density or affinity. We also suggest a simplified protocol consisting of a tracer injection of [11C]MQNB and a second injection of an excess of cold MQNB, which is sufficient to measure B'max and Kd in humans

  1. Blocking muscarinic receptors in the olfactory bulb impairs performance on an olfactory short-term memory task.

    Science.gov (United States)

    Devore, Sasha; Manella, Laura C; Linster, Christiane

    2012-01-01

    Cholinergic inputs to cortical processing networks have long been associated with attentional and top-down processing. Experimental and theoretical studies suggest that cholinergic inputs to the main olfactory bulb (OB) can modulate both neural and behavioral odor discrimination. Previous experiments from our laboratory and others demonstrate that blockade of nicotinic receptors directly impairs olfactory discrimination, whereas blockade of muscarinic receptors only measurably impairs olfactory perception when task demands are made more challenging, such as when very low-concentration odors are used or rats are required to maintain sensory memory over long durations. To further investigate the role of muscarinic signaling in the OB, we developed an olfactory delayed match-to-sample task using a digging-based behavioral paradigm. We find that rats are able to maintain robust short-term odor memory for 10-100 s. To investigate the role of muscarinic signaling in task performance, we bilaterally infused scopolamine into the OB. We find that high dosages of scopolamine (38 mM) impair performance on the task across all delays tested, including the baseline condition with no delay, whereas lower dosages (7.6 mM and 22.8 mM) had no measureable effects. These results indicate that general execution of the match-to-sample task, even with no delay, is at least partially dependent on muscarinic signaling in the OB.

  2. Molecular Modeling of the M3 Acetylcholine Muscarinic Receptor and Its Binding Site

    Directory of Open Access Journals (Sweden)

    Marlet Martinez-Archundia

    2012-01-01

    Full Text Available The present study reports the results of a combined computational and site mutagenesis study designed to provide new insights into the orthosteric binding site of the human M3 muscarinic acetylcholine receptor. For this purpose a three-dimensional structure of the receptor at atomic resolution was built by homology modeling, using the crystallographic structure of bovine rhodopsin as a template. Then, the antagonist N-methylscopolamine was docked in the model and subsequently embedded in a lipid bilayer for its refinement using molecular dynamics simulations. Two different lipid bilayer compositions were studied: one component palmitoyl-oleyl phosphatidylcholine (POPC and two-component palmitoyl-oleyl phosphatidylcholine/palmitoyl-oleyl phosphatidylserine (POPC-POPS. Analysis of the results suggested that residues F222 and T235 may contribute to the ligand-receptor recognition. Accordingly, alanine mutants at positions 222 and 235 were constructed, expressed, and their binding properties determined. The results confirmed the role of these residues in modulating the binding affinity of the ligand.

  3. Determinants of positive cooperativity between strychnine-like allosteric modulators and N-methylscopolamine at muscarinic receptors

    Czech Academy of Sciences Publication Activity Database

    Jakubík, Jan; Doležal, Vladimír

    2006-01-01

    Roč. 30, č. 1-2 (2006), s. 111-112 ISSN 0895-8696 R&D Projects: GA ČR(CZ) GA305/05/0452; GA MŠk(CZ) LC554 Institutional research plan: CEZ:AV0Z50110509 Keywords : muscarinic receptors * strychnine -like allosteric modulators * cooperativity Subject RIV: ED - Physiology Impact factor: 2.965, year: 2006

  4. Hydrostatic pressure and muscarinic receptors are involved in the release of inflammatory cytokines in human bladder smooth muscle cells.

    Science.gov (United States)

    Liang, Zhou; Xin, Wei; Qiang, Liu; Xiang, Cai; Bang-Hua, Liao; Jin, Yang; De-Yi, Luo; Hong, Li; Kun-Jie, Wang

    2017-06-01

    Abnormal intravesical pressure results in a series of pathological changes. We investigated the effects of hydrostatic pressure and muscarinic receptors on the release of inflammatory cytokines in rat and human bladder smooth muscle cells (HBSMCs). Animal model of bladder outlet obstruction was induced by urethra ligation. HBSMCs were subjected to elevated hydrostatic pressure and/or acetylcholine (Ach). Macrophage infiltration in the bladder wall was determined by immunohistochemical staining. The expression of inflammatory genes was measured by RT-PCR, ELISA and immunofluorescence. In obstructed bladder, inflammatory genes and macrophage infiltration were remarkably induced. When HBSMCs were subjected to 200-300 cm H 2 O pressure for 2-24 h in vitro, the expressions of IL-6 and RANTES were significantly increased. Hydrostatic pressure promoted the protein levels of phospho-NFκB p65 and phospho-ERK1/2 as well as muscarinic receptors. Moreover, NFκB or ERK1/2 inhibitors suppressed pressure-induced inflammatory genes mRNA. When cells were treated with 1 μM acetylcholine for 6 h, a significant increase in IL-6 mRNA expression was detected. Acetylcholine also enhanced pressure-induced phospho-NFκB p65 and IL-6 protein expression. Additionally, pressure-induced IL-6 was partially suppressed by muscarinic receptors antagonists. Hydrostatic pressure and muscarinic receptors were involved in the secretion of inflammatory cytokines in HBSMCs, indicating a pro-inflammatory effect of the two factors in the pathological process of BOO. © 2016 Wiley Periodicals, Inc.

  5. Muscarinic cholinergic and alpha 2-adrenergic receptors in the epithelium and muscularis of the human ileum

    International Nuclear Information System (INIS)

    Lepor, H.; Rigaud, G.; Shapiro, E.; Baumann, M.; Kodner, I.J.; Fleshman, J.W.

    1990-01-01

    The aim of this study was to characterize the binding and functional properties of muscarinic cholinergic (MCh) and alpha 2-adrenergic receptors in the human ileum to provide insight into pharmacologic strategies for managing urinary and fecal incontinence after bladder and rectal replacement with intestinal segments. MCh and alpha 2-adrenergic binding sites were characterized in the epithelium and muscularis of eight human ileal segments with 3H-N-methylscopolamine and 3H-rauwolscine, respectively. The dissociation constant for 3H-N-methylscopolamine in the epithelium and muscularis was 0.32 +/- 0.07 nmol/L and 0.45 +/- 0.10 nmol/L, respectively (p = 0.32). The MCh receptor content was approximately eightfold greater in the muscularis compared with the epithelium (p = 0.008). The dissociation constant for 3H-rauwolscine in the muscularis and epithelium was 2.55 +/- 0.42 nmol/L and 2.03 +/- 0.19 nmol/L, respectively (p = 0.29). The alpha 2-adrenoceptor density was twofold greater in the epithelium compared with the muscularis (p = 0.05). Noncumulative concentration-response experiments were performed with carbachol, an MCh agonist, and UK-14304, a selective alpha 2-adrenergic agonist. The epithelium did not contract in the presence of high concentrations of carbachol and UK-14304. The muscularis preparations were responsive only to carbachol. The muscularis contains primarily MCh receptors mediating smooth muscle contraction. The alpha 2-adrenoceptors are localized primarily to the epithelium and may regulate water secretion in the intestine. The distribution and functional properties of ileal MCh and alpha 2-adrenergic receptors provide a theoretic basis for the treatment of incontinence after bladder and rectal replacement with intestinal segments

  6. The effects of nicotinic and muscarinic receptor activation on patch-clamped cells in the optic tectum of Rana pipiens.

    Science.gov (United States)

    Yu, C-J; Debski, E A

    2003-01-01

    Both nicotinic and muscarinic cholinergic receptors are present in the optic tectum. To begin to understand how the activation of these receptors affects visual activity patterns, we have determined the types of physiological responses induced by their activation. Using tectal brain slices from the leopard frog, we found that application of nicotine (100 microM) evoked long-lasting responses in 60% of patch-clamped tectal cells. Thirty percent of these responses consisted of an increase in spontaneous postsynaptic currents (sPSCs) and had both a glutamatergic and GABAergic component as determined by the use of 6-cyano-7-nitroquinoxaline-2,3-dione (50 microM) and bicuculline (25 microM), respectively. Remaining response types consisted of an inward membrane current (16%) and an increase in sPSCs combined with an inward membrane current (14%). All responses could be elicited in the presence of tetrodotoxin (0.5 microM). Muscarinic receptor-mediated responses, induced by carbachol (100 microM) application after nicotinic receptor desensitization, produced responses in 70% of tectal cells. In contrast to responses elicited by nicotine, carbachol-induced responses could be evoked multiple times without significant decrement. Responses consisted of either an outward current (57%), a decrease in sPSCs (5%) or an increase in sPSCs, with (almost 6%) or without (almost 3%) an outward current. The response elicited by carbachol was not predicted by the response of the cell to nicotine. Our results suggest that nicotinic receptors are found predominantly at presynaptic locations in the optic tectum while muscarinic receptors are most often present at postsynaptic sites. We conclude that both of these receptor types could substantially modulate visual activity by changing either the input to tectal neurons or the level of their response to that input.

  7. Acute food deprivation reverses morphine-induced locomotion deficits in M5 muscarinic receptor knockout mice.

    Science.gov (United States)

    Steidl, Stephan; Lee, Esther; Wasserman, David; Yeomans, John S

    2013-09-01

    Lesions of the pedunculopontine tegmental nucleus (PPT), one of two sources of cholinergic input to the ventral tegmental area (VTA), block conditioned place preference (CPP) for morphine in drug-naïve rats. M5 muscarinic cholinergic receptors, expressed by midbrain dopamine neurons, are critical for the ability of morphine to increase nucleus accumbens dopamine levels and locomotion, and for morphine CPP. This suggests that M5-mediated PPT cholinergic inputs to VTA dopamine neurons critically contribute to morphine-induced dopamine activation, reward and locomotion. In the current study we tested whether food deprivation, which reduces PPT contribution to morphine CPP in rats, could also reduce M5 contributions to morphine-induced locomotion in mice. Acute 18-h food deprivation reversed the phenotypic differences usually seen between non-deprived wild-type and M5 knockout mice. That is, food deprivation increased morphine-induced locomotion in M5 knockout mice but reduced morphine-induced locomotion in wild-type mice. Food deprivation increased saline-induced locomotion equally in wild-type and M5 knockout mice. Based on these findings, we suggest that food deprivation reduces the contribution of M5-mediated PPT cholinergic inputs to the VTA in morphine-induced locomotion and increases the contribution of a PPT-independent pathway. The contributions of cholinergic, dopaminergic and GABAergic neurons to the effects of acute food deprivation are discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Topographical distribution of decrements and recovery in muscarinic receptors from rat brains repeatedly exposed to sublethal doses of soman

    International Nuclear Information System (INIS)

    Churchill, L.; Pazdernik, T.L.; Jackson, J.L.; Nelson, S.R.; Samson, F.E.; McDonough, J.H. Jr.

    1984-01-01

    [3H]Quinuclidinyl benzilate binding to rat brain muscarinic receptors decreased after repeated exposure to soman, a potent organophosphorus cholinesterase inhibitor. The topographical distribution of this decrement was analyzed by quantitative receptor autoradiography. After 4 weeks of soman, three times a week, quinuclidinyl benzilate binding decreased to 67 to 80% of control in frontal and parietal cortex, caudate-putamen, lateral septum, hippocampal body, dentate gyrus, superior colliculus, nucleus of the fifth nerve, and central grey. Minor or no decreases were observed in thalamic or hypothalamic nuclei, reticular formation, pontine nuclei, inferior colliculus, nucleus of the seventh nerve, and cerebellum. Scatchard analyses of saturation curves using frontal cortex sections from soman-treated rats revealed a decrease in maximal quinuclidinyl benzilate binding from that in control rats and a return toward control levels by 24 days without any significant change in affinity. These brain areas showing significant decrements in muscarinic receptors recovered with a similar time course. An estimate of the time for 50% recovery for some of the brain areas was 14 days for superior colliculus, 16 days for cortex, and 19 days for hippocampal body. The application of quantitative receptor autoradiography to analyze receptor alterations has been valuable in localizing the telencephalon as a region more susceptible to change in receptor concentration

  9. Topographical distribution of decrements and recovery in muscarinic receptors from rat brains repeatedly exposed to sublethal doses of soman

    Energy Technology Data Exchange (ETDEWEB)

    Churchill, L.; Pazdernik, T.L.; Jackson, J.L.; Nelson, S.R.; Samson, F.E.; McDonough, J.H. Jr.

    1984-08-01

    (3H)Quinuclidinyl benzilate binding to rat brain muscarinic receptors decreased after repeated exposure to soman, a potent organophosphorus cholinesterase inhibitor. The topographical distribution of this decrement was analyzed by quantitative receptor autoradiography. After 4 weeks of soman, three times a week, quinuclidinyl benzilate binding decreased to 67 to 80% of control in frontal and parietal cortex, caudate-putamen, lateral septum, hippocampal body, dentate gyrus, superior colliculus, nucleus of the fifth nerve, and central grey. Minor or no decreases were observed in thalamic or hypothalamic nuclei, reticular formation, pontine nuclei, inferior colliculus, nucleus of the seventh nerve, and cerebellum. Scatchard analyses of saturation curves using frontal cortex sections from soman-treated rats revealed a decrease in maximal quinuclidinyl benzilate binding from that in control rats and a return toward control levels by 24 days without any significant change in affinity. These brain areas showing significant decrements in muscarinic receptors recovered with a similar time course. An estimate of the time for 50% recovery for some of the brain areas was 14 days for superior colliculus, 16 days for cortex, and 19 days for hippocampal body. The application of quantitative receptor autoradiography to analyze receptor alterations has been valuable in localizing the telencephalon as a region more susceptible to change in receptor concentration.

  10. Z-(-,-)-[76Br]BrQNP: a high affinity PET radiotracer for central and cardiac muscarinic receptors

    International Nuclear Information System (INIS)

    Strijckmans, V.; Coulon, C.; Loc'h, C.; Maziere, B.; Luo, H.; McPherson, D.W.; Knapp, F.F.

    1996-01-01

    Racemic E-1-azabicyclo[2.2.2]oct-3-yl α-(1-bromo-1-1-propen-3-yl)-α -hydroxy-α-phenylacetate (BrQNP) was prepared and evaluated in vivo as a potential candidate for imaging muscarinic acetylcholinergic receptors by Positron Emission Tomography. Initial in vivo blocking studies utilizing Z-(-,-)-[ 125 I]IQNP as a radiolabelled muscarinic probe demonstrated that a preinjection of cold E-BrQNP effectively blocks the uptake of the radiolabelled probe in the brain and heart, by 71% and 86% respectively. Z-(-,-)-[ 76 Br]BrQNP was prepared by electrophilic substitution from a tributylstannyl precursor. Peracetic acid and chloramine T was evaluated as oxidizing agents. After purification by SPE and RP-HPLC, radiolabelling yields of 85% and 95% were obtained with peracetic acid and chloramine T, respectively. The final radiochemical yield was 70% for both oxidizing agents. (author)

  11. The muscarinic M1/M4 receptor agonist xanomeline exhibits antipsychotic-like activity in Cebus apella monkeys

    DEFF Research Database (Denmark)

    Andersen, Maibritt B; Fink-Jensen, Anders; Peacock, Linda

    2003-01-01

    (EPS) at therapeutically relevant doses. In the present study, we examined whether the xanomeline-induced functional dopamine antagonism found in rodent studies could also be observed in nonhuman primates. In addition, we studied whether the lack of EPS observed in rodents also applies to primates......Xanomeline is a muscarinic M(1)/M(4) preferring receptor agonist with little or no affinity for dopamine receptors. The compound reduces psychotic-like symptoms in patients with Alzheimer's disease and exhibits an antipsychotic-like profile in rodents without inducing extrapyramidal side effects...

  12. Biological sex influences learning strategy preference and muscarinic receptor binding in specific brain regions of prepubertal rats.

    Science.gov (United States)

    Grissom, Elin M; Hawley, Wayne R; Hodges, Kelly S; Fawcett-Patel, Jessica M; Dohanich, Gary P

    2013-04-01

    According to the theory of multiple memory systems, specific brain regions interact to determine how the locations of goals are learned when rodents navigate a spatial environment. A number of factors influence the type of strategy used by rodents to remember the location of a given goal in space, including the biological sex of the learner. We recently found that prior to puberty male rats preferred a striatum-dependent stimulus-response strategy over a hippocampus-dependent place strategy when solving a dual-solution task, while age-matched females showed no strategy preference. Because the cholinergic system has been implicated in learning strategy and is known to be sexually dimorphic prior to puberty, we explored the relationship between learning strategy and muscarinic receptor binding in specific brain regions of prepubertal males and female rats. We confirmed our previous finding that at 28 days of age a significantly higher proportion of prepubertal males preferred a stimulus-response learning strategy than a place strategy to solve a dual-solution visible platform water maze task. Equal proportions of prepubertal females preferred stimulus-response or place strategies. Profiles of muscarinic receptor binding as assessed by autoradiography varied according to strategy preference. Regardless of biological sex, prepubertal rats that preferred stimulus-response strategy exhibited lower ratios of muscarinic receptor binding in the hippocampus relative to the dorsolateral striatum compared to rats that preferred place strategy. Importantly, much of the variance in this ratio was related to differences in the ventral hippocampus to a greater extent than the dorsal hippocampus. The ratios of muscarinic receptors in the hippocampus relative to the basolateral amygdala also were lower in rats that preferred stimulus-response strategy over place strategy. Results confirm that learning strategy preference varies with biological sex in prepubertal rats with males

  13. Autoantibodies against Muscarinic Type 3 Receptor in Sjögren's Syndrome Inhibit Aquaporin 5 Trafficking

    Science.gov (United States)

    Lee, Byung Ha; Gauna, Adrienne E.; Perez, Geidys; Park, Yun-jong; Pauley, Kaleb M.; Kawai, Toshihisa; Cha, Seunghee

    2013-01-01

    Sjögren's syndrome (SjS) is a chronic autoimmune disease that mainly targets the salivary and lacrimal glands. It has been controversial whether anti-muscarinic type 3 receptor (α-M3R) autoantibodies in patients with SjS inhibit intracellular trafficking of aquaporin-5 (AQP5), water transport protein, leading to secretory dysfunction. To address this issue, GFP-tagged human AQP5 was overexpressed in human salivary gland cells (HSG-hAQP5) and monitored AQP5 trafficking to the plasma membrane following carbachol (CCh, M3R agonist) stimulation. AQP5 trafficking was indeed mediated by M3R stimulation, shown in partial blockage of trafficking by M3R-antagonist 4-DAMP. HSG-hAQP5 pre-incubated with SjS plasma for 24 hours significantly reduced AQP5 trafficking with CCh, compared with HSG-hAQP5 pre-incubated with healthy control (HC) plasma. This inhibition was confirmed by monoclonal α-M3R antibody and pre-absorbed plasma. Interestingly, HSG-hAQP5 pre-incubated with SjS plasma showed no change in cell volume, compared to the cells incubated with HC plasma showing shrinkage by twenty percent after CCh-stimulation. Our findings clearly indicate that binding of anti-M3R autoantibodies to the receptor, which was verified by immunoprecipitation, suppresses AQP5 trafficking to the membrane and contribute to impaired fluid secretion in SjS. Our current study urges further investigations of clinical associations between SjS symptoms, such as degree of secretory dysfunction, cognitive impairment, and/or bladder irritation, and different profiles (titers, isotypes, and/or specificity) of anti-M3R autoantibodies in individuals with SjS. PMID:23382834

  14. Exposure to Gulf War Illness chemicals induces functional muscarinic receptor maladaptations in muscle nociceptors.

    Science.gov (United States)

    Cooper, B Y; Johnson, R D; Nutter, T J

    2016-05-01

    Chronic pain is a component of the multisymptom disease known as Gulf War Illness (GWI). There is evidence that pain symptoms could have been a consequence of prolonged and/or excessive exposure to anticholinesterases and other GW chemicals. We previously reported that rats exposed, for 8 weeks, to a mixture of anticholinesterases (pyridostigmine bromide, chlorpyrifos) and a Nav (voltage activated Na(+) channel) deactivation-inhibiting pyrethroid, permethrin, exhibited a behavior pattern that was consistent with a delayed myalgia. This myalgia-like behavior was accompanied by persistent changes to Kv (voltage activated K(+)) channel physiology in muscle nociceptors (Kv7, KDR). In the present study, we examined how exposure to the above agents altered the reactivity of Kv channels to a muscarinic receptor (mAChR) agonist (oxotremorine-M). Comparisons between muscle nociceptors harvested from vehicle and GW chemical-exposed rats revealed that mAChR suppression of Kv7 activity was enhanced in exposed rats. Yet in these same muscle nociceptors, a Stromatoxin-insensitive component of the KDR (voltage activated delayed rectifier K(+) channel) exhibited decreased sensitivity to activation of mAChR. We have previously shown that a unique mAChR-induced depolarization and burst discharge (MDBD) was exaggerated in muscle nociceptors of rats exposed to GW chemicals. We now provide evidence that both muscle and vascular nociceptors of naïve rats exhibit MDBD. Examination of the molecular basis of the MDBD in naïve animals revealed that while the mAChR depolarization was independent of Kv7, the action potential burst was modulated by Kv7 status. mAChR depolarizations were shown to be dependent, in part, on TRPA1. We argue that dysfunction of the MDBD could be a functional convergence point for maladapted ion channels and receptors consequent to exposure to GW chemicals. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Blockade of muscarinic receptors impairs the retrieval of well-trained memory

    Directory of Open Access Journals (Sweden)

    Shogo eSoma

    2014-04-01

    Full Text Available Acetylcholine (ACh is known to play an important role in memory functions, and its deficit has been proposed to cause the cognitive decline associated with advanced age and Alzheimer’s disease (the cholinergic hypothesis. Although many studies have tested the cholinergic hypothesis for recently acquired memory, only a few have investigated the role of ACh in the retrieval process of well-trained cognitive memory, which describes the memory established from repetition and daily routine. To examine this point, we trained rats to perform a two-alternative forced-choice visual detection task. Each trial was started by having the rats pull upward a central-lever, which triggered the presentation of a visual stimulus to the right or left side of the display monitor, and then pulling upward a stimulus-relevant choice-lever located on both sides. Rats learned the task within 10 days, and the task training was continued for a month. Task performance was measured with or without systemic administration of a muscarinic ACh receptor (mAChR antagonist, scopolamine (SCOP, prior to the test. After 30 min of SCOP administration, rats stopped manipulating any lever even though they explored the lever and surrounding environment, suggesting a loss of the task-related associative memory. Three hours later, rats were recovered to complete the trial, but the rats selected the levers irrespective of the visual stimulus, suggesting they remembered a series of lever-manipulations in association with a reward, but not association between the reward and visual stimulation. Furthermore, an m1-AChR, but not nicotinic AChR antagonist caused a similar deficit in the task execution. SCOP neither interfered with locomotor activity nor drinking behavior, while it influenced anxiety. These results suggest that the activation of mAChRs at basal ACh levels is essential for the recall of well-trained cognitive memory.

  16. Characterization of cholinergic muscarinic receptor-stimulated phosphoinositide metabolism in brain from immature rats

    International Nuclear Information System (INIS)

    Balduini, W.; Murphy, S.D.; Costa, L.G.

    1990-01-01

    Hydrolysis of phosphoinositides elicited by stimulation of cholinergic muscarinic receptors has been studied in brain from neonatal (7-day-old) rats in order to determine: (1) whether the neonatal rat could provide a good model system to study this signal-transduction pathway; and (2) whether potential differences with adult nerve tissue would explain the differential, age-related effects of cholinergic agonists. Accumulation of [3H] inositol phosphates in [3H]inositol prelabeled slices from neonatal and adult rats was measured as an index of phosphoinositide metabolism. Full (acetylcholine, methacholine, carbachol) and partial (oxotremorine, bethanechol) agonists had qualitatively similar, albeit quantitatively different, effects in neonatal and adult rats. Atropine and pirenzepine effectively blocked the carbachol-induced response with inhibition constants of 1.2 and 20.7 nM, respectively. In all brain areas, response to all agonists was higher in neonatal than adult rats, and in hippocampus and cerebral cortex the response was higher than in cerebellum or brainstem. The relative intrinsic activity of partial agonists was higher in the latter two areas (0.6-0.7) than in the former two (0.3-0.4). Carbachol-stimulated phosphoinositide metabolism in brain areas correlated well with the binding of [3H]QNB (r2 = 0.627) and, particularly, with [3H]pirenzepine (r2 = 0.911). In cerebral cortex the effect of carbachol was additive to that of norepinephrine and glutamate. The presence of calcium (250-500 microM) was necessary for maximal response to carbachol to be elicited; the EC50 value for Ca2+ was 65.4 microM. Addition of EDTA completely abolished the response. Removal of sodium ions from the incubation medium reduced the response to carbachol by 50%

  17. Muscarinic receptor binding increases in anterior thalamus and cingulate cortex during discriminative avoidance learning

    International Nuclear Information System (INIS)

    Vogt, B.A.; Gabriel, M.; Vogt, L.J.; Poremba, A.; Jensen, E.L.; Kubota, Y.; Kang, E.

    1991-01-01

    Training-induced neuronal activity develops in the mammalian limbic system during discriminative avoidance conditioning. This study explores behaviorally relevant changes in muscarinic ACh receptor binding in 52 rabbits that were trained to one of five stages of conditioned response acquisition. Sixteen naive and 10 animals yoked to criterion performance served as control cases. Upon reaching a particular stage of training, the brains were removed and autoradiographically assayed for 3H-oxotremorine-M binding with 50 nM pirenzepine (OxO-M/PZ) or for 3H-pirenzepine binding in nine limbic thalamic nuclei and cingulate cortex. Specific OxO-M/PZ binding increased in the parvocellular division of the anterodorsal nucleus early in training when the animals were first exposed to pairing of the conditional and unconditional stimuli. Elevated binding in this nucleus was maintained throughout subsequent training. In the parvocellular division of the anteroventral nucleus (AVp), OxO-M/PZ binding progressively increased throughout training, reached a peak at the criterion stage of performance, and returned to control values during extinction sessions. Peak OxO-M/PZ binding in AVp was significantly elevated over that for cases yoked to criterion performance. In the magnocellular division of the anteroventral nucleus (AVm), OxO-M/PZ binding was elevated only during criterion performance of the task, and it was unaltered in any other limbic thalamic nuclei. Specific OxO-M/PZ binding was also elevated in most layers in rostral area 29c when subjects first performed a significant behavioral discrimination. Training-induced alterations in OxO-M/PZ binding in AVp and layer Ia of area 29c were similar and highly correlated

  18. Acetylcholine muscarinic receptors and response to anti-cholinesterase therapy in patients with Alzheimer's disease

    International Nuclear Information System (INIS)

    Brown, Derek; Chisholm, Jennifer A.; Patterson, Jim; Wyper, David; Owens, Jonathan; Pimlott, Sally

    2003-01-01

    An acetylcholine deficit remains the most consistent neurotransmitter abnormality found in Alzheimer's disease and various therapeutic agents have been targeted at this. In this study we investigated the action of Donepezil, a cholinesterase inhibitor that has few side-effects. In particular we set out to investigate whether muscarinic acetylcholine receptor (mAChR) availability influences the response to this therapy. We used the novel single-photon emission tomography (SPET) tracer (R,R)[ 123 I]I-quinuclidinyl benzilate (R,R[ 123 I]I-QNB), which has high affinity for the M1 subtype of mAChR. Regional cerebral perfusion was also assessed using technetium-99m hexamethylpropylene amine oxime. We investigated 20 patients on Donepezil treatment and ten age-matched controls. The results showed a reduction in (R,R)[ 123 I]I-QNB binding in the caudal anterior cingulate in patients compared with controls and relatively high binding in the putamen and rostral anterior cingulate, suggesting a relative sparing of mAChR in these regions. The main finding of the study was that mAChR availability as assessed by (R,R)[ 123 I]I-QNB binding did not distinguish responders from non-responders. Interestingly, we found that the extent of cognitive improvement showed no positive correlation with (R,R)[ 123 I]I-QNB binding in any brain region but was inversely related to binding in the insular cortex. This suggests that, within the advised cognitive performance band for use of Donepezil, response is greater in those patients with evidence of a more marked cholinergic deficit. A larger study should investigate this. (orig.)

  19. Mercury Vapour Long-Lasting Exposure: Lymphocyte Muscarinic Receptors as Neurochemical Markers of Accidental Intoxication

    Directory of Open Access Journals (Sweden)

    E. Roda

    2016-01-01

    Full Text Available Introduction. Chronic poisoning may result in home setting after mercury (Hg vapours inhalation from damaged devices. We report a chronic, nonoccupational Hg poisoning due to 10-year indoor exposure to mercury spillage. Case Report. A 72-year-old man with polyneuropathy of suspected toxic origin. At hospitalization, toxicological clinical evaluations confirmed the altered neurological picture documented across the last decade. Periodic blood and urine Hg levels (BHg, UHg monitoring were performed from admission (t0, until 1 year later (t2, paralleled by blood neurochemical markers assessment, that is, lymphocytes muscarinic receptors (l-MRs. At t0: BHg and UHg were 27 and 1.4 microg/L, respectively (normal values: BHg 1–4.5; UHg 0.1–4.5, associated with l-MRs increase, 185.82 femtomoL/million lymphocytes (normal range: 8.0–16.0. At t1 (two days after DMSA-mobilization test, BHg weak reduction, paralleled by UHg 3.7-fold increase, was measured together with further l-MRs enhancement (205.43 femtomoL/million lymphocytes. At t2 (eight months after two cycles of DMSA chelating therapy ending, gradual improving of clinical manifestations was accompanied by progressive decrease of BHg and UHg (4.0 and 2.8 microg/L, resp. and peripheral l-MRs neurochemical marker (24.89 femtomoL/million lymphocytes. Conclusion. l-MRs modulatory effect supports their use as peripheral neurochemical marker in Hg poisoning diagnosis and chelation therapy monitoring.

  20. Selective expression of muscarinic acetylcholine receptor subtype M3 by mouse type III taste bud cells.

    Science.gov (United States)

    Mori, Yusuke; Eguchi, Kohgaku; Yoshii, Kiyonori; Ohtubo, Yoshitaka

    2016-11-01

    Each taste bud cell (TBC) type responds to a different taste. Previously, we showed that an unidentified cell type(s) functionally expresses a muscarinic acetylcholine (ACh) receptor subtype, M3, and we suggested the ACh-dependent modification of its taste responsiveness. In this study, we found that M3 is expressed by type III TBCs, which is the only cell type that possesses synaptic contacts with taste nerve fibers in taste buds. The application of ACh to the basolateral membrane of mouse fungiform TBCs in situ increased the intracellular Ca 2+ concentration in 2.4 ± 1.4 cells per taste bud (mean ± SD, n = 14). After Ca 2+ imaging, we supravitally labeled type II cells (phospholipase C β2 [PLCβ2]-immunoreactive cells) with Lucifer yellow CH (LY), a fluorescent dye and investigated the positional relationship between ACh-responding cells and LY-labeled cells. After fixation, the TBCs were immunohistostained to investigate the positional relationships between immunohistochemically classified cells and LY-labeled cells. The overlay of the two positional relationships obtained by superimposing the LY-labeled cells showed that all of the ACh-responding cells were type III cells (synaptosomal-associated protein 25 [SNAP-25]-immunoreactive cells). The ACh responses required no added Ca 2+ in the bathing solution. The addition of 1 μM U73122, a phospholipase C inhibitor, decreased the magnitude of the ACh response, whereas that of 1 μM U73343, a negative control, had no effect. These results suggest that type III cells respond to ACh and release Ca 2+ from intracellular stores. We also discuss the underlying mechanism of the Ca 2+ response and the role of M3 in type III cells.

  1. Muscarinic M1 receptor inhibition reduces gastroduodenal bicarbonate secretion and promotes gastric prostaglandin E2 synthesis in healthy volunteers

    DEFF Research Database (Denmark)

    Mertz-Nielsen, A; Hillingsø, Jens; Eskerod, O

    1995-01-01

    stimulated gastric and basal duodenal bicarbonate secretion by about 50% (p basal and vagally stimulated PGE2 output increased significantly (p ...The selective muscarinic M1 receptor antagonist, pirenzepine, considerably stimulates duodenal mucosal bicarbonate secretion in the rat and increases gastric luminal release of prostaglandin E2 (PGE2) in humans. This study, therefore, looked at the effect of pirenzepine on bicarbonate secretion...... sham feeding and acid exposure (HCl 0.1 M; 20 ml; 5 min) of the duodenal bulb increased mucosal bicarbonate secretion from 191 (14) mumol/cm x h to 266 (27) mumol/cm x h (p basal and vagally...

  2. Role of protein glycosylation on the expression of muscarinic receptors of N4TG1 neuroblastoma cells

    International Nuclear Information System (INIS)

    Ahmad, A.; Chiang, P.K.

    1986-01-01

    Muscarinic acetylcholine receptors (mAChR) are glycoproteins. Experiments were conducted to determine whether active glycosylation of proteins in N4TG1 neuroblastoma cells could affect the expression of muscarinic receptors on the cell surface. The binding of radioactive N-methylscopolamine, a membrane impermeable ligand, to intact cells was used as a measure of mAChR. In the presence of the inhibitors of glycosylation, such as tunicamycin, monensin and amphomycin, N-linked glycosylation of proteins in the N4TG1 cells was inhibited, as measured by the incorporation of radioactive glucosamine or mannose in proteins. At the concentrations of tunicamycin and monensin used, the glycosylation of proteins after 3 hours were drastically reduced, but the number of mAChR in the cells was not altered. The apparent lack of effect within a short incubation period could be attributed to the presence of preformed oligosaccharide dolichol readily available for N-glycosylation. However, after 24 hours, tunicamycin (0.05 μg/ml) caused a decrease in the number of mAChR by 17% without having any effect on protein synthesis. Therefore, de novo glycosylation of proteins may be required for the expression of mAChR receptors in the N4TG1 neuroblastoma cell surface

  3. Differences between proximal and distal portions of the male rabbit posterior urethra in the physiological role of muscarinic cholinergic receptors

    Science.gov (United States)

    Nagahama, Katsushi; Tsujii, Toshihiko; Morita, Takashi; Azuma, Hiroshi; Oshima, Hiroyuki

    1998-01-01

    The aim of the present study was to elucidate functional differences between embryologically different portions of the posterior urethra of male rabbits in response to muscarinic acetylcholine receptor (mAChR) stimulation using in vitro isometric tension experiments and radioligand binding studies. In the in vitro isometric tension experiments, carbachol, produced a dose-dependent contraction of the proximal portion under the resting state, but did not change the basal tone of the distal portion. Contraction of the proximal portion by 10−5 M noradrenaline (NA) was dose-dependently enhanced by carbachol either in the presence or absence of NG-nitro-L-arginine (NOARG). In contrast, carbachol induced relaxation of the distal portion contracted by 10−5 M NA, which was reversed to dose-dependent contraction in the presence of NOARG. Both portions of the urethra had a similar number of [3H]-quinuclidinyl benzilate ([3H]-QNB) binding sites (195.3±74.1 fmols mg−1 protein for the proximal portion and 146.5±8.5 fmols mg−1 protein for the distal portion) with similar affinities (115.0±45.4 pM for the proximal portion and 79.9± 2.9 pM for the distal portion). The concentration-response curves to carbachol in both portions were shifted to the right in a parallel manner in the presence of pirenzepine (an M1 antagonist), 11-[[2-[(diethylamino)methyl]-1-piperidinyl] acetyl]-5, 11-dihydro-6H-pyrido-2,3-b)-(1,4)-benzodiazepin-6-one (AFDX-116, an M2 antgonist) and 4-diphenyl-acetoxy-N-methyl-piperidine (4-DAMP, an M1/M3 antagonist). The pA2 values for pirenzepine, AFDX-116 and 4-DAMP were 7.5±0.1, 7.2±0.02 and 9.3±0.1 respectively for the contraction of the proximal portion, and 7.2±0.1, 7.1±0.2 and 9.1±0.2, respectively for the relaxation of the distal portion. In conclusion mAChR subtypes distribute in a similar fashion throughout the length of the male rabbit posterior urethra with the discrepant responses to carbachol attributable to the

  4. Evaluation of the Interaction between NMDA Receptors of Nucleus Accumbens and Muscarinic Receptors in Memory

    Directory of Open Access Journals (Sweden)

    Saba Taheri

    2013-02-01

    Full Text Available Background and Objectives: Whereas studies have indicated the interaction between NMDA and cholinergic systems, this study was performed with the aim of determining the role of NMDA receptors in the nucleus accumbens (NAc in scopolamine-induced amnesia.Methods: In this study, at first rats were anesthetized with intra-peritoneal injection of ketamine hydrochloride plus xylazine, and then placed in a stereotaxic apparatus. Two stainless-steel cannulas were placed 2mm above nucleus accumbens shell. All animals were allowed to recover for one week, before beginning the behavioral testing. Then, animals were trained in a step-through type inhibitory avoidance task. The drugs were injected after successful training and before testing. The animals were tested 24h after training, and the step-through latency time was measured as the memory criterion in male Wistar rats. One-way analysis of variance and Tukey’s test were used for analysis of the data. p<0.05 was considered statistically significant.Results: Intra-nucleus accumbens (intra-NAc injection of scopolamine or NMDA caused impairment in memory in rats. Although, co-administration of an ineffective dose of NMDA with an ineffective dose of scopolamine had no significant effect on memory performance, effective doses of NMDA prevented the amnesic effect of scopolamine on inhibitory avoidance memory. On the other hand, intra-NAc injection of NMDA receptor antagonist, i.e., MK-801 caused no change in memory performance by itself, and its co-administration with an effective dose of scopolamine could not prevent the impairing effect of the latter drug. Conclusion: The finding of this study indicated that NMDA receptors in the nucleus accumbens are involved in the modulation of scopolamine-induced amnesia.

  5. Muscarinic receptor plasticity in the brain of senescent rats: down-regulation after repeated administration of diisopropyl fluorophosphate

    International Nuclear Information System (INIS)

    Pintor, A.; Fortuna, S.; Volpe, M.T.; Michalek, H.

    1988-01-01

    Potential age-related differences in the response of Fischer 344 rats to subchronic treatment with diisopropylfluorophosphate (DFP) were evaluated in terms of brain cholinesterase (ChE) inhibition and muscarinic receptor sites. Male 3- and 24-month old rats were sc injected with sublethal doses of DFP for 2 weeks and killed 48 hrs after the last treatment. In the cerebral cortex, hippocampus and striatum of control rats a significant age-related reduction of ChE and of maximum number of 3 H-QNB binding sites (Bmax) was observed. The administration of DFP to senescent rats resulted in more pronounced and longer lasting syndrome of cholinergic stimulation, with marked body weight loss and 60% mortality. The percentage inhibition of brain ChE induced by DFP did not differ between young and senescent rats. As expected, in young rats DFP caused a significant decrease of Bmax, which in the cerebral cortex reached about 40%. In the surviving senescent rats, the percentage decrease of Bmax due to DFP with respect to age-matched controls was very similar to that of young animals, especially in the cerebral cortex. Thus there is great variability in the response of aged rats to DFP treatment, from total failure of adaptive mechanisms resulting in death to considerable muscarinic receptor plasticity

  6. Muscarinic receptor plasticity in the brain of senescent rats: down-regulation after repeated administration of diisopropyl fluorophosphate

    Energy Technology Data Exchange (ETDEWEB)

    Pintor, A.; Fortuna, S.; Volpe, M.T.; Michalek, H.

    1988-01-01

    Potential age-related differences in the response of Fischer 344 rats to subchronic treatment with diisopropylfluorophosphate (DFP) were evaluated in terms of brain cholinesterase (ChE) inhibition and muscarinic receptor sites. Male 3- and 24-month old rats were sc injected with sublethal doses of DFP for 2 weeks and killed 48 hrs after the last treatment. In the cerebral cortex, hippocampus and striatum of control rats a significant age-related reduction of ChE and of maximum number of /sup 3/H-QNB binding sites (Bmax) was observed. The administration of DFP to senescent rats resulted in more pronounced and longer lasting syndrome of cholinergic stimulation, with marked body weight loss and 60% mortality. The percentage inhibition of brain ChE induced by DFP did not differ between young and senescent rats. As expected, in young rats DFP caused a significant decrease of Bmax, which in the cerebral cortex reached about 40%. In the surviving senescent rats, the percentage decrease of Bmax due to DFP with respect to age-matched controls was very similar to that of young animals, especially in the cerebral cortex. Thus there is great variability in the response of aged rats to DFP treatment, from total failure of adaptive mechanisms resulting in death to considerable muscarinic receptor plasticity.

  7. Differential involvement of cortical muscarinic and NMDA receptors in short- and long-term taste aversion memory.

    Science.gov (United States)

    Ferreira, G; Gutiérrez, R; De La Cruz, V; Bermúdez-Rattoni, F

    2002-09-01

    In conditioned taste aversion, an animal avoids a taste previously associated with toxic effects, and this aversive memory formation requires an intact insular cortex. In this paper, we investigated the possible differential involvement of cholinergic and glutamatergic receptors in the insular cortex in short-term memory (STM) and long-term memory (LTM) of taste aversion in rats. Taste aversion was induced by intraperitoneal administration of lithium chloride (a malaise-inducing drug) 15 min after experience with an unfamiliar taste. In order to test STM and LTM of taste aversion, taste stimulus was again presented 4 h and 72 h after lithium injection, respectively. During the acquisition, microinjection of the muscarinic antagonist, scopolamine, in the insular cortex before, but not after, the presentation of the new taste, abolished STM as well as LTM. Blockade of the NMDA receptor, in the insular cortex, by AP5 before, but not after, the presentation of the taste stimulus, impaired LTM but left STM intact. Moreover, when injected 1 h after malaise induction (i.e., during taste-illness association), AP5 disrupted both STM and LTM. These results suggest that activation of muscarinic receptors in the insular cortex is involved in the acquisition of taste memory, whereas NMDA receptors participate in taste memory consolidation. These data demonstrate that different neurochemical mechanisms subserve different memory phases. NMDA receptors are also probably involved in processing the visceral input, thus allowing subsequent taste-illness association. This indicates that in the same cortical area the same neurotransmitter system can be involved in distinct processes: taste memory consolidation vs. taste-illness association.

  8. The distribution of cerebral muscarinic acetylcholine receptors in vivo in patients with dementia. A controlled study with 123IQNB and single photon emission computed tomography

    International Nuclear Information System (INIS)

    Weinberger, D.R.; Gibson, R.; Coppola, R.; Jones, D.W.; Molchan, S.; Sunderland, T.; Berman, K.F.; Reba, R.C.

    1991-01-01

    A high-affinity muscarinic receptor antagonist, 123IQNB (3-quinuclidinyl-4-iodobenzilate labeled with iodine 123), was used with single photon emission computed tomography to image muscarinic acetylcholine receptors in 14 patients with dementia and in 11 healthy controls. High-resolution single photon emission computed tomographic scanning was performed 21 hours after the intravenous administration of approximately 5 mCi of IQNB. In normal subjects, the images of retained ligand showed a consistent regional pattern that correlated with postmortem studies of the relative distribution of muscarinic receptors in the normal human brain, having high radioactivity counts in the basal ganglia, occipital cortex, and insular cortex, low counts in the thalamus, and virtually no counts in the cerebellum. Eight of 12 patients with a clinical diagnosis of Alzheimer's disease had obvious focal cortical defects in either frontal or posterior temporal cortex. Both patients with a clinical diagnosis of Pick's disease had obvious frontal and anterior temporal defects. A region of interest statistical analysis of relative regional activity revealed a significant reduction bilaterally in the posterior temporal cortex of the patients with Alzheimer's disease compared with controls. This study demonstrates the practicability of acetylcholine receptor imaging with 123IQNB and single photon emission computed tomography. The data suggest that focal abnormalities in muscarinic binding in vivo may characterize some patients with Alzheimer's disease and Pick's disease, but further studies are needed to address questions about partial volume artifacts and receptor quantification

  9. Involvement of Striatal Cholinergic Interneurons and M1 and M4 Muscarinic Receptors in Motor Symptoms of Parkinson's Disease.

    Science.gov (United States)

    Ztaou, Samira; Maurice, Nicolas; Camon, Jeremy; Guiraudie-Capraz, Gaëlle; Kerkerian-Le Goff, Lydia; Beurrier, Corinne; Liberge, Martine; Amalric, Marianne

    2016-08-31

    Over the last decade, striatal cholinergic interneurons (ChIs) have reemerged as key actors in the pathophysiology of basal-ganglia-related movement disorders. However, the mechanisms involved are still unclear. In this study, we address the role of ChI activity in the expression of parkinsonian-like motor deficits in a unilateral nigrostriatal 6-hydroxydopamine (6-OHDA) lesion model using optogenetic and pharmacological approaches. Dorsal striatal photoinhibition of ChIs in lesioned ChAT(cre/cre) mice expressing halorhodopsin in ChIs reduces akinesia, bradykinesia, and sensorimotor neglect. Muscarinic acetylcholine receptor (mAChR) blockade by scopolamine produces similar anti-parkinsonian effects. To decipher which of the mAChR subtypes provides these beneficial effects, systemic and intrastriatal administration of the selective M1 and M4 mAChR antagonists telenzepine and tropicamide, respectively, were tested in the same model of Parkinson's disease. The two compounds alleviate 6-OHDA lesion-induced motor deficits. Telenzepine produces its beneficial effects by blocking postsynaptic M1 mAChRs expressed on medium spiny neurons (MSNs) at the origin of the indirect striatopallidal and direct striatonigral pathways. The anti-parkinsonian effects of tropicamide were almost completely abolished in mutant lesioned mice that lack M4 mAChRs specifically in dopamine D1-receptor-expressing neurons, suggesting that postsynaptic M4 mAChRs expressed on direct MSNs mediate the antiakinetic action of tropicamide. The present results show that altered cholinergic transmission via M1 and M4 mAChRs of the dorsal striatum plays a pivotal role in the occurrence of motor symptoms in Parkinson's disease. The striatum, where dopaminergic and cholinergic systems interact, is the pivotal structure of basal ganglia involved in pathophysiological changes underlying Parkinson's disease. Here, using optogenetic and pharmacological approaches, we investigated the involvement of striatal

  10. The Cu-Zn superoxide dismutase (SOD1) inhibits ERK phosphorylation by muscarinic receptor modulation in rat pituitary GH3 cells

    International Nuclear Information System (INIS)

    Secondo, Agnese; De Mizio, Mariarosaria; Zirpoli, Laura; Santillo, Mariarosaria; Mondola, Paolo

    2008-01-01

    The Cu-Zn superoxide dismutase (SOD1) belongs to a family of isoenzymes that are able to dismutate the oxygen superoxide in hydrogen peroxide and molecular oxygen. This enzyme is secreted by many cellular lines and it is also released trough a calcium-dependent depolarization mechanism involving SNARE protein SNAP 25. Using rat pituitary GH3 cells that express muscarinic receptors we found that SOD1 inhibits P-ERK1/2 pathway trough an interaction with muscarinic M1 receptor. This effect is strengthened by oxotremorine, a muscarinic M agonist and partially reverted by pyrenzepine, an antagonist of M1 receptor; moreover this effect is independent from increased intracellular calcium concentration induced by SOD1. Finally, P-ERK1/2 inhibition was accompanied by the reduction of GH3 cell proliferation. These data indicate that SOD1 beside the well studied antioxidant properties can be considered as a neuromodulator able to affect mitogen-activated protein kinase in rat pituitary cells trough a M1 muscarinic receptor

  11. PASSIVE-AVOIDANCE TRAINING INDUCES ENHANCED LEVELS OF IMMUNOREACTIVITY FOR MUSCARINIC ACETYLCHOLINE-RECEPTOR AND COEXPRESSED PKC-GAMMA AND MAP-2 IN RAT CORTICAL-NEURONS

    NARCIS (Netherlands)

    VANDERZEE, EA; DOUMA, BRK; BOHUS, B; LUITEN, PGM

    1994-01-01

    Changes in neocortical immunoreactivity (ir) for muscarinic acetylcholine receptors (mAChRs), protein kinase C gamma (PKC gamma), microtubule-associated protein 2 (MAP-2), and the calcium-binding protein parvalbumin (PARV) induced by the performance of a one-trial passive shock avoidance (PSA) task

  12. Changes of cooperativity between N-methylscopolamine and allosteric modulators alcuronium and gallamine induced by mutations of external loops of muscarinic M(3) receptors

    Czech Academy of Sciences Publication Activity Database

    Krejčí, Alena; Tuček, Stanislav

    2001-01-01

    Roč. 60, č. 4 (2001), s. 761-767 ISSN 0026-895X R&D Projects: GA ČR GA309/99/0214 Institutional research plan: CEZ:AV0Z5011922 Keywords : muscarinic receptors * allosteric modulators Subject RIV: FH - Neurology Impact factor: 5.297, year: 2001

  13. A novel mechanism of hippocampal LTD involving muscarinic receptor-triggered interactions between AMPARs, GRIP and liprin-α

    Directory of Open Access Journals (Sweden)

    Dickinson Bryony A

    2009-06-01

    Full Text Available Abstract Background Long-term depression (LTD in the hippocampus can be induced by activation of different types of G-protein coupled receptors, in particular metabotropic glutamate receptors (mGluRs and muscarinic acethycholine receptors (mAChRs. Since mGluRs and mAChRs activate the same G-proteins and isoforms of phospholipase C (PLC, it would be expected that these two forms of LTD utilise the same molecular mechanisms. However, we find a distinct mechanism of LTD involving GRIP and liprin-α. Results Whilst both forms of LTD require activation of tyrosine phosphatases and involve internalisation of AMPARs, they use different molecular interactions. Specifically, mAChR-LTD, but not mGluR-LTD, is blocked by peptides that inhibit the binding of GRIP to the AMPA receptor subunit GluA2 and the binding of GRIP to liprin-α. Thus, different receptors that utilise the same G-proteins can regulate AMPAR trafficking and synaptic efficacy via distinct molecular mechanisms. Conclusion Our results suggest that mAChR-LTD selectively involves interactions between GRIP and liprin-α. These data indicate a novel mechanism of synaptic plasticity in which activation of M1 receptors results in AMPAR endocytosis, via a mechanism involving interactions between GluA2, GRIP and liprin-α.

  14. Effects of agonist efficacy on desensitization of phosphoinositide hydrolysis mediated by m1 and m3 muscarinic receptors expressed in Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    Hu, J.; Wang, S.Z.; el-Fakahany, E.E.

    1991-01-01

    Muscarinic receptor agonist-induced desensitization of phosphoinositide (PI) hydrolysis and loss of receptors were studied in Chinese hamster ovary (CHO) cells transfected with the m1 and m3 muscarinic receptor genes. Long-term exposure to the full agonist carbamylcholine (CBC) resulted in a time-dependent attenuation of the maximal PI response and a decrease in agonist potency. This desensitization was accompanied by a parallel loss of maximal ligand binding without an alteration of the binding affinity. The time course of both receptor desensitization and down-regulation was similar in m1 and m3 CHO cells. The PI response to the partial agonist McN-A-343 (McN) in m1 cells was more sensitive to desensitization by CBC than the response to the latter agonist, and this desensitization was faster than receptor down-regulation. Desensitization of the PI response to McN was reflected as a decrease in the maximal response without a marked change in potency. McN induced slow desensitization of the PI response to CBC but a much faster desensitization of its own response. Our data provide evidence that although muscarinic agonist-induced desensitization of PI hydrolysis in CHO cells is due mainly to loss of receptors, there are other important factors which play a role in this process, e.g., receptor-effector uncoupling. The relative contribution of these different mechanisms depends on the efficacy of the agonists used for the receptor desensitization and activation steps

  15. Iodine-123 N-methyl-4-iododexetimide: a new radioligand for single-photon emission tomographic imaging of myocardial muscarinic receptors

    International Nuclear Information System (INIS)

    Hicks, R.J.; Kassiou, M.; Eu, P.; Katsifis, A.G.; Garra, M.; Power, J.; Najdovski, L.; Lambrecht, R.M.

    1995-01-01

    Cardiac muscarinic receptor ligands suitable for positron emission tomography have previously been characterised. Attempts to develop radioligands of these receptors suitable for single-photon emission tomographic (SPET) imaging have not been successful due to high lung retention and high non-specific binding of previously investigated potential tracers. The purpose of this study was to evaluate the biodistribution and in vivo imaging characteristics of a new radiopharmaceutical, [ 123 I]N-methyl-4-iododexetimide. Biodistribution studies performed in rats showed high cardiac uptake (2.4% ID/g) 10 min after injection with a heart to lung activity ratio of 5:1. Specificity and stereoselectivity of cardiac binding were demonstrated using blocking experiments in rats. Dynamic imaging studies in anaesthetised greyhounds demonstrated rapid and high myocardial uptake and low lung binding with stable heart to lung activity ratios of >2.5:1 between 10 and 30 min, making SPET imaging feasible. Administration of an excess of an unlabelled muscarinic antagonist, methyl-quinuclidinyl benzylate rapidly displaced myocardial activity to background levels and the pharmacologically inactive enantiomer, [ 123 I]N-methyl-4-iodolevetimide, had no detectable cardiac uptake, indicating specific and stereoselective muscarinic receptor binding. SPET revealed higher activity in the inferior than in the anterior wall, this being consistent with previously described regional variation of cardiac parasympathetic innervation. [ 123 I]N-methyl-4-iododexetimide shows promise as an imaging agent for muscarinic receptor distribution in the heart and may be helpful in evaluating diverse cardiac diseases associated with altered muscarinic receptor function, including heart failure and diabetic heart disease. (orig.)

  16. Effects of trihexyphenidyl and L-dopa on brain muscarinic cholinergic receptor binding measured by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Shinotoh, H; Asahina, M; Hirayama, K [Dept. of Neurology, School of Medicine, Chiba Univ., Chiba (Japan); Inoue, O; Suhara, T; Tateno, Y [Division of Clinical Research, National Inst. of Radiological Sciences, Chiba (Japan)

    1994-01-01

    The effects of pharmacological intervention on brain muscarinic cholinergic receptor (mAChR) binding were assessed in seven patients with Parkinson's disease by positron emission tomography and carbon-11 labelled N-methyl-4-piperidyl benzilate ([[sup 11]C]NMPB). [[sup 11]C]NMPB was injected twice, approximately 2 hours apart, in each patient, to assess the effect of single doses of 4 mg of trihexyphenidyl (n=5) or 400 mg of L-dopa with 57 mg of benserazide (n=2) on the binding parameter of mAChRs (K[sub 3]). There was a mean 28% inhibition of K[sub 3] values in the brain in the presence of trihexyphenidyl, which was assumed to reflect mAChR occupancy. No significant change in K[sub 3] was observed in the presence of L-dopa. This study demonstrates the feasibility of measuring mAChR occupancy by an anticholinergic medication with PET.

  17. Preparation of an imaging agent for cerebral muscarinic acetylcholine receptor, (R,S)131I-QNB

    International Nuclear Information System (INIS)

    Ding Shiyu; Chen Zhengping; Ji Shuren; Lu Chunxiong; Zhou Xiang; Fang Ping; Wu Chunying; Wang Bocheng; Xiang Jingde; Lin Yansong

    2003-01-01

    The method to synthesize a high affinity muscarinic receptor antagonist (R,S)I-QNB[(R)-(-)-l-azabicyclo [2,2,2]oct-3-yl-(S)-(+)-α-hydroxy-α-(4-[127I]iodophenyl)-α-phenyl acetate] from 4-nitrobenzophenone with improvement compared to literatures was reported in this article. IR, MS and 1 HNMR characterized the final product. (R,S) 131 I-QNB was prepared using Cu(I) assisted iodine exchange labeling, and showed by TLC that the radiolabeling yield (RLY) was over 80%, and radiochemical purity (RCP) was over 95%. Stability of the labelled compound was also determined. It was found that (R,S) 131 I-QNB dried by nitrogen blowing can stay at 4-10 degree C for a week without change of RCP

  18. An interspecies comparison of mercury inhibition on muscarinic acetylcholine receptor binding in the cerebral cortex and cerebellum

    International Nuclear Information System (INIS)

    Basu, Niladri; Stamler, Christopher J.; Loua, Kovana Marcel; Chan, H.M.

    2005-01-01

    Mercury (Hg) is a ubiquitous pollutant that can disrupt neurochemical signaling pathways in mammals. It is well documented that inorganic Hg (HgCl 2 ) and methyl Hg (MeHg) can inhibit the binding of radioligands to the muscarinic acetylcholine (mACh) receptor in rat brains. However, little is known concerning this relationship in specific anatomical regions of the brain or in other species, including humans. The purpose of this study was to explore the inhibitory effects of HgCl 2 and MeHg on [ 3 H]-quinuclidinyl benzilate ([ 3 H]-QNB) binding to the mACh receptor in the cerebellum and cerebral cortex regions from human, rat, mouse, mink, and river otter brain tissues. Saturation binding curves were obtained from each sample to calculate receptor density (B max ) and ligand affinity (K d ). Subsequently, samples were exposed to HgCl 2 or MeHg to derive IC50 values and inhibition constants (K i ). Results demonstrate that HgCl 2 is a more potent inhibitor of mACh receptor binding than MeHg, and the receptors in the cerebellum are more sensitive to Hg-mediated mACh receptor inhibition than those in the cerebral cortex. Species sensitivities, irrespective of Hg type and brain region, can be ranked from most to least sensitive: river otter > rat > mink > mouse > humans. In summary, our data demonstrate that Hg can inhibit the binding [ 3 H]-QNB to the mACh receptor in a range of mammalian species. This comparative study provides data on interspecies differences and a framework for interpreting results from human, murine, and wildlife studies

  19. Differential S1P Receptor Profiles on M1- and M2-Polarized Macrophages Affect Macrophage Cytokine Production and Migration.

    Science.gov (United States)

    Müller, Jan; von Bernstorff, Wolfram; Heidecke, Claus-Dieter; Schulze, Tobias

    2017-01-01

    Introduction . Macrophages are key players in complex biological processes. In response to environmental signals, macrophages undergo polarization towards a proinflammatory (M1) or anti-inflammatory (M2) phenotype. Sphingosine 1-phosphate (S1P) is a bioactive lysophospholipid that acts via 5 G-protein coupled receptors (S1P 1-5 ) in order to influence a broad spectrum of biological processes. This study assesses S1P receptor expression on macrophages before and after M1 and M2 polarization and performs a comparative analysis of S1P signalling in the two activational states of macrophages. Methods . Bone marrow derived macrophages (BMDM) from C57 BL/6 mice were cultured under either M1- or M2-polarizing conditions. S1P-receptor expression was determined by quantitative RT-PCR. Influence of S1P on macrophage activation, migration, phagocytosis, and cytokine secretion was assessed in vitro. Results . All 5 S1P receptor subclasses were expressed in macrophages. Culture under both M1- and M2-polarizing conditions led to significant downregulation of S1P 1 . In contrast, M1-polarized macrophages significantly downregulated S1P 4 . The expression of the remaining three S1P receptors did not change. S1P increased expression of iNOS under M2-polarizing conditions. Furthermore, S1P induced chemotaxis in M1 macrophages and changed cytokine production in M2 macrophages. Phagocytosis was not affected by S1P-signalling. Discussion . The expression of different specific S1P receptor profiles may provide a possibility to selectively influence M1- or M2-polarized macrophages.

  20. Regional distribution of muscarinic acetylcholine receptors in the telencephalon of the pigeon (Columba livia f. domestica). [Use of TH-quinuclidinylbenzylate

    Energy Technology Data Exchange (ETDEWEB)

    Waechtler, K.

    1985-01-01

    The distribution of muscarinic acetylcholine receptors was studied autoradiographically in croystat sections of the pigeon telencephalon using TH-quinuclidinylbenzylate as a ligand. Highest receptor density was observed in the hyperstriatum ventrale, palaeostriatum augmentatum, septum, and parts of the archistriatum. In sites of known sensory input of neostriatum (field L) and ectostriatum low receptor binding was observed. Acetylcholinesterase distribution is in good agreement with the receptor picture only in the basal telencephalon. In the pallium differences in the pattern of these two components can be seen.

  1. Role of ventrolateral orbital cortex muscarinic and nicotinic receptors in modulation of capsaicin-induced orofacial pain-related behaviors in rats.

    Science.gov (United States)

    Tamaddonfard, Esmaeal; Erfanparast, Amir; Abbas Farshid, Amir; Delkhosh-Kasmaie, Fatmeh

    2017-11-15

    Acetylcholine, as a major neurotransmitter, mediates many brain functions such as pain. This study was aimed to investigate the effects of microinjection of muscarinic and nicotinic acetylcholine receptor antagonists and agonists into the ventrolateral orbital cortex (VLOC) on capsaicin-induced orofacial nociception and subsequent hyperalgesia. The right side of VLOC was surgically implanted with a guide cannula in anaesthetized rats. Orofacial pain-related behaviors were induced by subcutaneous injection of a capsaicin solution (1.5µg/20µl) into the left vibrissa pad. The time spent face rubbing with ipsilateral forepaw and general behavior were recorded for 10min, and then mechanical hyperalgesia was determined using von Frey filaments at 15, 30, 45 and 60min post-capsaicin injection. Alone intra-VLOC microinjection of atropine (a muscarinic acetylcholine receptor antagonist) and mecamylamine (a nicotinic acetylcholine receptor antagonist) at a similar dose of 200ng/site did not alter nocifensive behavior and hyperalgesia. Microinjection of oxotremorine (a muscarinic acetylcholine receptor agonist) at doses of 50 and 100ng/site and epibatidine (a nicotinic acetylcholine receptor agonist) at doses of 12.5, 25, 50 and 100ng/site into the VLOC suppressed pain-related behaviors. Prior microinjections of 200ng/site atropine and mecamylamine (200ng/site) prevented oxotremorine (100ng/site)-, and epibatidine (100ng/site)-induced antinociception, respectively. None of the above-mentioned chemicals changed general behavior. These results showed that the VLOC muscarinic and nicotinic acetylcholine receptors might be involved in modulation of orofacial nociception and hypersensitivity. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Boronic acid adducts of technetium dioxime (BATO) complexes derived from quinuclidine benzilate (QNB) boronic acid stereoisomers: Syntheses and studies of their binding to the muscarinic acetylcholine receptor

    International Nuclear Information System (INIS)

    Jurisson, Silvia S.; Pirro, John; DiRocco, Richard J.; Rosenspire, Karen C.; Jagoda, Elaine; Nanjappan, Palaniappa; Eckelman, William C.; Nowotnik, David P.; Nunn, Adrian D.

    1995-01-01

    We have investigated the possibility of using BATO complexes derivatized with the muscarinic acetylcholine receptor (mAChR) antagonist, quinuclidinyl benzilate (QNB), for mAChR imaging. The BATO complexes, TcCl(DMG) 3 B-QNB, were prepared using QNB derivatives containing a 4'-boronic acid substituent on one of the benzilic benzene rings (QNB-boronic acid). The QNB-boronic acid molecule has two chiral centers, and all four QNB-BATO stereoisomers were made and evaluated. When studied using in vitro receptor binding assays based on tissue from rat brain caudate-putamen (which contains primarily M 1 and M 4 mAChR) and rat heart (M 2 mAChR), the QNB-boronic acid stereoisomers had binding affinities (K A ) in the range 2 x 10 5 -1 x 10 8 , at least 10-fold lower than theK A for QNB (ca 2 x 10 9 ). The stereochemistry of both centers had some influence on the affinity constant. When the TcCl(DMG) 3 B-QNB complexes were studied, none of the stereoisomeric complexes displayed measurable specific binding (K A 6 ), but all showed high non-specific binding. In vitro autoradiography with rat brain slices confirmed the absence of specific binding in these tracers. In vivo, the 99m TcCl(DMG) 3 B-QNB complexes displayed minimal brain uptake, and modest heart uptake; the latter was unlikely to be related to uptake by the mAChR. In light of these findings, we conclude that the interaction between the TcCl(DMG) 3 B-QNB complexes and biological membranes is dominated by the hydrophobicity of the BATO moiety. The TcCl(DMG) 3 B-QNB complexes, therefore, have little potential for mAChR imaging

  3. Immunocytochemical localization of choline acetyltransferase and muscarinic ACh receptors in the antenna during development of the sphinx moth Manduca sexta.

    Science.gov (United States)

    Clark, Julie; Meisner, Shannon; Torkkeli, Päivi H

    2005-04-01

    Immunocytochemistry with monoclonal antibodies was used to investigate the locations of muscarinic acetylcholine receptors (mAChR) and choline acetyltransferase (ChAT) in sections of the developing antennae of the moth Manduca sexta. The results were correlated with a previous morphological investigation in the developing antennae which allowed us to locate different cell types at various stages of development. Our findings indicated that the muscarinic cholinergic system was not restricted to the sensory neurons but was also present in glial and epidermal cells. By day 4-5 of adult development, immunoreactivity against both antibodies was present in the axons of the antennal nerve, and more intense labeling was present in sections from older pupae. At days 4-9, the cell bodies of the sensory neurons in the basal part of the epidermis were also intensely immunolabeled by the anti-mAChR antibody. In mature flagella, large numbers of cells, some with processes into hairs, were strongly labeled by both antibodies. Antennal glial cells were intensely immunolabeled with both antibodies by days 4-5, but in later stages, it was not possible to discriminate between glial and neural staining. At days 4-9, we observed a distinctly labeled layer of epidermal cells close to the developing cuticle. The expression of both ChAT and mAChRs by neurons in moth antennae may allow the regulation of excitability by endogenous ACh. Cholinergic communication between neurons and glia may be part of the system that guides axon elongation during development. The cholinergic system in the apical part of the developing epidermis could be involved in cuticle formation.

  4. Brain regional acetylcholinesterase activity and muscarinic acetylcholine receptors in rats after repeated administration of cholinesterase inhibitors and its withdrawal

    International Nuclear Information System (INIS)

    Kobayashi, Haruo; Suzuki, Tadahiko; Sakamoto, Maki; Hashimoto, Wataru; Kashiwada, Keiko; Sato, Itaru; Akahori, Fumiaki; Satoh, Tetsuo

    2007-01-01

    Activity of acetylcholinesterase (AChE) and specific binding of [ 3 H]quinuclidinyl benzilate (QNB), [ 3 H]pirenzepine (PZP) and [ 3 H]AF-DX 384 to muscarinic acetylcholine receptor (mAChR) preparations in the striatum, hippocampus and cortex of rats were determined 1, 6 and 11 days after the last treatment with an organophosphate DDVP, a carbamate propoxur or a muscarinic agonist oxotremorine as a reference for 7 and 14 days. AChE activity was markedly decreased in the three regions 1 day after the treatment with DDVP for 7 and 14 days with a gradual recovery 6 to 11 days, and much less decreased 1, 6 and 11 days after the treatment with propoxur for 7 days but not for 14 days in the hippocampus and cortex. The binding of [ 3 H]-QNB, PZP and AF-DX 384 in the three regions was generally decreased by the treatment with DDVP for 7 and 14 days. Such down-regulations were generally restored 6 or 11 days after the treatment for 7 but not for 14 days. The down-regulation or up-regulation as measured by [ 3 H]-QNB, PZP and AF-DX 384 was observed 1, 6 or 11 days after treatment with propoxur for 7 days and/or 14 days. Repeated treatment with oxotremorine produced similar effects except AChE activity to DDVP. These results suggest that repeated inhibition of AChE activity may usually cause down-regulation of mAChRs with some exception in the hippocampus when a reversible antiChE propoxur is injected

  5. The M1 muscarinic receptor and its second messenger coupling in human neuroblastoma cells and transfected murine fibroblast cells

    International Nuclear Information System (INIS)

    Mei, Lin.

    1989-01-01

    The data of this study indicate that pirenzepine (PZ)-high affinity muscarinic receptors (mAChRs) are coupled to the hydrolysis of inositol lipids and not to the adenylate cyclase system in human neuroblastoma SH-SY5Y cells. The maximal carbachol(CCh)-stimulated [ 3 H]IP 1 accumulation in the SH-SY5Y cells was decreased in the presence of 1μg/ml pertussis toxin, suggesting that a pertussis toxin sensitive G-protein may be involved in the coupling. Several cell clones which express only M 1 mAChR were generated by transfecting the murine fibroblast B82 cells with the cloned rat genomic m 1 gene. The transfected B82 cells (cTB10) showed specific [ 3 H](-)QNB binding activity. The mAChRs in these cells are of the M 1 type defined by their high affinity for PZ and low affinity for AF-DX 116 and coupled to hydrolysis of inositol lipids, possibly via a pertussis toxin sensitive G protein. The relationship between the M 1 mAChR density and the receptor-mediated hydrolysis of inositol lipids was studied in 7 clones. The M 1 mAChR densities in these cells characterized by [ 3 H](-)MQNB binding ranged from 12 fmol/10 6 cells in LK3-1 cells to 260 fmol/10 6 cells in the LK3-8 cells

  6. Mutations in the third extracellular loop of M3 muscarinic receptor induce positive cooperativity between N-Methylscopolamine and Wieland-Gumlich aldehyde

    Czech Academy of Sciences Publication Activity Database

    Jakubík, Jan; Doležal, Vladimír

    2005-01-01

    Roč. 272, č. S1 (2005), s. 221-221 ISSN 1474-3833. [FEBS Congress /30./ and IUBMB Conference /9./. 02.07.2005-07.07.2005, Budapest] R&D Projects: GA AV ČR(CZ) IAA5011306; GA ČR(CZ) GP305/02/D090 Institutional research plan: CEZ:AV0Z5011922 Keywords : muscarinic receptors * allosteric interaction * strychnine -like modulators * mutations * extracellular loop Subject RIV: ED - Physiology

  7. Nucleus accumbens neurotransmission and effort-related choice behavior in food motivation: effects of drugs acting on dopamine, adenosine, and muscarinic acetylcholine receptors.

    Science.gov (United States)

    Nunes, Eric J; Randall, Patrick A; Podurgiel, Samantha; Correa, Mercè; Salamone, John D

    2013-11-01

    Mesolimbic dopamine (DA) is a critical component of the brain circuitry regulating behavioral activation and effort-related processes. Although nucleus accumbens (NAc) DA depletions or antagonism leave aspects of appetite and primary food motivation intact, rats with impaired DA transmission reallocate their instrumental behavior away from food-reinforced tasks with high response requirements, and instead select less effortful food-seeking behaviors. Previous work showed that adenosine A2A antagonists can reverse the effects of DA D2 antagonists on effort-related choice, and that stimulation of adenosine A2A receptors produces behavioral effects that are similar to those induced by DA antagonism. The present review summarizes the literature on the role of NAc DA and adenosine in effort-related processes, and also presents original data on the effects of local stimulation of muscarinic acetylcholine receptors in NAc core. Local injections of the muscarinic agonist pilocarpine directly into NAc core produces shifts in effort-related choice behavior similar to those induced by DA antagonism or A2A receptor stimulation, decreasing lever pressing but increasing chow intake in rats responding on a concurrent fixed ratio/chow feeding choice task. In contrast, injections into a neostriatal control site dorsal to the NAc were ineffective. The actions of pilocarpine on this task were attenuated by co-administration of the muscarinic antagonist scopolamine. Thus, drugs that act on DA, adenosine A2A, and muscarinic receptors regulate effort-related choice behavior, which may have implications for the treatment of psychiatric symptoms such as psychomotor slowing, fatigue or anergia that can be observed in depression and other disorders. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Changes in Membrane Cholesterol Differentially Influence Preferential and Non-preferential Signaling of the M1 and M3 Muscarinic Acetylcholine Receptors

    Czech Academy of Sciences Publication Activity Database

    Michal, Pavel; El-Fakahany, E. E.; Doležal, Vladimír

    2015-01-01

    Roč. 40, č. 10 (2015), s. 2068-2070 ISSN 0364-3190 R&D Projects: GA ČR(CZ) GA14-05696S; GA ČR(CZ) GBP304/12/G069; GA MŠk(CZ) 7E10060 Institutional support: RVO:67985823 Keywords : muscarinic receptors * agonist binding * cholesterol * G-proteins * signal transduction * cAMP synthesis Subject RIV: FH - Neurology Impact factor: 2.472, year: 2015

  9. Asparagine, valine, and threonine in the third extracellular loop of muscarinic receptor have essential roles in the positive cooperativity of strychnine-like allosteric modulators

    Czech Academy of Sciences Publication Activity Database

    Jakubík, Jan; Krejčí, Alena; Doležal, Vladimír

    2005-01-01

    Roč. 313, č. 2 (2005), s. 688-696 ISSN 0022-3565 R&D Projects: GA ČR(CZ) GA309/02/1331; GA ČR(CZ) GP305/02/D090; GA AV ČR(CZ) IAA5011306; GA MŠk(CZ) LC554 Institutional research plan: CEZ:AV0Z50110509 Keywords : muscarinic receptors * positive cooperativity * mutation Subject RIV: ED - Physiology Impact factor: 4.098, year: 2005

  10. Muscarinic M1 acetylcholine receptors regulate the non-quantal release of acetylcholine in the rat neuromuscular junction via NO-dependent mechanism

    Czech Academy of Sciences Publication Activity Database

    Malomouzh, A. I.; Mukhtarov, M. R.; Nikolsky, E. E.; Vyskočil, František

    2007-01-01

    Roč. 102, č. 6 (2007), s. 2110-2117 ISSN 0022-3042 R&D Projects: GA AV ČR(CZ) IAA5011411; GA MŠk(CZ) LC554 Grant - others:-(RU) 112.0/001/481 Institutional research plan: CEZ:AV0Z50110509 Keywords : muscarinic receptors * NO synthese Subject RIV: ED - Physiology Impact factor: 4.451, year: 2007

  11. A comparison of β-adrenoceptors and muscarinic cholinergic receptors in tissues of brown bullhead catfish (Ameiurus nebulosus) from the black river and old woman creek, Ohio

    Science.gov (United States)

    Steevens, Jeffery A.; Baumann, Paul C.; Jones, Susan B.

    1996-01-01

    β-Adrenoceptors (βARs) and muscarinic cholinergic receptors were measured in brain, gill, and heart tissues of brown bullhead catfish exposed to polycyclic aromatic hydrocarbons in the Black River, Ohio, USA, and were compared to values from Old Woman Creek, Ohio, a reference site. A decreased number of βARs were found in the gill from Black River fish, possibly indicating a compensatory response subsequent to chemical stress.

  12. Muscarinic M4 Receptors on Cholinergic and Dopamine D1 Receptor-Expressing Neurons Have Opposing Functionality for Positive Reinforcement and Influence Impulsivity

    Directory of Open Access Journals (Sweden)

    Anna M. Klawonn

    2018-04-01

    Full Text Available The neurotransmitter acetylcholine has been implicated in reward learning and drug addiction. However, the roles of the various cholinergic receptor subtypes on different neuron populations remain elusive. Here we study the function of muscarinic M4 receptors (M4Rs in dopamine D1 receptor (D1R expressing neurons and cholinergic neurons (expressing choline acetyltransferase; ChAT, during various reward-enforced behaviors and in a “waiting”-impulsivity test. We applied cell-type-specific gene deletions targeting M4Rs in D1RCre or ChATCre mice. Mice lacking M4Rs in D1R-neurons displayed greater cocaine seeking and drug-primed reinstatement than their littermate controls in a Pavlovian conditioned place preference (CPP paradigm. Furthermore, the M4R-D1RCre mice initiated significantly more premature responses (PRs in the 5-choice-serial-reaction-time-task (5CSRTT than their littermate controls, indicating impaired waiting impulse control. In contrast, mice lacking M4Rs in cholinergic neurons did not acquire cocaine Pavlovian conditioning. The M4R-ChATCre mice were also unable to learn positive reinforcement to either natural reward or cocaine in an operant runway paradigm. Immediate early gene (IEG expression (cFos and FosB induced by repeated cocaine injections was significantly increased in the forebrain of M4R-D1RCre mice, whereas it remained normal in the M4R-ChATCre mice. Our study illustrates that muscarinic M4Rs on specific neural populations, either cholinergic or D1R-expressing, are pivotal for learning processes related to both natural reward and drugs of abuse, with opposing functionality. Furthermore, we found that neurons expressing both M4Rs and D1Rs are important for signaling impulse control.

  13. Muscarinic M4 Receptors on Cholinergic and Dopamine D1 Receptor-Expressing Neurons Have Opposing Functionality for Positive Reinforcement and Influence Impulsivity.

    Science.gov (United States)

    Klawonn, Anna M; Wilhelms, Daniel B; Lindström, Sarah H; Singh, Anand Kumar; Jaarola, Maarit; Wess, Jürgen; Fritz, Michael; Engblom, David

    2018-01-01

    The neurotransmitter acetylcholine has been implicated in reward learning and drug addiction. However, the roles of the various cholinergic receptor subtypes on different neuron populations remain elusive. Here we study the function of muscarinic M4 receptors (M4Rs) in dopamine D1 receptor (D1R) expressing neurons and cholinergic neurons (expressing choline acetyltransferase; ChAT), during various reward-enforced behaviors and in a "waiting"-impulsivity test. We applied cell-type-specific gene deletions targeting M4Rs in D1RCre or ChATCre mice. Mice lacking M4Rs in D1R-neurons displayed greater cocaine seeking and drug-primed reinstatement than their littermate controls in a Pavlovian conditioned place preference (CPP) paradigm. Furthermore, the M4R-D1RCre mice initiated significantly more premature responses (PRs) in the 5-choice-serial-reaction-time-task (5CSRTT) than their littermate controls, indicating impaired waiting impulse control. In contrast, mice lacking M4Rs in cholinergic neurons did not acquire cocaine Pavlovian conditioning. The M4R-ChATCre mice were also unable to learn positive reinforcement to either natural reward or cocaine in an operant runway paradigm. Immediate early gene (IEG) expression ( cFos and FosB ) induced by repeated cocaine injections was significantly increased in the forebrain of M4R-D1RCre mice, whereas it remained normal in the M4R-ChATCre mice. Our study illustrates that muscarinic M4Rs on specific neural populations, either cholinergic or D1R-expressing, are pivotal for learning processes related to both natural reward and drugs of abuse, with opposing functionality. Furthermore, we found that neurons expressing both M4Rs and D1Rs are important for signaling impulse control.

  14. The selective positive allosteric M1 muscarinic receptor modulator PQCA attenuates learning and memory deficits in the Tg2576 Alzheimer's disease mouse model.

    Science.gov (United States)

    Puri, Vanita; Wang, Xiaohai; Vardigan, Joshua D; Kuduk, Scott D; Uslaner, Jason M

    2015-01-01

    We have recently shown that the M1 muscarinic receptor positive allosteric modulator, PQCA, improves cognitive performance in rodents and non-human primates administered the muscarinic receptor antagonist scopolamine. The purpose of the present experiments was to characterize the effects of PQCA in a model more relevant to the disease pathology of Alzheimer's disease. Tg2576 transgenic mice that have elevated Aβ were tested in the novel object recognition task to characterize recognition memory as a function of age and treatment with the PQCA. The effects of PQCA were compared to the acetylcholinesterase inhibitor donepezil, the standard of care for Alzheimer's disease. In addition, the effect of co-administering PQCA and donepezil was evaluated. Aged Tg2576 mice demonstrated a deficit in recognition memory that was significantly attenuated by PQCA. The positive control donepezil also reversed the deficit. Furthermore, doses of PQCA and donepezil that were inactive on their own were found to improve recognition memory when given together. These studies suggest that M1 muscarinic receptor positive allosteric modulation can ameliorate memory deficits in disease relevant models of Alzheimer's disease. These data, combined with our previous findings demonstrating PQCA improves scopolamine-induced cognitive deficits in both rodents and non-human primates, suggest that M1 positive allosteric modulators have therapeutic potential for the treatment of Alzheimer's disease. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Effect of partial volume correction on muscarinic cholinergic receptor imaging with single-photon emission tomography in patients with temporal lobe epilepsy

    International Nuclear Information System (INIS)

    Weckesser, M.; Ziemons, K.; Griessmeier, M.; Sonnenberg, F.; Langen, K.J.; Mueller-Gaertner, H.W.; Hufnagel, A.; Elger, C.E.; Hacklaender, T.; Holschbach, M.

    1997-01-01

    Animal experiments and preliminary results in humans have indicated alterations of hippocampal muscarinic acetylcholine receptors (mAChR) in temporal lobe epilepsy. Patients with temporal lobe epilepsy often present with a reduction in hippocampal volume. The aim of this study was to investigate the influence of hippocampal atrophy on the quantification of mAChR with single photon emission tomography (SPET) in patients with temporal lobe epilepsy. Cerebral uptake of the muscarinic cholinergic antagonist [ 123 I]4-iododexetimide (IDex) was investigated by SPET in patients suffering from temporal lobe epilepsy of unilateral (n=6) or predominantly unilateral (n=1) onset. Regions of interest were drawn on co-registered magnetic resonance images. Hippocampal volume was determined in these regions and was used to correct the SPET results for partial volume effects. A ratio of hippocampal IDex binding on the affected side to that on the unaffected side was used to detect changes in muscarinic cholinergic receptor density. Before partial volume correction a decrease in hippocampal IDex binding on the focus side was found in each patient. After partial volume no convincing differences remained. Our results indicate that the reduction in hippocampal IDex binding in patients with epilepsy is due to a decrease in hippocampal volume rather than to a decrease in receptor concentration. (orig.). With 2 figs., 2 tabs

  16. In vivo and in vitro studies on the potentiation of muscarinic receptor stimulation by alaproclate, a selective 5-HT uptake blocker

    International Nuclear Information System (INIS)

    Oegren, S.O.; Nordstroem, Oe.; Danielsson, E.; Peterson, L.-L.; Bartfai, T.

    1985-01-01

    Alaproclate (10-60 mg/kg) injected i.p. into male mice potentiated and prolonged the oxotremorine and physostigmine-induced tremor in a dosedependent manner. Atropine completely blocked the tremor caused by oxotremorine or physostigmine both in the presence and absence of alaproclate. Pretreatment with the 5-HT receptor antagonist metitepine completely blocked the enhancement of oxotremorine-induced tremor caused by alaproclate. Biochemical studies indicated that the above effects cannot be explained by assuming that alaproclate a) acts as a cholinergic agonist, b) inhibits the acetylcholine esterase, c) interferes with choline uptake or acetylcholine synthesis, or d) directly potentiates the release of acetylcholine. In ligand binding studies alaproclate was found to be a weak competitive inhibitor of muscarinic antagonist binding to membranes from the rat cerebral cortex, rat striatum, human cerebral cortex and human striatum. (Ksub(i) approximately 28-40 μM in all four tissues). The present results suggest that alaproclate may potentiate muscarinic responses by a mechanism involving serotonergic receptor mechanisms rather than by a direct interaction with the muscarinic cholinergic receptors. (Author)

  17. In vivo and in vitro studies on the potentiation of muscarinic receptor stimulation by alaproclate, a selective 5-HT uptake blocker

    Energy Technology Data Exchange (ETDEWEB)

    Oegren, S.O. (Astra Pharmaceuticals AB, Soedertaelje (Sweden)); Nordstroem, Oe.; Danielsson, E.; Peterson, L.L.; Bartfai, T.

    1985-01-01

    Alaproclate (10-60 mg/kg) injected i.p. into male mice potentiated and prolonged the oxotremorine and physostigmine-induced tremor in a dose dependent manner. Atropine completely blocked the tremor caused by oxotremorine or physostigmine both in the presence and absence of alaproclate. Pretreatment with the 5-HT receptor antagonist metitepine completely blocked the enhancement of oxotremorine-induced tremor caused by alaproclate. Biochemical studies indicated that the above effects cannot be explained by assuming that alaproclate a) acts as a cholinergic agonist, b) inhibits the acetylcholine esterase, c) interferes with choline uptake or acetylcholine synthesis, or d) directly potentiates the release of acetylcholine. In ligand binding studies alaproclate was found to be a weak competitive inhibitor of muscarinic antagonist binding to membranes from the rat cerebral cortex, rat striatum, human cerebral cortex and human striatum. (Ksub(i) approximately 28-40 ..mu..M in all four tissues). The present results suggest that alaproclate may potentiate muscarinic responses by a mechanism involving serotonergic receptor mechanisms rather than by a direct interaction with the muscarinic cholinergic receptors.

  18. A crosstalk between muscarinic and CRF2 receptors regulates cellular adhesion properties of human colon cancer cells.

    Science.gov (United States)

    Pelissier-Rota, M; Chartier, N T; Bonaz, B; Jacquier-Sarlin, M R

    2017-07-01

    Patients with inflammatory bowel disease often suffer from chronic and relapsing intestinal inflammation that favor the development of colitis associated cancer. An alteration of the epithelial intestinal barrier function observed in IBD is supposed to be a consequence of stress. It has been proposed that corticotrophin-releasing factor receptor (CRF2), one of the two receptors of CRF, the principal neuromediator of stress, acts on cholinergic nerves to induce stress-mediated epithelial barrier dysfunction. Non-neuronal acetylcholine (Ach) and muscarinic receptors (mAchR) also contribute to alterations of epithelial cell functions. In this study, we investigated the mechanisms through which stress and Ach modulate epithelial cell adhesive properties. We show that Ach-induced activation of mAchR in HT-29 cells results in cell dissociation together with changes in cell-matrix contacts, which correlates with the acquisition of invasive potential consistent with a matrix metalloproteinase (MMP) mode of invasion. These processes result from mAchR subsequent stimulation of the cascade of src/Erk and FAK activation. Ach-induced secretion of laminin 332 leads to α3β1 integrin activation and RhoA-dependent reorganization of the actin cytoskeleton. We show that Ach-mediated effects on cell adhesion are blocked by astressin 2b, a CRF2 antagonist, suggesting that Ach action depends partly on CRF2 signaling. This is reinforced by the fact that Ach-mediated activation of mAchR stimulates both the synthesis and the release of CRF2 ligands in HT-29 cells (effects blocked by atropine). In summary, our data provides evidence for a novel intracellular circuit involving mAchR acting on CRF2-signaling that could mediate colonic mucosal barrier dysfunction and exacerbate mucosal inflammation. Copyright © 2017. Published by Elsevier B.V.

  19. Selective Activation of M4 Muscarinic Acetylcholine Receptors Reverses MK-801-Induced Behavioral Impairments and Enhances Associative Learning in Rodents

    Science.gov (United States)

    2015-01-01

    Positive allosteric modulators (PAMs) of the M4 muscarinic acetylcholine receptor (mAChR) represent a novel approach for the treatment of psychotic symptoms associated with schizophrenia and other neuropsychiatric disorders. We recently reported that the selective M4 PAM VU0152100 produced an antipsychotic drug-like profile in rodents after amphetamine challenge. Previous studies suggest that enhanced cholinergic activity may also improve cognitive function and reverse deficits observed with reduced signaling through the N-methyl-d-aspartate subtype of the glutamate receptor (NMDAR) in the central nervous system. Prior to this study, the M1 mAChR subtype was viewed as the primary candidate for these actions relative to the other mAChR subtypes. Here we describe the discovery of a novel M4 PAM, VU0467154, with enhanced in vitro potency and improved pharmacokinetic properties relative to other M4 PAMs, enabling a more extensive characterization of M4 actions in rodent models. We used VU0467154 to test the hypothesis that selective potentiation of M4 receptor signaling could ameliorate the behavioral, cognitive, and neurochemical impairments induced by the noncompetitive NMDAR antagonist MK-801. VU0467154 produced a robust dose-dependent reversal of MK-801-induced hyperlocomotion and deficits in preclinical models of associative learning and memory functions, including the touchscreen pairwise visual discrimination task in wild-type mice, but failed to reverse these stimulant-induced deficits in M4 KO mice. VU0467154 also enhanced the acquisition of both contextual and cue-mediated fear conditioning when administered alone in wild-type mice. These novel findings suggest that M4 PAMs may provide a strategy for addressing the more complex affective and cognitive disruptions associated with schizophrenia and other neuropsychiatric disorders. PMID:25137629

  20. Sex-related differences in the muscarinic acetylcholinergic receptor in the healthy human brain. A positron emission tomography study

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Tsuyoshi; Kuwabara, Yasuo; Sasaki, Masayuki; Ichimiya, Atsushi; Takita, Masashi; Ogomori, Koji; Masuda, Kouji [Kyushu Univ., Fukuoka (Japan). Graduate School of Medical Sciences; Fukumura, Toshimitsu; Ichiya, Yuichi

    2000-04-01

    We evaluated the sex-related differences in the decline of the cerebral muscarinic acetylcholinergic receptor (mACh-R) due to aging by using {sup 11}C-N-methyl-4-piperidyl benzilate ({sup 11}C-NMPB) and positron emission tomography (PET). The subjects consisted of 37 (20 males and 17 females) healthy volunteers. The {sup 11}C-NMPB uptake was evaluated by the ratio method (regional {sup 11}C-NMPB uptake/Cerebellar {sup 11}C-NMPB uptake; rNMPB ratio). The correlation between sex, aging, and the rNMPB ratio in normal aging was evaluated by a multiple regression analysis. The rNMPB ratio was higher in females than in males throughout the entire cerebral region (p<0.01-p<0.0001) and the rNMPB ratio might thus possibly decline with age more rapidly in females. Our study therefore revealed the existence of sex-related differences in the cerebral mACh-R. (author)

  1. Sex-related differences in the muscarinic acetylcholinergic receptor in the healthy human brain. A positron emission tomography study

    International Nuclear Information System (INIS)

    Yoshida, Tsuyoshi; Kuwabara, Yasuo; Sasaki, Masayuki; Ichimiya, Atsushi; Takita, Masashi; Ogomori, Koji; Masuda, Kouji; Fukumura, Toshimitsu; Ichiya, Yuichi

    2000-01-01

    We evaluated the sex-related differences in the decline of the cerebral muscarinic acetylcholinergic receptor (mACh-R) due to aging by using 11 C-N-methyl-4-piperidyl benzilate ( 11 C-NMPB) and positron emission tomography (PET). The subjects consisted of 37 (20 males and 17 females) healthy volunteers. The 11 C-NMPB uptake was evaluated by the ratio method (regional 11 C-NMPB uptake/Cerebellar 11 C-NMPB uptake; rNMPB ratio). The correlation between sex, aging, and the rNMPB ratio in normal aging was evaluated by a multiple regression analysis. The rNMPB ratio was higher in females than in males throughout the entire cerebral region (p<0.01-p<0.0001) and the rNMPB ratio might thus possibly decline with age more rapidly in females. Our study therefore revealed the existence of sex-related differences in the cerebral mACh-R. (author)

  2. Experiment K-6-18. Study of muscarinic and gaba (benzodiazepine) receptors in the sensory-motor cortex, hippcampus and spinal code

    Science.gov (United States)

    Daunton, N.; Damelio, F.; Krasnov, I.

    1990-01-01

    Frontal lobe samples of rat brains flown aboard Cosmos 1887 were processed for the study of muscarinic (cholinergic) and GABA (benzodiazepine) receptors and for immunocytochemical localization of the neurotransmitter gamma-aminobutyric acid (GABA) and glial fibrillary acidic protein (GFAP). Although radioactive labeling of both muscarinic cholinergic and GABA (benzodiazepine) receptors proved to be successful with the techniques employed, distinct receptor localization of individual laminae of the frontal neocortex was not possible since the sampling of the area was different in the various groups of animals. In spite of efforts made for proper orientation and regional identification of laminae, it was found that a densitometric (quantitation of autoradiograms) analysis of the tissue did not contribute to the final interpretation of the effects of weightlessness on these receptors. As to the immunocytochemical studies the use of both markers, GFAP and GABA antiserum, confirmed the suitability of the techniques for use in frozen material. However, similar problems to those encountered in the receptor studies prevented an adequate interpretation of the effects of micro-G exposure on the localization and distribution of GABA and GFAP. This study did, however, confirm the feasibility of investigating neurotransmitters and their receptors in future space flight experiments.

  3. Muscarinic, adenosine and tropomyosin-related kinase B receptors modulate the neuromuscular developmental synapse elimination process

    OpenAIRE

    Nadal Magriñà, Laura

    2017-01-01

    El desarrollo del sistema nervioso periférico implica una inicial exuberante producción de neuronas y, una posterior reducción dependiente de actividad del número de sinapsis en las uniones neuromusculares (NMJ). Este proceso se denomina eliminación sináptica. Al final de la segunda semana postnatal, cada fibra muscular esta inervadas por una solo motoneurona. Los receptores muscarínicos de acetilcolina (mAChR), los receptores de adenosina (AR) y el receptor quinasa de tropomiosina B (TrkB) p...

  4. Reduced muscarinic receptors in the cingulate cortex in mild Alzheimer's disease demonstrated with 123I iodo-dexetamide SPECT

    International Nuclear Information System (INIS)

    Rowe, C.C.; Barnden, L.R.; Nicholas, C.; Nowakowski, K.; Boundy, K.

    2000-01-01

    Full text: Parietal hypoperfusion/hypometabolism is a feature of Alzheimer's disease (AD). In early AD this may be preceded by changes in the posterior cingulate cortex, part of the cortico-limbic circuit with connections to the medial temporal lobes. Because cholinergic function is affected in early AD, we aimed to investigate the binding of the muscarinic receptor label, I-123 iodo-dexetamide (IDEX). We recruited 11 mild (MiniMental State Examination 27-24) and 11 moderate (MMSE 23-16) Alzheimer's patients and 10 age and sex-matched normal subjects. SPECT was performed six hours after injection of 185 MBq IDEX. Sections were reconstructed with attenuation correction using an iterative algorithm (OSEM). Statistical Parametric Mapping (SPM 99) was used to analyse the data. Because there is very little IDEX uptake in the cerebellum and thalamus it was necessary to edit them from the SPM PET template. Facial and scalp activity was also edited. Global scaling relative to the basal ganglia was used. Significant areas of decreased IDEX binding were found in the mild Alzheimer's group in the cingulate cortex with pvoxel = .08 and pcluster < 0.001, (particularly the posterior cingulate), left parietotemporal junction (pcluster = 0.01) and posteromedial left temporal lobe (pcluster = 0.03). In moderate AD extensive areas of decreased binding were found in the posterior cingulate, parietal and temporal lobes. The difference between the group-means at the posterior cingulate was 14% (mild AD) and 22% (moderate AD). Hypoperfusion, hypometabolism and now reduced cholinergic receptors have been demonstrated in the posterior cingulate in mild AD. Greater attention to this area may enhance the diagnostic value of functional imaging in early AD. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

  5. Studies for transitional changes of the muscarinic acetylcholine receptor and mRNA distribution by focal ischemia using nuclear medicine

    Energy Technology Data Exchange (ETDEWEB)

    Kuji, Ichiei [Kanazawa Univ. (Japan). School of Medicine

    1994-04-01

    Assessing stress-induced brain receptor responses is important in understanding clinical brain receptor images for nuclear medicine. It is known that cholinergic neurons are decreased by Alzheimer`s disease and that there is a close relationship between cholinergic neurons and muscarinic acetylcholine receptors (mAchR). Thus, this study assessed the response of mAchR to focal ischemia using infarction model rats (prepared by middle cerebral artery occlusion) and sham-operated rats. In the same rats, three kinds of images -- ex vivo regional cerebral blood flow (rCBF) images with {sup 99m}Tc-hexametyl-propyleneamine oxime ({sup 99m}Tc-HMPAO), in vitro mAchR binding images with [{sup 3}H] quinuclidinyl benzilate ({sup 3}H-QNB), and mAchR-mRNA images by in situ hybridization method using {sup 35}S-labeled-oligonucleotide probes specific for mAchR gene subtypes of m1 to m5 -- were obtained in acute and chronic phases. Each image datum was digitalized and assessed semi-quantitatively. There were significant changes in global distribution among rCBF, mAchR and mAchR-mRNAs. In the acute phase, there was no significant change in mAchR in the infarcted area, although rCBF markedly decreased. In the chronic phase, there was a significant decrease in mAchR in the infarct-sided thalamus, although there was no change in rCBF; and there was a significant decrease in mAchR of the infarct-sided substantia nigra in spite of increase in rCBF. In the acute phase, mAchR-mRNAs of the infarct-sided caudate-putamen was decreased, suggesting that the ability of cholinergic neuron to synthesize receptor protein had decreased in the acute phase. Because mAchR was not decreased in the acute phase, some viable neurons with no normal function may be preserved in the acute phase. These results were encouraging in understanding mAchR brain images of patients with memory disturbances such as cerebrovascular dementia and Alzheimer`s disease. (N.K.).

  6. SPET imaging of central muscarinic acetylcholine receptors with iodine-123 labelled E-IQNP and Z-IQNP

    Energy Technology Data Exchange (ETDEWEB)

    Nobuhara, K.; Farde, L.; Halldin, C.; Karlsson, P.; Swahn, C.G.; Olsson, H.; Sedvall, G. [Dept. of Clinical Neuroscience, Psychiatry Section, Karolinska Hospital, Stockholm (Sweden); Bergstroem, K.A. [Dept. of Clinical Physiology, Kuopio University Hospital, Kuopio (Finland); Larsson, S.A.; Schnell, P.-O. [Dept. of Radiation Physics, Karolinska Hospital, Stockholm (Sweden); McPherson, D.W. [Oak Ridge National Laboratory (ORNL), Nuclear Medicine Group, TN (United States); Savonen, A.; Hiltunen, J. [MAP Medical Technologies Oy, Tikkakoski (Finland)

    2001-01-01

    1-Azabicyclo[2.2.2]oct-3-yl {alpha}-hydroxy-{alpha}-(1-iodo-1-propen-3-yl)-{alpha}-phenylacetate (IQNP) is a muscarinic acetylcholine receptor (mAChR) antagonist and the racemic ligand contains eight stereoisomers. In a single-photon emission tomography (SPET) study in monkeys we recently confirmed that [{sup 123}I]E-(R,R)-IQNP ([{sup 123}I]E-IQNP) is a radioligand with modest selectivity for the M{sub 1} and M{sub 4} subtypes, whereas [{sup 123}I]Z-(R,R)-IQNP ([{sup 123}I]Z-IQNP) is non-subtype selective. In the present SPET study, E- and Z-IQNP were examined in human subjects. SPET examination was performed on three male subjects after i.v. injection of [{sup 123}I]E-IQNP and in another three after i.v. injection of [{sup 123}I]Z-IQNP. The binding potential (BP) for [{sup 123}I]E-IQNP was calculated using several quantitative approaches with the cerebellum as a reference region. High-performance liquid chromatography was used to measure radioligand metabolism in plasma. Following [{sup 123}I]E-IQNP, the radioactivity was high in the neocortex and striatum, intermediate in the thalamus and low in the pons and cerebellum, which is consistent with the rank order for the regional density of M{sub 1} and M{sub 4} subtypes in vitro. For all regions, peak equilibrium was identified within the 48-h data acquisition. The simplified reference tissue approach using SPET data from 0 to 48 h was the most reliable in this limited series of subjects. Following injection of [{sup 123}I]Z-IQNP, radioactivity was high in the neocortex and striatum, intermediate in the thalamus and pons and low in the cerebellum, which is in agreement with the density of M{sub 1}, M{sub 2} and M{sub 4} subtypes as measured in vitro. Quantitative analyses provided indirect support for specific M{sub 2} binding of Z-IQNP in the cerebellum. The high selectivity of [{sup 123}I]E-IQNP for M{sub 1} and M{sub 4} receptors allowed the use of cerebellum as a reference region devoid of specific binding, and

  7. Involvement of Ca2+ Signaling in the Synergistic Effects between Muscarinic Receptor Antagonists and β2-Adrenoceptor Agonists in Airway Smooth Muscle

    Directory of Open Access Journals (Sweden)

    Kentaro Fukunaga

    2016-09-01

    Full Text Available Long-acting muscarinic antagonists (LAMAs and short-acting β2-adrenoceptor agonists (SABAs play important roles in remedy for COPD. To propel a translational research for development of bronchodilator therapy, synergistic effects between SABAs with LAMAs were examined focused on Ca2+ signaling using simultaneous records of isometric tension and F340/F380 in fura-2-loaded tracheal smooth muscle. Glycopyrronium (3 nM, a LAMA, modestly reduced methacholine (1 μM-induced contraction. When procaterol, salbutamol and SABAs were applied in the presence of glycopyrronium, relaxant effects of these SABAs are markedly enhanced, and percent inhibition of tension was much greater than the sum of those for each agent and those expected from the BI theory. In contrast, percent inhibition of F340/F380 was not greater than those values. Bisindolylmaleimide, an inhibitor of protein kinase C (PKC, significantly increased the relaxant effect of LAMA without reducing F340/F380. Iberiotoxin, an inhibitor of large-conductance Ca2+-activated K+ (KCa channels, significantly suppressed the effects of these combined agents with reducing F340/F380. In conclusion, combination of SABAs with LAMAs synergistically enhances inhibition of muscarinic contraction via decreasing both Ca2+ sensitization mediated by PKC and Ca2+ dynamics mediated by KCa channels. PKC and KCa channels may be molecular targets for cross talk between β2-adrenoceptors and muscarinic receptors.

  8. Weak toxin WTX from Naja kaouthia cobra venom interacts with both nicotinic and muscarinic acetylcholine receptors

    Czech Academy of Sciences Publication Activity Database

    Mordvintsev, D.Y.; Polyak, Y.L.; Rodionov, D.I.; Jakubík, Jan; Doležal, Vladimír; Karlsson, E.; Tsetlin, V.I.; Utkin, Y.N.

    2009-01-01

    Roč. 276, č. 18 (2009), s. 5065-5075 ISSN 1742-464X R&D Projects: GA MŠk(CZ) LC554; GA AV ČR(CZ) IAA500110703 Institutional research plan: CEZ:AV0Z50110509 Keywords : acetylcholine receptors * allosteric interaction * toxins Subject RIV: ED - Physiology Impact factor: 3.042, year: 2009

  9. Gating at the mouth of the acetylcholine receptor channel: energetic consequences of mutations in the alphaM2-cap.

    Directory of Open Access Journals (Sweden)

    Pallavi A Bafna

    2008-06-01

    Full Text Available Gating of nicotinic acetylcholine receptors from a C(losed to an O(pen conformation is the initial event in the postsynaptic signaling cascade at the vertebrate nerve-muscle junction. Studies of receptor structure and function show that many residues in this large, five-subunit membrane protein contribute to the energy difference between C and O. Of special interest are amino acids located at the two transmitter binding sites and in the narrow region of the channel, where CO gating motions generate a lowhigh change in the affinity for agonists and in the ionic conductance, respectively. We have measured the energy changes and relative timing of gating movements for residues that lie between these two locations, in the C-terminus of the pore-lining M2 helix of the alpha subunit ('alphaM2-cap'. This region contains a binding site for non-competitive inhibitors and a charged ring that influences the conductance of the open pore. alphaM2-cap mutations have large effects on gating but much smaller effects on agonist binding, channel conductance, channel block and desensitization. Three alphaM2-cap residues (alphaI260, alphaP265 and alphaS268 appear to move at the outset of channel-opening, about at the same time as those at the transmitter binding site. The results suggest that the alphaM2-cap changes its secondary structure to link gating motions in the extracellular domain with those in the channel that regulate ionic conductance.

  10. Conformational variability of the glycine receptor M2 domain in response to activation by different agonists

    DEFF Research Database (Denmark)

    Pless, Stephan Alexander; Dibas, Mohammed I; Lester, Henry A

    2007-01-01

    change. Although taurine and beta-alanine were weak partial agonists at the alpha1R19'C glycine receptor, they induced large fluorescence changes. Propofol, which drastically enhanced these currents, did not induce a glycine-like blue shift in the spectral emission peak. The inhibitors strychnine...... and picrotoxin elicited fluorescence and current changes as expected for a competitive antagonist and an open channel blocker, respectively. Glycine and taurine (or beta-alanine) also produced an increase and a decrease, respectively, in the fluorescence of a label attached to the nearby L22'C residue. Thus...

  11. Annulated heterocyclic bioisosteres of norarecoline. Synthesis and molecular pharmacology at five recombinant human muscarinic acetylcholine receptors

    DEFF Research Database (Denmark)

    Bräuner-Osborne, Hans; Ebert, B; Brann, M R

    1995-01-01

    = 0.011 microM), and 4d (IC50 = 0.0008 microM). Pharmacological effects (EC50 or Ki values) and intrinsic activities (per cent of maximal carbachol responses) were determined using five recombinant human mAChRs (m1-m5) and the functional assay, receptor selection and amplification technology (R...... inhibitors of the binding of tritiated quinuclidinyl benzilate (QNB), pirenzepine (PZ), and oxotremorine-M (Oxo-M) to tissue membrane preparations. In the [3H]-Oxo-M binding assay, receptor affinities in the low nanomolar range were measured for 4a (IC50 = 0.010 microM), 4b (IC50 = 0.003 microM), 4c (IC50...

  12. Activation of muscarinic acetylcholine receptors elicits pigment granule dispersion in retinal pigment epithelium isolated from bluegill

    OpenAIRE

    González, Alfredo; Crittenden, Elizabeth L; García, Dana M

    2004-01-01

    Abstract Background In fish, melanin pigment granules in the retinal pigment epithelium disperse into apical projections as part of the suite of responses the eye makes to bright light conditions. This pigment granule dispersion serves to reduce photobleaching and occurs in response to neurochemicals secreted by the retina. Previous work has shown that acetylcholine may be involved in inducing light-adaptive pigment dispersion. Acetylcholine receptors are of two main types, nicotinic and musc...

  13. Concomitant alteration in number and affinity of P2X and muscarinic receptors are associated with bladder dysfunction in early stage of diabetic rats.

    Science.gov (United States)

    Yoshizawa, Tsuyoshi; Hayashi, Yukio; Yoshida, Akira; Yoshida, Shohei; Ito, Yoshihiko; Yamaguchi, Kenya; Yamada, Shizuo; Takahashi, Satoru

    2018-03-01

    To investigate time course of bladder dysfunction and concurrent changes in number and affinity of the muscarinic and P 2 X receptor in the early stage of streptozotocin (STZ)-induced diabetic rats. Diabetic rats were prepared by the intraperitoneal injection of 50 mg/kg of STZ to 7-week-old female Wistar rats. We performed recording of 24-h voiding behavior and cystometry at 1, 4, 8, and 12 weeks after the induction of diabetes. A muscle strip experiments with electrical field stimulation (EFS), carbachol, and α,β-methylene adenosine 5'-triphosphate (α,β-MeATP) were also performed at the same time-points. Additionally, concurrent changes in number and affinity of bladder muscarinic and P 2 X receptor were measured by a radioreceptor assay using [N-methyl- 3 H] scopolamine methyl chloride ([ 3 H]NMS) and α,β-methylene-ATP (2,8- 3 H) tetrasodium salt ([ 3 H]α,β-MeATP). In STZ-induced diabetic rats, polydipsic polyuric pollakiuria were noted on recording of 24-h voiding behavior from early stage. Also, the residual urine volume markedly increased in diabetic rats on cystometry. In the muscle strip experiment, the detrusor contractions induced by EFS, carbachol, and α,β-MeATP were enhanced in STZ-induced diabetic rats. Based on the radioreceptor assay, the maximum number of sites (Bmax) for the specific binding of [ 3 H]NMS and [ 3 H]α,β-MeATP was concurrently increased in the bladder from diabetic rats. Increased bladder contractility is found in early stage of diabetic rats. Then, bladder dysfunction is associated with increased number of muscarinic and P 2 X receptors in STZ-induced diabetic rats.

  14. The interaction between tropomyosin-related kinase B receptors and presynaptic muscarinic receptors modulates transmitter release in adult rodent motor nerve terminals.

    Science.gov (United States)

    Garcia, Neus; Tomàs, Marta; Santafé, Manel M; Besalduch, Nuria; Lanuza, Maria A; Tomàs, Josep

    2010-12-08

    The neurotrophin brain-derived neurotrophic factor (BDNF), neurotrophin-4 (NT-4) and the receptors tropomyosin-related kinase B (trkB) and p75(NTR) are present in the nerve terminals on the neuromuscular junctions (NMJs) of the levator auris longus muscle of the adult mouse. Exogenously added BDNF or NT-4 increased evoked ACh release after 3 h. This presynaptic effect (the size of the spontaneous potentials is not affected) is specific because it is not produced by neurotrophin-3 (NT-3) and is prevented by preincubation with trkB-IgG chimera or by pharmacological block of trkB [K-252a (C₂₇H₂₁N₃O₅)] or p75(NTR) [Pep5 (C₈₆H₁₁₁N₂₅O₁₉S₂] signaling. The effect of BDNF depends on the M₁ and M₂ muscarinic acetylcholine autoreceptors (mAChRs) because it is prevented by atropine, pirenzepine and methoctramine. We found that K-252a incubation reduces ACh release (~50%) in a short time (1 h), but the p75(NTR) signaling inhibitor Pep5 does not have this effect. The specificity of the K-252a blocking effect on trkB was confirmed with the anti-trkB antibody 47/trkB, which reduces evoked ACh release, like K-252a, whereas the nonpermeant tyrosine kinase blocker K-252b does not. Neither does incubation with the fusion protein trkB-IgG (to chelate endogenous BDNF/NT-4), anti-BDNF or anti-NT-4 change ACh release. Thus, the trkB receptor normally seems to be coupled to ACh release when there is no short-term local effect of neurotrophins at the NMJ. The normal function of the mAChR mechanism is a permissive prerequisite for the trkB pathway to couple to ACh release. Reciprocally, the normal function of trkB modulates M₁- and M₂-subtype muscarinic pathways.

  15. Drugs interfering with Muscarinic Acetylcholine Receptors and Their effects on Place Navigation

    Czech Academy of Sciences Publication Activity Database

    Svoboda, Jan; Popelíková, Anna; Stuchlík, Aleš

    2017-01-01

    Roč. 8, Nov 9 (2017), č. článku 215. ISSN 1664-0640 R&D Projects: GA ČR(CZ) GA17-04047S; GA ČR NV17-30833A; GA MŠk(CZ) LM2015062 Grant - others:AV ČR(CZ) PAN-17-07 Program:Bilaterální spolupráce Institutional support: RVO:67985823 Keywords : scopolamine * biperiden * acetylcholine * receptor * behavior * learning Subject RIV: FH - Neurology OBOR OECD: Neurosciences (including psychophysiology Impact factor: 3.532, year: 2016

  16. Nicotinic and muscarinic cholinergic receptors are recruited by acetylcholine-mediated neurotransmission within the locus coeruleus during the organisation of post-ictal antinociception.

    Science.gov (United States)

    de Oliveira, Rithiele Cristina; de Oliveira, Ricardo; Biagioni, Audrey Franceschi; Falconi-Sobrinho, Luiz Luciano; Dos Anjos-Garcia, Tayllon; Coimbra, Norberto Cysne

    2016-10-01

    Post-ictal antinociception is characterised by an increase in the nociceptive threshold that accompanies tonic and tonic-clonic seizures (TCS). The locus coeruleus (LC) receives profuse cholinergic inputs from the pedunculopontine tegmental nucleus. Different concentrations (1μg, 3μg and 5μg/0.2μL) of the muscarinic cholinergic receptor antagonist atropine and the nicotinic cholinergic receptor antagonist mecamylamine were microinjected into the LC of Wistar rats to investigate the role of cholinergic mechanisms in the severity of TCS and the post-ictal antinociceptive response. Five minutes later, TCS were induced by systemic administration of pentylenetetrazole (PTZ) (64mg/kg). Seizures were recorded inside the open field apparatus for an average of 10min. Immediately after seizures, the nociceptive threshold was recorded for 130min using the tail-flick test. Pre-treatment of the LC with 1μg, 3μg and 5μg/0.2μL concentrations of both atropine and mecamylamine did not cause a significant effect on seizure severity. However, the same treatments decreased the post-ictal antinociceptive phenomenon. In addition, mecamylamine caused an earlier decrease in the post-ictal antinociception compared to atropine. These results suggest that muscarinic and mainly nicotinic cholinergic receptors of the LC are recruited to organise tonic-clonic seizure-induced antinociception. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Demonstration of a reduction in muscarinic receptor binding in early Alzheimer's disease using iodine-123 dexetimide single-photon emission tomography

    International Nuclear Information System (INIS)

    Claus, J.J.; Dubois, E.A.; Booij, J.; Habraken, J.; Munck, J.C. van; Herk, M. van; Verbeeten, B. Jr.; Royen, E.A. van

    1997-01-01

    Decreased muscarinic receptor binding has been suggested in single-photon emission tomography (SPET) studies of Alzheimer's disease. However, it remains unclear whether these changes are present in mildly demented patients, and the role of cortical atrophy in receptor binding assessment has not been investigated. We studied muscarinic receptor binding normalized to neostriatum with SPET using [ 123 I[4-iododexetimide in five mildly affected patients with probable Alzheimer's disease and in five age-matched control subjects. Region of interest (ROI) analysis was performed in a consensus procedure blind to clinical diagnosis using matched magnetic resonance (MRI) images. Cortical atrophy was assessed by calculating percentages of cerebrospinal fluid in each ROI. An observer study with three observers was conducted to validate this method. Alzheimer patients showed statistically significantly less [ 123 I[4-iododexetimide binding in left temporal and right temporo-parietal cortex compared with controls, independent of age, sex and cortical atrophy. Mean intra-observer variability was 3.6% and inter-observer results showed consistent differences in [ 123 I[4-iododexetimide binding between observers. However, differences between patients and controls were comparable among observers and statistically significant in the same regions as in the consensus procedure. Using an MRI-SPET matching technique, we conclude that [ 123 I[4-iododexetimide binding is reduced in patients with mild probable Alzheimer's disease in areas of temporal and temporo-parietal cortex. (orig.). With 1 fig., 4 tabs

  18. In vivo biodistribution of two [18F]-labelled muscarinic cholinergic receptor ligands: 2-[18F]- and 4-[18F]-fluorodexetimide

    International Nuclear Information System (INIS)

    Wilson, A.A.; Scheffel, U.A.; Dannals, R.F.; Stathis, M.; Ravert, H.T.; Wagner, H.N. Jr.

    1991-01-01

    Two [ 18 F]-labelled analogues of the potent muscarinic cholinergic receptor (m-AChR) antagonist, dexetimide, were evaluated as potential ligands for imaging m-AChR by positron emission tomography (PET). Intravenous administration of both 2-[ 18 F]- or 4-[ 18 F]-fluorodexetimide resulted in high brain uptake of radioactivity in mice. High binding levels were observed in m-AChR rich areas, such as cortex and striatum, with low levels in the receptor-poor cerebellum. Uptake of radioactivity was saturable and could be blocked by pre-administration of dexetimide or atropine. Drugs with different sites of action were ineffective at blocking receptor binding. The results indicate that both radiotracers are promising candidates for use in PET studies

  19. Guanosine 5'-triphosphate binding protein (G/sub i/) and two additional pertussis toxin substrates associated with muscarinic receptors in rat heart myocytes: characterization and age dependency

    International Nuclear Information System (INIS)

    Moscona-Amir, E.; Henis, Y.I.; Sokolovsky, M.

    1988-01-01

    The coupling of muscarinic receptors with G-proteins was investigated in cultured myocytes prepared from the hearts of newborn rats. The coupling was investigated in both young (5 days after plating) and aged (14 days after plating) cultures, in view of the completely different effects of 5'-guanylyl imidodiphosphate [Gpp(NH)p] on muscarinic agonist binding to homogenates from young vs aged cultures. Pretreatment of cultures from both ages by Bordetella pertussis toxin (IAP) was found to eliminate any Gpp(NH)p effect on carbamylcholine binding. IAP by itself induced a rightward shift in the carbamylcholine competition curve in homogenates from aged cultures, but no such effect was observed in homogenates from young cultures. IAP-catalyzed [ 32 P]ADP-ribosylation of membrane preparations from young and aged cultures revealed major differences between them. Young cultures exhibited a major IAP substrate at 40 kDa, which was also recognized by anti-α/sub i/ antibodies, and two novel IAP substrates at 28 and 42 kDa, which were weakly ADP-ribosylated by the toxin and were not recognized with either anti-α/sub i/ or anti-α 0 antibodies. In aged cultures, only the 40-kDa band (ribosylated to a lower degree) was detected. The parallel age-dependent changes in the three IAP substrates (28, 40, and 42 kDa) and in the interactions of the G-protein(s) with the muscarinic receptors strongly suggest close association between the two phenomena. All of these age-dependent changes in the G-protein related parameters were prevented by phosphatidylcholine-liposome treatment of the aged cultures. The role of the membrane lipid composition in these phenomena is discussed

  20. Biochemical characterization of a heterotrimeric G(i)-protein activator peptide designed from the junction between the intracellular third loop and sixth transmembrane helix in the m4 muscarinic acetylcholine receptor.

    Science.gov (United States)

    Terawaki, Shin-ichi; Matsubayashi, Rina; Hara, Kanako; Onozuka, Tatsuki; Kohno, Toshiyuki; Wakamatsu, Kaori

    Muscarinic acetylcholine receptors (mAChRs) are G-protein coupled receptors (GPCRs) that are activated by acetylcholine released from parasympathetic nerves. The mAChR family comprises 5 subtypes, m1-m5, each of which has a different coupling selectivity for heterotrimeric GTP-binding proteins (G-proteins). m4 mAChR specifically activates the Gi/o family by enhancing the guanine nucleotide exchange factor (GEF) reaction with the Gα subunit through an interaction that occurs via intracellular segments. Here, we report that the m4 mAChR mimetic peptide m4i3c(14)Gly, comprising 14 residues in the junction between the intracellular third loop (i3c) and transmembrane helix VI (TM-VI) extended with a C-terminal glycine residue, presents GEF activity toward the Gi1 α subunit (Gαi1). The m4i3c(14)Gly forms a stable complex with guanine nucleotide-free Gαi1 via three residues in the VTI(L/F) motif, which is conserved within the m2/4 mAChRs. These results suggest that this m4 mAChR mimetic peptide, which comprises the amino acid of the mAChR intracellular segments, is a useful tool for understanding the interaction between GPCRs and G-proteins. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. The Beneficial Effect of Fesoterodine, a Competitive Muscarinic Receptor Antagonist on Erectile Dysfunction in Streptozotocin-induced Diabetic Rats.

    Science.gov (United States)

    Yilmaz-Oral, Didem; Bayatli, Nur; Gur, Serap

    2017-09-01

    To investigate the possible role of fesoterodine (a competitive muscarinic receptor antagonist) on erectile dysfunction in streptozotocin-induced diabetic rats. A total of 16 adult male Sprague-Dawley rats were equally divided into control and diabetic groups. Diabetes was induced by a single intravenous injection of streptozotocin (25-35 mg/kg). In vivo erectile responses were evaluated by the stimulation of cavernosal nerves, and measurements were repeated after the intracavernosal injection of fesoterodine (1 µM) in rats. The relaxation responses to fesoterodine were examined via incubation with various inhibitors. The relaxant responses of corpus cavernosum (CC) strips were observed in the presence or the absence of fesoterodine (10 µM). Intracavernous administration of fesoterodine restored in vivo erectile response at 5.0- and 7.5-V levels, except for 2.5 V in diabetic rats. Basal intracavernosal pressure (5.4 ± 0.9 mm Hg) in diabetic rats was markedly increased after injection of fesoterodine (33.9 ± 7.9 mm Hg, P <.001). In bath studies, fesoterodine resulted in a relaxation of CC in a concentration-dependent manner, which was reduced in diabetic rats. Nifedipine (l-type Ca 2+ channel blocker) inhibited maximum fesoterodine-induced relaxation by 58%. The nonselective K + channel blocker tetraethylammonium and glibenclamide incubation did not change the relaxant response to fesoterodine. The relaxant responses to acetylcholine (10 µM), electrical field stimulation (10 Hz), and sodium nitroprusside (0.01 µM) in diabetic rats were increased after incubation with fesoterodine (10 µM). Fesoterodine improved erectile function and relaxation of isolated strips of rat CC. The underlying mechanism of fesoterodine is likely due to the blocking of l-type calcium channels independent of the nitric oxide-cyclic guanosine monophosphate pathway. Further investigations are warranted to fully elucidate the restorative effects of

  2. Ligand binding and functional characterization of muscarinic acetylcholine receptors on the TE671/RD human cell line

    International Nuclear Information System (INIS)

    Bencherif, M.; Lukas, R.J.

    1991-01-01

    Cells of the TE671/RD human clonal line express a finite number ((Bmax) of about 350 fmol/mg of membrane protein) of apparently noninteracting, high-affinity binding sites (KD of 0.07 nM and a Hill coefficient close to unity, nH = 0.94) for the muscarinic acetylcholine receptor (mAChR) radio antagonist, tritium-labeled quinuclidinyl benzilate [ 3 H-QNB]. The rank order potency of selective antagonists that inhibit specific 3 HQNB binding is: atropine greater than 4-DAMP (4-diphenylacetoxy-N-methylpiperidine methiodide) greater than pirenzepine greater than methoctramine greater than AFDx-116 (11-2[2-[(diethylamino)methyl]-1-[piperidinyl] acetyl]-5,11-dihydro-6H-pyrido[2,3-b][1,4]benzodiazepin-6-one). Functional studies indicate that phosphoinositide (PIns) hydrolysis in TE671/RD cells is increased by carbachol (EC50 of 10 microM), but not by nicotine (to concentrations as high as 1 mM). Agonist-stimulated PIns metabolism is inhibited by antagonists with the same rank order potency as for inhibition of 3 HQNB binding. Functional responses are augmented in the presence of a nonhydrolyzable GTP analog, are strongly inhibited after 24-hr exposure to cholera toxin, but are only slightly inhibited after long-term exposure to pertussis toxin or forskolin. These studies identify a pharmacologically-defined M3-subtype of mAChR strongly coupled via a cholera toxin-sensitive mechanism to PIns hydrolysis in these cells. Within 1 hr of treatment of TE671/RD cells with 1 mM dibutyryl cyclic AMP or with 10 microM phorbol-12-myristate-13-acetate (PMA), there is a 30 to 50% decrease in carbachol-stimulated PIns responsiveness that recovers to control values after 5 days of continued drug treatment. However, a comparable and more persistent inhibition of mAChR function is observed on cell treatment with 20 nM PMA

  3. Ligand binding and functional characterization of muscarinic acetylcholine receptors on the TE671/RD human cell line

    Energy Technology Data Exchange (ETDEWEB)

    Bencherif, M.; Lukas, R.J. (Division of Neurobiology, Barrow Neurological Institute, Phoenix, Arizona (USA))

    1991-06-01

    Cells of the TE671/RD human clonal line express a finite number ((Bmax) of about 350 fmol/mg of membrane protein) of apparently noninteracting, high-affinity binding sites (KD of 0.07 nM and a Hill coefficient close to unity, nH = 0.94) for the muscarinic acetylcholine receptor (mAChR) radio antagonist, tritium-labeled quinuclidinyl benzilate ({sup 3}H-QNB). The rank order potency of selective antagonists that inhibit specific {sup 3}HQNB binding is: atropine greater than 4-DAMP (4-diphenylacetoxy-N-methylpiperidine methiodide) greater than pirenzepine greater than methoctramine greater than AFDx-116 (11-2(2-((diethylamino)methyl)-1-(piperidinyl) acetyl)-5,11-dihydro-6H-pyrido(2,3-b)(1,4)benzodiazepin-6-one). Functional studies indicate that phosphoinositide (PIns) hydrolysis in TE671/RD cells is increased by carbachol (EC50 of 10 microM), but not by nicotine (to concentrations as high as 1 mM). Agonist-stimulated PIns metabolism is inhibited by antagonists with the same rank order potency as for inhibition of {sup 3}HQNB binding. Functional responses are augmented in the presence of a nonhydrolyzable GTP analog, are strongly inhibited after 24-hr exposure to cholera toxin, but are only slightly inhibited after long-term exposure to pertussis toxin or forskolin. These studies identify a pharmacologically-defined M3-subtype of mAChR strongly coupled via a cholera toxin-sensitive mechanism to PIns hydrolysis in these cells. Within 1 hr of treatment of TE671/RD cells with 1 mM dibutyryl cyclic AMP or with 10 microM phorbol-12-myristate-13-acetate (PMA), there is a 30 to 50% decrease in carbachol-stimulated PIns responsiveness that recovers to control values after 5 days of continued drug treatment. However, a comparable and more persistent inhibition of mAChR function is observed on cell treatment with 20 nM PMA.

  4. Highly specific detection of muscarinic M3 receptor, G protein interaction and intracellular trafficking in human detrusor using Proximity Ligation Assay (PLA).

    Science.gov (United States)

    Berndt-Paetz, Mandy; Herbst, Luise; Weimann, Annett; Gonsior, Andreas; Stolzenburg, Jens-Uwe; Neuhaus, Jochen

    2018-05-01

    Muscarinic acetylcholine receptors (mAChRs) regulate a number of important physiological functions. Alteration of mAChR expression or function has been associated in the etiology of several pathologies including functional bladder disorders (e.g bladder pain syndrome/interstitial cystitis - BPS/IC). In a previous study we found specific mAChR expression patterns associated with BPS/IC, while correlation between protein and gene expression was lacking. Posttranslational regulatory mechanisms, e.g. altered intracellular receptor trafficking, could explain those differences. In addition, alternative G protein (GP) coupling could add to the pathophysiology via modulation of muscarinic signaling. In our proof-of-principle study, we addressed these questions in situ. We established PLA in combination with confocal laserscanning microscopy (CLSM) and 3D object reconstruction for highly specific detection and analysis of muscarinic 3 receptors (M3), G protein (GP) coupling and intracellular trafficking in human detrusor samples. Paraffin sections of formalin-fixed bladder tissue (FFPE) of BPS/IC patients receiving transurethral biopsy were examined by Cy3-PLA for M3 expression, coupling of M3 to GPs (G αq/11 , G αs , G αi ) and interaction of M3 with endocytic regulator proteins. Membranes were labeled with wheat germ agglutinin-Alexa Fluor ® 488, nuclei were stained with DAPI. Object density and co-localization were analyzed in 3D-reconstruction of high resolution confocal z-stacks. Confocal image stack processing resulted in well demarcated objects. Calculated receptor densities correlated significantly with existing confocal expression data, while significantly improved specificity of M3 detection by PLA was verified using bladder tissue samples from transgenic mice. 50-60% of the M3 receptor complexes were plasma membrane associated in human bladder detrusor. Application of PLA for M3 and GPs allowed visualization of M3-GP interactions and revealed individual GP

  5. Muscarinic responses of gastric parietal cells

    International Nuclear Information System (INIS)

    Wilkes, J.M.; Kajimura, M.; Scott, D.R.; Hersey, S.J.; Sachs, G.

    1991-01-01

    Isolated rabbit gastric glands were used to study the nature of the muscarinic cholinergic responses of parietal cells. Carbachol stimulation of acid secretion, as measured by the accumulation of aminopyrine, was inhibited by the M1 antagonist, pirenzepine, with an IC50 of 13 microM; by the M2 antagonist, 11,2-(diethylamino)methyl-1 piperidinyl acetyl-5,11-dihydro-6H-pyrido 2,3-b 1,4 benzodiazepin-6-one (AF-DX 116), with an IC50 of 110 microM; and by the M1/M3 antagonist, diphenyl-acetoxy-4-methylpiperidinemethiodide, with an IC50 of 35 nM. The three antagonists displayed equivalent IC50 values for the inhibition of carbachol-stimulated production of 14CO2 from radiolabeled glucose, which is a measure of the turnover of the H,K-ATPase, the final step of acid secretion. Intracellular calcium levels were measured in gastric glands loaded with FURA 2. Carbachol was shown to both release calcium from an intracellular pool and to promote calcium entry across the plasma membrane. The calcium entry was inhibitable by 20 microM La3+. The relative potency of the three muscarinic antagonists for inhibition of calcium entry was essentially the same as for inhibition of acid secretion or pump related glucose oxidation. Image analysis of the glands showed the effects of carbachol, and of the antagonists, on intracellular calcium were occurring largely in the parietal cell. The rise in cell calcium due to release of calcium from intracellular stores was inhibited by 4-DAMP with an IC50 of 1.7 nM, suggesting that the release pathway was regulated by a low affinity M3 muscarinic receptor or state; Ca entry and acid secretion are regulated by a high affinity M3 muscarinic receptor or state, inhibited by higher 4-DAMP concentrations, suggesting that it is the steady-state elevation of Ca that is related to parietal cell function rather than the [Ca]i transient

  6. Effects of Saw Palmetto Extract on Urodynamic Parameters, Bladder Muscarinic and Purinergic Receptors and Urinary Cytokines in Rats with Cyclophosphamide-Induced Cystitis.

    Science.gov (United States)

    Nasrin, Sweety; Masuda, Eiji; Kugaya, Haruna; Osano, Ayaka; Ito, Yoshihiko; Yamada, Shizuo

    2014-01-01

    To clarify the effect of saw palmetto extract (SPE), a phytotherapeutic agent, on urodynamic parameters, bladder muscarinic and purinergic receptors, and urinary cytokines in rats with cystitis induced by cyclophosphamide (CYP). Saw palmetto extract (60 mg/kg per day) was administered orally twice a day for 7 days to rats. The urodynamic parameters in CYP (150 mg/kg i.p.)-treated rats were monitored by a cystometric method under anesthesia. The muscarinic and purinergic receptors in the bladder and submaxillary gland were measured by radioreceptor assays using [N-methyl-(3) H] scopolamine chloride([(3) H]NMS) and αβ-methylene-ATP [2,8-(3) H] tetrasodium salt ([(3) H]αβ-MeATP), respectively. Urinary cytokines (interleukin-1β [IL-1β], IL-6 and L-17) were measured with enzyme linked immunosorbent assay kits. Micturition interval and micturition volume were significantly decreased and the frequency of micturition and basal pressure were significantly increased in the CYP-treated rats compared with sham-operated rats. Orally administered SPE significantly increased the micturition interval and micturition volume and decreased the frequency of micturition and basal pressure. The maximal number of sites (Bmax ) for the specific binding of [(3) H]NMS and [(3) H]αβ-MeATP was significantly decreased in the bladder. The decrease in receptors was attenuated by repeated treatment with SPE. An elevation in urinary cytokine (IL-1β and IL-17) levels were seen, and this increase was effectively suppressed by SPE treatment. Saw palmetto extract attenuates the alteration of urodynamic parameters, pharmacologically relevant receptors, and urinary cytokines in CYP-treated rats. Therefore, SPE may be a potential therapeutic agent for improving the clinical symptoms of cystitis. © 2013 Wiley Publishing Asia Pty Ltd.

  7. Differential anti-ischaemic effects of muscarinic receptor blockade in patients with obstructive coronary artery disease; impaired vs normal left ventricular function.

    NARCIS (Netherlands)

    A.F. van den Heuvel; D.J. van Veldhuisen (Dirk); G.L. Bartels; M. van der Ent (Martin); W.J. Remme (Willem)

    1999-01-01

    textabstractAIMS: In patients with coronary artery disease acetylcholine (a muscarinic agonist) causes vasoconstriction. The effect of atropine (a muscarinic antagonist) on coronary vasotone in patients with normal or impaired left ventricular function is unknown.

  8. Interactions between allosteric modulators and 4-DAMP and other antagonists at muscarinic receptors: potential significance of the distance between the N and Carboxyl C atoms in the molecules of antagonists

    Czech Academy of Sciences Publication Activity Database

    Lysíková, Michaela; Havlas, Zdeněk; Tuček, Stanislav

    2001-01-01

    Roč. 26, č. 4 (2001), s. 383-394 ISSN 0364-3190 R&D Projects: GA ČR GA309/99/0214; GA MŠk LN00A032 Institutional research plan: CEZ:AV0Z5011922 Keywords : muscarinic receptors * allosteric modulation * 4-DAMP Subject RIV: ED - Physiology Impact factor: 1.638, year: 2001

  9. Interactions of alaproclate, a selective 5HT-uptake blocker, with muscarinic receptors: in vivo and in vitro studies

    International Nuclear Information System (INIS)

    Danielsson, E.; Bartfai, T.; Nordstrom, O.; Ogren, S.O.; Unden, A.

    1986-01-01

    Cholinergic mechanisms play an important role in higher brain functions such as learning or memory. It is hoped that drugs which improve cholinergic transmission would be therapeutically effective in senile dementia. The results of biochemical studies on the interaction of alaproclate with the muscarinic system are summarized. Tritium-4-N-methylpiperidinylbenzilate and methyl tritium-choline chloride were used in the studies. Salivation and hypothermia were studied in adult male mice following injection of alaproclate preceding the injection of oxotremorine by 30 min. Salivation, tremor and hypothermia caused by oxotremorine were found to be centrally mediated muscarinic responses. Tritium-ACh release was studied from synaptosomes. The metabolites of alaproclate, alanine and 2(4 chlorophenyl) 1-1 dimethylethanol, do not produce tremor

  10. Evidence for cholinergic participation in the control of bird song; acetylcholinesterase distribution and muscarinic receptor autoradiography in the zebra finch brain

    International Nuclear Information System (INIS)

    Ryan, S.M.; Arnold, A.P.

    1981-01-01

    Brain regions thought to be involved in the control of song in the zebra finch (Poephila guttata), were examined histochemically using the Karnovsky and Roots direct-coloring method for the detection of acetylcholinesterase (AChE) and the autoradiographic method for the localization of muscarinic cholinergic receptors following injection of tritiated quinuclidinyl benzilate (3H QNB). All presently identified vocal control nuclei in both males and females contain AChE. These nuclei include Area X, magnocellular nucleus of the anterior neostriatum (MAN), nucleus interface (NIF), caudal nucleus of the hyperstriatum ventrale (HVc), intercollicular nucleus (ICo), nucleus uva, robust nucleus of the archistriatum (RA), and tracheosyringeal portion of the hypoglossal nerve nucleus (nXIIts). All nuclei except Area X contain mostly AChE-synthesizing cell bodies. All of these nuclei contain some AChE in the neuropil, with particularly intense staining in Area X, the surrounding LPO, and the dorsomedial portion of ICo. In agreement with this description are very high concentrations of 3H QNB in both Area X and the dorsomedial ICo. HVc also appears specifically labeled. Evidence from these two histological technique suggests that efferent projections of most vocal control area may utilize acetylcholine, and that several of the vocal control nuclei may themselves receive muscarinic cholinergic projection. In Area X, there are sex differences of AChE neuropil staining. This evidence suggesting that sexually dimorphic projections to or within Area X are cholinergic or cholinoceptive

  11. Effect of aqueous extract of mango kernel (Mangifera Indica on basal activity of virgin rat uterine smooth muscle: role of muscarinic receptors

    Directory of Open Access Journals (Sweden)

    Mehdi Noureddini

    2017-04-01

    Full Text Available Background: Mango belongs to the Anacardiaceae and the extracts from its stems, leaves, fruit and kernel are reported to affect smooth muscle contractility. We studied the role of cholinergic muscarinic receptors for the effects of aqueous extract of mango kernel (Mangifera indica on the basal activity of virgin rat uterine smooth muscle. Materials and Methods: In this experimental study, mid-sections (n=24 of the uterine of healthy virgin rats were placed in an organ bath containing carbonated Tyrode’s solution under 1 g tension. The cumulative effects of the aqueous extracts of mango kernel (0.002, 0.02, 0.2, 2, 20, 200, and 2000 μg/mL or extract vehicle (Tyrode’s solution in the presence or absence of atropine were examined by isometric method using the strength, frequency and contractile activity of uterine smooth muscle. Results: The cumulative concentrations (0.002-20 µg/ml of mango kernel aqueous extract was significantly decreased the strength, frequency and contractile activity of uterine smooth muscle, but the contractile activity was returned to the basal level at the concentrations of 200 and 2000 µg/ml. Atropine (1 µM could not significantly change the effects of cumulative use of extract on the strength and contractile activity of uterine smooth muscle, but it significantly enhanced the contractile frequency at low concentrations. Conclusion: The effects of aqueous extract of mango kernel on the activity of the uterine smooth muscle might not be through cholinergic muscarinic receptors and atropine could enhance the effects of the extract on frequency through other receptors.

  12. Nitric oxide/cGMP/PKG signaling pathway activated by M1-type muscarinic acetylcholine receptor cascade inhibits Na+-activated K+ currents in Kenyon cells

    Science.gov (United States)

    Hasebe, Masaharu

    2016-01-01

    The interneurons of the mushroom body, known as Kenyon cells, are essential for the long-term memory of olfactory associative learning in some insects. Some studies have reported that nitric oxide (NO) is strongly related to this long-term memory in Kenyon cells. However, the target molecules and upstream and downstream NO signaling cascades are not completely understood. Here we analyzed the effect of the NO signaling cascade on Na+-activated K+ (KNa) channel activity in Kenyon cells of crickets (Gryllus bimaculatus). We found that two different NO donors, S-nitrosoglutathione (GSNO) and S-nitroso-N-acetyl-dl-penicillamine (SNAP), strongly suppressed KNa channel currents. Additionally, this inhibitory effect of GSNO on KNa channel activity was diminished by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), an inhibitor of soluble guanylate cyclase (sGC), and KT5823, an inhibitor of protein kinase G (PKG). Next, we analyzed the role of ACh in the NO signaling cascade. ACh strongly suppressed KNa channel currents, similar to NO donors. Furthermore, this inhibitory effect of ACh was blocked by pirenzepine, an M1 muscarinic ACh receptor antagonist, but not by 1,1-dimethyl-4-diphenylacetoxypiperidinium iodide (4-DAMP) and mecamylamine, an M3 muscarinic ACh receptor antagonist and a nicotinic ACh receptor antagonist, respectively. The ACh-induced inhibition of KNa channel currents was also diminished by the PLC inhibitor U73122 and the calmodulin antagonist W-7. Finally, we found that ACh inhibition was blocked by the nitric oxide synthase (NOS) inhibitor NG-nitro-l-arginine methyl ester (l-NAME). These results suggested that the ACh signaling cascade promotes NO production by activating NOS and NO inhibits KNa channel currents via the sGC/cGMP/PKG signaling cascade in Kenyon cells. PMID:26984419

  13. Triazolam-induced modulation of muscarinic acetylcholine receptor in living brain slices as revealed by a new positron-based imaging technique

    International Nuclear Information System (INIS)

    Murata, T.; Matsumura, K.; Onoe, H.; Watanabe, Y.; Sihver, S.; Sihver, W.; Langstroem, B.; Bergstroem, M.; Yonekura, Y.

    1997-01-01

    The effect of triazolam, a potent benzodiazepine (BZ) agonist, on muscarinic acetylcholinergic receptor (mAChR) binding was investigated in living brain slices by use of a novel positron-based imaging technique. Fresh rat brain slices were incubated with [ 11 C]N-methyl-4-piperidylbenzilate ([ 11 C]NMPB), a mAChR antagonist, in oxygenated Krebs-Ringer solution at 37 degree C. During incubation, time-resolved imaging of [ 11 C]NMPB binding in the slices was constructed on the storage phosphor screens. Addition of triazolam (1 μM) plus muscimol (30 μM), a GABA A receptor agonist, to the incubation mixture decreased the specific binding of [ 11 C]NMPB. Ro15-1788, a BZ receptor antagonist, prevented this effect, indicating that the effect was exerted through the GABA A /BZ receptor complex. These results demonstrated that stimulation of the GABA A /BZ receptor lowers the affinity of the mAChR for its ligand, which may underlie the BZ-induced amnesia, a serious clinical side effect of BZ. No such effect in the P2-fraction instead implies that the integrity of the neuronal cells and/or their environment is prerequisite for the modulation of mAChR by GABA A /BZ stimulation. (author)

  14. Combined treatment with a β3 -adrenergic receptor agonist and a muscarinic receptor antagonist inhibits detrusor overactivity induced by cold stress in spontaneously hypertensive rats.

    Science.gov (United States)

    Imamura, Tetsuya; Ogawa, Teruyuki; Minagawa, Tomonori; Nagai, Takashi; Suzuki, Toshiro; Saito, Tetsuichi; Yokoyama, Hitoshi; Nakazawa, Masaki; Ishizuka, Osamu

    2017-04-01

    This study determined if combined treatment with the muscarinic receptor (MR) antagonist solifenacin and the β 3 -adrenergic receptor (AR) agonist mirabegron could inhibit detrusor overactivity induced by cold stress in spontaneously hypertensive rats (SHRs). Thirty-two female 10-week-old SHRs were fed an 8% NaCl-supplemented diet for 4 weeks. Cystometric measurements of the unanesthetized, unrestricted rats were performed at room temperature (RT, 27 ± 2°C) for 20 min. The rats were then intravenously administered vehicle, 0.1 mg/kg solifenacin alone, 0.1 mg/kg mirabegron alone, or the combination of 0.1 mg/kg mirabegron and 0.1 mg/kg solifenacin (n = 8 each group). Five minutes later, the treated rats were exposed to low temperature (LT, 4 ± 2°C) for 40 min. Finally, the rats were returned to RT. After the cystometric investigations, the β 3 -ARs and M 3 -MRs expressed within the urinary bladders were analyzed. Just after transfer from RT to LT, vehicle-, solifenacin-, and mirabegron-treated SHRs exhibited detrusor overactivity that significantly decreased voiding interval and bladder capacity. However, treatment with the combination of solifenacin and mirabegron partially inhibited the cold stress-induced detrusor overactivity patterns. The decreases of voiding interval and bladder capacity in the combination-treated rats were significantly inhibited compared to other groups. Within the urinary bladders, there were no differences between expression levels of M 3 -MR and β 3 -AR mRNA. The tissue distribution of M 3 -MRs was similar to that of the β 3 -ARs. This study suggested that the combination of solifenacin and mirabegron act synergistically to inhibit the cold stress-induced detrusor overactivity in SHRs. Neurourol. Urodynam. 36:1026-1033, 2017. © 2016 The Authors. Neurourology and Urodynamics Published by Wiley Periodicals, Inc. © 2016 The Authors. Neurourology and Urodynamics Published by Wiley Periodicals, Inc.

  15. Effects of muscarinic M1 and M4 acetylcholine receptor stimulation on extinction and reinstatement of cocaine seeking in male mice, independent of extinction learning.

    Science.gov (United States)

    Stoll, Kevin; Hart, Rachel; Lindsley, Craig W; Thomsen, Morgane

    2018-03-01

    Stimulating muscarinic M 1 /M 4 receptors can blunt reinforcing and other effects of cocaine. A hallmark of addiction is continued drug seeking/craving after abstinence and relapse. We tested whether stimulating M 1 and/or M 4 receptors could facilitate extinction of cocaine seeking, and whether this was mediated via memory consolidation. Experimentally naïve C57BL/6J mice were allowed to acquire self-administration of intravenous cocaine (1 mg/kg/infusion) under a fixed-ratio 1 schedule of reinforcement. Then, saline was substituted for cocaine until responding extinguished to ≤30% of cocaine-reinforced responding. Immediately after each extinction session, mice received saline, the M 1 /M 4 receptor-preferring agonist xanomeline, the M 1 receptor-selective allosteric agonist VU0357017, the M 4 receptor-selective positive allosteric modulator VU0152100, or VU0357017 + VU0152100. In additional experiments, xanomeline was administered delayed after the session or in the home cage before extinction training began. In the latter group, reinstatement of responding by a 10-mg/kg cocaine injection was also tested. Stimulating M 1  + M 4 receptors significantly expedited extinction from 17.2 sessions to 8.3 using xanomeline or 7.8 using VU0357017 + VU0152100. VU0357017 alone and VU0152100 alone did not significantly modify rates of extinction (12.6 and 14.6 sessions). The effect of xanomeline was fully preserved when administered delayed after or unpaired from extinction sessions (7.5 and 6.4 sessions). Xanomeline-treated mice showed no cocaine-induced reinstatement. These findings show that M 1 /M 4 receptor stimulation can decrease cocaine seeking in mice. The effect lasted beyond treatment duration and was not dependent upon extinction learning. This suggests that M 1 /M 4 receptor stimulation modulated or reversed some neurochemical effects of cocaine exposure.

  16. Activation of muscarinic receptors by a hydroalcoholic extract of Dicksonia sellowiana Presl. HooK (Dicksoniaceae) induces vascular relaxation and hypotension in rats.

    Science.gov (United States)

    Rattmann, Yanna D; Crestani, Sandra; Lapa, Fernanda R; Miguel, Obdúlio G; Marques, Maria C A; da Silva-Santos, J Eduardo; Santos, Adair R S

    2009-01-01

    Dicksonia sellowiana (Presl.) Hook is a native plant from the Central and South Americas that contain high levels of polyphenols, antioxidant compounds involved in protection against inflammation, cancer and cardiovascular risk. A phytomedicinal preparation obtained from aerial parts of D. sellowiana is currently under clinical evaluation in Brazil against asthma, and has been associated with several other beneficial effects. This study demonstrates that a hydroalcoholic extract obtained from D. sellowiana leaves (HEDS) fully relax, in a concentration-dependent manner, rat aortic rings precontracted with phenylephrine. Moreover, administration of HEDS (10, 20 and 40 mg/kg, i.v.) in anaesthetized rats resulted in a strong but reversible hypotension. Aortic relaxation induced by HEDS was abolished by endothelium removal, by incubation of the nitric oxide synthase inhibitor L-NAME, or the soluble guanylate cyclase inhibitor ODQ. In addition, this effect was partially inhibited by indomethacin (a cyclooxygenase inhibitor) and KT 5730 (a PKA inhibitor). The potassium channels blockade by either tetraethylammonium or charybdotoxin also resulted in a potent inhibition of HEDS-induced aortic relaxation, whereas apamine only slightly reduced it. In addition HEDS-induced relaxation was unchanged by 4-amynopiridine and glibenclamide. The selective muscarinic receptor antagonist atropine counteracted both aortic relaxation and blood pressure reduction generated by HEDS. Experiments using HPLC revealed the presence of high amounts of phenolic compounds in this extract. Taken together, our results reveal that the D. sellowiana possess substances with both in vivo and in vitro activities and that the vascular effect of HEDS involves activation of muscarinic receptors, stimulation of the nitric oxide pathway and opening of calcium-activated potassium channels.

  17. Hook-up of GluA2, GRIP and liprin-α for cholinergic muscarinic receptor-dependent LTD in the hippocampus

    Directory of Open Access Journals (Sweden)

    Wu Long-Jun

    2009-06-01

    Full Text Available Abstract The molecular mechanism underlying muscarinic acetylcholine receptor-dependent LTD (mAChR-LTD in the hippocampus is less studied. In a recent study, a novel mechanism is described. The induction of mAChR-LTD required the activation of protein tyrosine phosphatase (PTP, and the expression was mediated by AMPA receptor endocytosis via interactions between GluA2, GRIP and liprin-α. The hook-up of these proteins may result in the recruitment of leukocyte common antigen-related receptor (LAR, a PTP that is known to be involved in AMPA receptor trafficking. Interestingly, the similar molecular interaction cannot be applied to mGluR-LTD, despite the fact that the same G-protein involved in LTD is activated by both mAChR and mGluR. This discovery provides key molecular insights for cholinergic dependent cognitive function, and mAChR-LTD can serve as a useful cellular model for studying the roles of cholinergic mechanism in learning and memory.

  18. Inverse Effects on Gating and Modulation Caused by a Mutation in the M2-M3 Linker of the GABAA Receptor γ SubunitS⃞

    OpenAIRE

    O'Shea, Sean M.; Williams, Carrie A.; Jenkins, Andrew

    2009-01-01

    M2-M3 linkers are receptor subunit domains known to be critical for the normal function of cysteine-loop ligand-gated ion channels. Previous studies of α and β subunits of type “A” GABA receptors suggest that these linkers couple extracellular elements involved in GABA binding to the transmembrane segments that control the opening of the ion channel. To study the importance of the γ subunit M2-M3 linker, we examined the macroscopic and single-channel effects of an engi...

  19. Sexual dimorphism in the volume of song control nuclei in European starlings: assessment by a Nissl stain and autoradiography for muscarinic cholinergic receptors.

    Science.gov (United States)

    Bernard, D J; Casto, J M; Ball, G F

    1993-08-22

    Previous studies have found that the volume of several song control nuclei is larger in male songbirds than in female songbirds. The degree of this volumetric sex difference within a given species appears to be systematically related to the degree of the behavioral sex difference. The largest volumetric differences have been reported in species in which the male sings and the female sings little, if at all, and the smallest sex differences in volume have been reported in species in which males and females both sing in nearly equal amounts. We compared the volume of three song control nuclei in male and female European starlings (Sturnus vulgaris), a species in which females are known to sing, though at a much lower rate than males. We investigated the volume of hyperstriatum ventrale, pars caudale, nucleus robustus archistriatalis, and area X of the lobus parolfactorius as defined with the use of a Nissl stain. In addition, we measured the volume of area X as defined by the density of muscarinic cholinergic receptors visualized by in vitro receptor autoradiographic methods. The volumes of all three of the song nuclei, as defined by Nissl staining, are significantly larger in males than in females. For area X, Nissl staining and receptor autoradiography indicate the same significant volumetric sex difference. The three nuclei are approximately one and one half to two times larger in males than in females, a degree of dimorphism that is intermediate to those reported for other species. Previous investigations of sex differences in the avian vocal control system have used only Nissl stains to define nuclear volumes. We demonstrate in this paper that receptor autoradiography can be used to assess dimorphisms in nuclear volume. Broad application of this approach to a number of neurotransmitter receptor systems will better characterize the dimorphisms in the song system, and therefore will provide greater insight into the neuroanatomical and neurochemical control of

  20. Beta amyloid differently modulate nicotinic and muscarinic receptor subtypes which regulate in vitro and in vivo the release of glycine in the rat hippocampus

    Directory of Open Access Journals (Sweden)

    Stefania eZappettini

    2012-07-01

    Full Text Available Using both in vitro (hippocampal synaptosomes in superfusion and in vivo (microdialysis approaches we investigated whether and to what extent β amyloid peptide 1-40 (Aβ 1-40 interferes with the cholinergic modulation of the release of glycine (GLY in the rat hippocampus. The nicotine-evoked overflow of endogenous GLY in hippocampal synaptosomes in superfusion was significantly inhibited by Aβ 1-40 (10 nM while increasing the concentration to 100 nM the inhibitory effect did not further increase. Both the Choline (Ch (α7 agonist; 1 mM and the 5-Iodo-A-85380 dihydrochloride (5IA85380, α4β2 agonist; 10 nM-evoked GLY overflow were inhibited by Aβ1-40 at 100 nM but not at 10nM concentrations. The KCl evoked [3H]GLY and [3H]Acetylcholine (ACh overflow were strongly inhibited in presence of oxotremorine; however this inhibitory muscarinic effect was not affected by Aβ1-40. The effects of Aβ1-40 on the administration of nicotine, veratridine, 5IA85380 and PHA 543613 hydrochloride (PHA543613 (a selective agonist of α7 subtypes on hippocampal endogenous GLY release in vivo were also studied. Aβ 1-40 significantly reduced (at 10 μM but not at 1 μM the nicotine evoked in vivo release of GLY. Aβ 1-40 (at 10 μM but not at 1 μM significantly inhibited the PHA543613 (1 mM-elicited GLY overflow while was ineffective on the GLY overflow evoked by 5IA85380 (1 mM. Aβ 40-1 (10 μM did not produce any inhibitory effect on nicotine evoked GLY overflow both in the in vitro and in vivo experiments. Our results indicate that a the cholinergic modulation of the release of GLY occurs by the activation of both α7 and α4β2 nicotinic ACh receptors (nAChRs as well as by the activation of inhibitory muscarinic ACh receptors (mAChRs and b Aβ 1-40 can modulate cholinergic evoked GLY release exclusively through the interaction with α7 and the α4β2 nAChR nicotinic receptors but not through mAChR subtypes.

  1. No changes in lymphocyte muscarinic receptors and platelet monoamine oxidase-B examined as surrogate central nervous system biomarkers in a Faroese children cohort prenatally exposed to methylmercury and polychlorinated biphenyls

    DEFF Research Database (Denmark)

    Coccini, Teresa; Manzo, Luigi; Debes, Frodi

    2009-01-01

    Experimental evidence suggests that monoamine oxidase B (MAO-B) and muscarinic cholinergic receptors (mAChRs) are involved in the pathogenesis of neurotoxicity caused by methylmercury and polychlorinated biphenyls (PCBs). Blood samples from 7-year-old exposed children were analyzed for platelet M....../or PCB exposure, whereas these markers are significantly altered in sustained exposure scenarios, as shown by clinical studies in drug addicts or patients treated with psychopharmacological agents....

  2. Increased amphetamine-induced locomotor activity, sensitization, and accumbal dopamine release in M5 muscarinic receptor knockout mice

    DEFF Research Database (Denmark)

    Schmidt, Lene S; Miller, Anthony D; Lester, Deranda B

    2010-01-01

    showed that M(5) receptor knockout (M (5) (-/-) ) mice are less sensitive to the reinforcing properties of addictive drugs. MATERIALS AND METHODS: Here, we investigate the role of M(5) receptors in the effects of amphetamine and cocaine on locomotor activity, locomotor sensitization, and dopamine release......-induced hyperactivity and dopamine release as well as amphetamine sensitization are enhanced in mice lacking the M(5) receptor. These results support the concept that the M(5) receptor modulates effects of addictive drugs....

  3. The Role of Muscarinic Receptors on spasmolytic Activity of Hydroalcohlic Extract of Parsley(petroselinum crispumSeed in Adult Male Rat's Ileum

    Directory of Open Access Journals (Sweden)

    Raede Tavalaee

    2016-08-01

    Full Text Available Abstract Background: because of the side effects of chemical drugs, using plant drugs was considered during recent decades. Based on previous studies, various concentrations of plant extracts can reduce ileum contraction caused by KCl and carbachol. Therefore, in this study, the role of muscarinic receptors in anti-spasmolytic activity of hydroalcohlic extract of parsley(petroselinum crispumseed in adult male rat's ileum was investigated. Materials and Methods: The distal part of Wistar rat’s ileum was separated and its contractions were recorded under 1 gr stretching and 37oC temperature in the bathroom containing the solution of Tyrode by Isotonic method. The ileum tissue was inserted in separately in first group affected by KCl and parsley seed, in the second group affected by KCl and carbachol with concentration 10-2 mg/ml and after that parsley seed, the third group affected by carbachol with concentration 10-2 mg/ml and then the extraction of parsley seed and the fourth group affected by scopolamine with concentration 10-3 M and after that KCl and then the extraction of parsley seed. Results: Non-cumulative concentrations of extract reduced the ileum contraction caused by KCl (60mM in a concentration-dependent form (p<0.001. There was a significant difference between the effect of extract in the presence of carbachol and extract concentration 0.2 mg/ml (p<0.01. There was no significant difference between the effect of extract in the presence of carbachol without stimulating tissue by KCl (60mM with extract concentration 0.2mg/ml (p<0.05. There was no significant difference between the effect of extract in the presence of scopolamine with extract concentration 0.2mg/ml(p<0.05. Conclusion: This study showed that the hydroalcholic of parsley seed extract has a relaxatory effect on rat’s ileum. Carbachol with KCl has a synergistic effect on smooth muscle contraction of the ileum wall and muscarinic receptors do not involve in the

  4. Imaging of muscarinic acetylcholine receptors using (+)N-[11C]methyl-3-piperidyl benzilate (11C-3NMPB) in vascular dementia and Alzheimer's disease

    International Nuclear Information System (INIS)

    Saito, Hirohiko

    2006-01-01

    In order to clarify the integrity of muscarinic acetylcholine receptor (mAChR) in vascular dementia (VaD) and Alzheimer's disease (AD), PET imaging with (+) N-[ 11 C]methyl-3-piperidyl benzilate ( 11 C-3NMPB) was performed in 12 patients with VaD, 11 patients with AD, and 7 normal controls (NC group). The mAChR binding was compared by the ratios compared with the cerebellum which were calculated from the regions of interest (ROI), and by three-dimensional statistic analysis. Compared with the NC group, mAChR was not significantly reduced in any ROI in AD patients. In those with VaD due to cortical lesions, mAChR was reduced in the infarcted areas. On the other hand, mAChR was significantly reduced in the thalamus and anterior cingulated gyrus, but not in other cerebral cortices in patients with VaD due to subcortical lesions. Accordingly, it is suggested that the mAChR is preserved in the cerebral cortices in patients with VaD due to subcortical lesions as well as in AD patients. (author)

  5. Presynaptic muscarinic receptors, calcium channels, and protein kinase C modulate the functional disconnection of weak inputs at polyinnervated neonatal neuromuscular synapses.

    Science.gov (United States)

    Santafe, M M; Garcia, N; Lanuza, M A; Tomàs, M; Besalduch, N; Tomàs, J

    2009-04-01

    We studied the relation among calcium inflows, voltage-dependent calcium channels (VDCC), presynaptic muscarinic acetylcholine receptors (mAChRs), and protein kinase C (PKC) activity in the modulation of synapse elimination. We used intracellular recording to determine the synaptic efficacy in dually innervated endplates of the levator auris longus muscle of newborn rats during axonal competition in the postnatal synaptic elimination period. In these dual junctions, the weak nerve terminal was potentiated by partially reducing calcium entry (P/Q-, N-, or L-type VDCC-specific block or 500 muM magnesium ions), M1- or M4-type selective mAChR block, or PKC block. Moreover, reducing calcium entry or blocking PKC or mAChRs results in unmasking functionally silent nerve endings that now recover neurotransmitter release. Our results show interactions between these molecules and indicate that there is a release inhibition mechanism based on an mAChR-PKC-VDCC intracellular cascade. When it is fully active in certain weak motor axons, it can depress ACh release and even disconnect synapses. We suggest that this mechanism plays a central role in the elimination of redundant neonatal synapses, because functional axonal withdrawal can indeed be reversed by mAChRs, VDCCs, or PKC block.

  6. TITERS OF ANTIBODIES TO Β1-ADRENOCEPTOR AND M2 CHOLINERGIC RECEPTORS IN PATIENTS WITH VENTRICULAR ARRHYTHMIAS WITHOUT AN ORGANIC CARDIOVASCULAR DISEASE AND THEIR POSSIBLE CLINICAL SIGNIFICANCE

    Directory of Open Access Journals (Sweden)

    M. M. Rogova

    2012-01-01

    Full Text Available Aim. To identify the most promising epitopes that simulate various sites β1-adrenergic and M2-cholinergic receptors, and to evaluate their possible contribution to the development and maintenance of cardiac arrhythmias, particularly idiopathic ventricular arrhythmia. Material and methods. Patients with ventricular arrhythmias without organic cardiovascular disease (the study group; n=70 were included in the study. The control group consisted of 20 healthy volunteers. Evaluation of levels of antibodies to antigenic determinants, modeling various sites β1-adrenergic and M2-cholinergic performed in all patients. Causal treatment with clarithromycin and valacyclovir performed in part of patients. Results. Antibodies to different peptide sequences of β1-adrenergic and M2-cholinergic receptors have been identified in 25% of main group patients. A direct correlation between the frequency of episodes of ventricular tachycardia and IgG levels to MRI-MRIV (p=0.02 revealed. Increase in titre of antibodies to β1-adrenoceptors, to a peptide sequence β8 (p=0.02, and lower titers of antibodies to the M2 acetylcholine receptor — chimera MRI-MRIV IgM (p=0.06 and ARI-MRIV IgM (p=0.07 were observed when assessing the efficacy of the therapy in the causal dynamics in the group of "untreated" patients. IgG titer reduction of ARI-MRIV (p=0.02, which is 4 times out of 10 with reduction of ventricular ectopic activity , recorded after valacyclovir therapy. Clarithromycin therapy on the level of antibodies exerted no significant effect. Conclusion. Possible involvement of antibodies to β1-adrenoceptor and M2-cholinergic receptors in the development of idiopathic ventricular arrhythmias demonstrated. The relationship between the frequency of episodes of ventricular tachycardia and levels of antibody titers to M2-cholinergic receptors found. Attempt of causal treatment, depending on the possible mechanisms of the autoimmune process is executed. Further studies to

  7. Impaired recovery of brain muscarinic receptor sites following an adaptive down-regulation induced by repeated administration of diisopropyl fluorophosphate in aged rats

    International Nuclear Information System (INIS)

    Pintor, A.; Fortuna, S.; De Angelis, S.; Michalek, H.

    1990-01-01

    Potential age-related differences in the recovery rate of brain cholinesterase activity (ChE) and muscarinic acetylcholine receptor binding sites (mAChRs) following reduction induced by repeated treatment with diisopropyl fluorophosphate (DFP) were evaluated in Sprague-Dawley rats. Male 3- and 24-month old rats were s.c. injected with DFP on alternate days for 2 weeks and killed 48 hr and 7, 14, 21, 28 and 35 days after the last treatment. In the hippocampus and striatum, but not in the cerebral cortex, of control rats there as a significant age-related decline of ChE activity and maximal density of 3H-QNB binding sites (Bmax). The repeated administration of DFP during the first week caused a syndrome of cholinergic stimulation both in aged and young rats. The syndrome was more pronounced, in terms of intensity and duration in aged than in young animals resulting in 40 and 12% mortality, respectively; during the second week the syndrome attenuated in the two age-groups. The percentage inhibition of brain ChE at the end of DFP treatment did not differ between young and surviving aged rats. The down-regulation of mACRs was present in the three brain regions of both young and age rats (from 20 to 40%). Factorial analysis of variance showed significant differences for age, recovery rate, and significant interaction between age and recovery rate, both for ChE and mAChRs in young rats the three brain areas

  8. Impaired recovery of brain muscarinic receptor sites following an adaptive down-regulation induced by repeated administration of diisopropyl fluorophosphate in aged rats

    Energy Technology Data Exchange (ETDEWEB)

    Pintor, A.; Fortuna, S.; De Angelis, S.; Michalek, H. (Istituto Superiore di Sanita, Rome (Italy))

    1990-01-01

    Potential age-related differences in the recovery rate of brain cholinesterase activity (ChE) and muscarinic acetylcholine receptor binding sites (mAChRs) following reduction induced by repeated treatment with diisopropyl fluorophosphate (DFP) were evaluated in Sprague-Dawley rats. Male 3- and 24-month old rats were s.c. injected with DFP on alternate days for 2 weeks and killed 48 hr and 7, 14, 21, 28 and 35 days after the last treatment. In the hippocampus and striatum, but not in the cerebral cortex, of control rats there as a significant age-related decline of ChE activity and maximal density of 3H-QNB binding sites (Bmax). The repeated administration of DFP during the first week caused a syndrome of cholinergic stimulation both in aged and young rats. The syndrome was more pronounced, in terms of intensity and duration in aged than in young animals resulting in 40 and 12% mortality, respectively; during the second week the syndrome attenuated in the two age-groups. The percentage inhibition of brain ChE at the end of DFP treatment did not differ between young and surviving aged rats. The down-regulation of mACRs was present in the three brain regions of both young and age rats (from 20 to 40%). Factorial analysis of variance showed significant differences for age, recovery rate, and significant interaction between age and recovery rate, both for ChE and mAChRs in young rats the three brain areas.

  9. The effect of ZMS on the coupling of muscarinic receptor to G-proteins activation in rat brain

    International Nuclear Information System (INIS)

    Fang Cailong; Hu Yaer; Gao Ruxue; Xia Zongqin

    1999-01-01

    The carbachol-stimulated [ 35 S]GTP γ S binding method was used to observe the effect of ZMS, an active component from Zhimu, on the coupling of M-receptor to G-protein. the effect of ZMS on the ability of learning and memory in aged rats was also observed. It was shown that the carbachol-stimulated elevation of [ 35 S]GTPγS binding was significantly decreased in aged rats as compared with young rats. The carbachol-induced [ 35 S]STPγS binding showed that administration of ZMS at median or high dose have a definite elevation effect on the coupling activity of M-receptors to G-protein in brain, and this elevation was accompanied by an improvement of learning and memory ability

  10. Probing topology and dynamics of the second transmembrane domain (M2δ) of the acetyl choline receptor using magnetically aligned lipid bilayers (bicelles) and EPR spectroscopy.

    Science.gov (United States)

    Sahu, Indra D; Mayo, Daniel J; Subbaraman, Nidhi; Inbaraj, Johnson J; McCarrick, Robert M; Lorigan, Gary A

    2017-08-01

    Characterizing membrane protein structure and dynamics in the lipid bilayer membrane is very important but experimentally challenging. EPR spectroscopy offers a unique set of techniques to investigate a membrane protein structure, dynamics, topology, and distance constraints in lipid bilayers. Previously our lab demonstrated the use of magnetically aligned phospholipid bilayers (bicelles) for probing topology and dynamics of the membrane peptide M2δ of the acetyl choline receptor (AchR) as a proof of concept. In this study, magnetically aligned phospholipid bilayers and rigid spin labels were further utilized to provide improved dynamic information and topology of M2δ peptide. Seven TOAC-labeled AchR M2δ peptides were synthesized to demonstrate the utility of a multi-labeling amino acid substitution alignment strategy. Our data revealed the helical tilts to be 11°, 17°, 9°, 17°, 16°, 11°, 9°±4° for residues I7TOAC, Q13TOAC, A14TOAC, V15TOAC, C16TOAC, L17TOAC, and L18TOAC, respectively. The average helical tilt of the M2δ peptide was determined to be ∼13°. This study also revealed that the TOAC labels were attached to the M2δ peptide with different dynamics suggesting that the sites towards the C-terminal end are more rigid when compared to the sites towards the N-terminus. The dynamics of the TOAC labeled sites were more resolved in the aligned samples when compared to the randomly disordered samples. This study highlights the use of magnetically aligned lipid bilayer EPR technique to determine a more accurate helical tilt and more resolved local dynamics of AchR M2δ peptide. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Selective activation of M4 muscarinic acetylcholine receptors reverses MK-801-induced behavioral impairments and enhances associative learning in rodents

    DEFF Research Database (Denmark)

    Bubser, Michael; Bridges, Thomas M; Dencker, Ditte

    2014-01-01

    PAMs, enabling a more extensive characterization of M4 actions in rodent models. We used VU0467154 to test the hypothesis that selective potentiation of M4 receptor signaling could ameliorate the behavioral, cognitive, and neurochemical impairments induced by the noncompetitive NMDAR antagonist MK-801....... VU0467154 produced a robust dose-dependent reversal of MK-801-induced hyperlocomotion and deficits in preclinical models of associative learning and memory functions, including the touchscreen pairwise visual discrimination task in wild-type mice, but failed to reverse these stimulant...

  12. A subpopulation of neuronal M4 muscarinic acetylcholine receptors plays a critical role in modulating dopamine-dependent behaviors

    DEFF Research Database (Denmark)

    Jeon, Jongrye; Dencker, Ditte; Wörtwein, Gitta

    2010-01-01

    AChRs are coexpressed with D(1) dopamine receptors in a specific subset of striatal projection neurons. To investigate the physiological relevance of this M(4) mAChR subpopulation in modulating dopamine-dependent behaviors, we used Cre/loxP technology to generate mutant mice that lack M(4) mAChRs only in D(1) dopamine....... Since enhanced central dopaminergic neurotransmission is a hallmark of several severe disorders of the CNS, including schizophrenia and drug addiction, our findings have substantial clinical relevance....

  13. Muscarinic receptors, nitric oxide formation and cyclooxygenase pathway involved in tracheal smooth muscle relaxant effect of hydro-ethanolic extract of Lavandula angustifolia flowers.

    Science.gov (United States)

    Naghdi, Farzaneh; Gholamnezhad, Zahra; Boskabady, Mohammad Hossein; Bakhshesh, Morteza

    2018-06-01

    Lavandula angustifolia (L. angustifolia) Mill. (Common name Lavender) is used in traditional and folk medicines for the treatment of various diseases including respiratory disorders worldwide. The relaxant effect of the plant on the smooth muscle of some tissues was shown previously. The present study has investigated the role of different receptors and pathways in the relaxant effect of L. angustifolia on tracheal smooth muscle. Cumulative concentrations of the hydro-ethanolic extract of L. angustifolia flowers (0.5, 1, 2 and 4 mg/ml) were added on pre-contracted tracheal smooth muscle by methacholine (10 μM) or KCl (60 mM) on non-preincubated or preincubated tissues with atropine, chlorpheniramine, propranolol, diltiazem, glibenclamide, indomethacin, ω-nitro-L-arginine methyl ester (L-NAME) and papaverine. The results compared with of theophylline (0.2, 0.4, 0.6 and 0.8 mM) as positive control and saline (1 ml) as negative control. The extract showed concentration-dependent relaxant effects in non-preincubated tracheal smooth muscle contracted by KCl and methacholine (p effect ofL. angustifolia was not significantly different between non-preincubated and preincubated tissues with chlorpheniramine, propranolol, diltiazem, glibenclamide, and papaverine. However, two higher concentrations of L. angustifolia in preincubated tissues with L-NAME (p effects than non-preincubated tissues. The EC 50 values of L. angustifolia in tissues preincubated with indomethacin was significantly higher than non-preincubated trachea (p effects of three first concentrations of the extract on KCl and methacholine-induced muscle contraction were significantly lower than those of theophylline (p effect ofL. angustifolia that was lower than the effect of theophylline. The possible mechanisms of relaxant effect of this plant on tracheal smooth muscle are muscarinic receptors blockade, inhibition of cyclooxygenase pathways and/or involvement of nitric oxide production

  14. Proceedings of the International Symposium on Subtypes of Muscarinic Receptors (5th), Held in Newport Beach, California, October 22-24, 1992.

    Science.gov (United States)

    1993-02-22

    AHMED , Chest 96 1285-1291 (1991). 29. P.J. BARNES, Thorax 44 161-167 (1989). 30. P.W. IND, C.M.S. DIXON, R.W. FULLER and P.J. BARNES, Am Rev Respir...mechanism by which muscarinic agonists, such as pilocarpiný_ lower the intraocular pressure of glaucoma patients. Pharmacological studies with subtype

  15. New epitopes and function of anti-M3 muscarinic acetylcholine receptor antibodies in patients with Sjögren's syndrome.

    Science.gov (United States)

    Tsuboi, H; Matsumoto, I; Wakamatsu, E; Nakamura, Y; Iizuka, M; Hayashi, T; Goto, D; Ito, S; Sumida, T

    2010-10-01

    M3 muscarinic acetylcholine receptor (M3R) plays a crucial role in the secretion of saliva from salivary glands. It is reported that some patients with Sjögren's syndrome (SS) carried inhibitory autoantibodies against M3R. The purpose of this study is to clarify the epitopes and function of anti-M3R antibodies in SS. We synthesized peptides encoding the extracellular domains of human-M3R including the N-terminal region and the first, second and third extracellular loops. Antibodies against these regions were examined by enzyme-linked immunosorbent assay in sera from 42 SS and 42 healthy controls. For functional analysis, human salivary gland (HSG) cells were preincubated with immunoglobulin G (IgG) separated from sera of anti-M3R antibody-positive SS, -negative SS and controls for 12 h. After loading with Fluo-3, HSG cells were stimulated with cevimeline hydrochloride, and intracellular Ca(2+) concentrations [(Ca(2+) )i] were measured. Antibodies to the N-terminal, first, second and third loops were detected in 42·9% (18 of 42), 47·6% (20 of 42), 54·8% (23 of 42) and 45·2% (19 of 42) of SS, while in 4·8% (two of 42), 7·1% (three of 42), 2·4% (one of 42) and 2·4% (one of 42) of controls, respectively. Antibodies to the second loop positive SS-IgG inhibited the increase of (Ca(2+) )i induced by cevimeline hydrochloride. Antibodies to the N-terminal positive SS-IgG and antibodies to the first loop positive SS-IgG enhanced it, while antibodies to the third loop positive SS-IgG showed no effect on (Ca(2+) )i as well as anti-M3R antibody-negative SS-IgG. Our results indicated the presence of several B cell epitopes on M3R in SS. The influence of anti-M3R antibodies on salivary secretion might differ based on these epitopes. © 2010 The Authors. Clinical and Experimental Immunology © 2010 British Society for Immunology.

  16. [Analysis of epitopes and function of anti-M3 muscarinic acetylcholine receptor antibodies in patients with Sjögren's syndrome].

    Science.gov (United States)

    Tsuboi, Hiroto; Matsuo, Naomi; Iizuka, Mana; Nakamura, Yumi; Matsumoto, Isao; Sumida, Takayuki

    2010-01-01

    Sjögren's syndrome (SS) is an autoimmune disease that affects exocrine glands including salivary and lacrimal glands. It is characterized by lymphocytic infiltration into exocrine glands, leading to dry mouth and eyes. A number of auto-antibodies, such as anti-SS-A and SS-B antibodies, are detected in patients with SS. However, no SS-specific pathologic auto-antibodies have yet been found in this condition. M3 muscarinic acetylcholine receptor (M3R) plays a crucial role in the secretion of saliva from salivary glands. It is reported that some patients with SS carried inhibitory auto-antibodies against M3R. To clarify the epitopes and function of anti-M3R antibodies in SS, we examined antibodies to the extracellular domains (N terminal region, the first, second, and third extracellular loop) of M3R by ELISA using synthesized peptide antigens encoding these domains in 42 SS and 42 healthy controls (HC). Titers and positivity of anti-M3R antibodies to every extracellular domain of M3R were significantly higher in SS than in HC. For functional analysis, human salivary gland (HSG) cells were pre-cultured with IgG from anti-M3R antibodies positive SS, negative SS, and HC. HSG cells were stimulated with cevimeline hydrochloride and intracellular calcium concentration ([Ca(2+)](i)) was measured. IgG from anti-M3R antibodies to the second loop positive SS inhibited the increase of [Ca(2+)](i), but IgG from antibodies to the N terminal or the first loop positive SS enhanced it, while IgG from antibodies to the third loop positive SS showed no effect on [Ca(2+)](i) as well as IgG from anti-M3R antibodies negative SS and HC. These findings indicated the presence of several B cell epitopes on M3R in SS and effect of anti-M3R antibodies on the salivary secretion might differ with these epitopes.

  17. Regulation of Human Macrophage M1–M2 Polarization Balance by Hypoxia and the Triggering Receptor Expressed on Myeloid Cells-1

    Directory of Open Access Journals (Sweden)

    Federica Raggi

    2017-09-01

    Full Text Available Macrophages (Mf are a heterogeneous population of tissue-resident professional phagocytes and a major component of the leukocyte infiltrate at sites of inflammation, infection, and tumor growth. They can undergo diverse forms of activation in response to environmental factors, polarizing into specialized functional subsets. A common hallmark of the pathologic environment is represented by hypoxia. The impact of hypoxia on human Mf polarization has not been fully established. The objective of this study was to elucidate the effects of a hypoxic environment reflecting that occurring in vivo in diseased tissues on the ability of human Mf to polarize into classically activated (proinflammatory M1 and alternatively activated (anti-inflammatory M2 subsets. We present data showing that hypoxia hinders Mf polarization toward the M1 phenotype by decreasing the expression of T cell costimulatory molecules and chemokine homing receptors and the production of proinflammatory, Th1-priming cytokines typical of classical activation, while promoting their acquisition of phenotypic and secretory features of alternative activation. Furthermore, we identify the triggering receptor expressed on myeloid cells (TREM-1, a member of the Ig-like immunoregulatory receptor family, as a hypoxia-inducible gene in Mf and demonstrate that its engagement by an agonist Ab reverses the M2-polarizing effect of hypoxia imparting a M1-skewed phenotype to Mf. Finally, we provide evidence that Mf infiltrating the inflamed hypoxic joints of children affected by oligoarticular juvenile idiopatic arthritis express high surface levels of TREM-1 associated with predominant M1 polarization and suggest the potential of this molecule in driving M1 proinflammatory reprogramming in the hypoxic synovial environment.

  18. The combination of glutamate receptor antagonist MK-801 with tamoxifen and its active metabolites potentiates their antiproliferative activity in mouse melanoma K1735-M2 cells

    International Nuclear Information System (INIS)

    Ribeiro, Mariana P.C.; Nunes-Correia, Isabel; Santos, Armanda E.; Custódio, José B.A.

    2014-01-01

    Recent reports suggest that N-methyl-D-aspartate receptor (NMDAR) blockade by MK-801 decreases tumor growth. Thus, we investigated whether other ionotropic glutamate receptor (iGluR) antagonists were also able to modulate the proliferation of melanoma cells. On the other hand, the antiestrogen tamoxifen (TAM) decreases the proliferation of melanoma cells, and is included in combined therapies for melanoma. As the efficacy of TAM is limited by its metabolism, we investigated the effects of the NMDAR antagonist MK-801 in combination with TAM and its active metabolites, 4-hydroxytamoxifen (OHTAM) and endoxifen (EDX). The NMDAR blockers MK-801 and memantine decreased mouse melanoma K1735-M2 cell proliferation. In contrast, the NMDAR competitive antagonist APV and the AMPA and kainate receptor antagonist NBQX did not affect cell proliferation, suggesting that among the iGluR antagonists only the NMDAR channel blockers inhibit melanoma cell proliferation. The combination of antiestrogens with MK-801 potentiated their individual effects on cell biomass due to diminished cell proliferation, since it decreased the cell number and DNA synthesis without increasing cell death. Importantly, TAM metabolites combined with MK-801 promoted cell cycle arrest in G1. Therefore, the data obtained suggest that the activity of MK-801 and antiestrogens in K1735-M2 cells is greatly enhanced when used in combination. - Highlights: • MK-801 and memantine decrease melanoma cell proliferation. • The combination of MK-801 with antiestrogens inhibits melanoma cell proliferation. • These combinations greatly enhance the effects of the compounds individually. • MK-801 combined with tamoxifen active metabolites induces cell cycle arrest in G1. • The combination of MK-801 and antiestrogens is an innovative strategy for melanoma

  19. Regulation of Human Macrophage M1–M2 Polarization Balance by Hypoxia and the Triggering Receptor Expressed on Myeloid Cells-1

    Science.gov (United States)

    Raggi, Federica; Pelassa, Simone; Pierobon, Daniele; Penco, Federica; Gattorno, Marco; Novelli, Francesco; Eva, Alessandra; Varesio, Luigi; Giovarelli, Mirella; Bosco, Maria Carla

    2017-01-01

    Macrophages (Mf) are a heterogeneous population of tissue-resident professional phagocytes and a major component of the leukocyte infiltrate at sites of inflammation, infection, and tumor growth. They can undergo diverse forms of activation in response to environmental factors, polarizing into specialized functional subsets. A common hallmark of the pathologic environment is represented by hypoxia. The impact of hypoxia on human Mf polarization has not been fully established. The objective of this study was to elucidate the effects of a hypoxic environment reflecting that occurring in vivo in diseased tissues on the ability of human Mf to polarize into classically activated (proinflammatory M1) and alternatively activated (anti-inflammatory M2) subsets. We present data showing that hypoxia hinders Mf polarization toward the M1 phenotype by decreasing the expression of T cell costimulatory molecules and chemokine homing receptors and the production of proinflammatory, Th1-priming cytokines typical of classical activation, while promoting their acquisition of phenotypic and secretory features of alternative activation. Furthermore, we identify the triggering receptor expressed on myeloid cells (TREM)-1, a member of the Ig-like immunoregulatory receptor family, as a hypoxia-inducible gene in Mf and demonstrate that its engagement by an agonist Ab reverses the M2-polarizing effect of hypoxia imparting a M1-skewed phenotype to Mf. Finally, we provide evidence that Mf infiltrating the inflamed hypoxic joints of children affected by oligoarticular juvenile idiopatic arthritis express high surface levels of TREM-1 associated with predominant M1 polarization and suggest the potential of this molecule in driving M1 proinflammatory reprogramming in the hypoxic synovial environment. PMID:28936211

  20. Acetylcholine Attenuates Hypoxia/ Reoxygenation-Induced Mitochondrial and Cytosolic ROS Formation in H9c2 Cells via M2 Acetylcholine Receptor

    Directory of Open Access Journals (Sweden)

    Yi Miao

    2013-02-01

    Full Text Available Background: The anti-infammatory and cardioprotective effect of acetylcholine (ACh has been reported; nevertheless, whether and how ACh exhibits an antioxidant property against ischemia/reperfusion (I/R-induced oxidative stress remains obscure. Methods: In the present study, H9c2 rat cardiomyocytes were exposed to hypoxia/reoxygenation (H/R to mimic I/R injury. We estimated intracellular different sources of reactive oxygen species (ROS by measuring mitochondrial ROS (mtROS, mitochondrial DNA (mtDNA copy number, xanthine oxidase (XO and NADPH oxidase (NOX activity and expression of rac 1. Cell injury was determined by lactate dehydrogenase (LDH release and cleaved caspase-3 expression. The siRNA transfection was performed to knockdown of M2 acetylcholine receptor (M2 AChR expression. Results: 12-h hypoxia followed by 2-h reoxygenation resulted in an abrupt burst of ROS in H9c2 cells. Administration of ACh reduced the levels of ROS in a concentration-dependent manner. Compared to the H/R group, ACh decreased mtROS, recovered mtDNA copy number, diminished XO and NOX activity, rac 1 expression as well as cell injury. Co- treatment with atropine rather than hexamethonium abolished the antioxidant and cardioprotective effect of ACh. Moreover, knockdown of M2 AChR by siRNA showed the similar trends as atropine co-treatment group. Conclusions: ACh inhibits mitochondria-, XO- and NOX-derived ROS production thus protecting H9c2 cells against H/R-induced oxidative stress, and these benefcial effects are mainly mediated by M2 AChR. Our findings suggested that increasing ACh release could be a potential therapeutic strategy for treatment and prevention of I/R injury.

  1. Effect of insulin analogues on insulin/IGF1 hybrid receptors: increased activation by glargine but not by its metabolites M1 and M2.

    Directory of Open Access Journals (Sweden)

    Cécile Pierre-Eugene

    Full Text Available BACKGROUND: In diabetic patients, the pharmacokinetics of injected human insulin does not permit optimal control of glycemia. Fast and slow acting insulin analogues have been developed, but they may have adverse properties, such as increased mitogenic or anti-apoptotic signaling. Insulin/IGF1 hybrid receptors (IR/IGF1R, present in most tissues, have been proposed to transmit biological effects close to those of IGF1R. However, the study of hybrid receptors is difficult because of the presence of IR and IGF1R homodimers. Our objective was to perform the first study on the pharmacological properties of the five marketed insulin analogues towards IR/IGF1R hybrids. METHODOLOGY: To study the effect of insulin analogues on IR/IGF1R hybrids, we used our previously developed Bioluminescence Resonance Energy Transfer (BRET assay that permits specific analysis of the pharmacological properties of hybrid receptors. Moreover, we have developed a new, highly sensitive BRET-based assay to monitor phophatidylinositol-3 phosphate (PIP(3 production in living cells. Using this assay, we performed a detailed pharmacological analysis of PIP(3 production induced by IGF1, insulin and insulin analogues in living breast cancer-derived MCF-7 and MDA-MB231 cells. RESULTS: Among the five insulin analogues tested, only glargine stimulated IR/IGF1R hybrids with an EC50 that was significantly lower than insulin and close to that of IGF1. Glargine more efficiently stimulated PIP(3 production in MCF-7 cells but not in MDA-MB231 cells as compared to insulin. In contrast, glargine metabolites M1 and M2 showed lower potency for hybrid receptors stimulation, PIP(3 production, Akt and Erk1/2 phosphorylation and DNA synthesis in MCF-7 cells, compared to insulin. CONCLUSION: Glargine, possibly acting through IR/IGF1R hybrids, displays higher potency, whereas its metabolites M1 and M2 display lower potency than insulin for the stimulation of proliferative/anti-apoptotic pathways in

  2. Trichoderma asperelloides Spores Downregulate dectin1/2 and TLR2 Receptors of Mice Macrophages and Decrease Candida parapsilosis Phagocytosis Independent of the M1/M2 Polarization

    Directory of Open Access Journals (Sweden)

    Andréa G. dos Santos

    2017-09-01

    Full Text Available The intensive use of pesticides to control pests in agriculture has promoted several issues relating to environment. As chemical pesticides remain controversial, biocontrol agents originating from fungi could be an alternative. Among them, we highlight biocontrol agents derived from the fungi genus Trichoderma, which have been documented in limiting the growth of other phytopathogenic fungus in the roots and leaves of several plant species. An important member of this genus is Trichoderma asperelloides, whose biocontrol agents have been used to promote plant growth while also treating soil diseases caused by microorganisms in both greenhouses and outdoor crops. To evaluate the safety of fungal biological agents for human health, tests to detect potentially adverse effects, such as allergenicity, toxicity, infectivity and pathogenicity, are crucial. In addition, identifying possible immunomodulating properties of fungal biocontrol agents merits further investigation. Thus, the aim of this study was to evaluate the effects of T. asperelloides spores in the internalization of Candida parapsilosis yeast by mice phagocytes, in order to elucidate the cellular and molecular mechanism of this interaction, as a model to understand possible in vivo effects of this fungus. For this, mice were exposed to a fungal spore suspension through-intraperitoneal injection, euthanized and cells from the peripheral blood and peritoneal cavity were collected for functional, quantitative and phenotypic analysis, throughout analysis of membrane receptors gene expression, phagocytosis ability and cells immunophenotyping M1 (CCR7 and CD86 and M2 (CCR2 and CD206. Our analyses showed that phagocytes exposed to fungal spores had reduced phagocytic capacity, as well as a decrease in the quantity of neutrophils and monocytes in the peripheral blood and peritoneal cavity. Moreover, macrophages exposed to T. asperelloides spores did not display the phenotypic profile M1/M2, and

  3. Pre- and postynaptic effects of muscarinic antagonists in the isolated guinea pig ileum

    International Nuclear Information System (INIS)

    Kilbinger, H.; Weiler, W.; Wessler, I.

    1986-01-01

    The authors have studied in the guinea-pig ileum whether the presynaptic muscarinic receptors of he cholinergic nerves differ from the postsynaptic muscarinic receptors of tthe longitudinal muscle in their affinities for several muscarinic antagonists. The method of measuring the release of tritium-ACh from the myenteric plexus-longitudinal muscle preparation in tthe guinea-pig ileum in the absence of a chlinesterase inhibitor is described in which two longitudinal muscle strips were incubated in a 2 ml organ bath with tritium-choline are subsequently superfused with Tyrode solution

  4. Evaluation and metabolite studies of {sup 125}I- and {sup 123}I-labelled E-(R,R)-IQNP: potential radioligands for visualization of M{sub 1} muscarinic acetylcholine receptors in brain

    Energy Technology Data Exchange (ETDEWEB)

    Bergstroem, Kim A.; Halldin, Christer; Hiltunen, Jukka; Swahn, Carl-Gunnar; Ito, Hiroshi; Ginovart, Nathalie; Hall, Haakan; McPherson, Daniel W.; Knapp, F. F. (Russ); Larsson, Stig; Schnell, Per-Olof; Farde, Lars

    1998-04-01

    A new ligand for the M{sub 1} muscarinic receptor subtype, E-(R,R)-1-azabicyclo[2.2.2]oct-3-yl {alpha}-hydroxy-{alpha}-(1-iodo-1-propen-3-yl)-{alpha}-phenylacetate (E-IQNP), was labelled with {sup 125}I and {sup 123}I for autoradiographic studies on human whole-brain cryosections and SPET studies, respectively, in Cynomolgus monkey. Autoradiography demonstrated E-[{sup 125}I]IQNP binding in M{sub 1} receptor-rich regions such as the neocortex and the striatum. The binding was displaceable by the selective M{sub 1} antagonist biperiden. In vivo single photon emission tomography (SPET) studies with E-[{sup 123}I]IQNP demonstrated a high accumulation of radioactivity in the monkey neocortex. Rapid hydrolysis of the quinuclidinyl ester to the free acid was found to be a major biotransformation route for E-[{sup 123}I]IQNP. The free acid of E-[{sup 123}I]IQNP does not pass the blood-brain barrier, but the plasma concentration was high as compared to the total radioactivity in brain. It is thus necessary to correct for the high concentration of radioactive metabolites in parenchymal blood (CBV) to obtain accurate values for E-[{sup 123}I]IQNP binding in brain.

  5. The M2 Channel

    DEFF Research Database (Denmark)

    Santner, Paul

    Drug resistance of Influenza A against antivirals is an increasing problem. No effective Influenza A drugs targeting the crucial viral protein, the proton transporter M2 are available anymore due to widespread resistance. Thanks to research efforts elucidating M2 protein structure, function and i...... resistance escape routes from drug inhibition. We thereby were hopefully able to provide a platform for the large-scale evaluation of M2 channel activity, inhibitors and resistance....

  6. An Anti-Nicotinic Cognitive Challenge Model using Mecamylamine in Comparison with the Anti-Muscarinic Cognitive Challenge using Scopolamine

    NARCIS (Netherlands)

    Baakman, A. C.; Alvarez-jimenez, R.; Rissmann, R.; Klaassen, E. S.; Stevens, J.; Goulooze, S. C.; Burger, J.; Swart, E. L.; Van Gerven, J. M. A.; Groeneveld, G. J.

    Aims The muscarinic acetylcholine receptor antagonist scopolamine is often used for proof-of-pharmacology studies with pro-cognitive compounds. From a pharmacological point of view, it would seem more rational to use a nicotinic rather than a muscarinic anticholinergic challenge to prove

  7. (+/-)-cis-2-methylspiro[1,3-oxathiolane-5,3'-quinuclidine] hydrochloride, hemihydrate (SNI-2011, cevimeline hydrochloride) induces saliva and tear secretions in rats and mice: the role of muscarinic acetylcholine receptors.

    Science.gov (United States)

    Iga, Y; Arisawa, H; Ogane, N; Saito, Y; Tomizuka, T; Nakagawa-Yagi, Y; Masunaga, H; Yasuda, H; Miyata, N

    1998-11-01

    We investigated effects of (+/-)-cis-2-methylspiro[1,3-oxathiolane-5,3'-quinuclidine] hydrochloride, hemihydrate (SNI-2011, cevimeline hydrochloride), a rigid analogue of acetylcholine, on saliva and tear secretions in rats and mice to evaluate its therapeutical efficacy for xerostomia and xerophthalmia in patients with Sjogren's syndrome and X-ray exposure in the head and neck. Intraduodenal administrations of SNI-2011 increased saliva secretion in a dose-dependent manner at doses ranging from 3 to 30 mg/kg in normal rats and mice, two strains of autoimmune disease mice and X-irradiated saliva secretion defective rats. The salivation elicited by SNI-2011 was completely inhibited by atropine. A similar atropine-sensitive response was observed in tear secretion. In rat submandibular/sublingual gland membranes, [3H]quinuclidinyl benzilate (QNB) binding was saturable, and Scatchard plot analysis revealed a single population of binding sites with a Kd of 22 pM and a maximal binding capacity of 60 fmol/mg protein. The competitive inhibition curve of the [3H]QNB binding by SNI-2011 was obtained, and its dissociation constant value calculated from IC50 was 1-2 microM. These results suggest that SNI-2011 increases saliva and tear secretions through a direct stimulation to muscarinic receptors in salivary and lacrimal glands, and they suggest that SNI-2011 should be beneficial to patients with Sjögren's syndrome and X-ray exposure in the head and neck.

  8. Cervical Cancer Cell Supernatants Induce a Phenotypic Switch from U937-Derived Macrophage-Activated M1 State into M2-Like Suppressor Phenotype with Change in Toll-Like Receptor Profile

    Directory of Open Access Journals (Sweden)

    Karina Sánchez-Reyes

    2014-01-01

    Full Text Available Cervical cancer (CC is the second most common cancer among women worldwide. Infection with human papillomavirus (HPV is the main risk factor for developing CC. Macrophages are important immune effector cells; they can be differentiated into two phenotypes, identified as M1 (classically activated and M2 (alternatively activated. Macrophage polarization exerts profound effects on the Toll-like receptor (TLR profile. In this study, we evaluated whether the supernatant of human CC cells HeLa, SiHa, and C-33A induces a shift of M1 macrophage toward M2 macrophage in U937-derived macrophages. Results. The results showed that soluble factors secreted by CC cells induce a change in the immunophenotype of macrophages from macrophage M1 into macrophage M2. U937-derived macrophages M1 released proinflammatory cytokines and nitric oxide; however, when these cells were treated with the supernatant of CC cell lines, we observed a turnover of M1 toward M2. These cells increased CD163 and IL-10 expression. The expression of TLR-3, -7, and -9 is increased when the macrophages were treated with the supernatant of CC cells. Conclusions. Our result strongly suggests that CC cells may, through the secretion of soluble factors, induce a change of immunophenotype M1 into M2 macrophages.

  9. Structural Insight into Specificity of Interactions between Nonconventional Three-finger Weak Toxin from Naja kaouthia (WTX) and Muscarinic Acetylcholine Receptors

    Czech Academy of Sciences Publication Activity Database

    Lyukmanova, E. N.; Shenkarev, Z. O.; Shulepko, M. A.; Paramonov, A. S.; Chugunov, A. O.; Janíčková, Helena; Dolejší, Eva; Doležal, Vladimír; Utkin, Y.N.; Tsetlin, V.I.; Arseniev, A. S.; Efremov, R. G.; Dolgikh, D. A.; Kirpichnikov, M. P.

    2015-01-01

    Roč. 290, č. 39 (2015), s. 23616-23630 ISSN 0021-9258 R&D Projects: GA ČR(CZ) GA14-05696S Institutional support: RVO:67985823 Keywords : computer modeling * G protein-coupled receptor (GPCR) * site-directed mutagenesis Subject RIV: ED - Physiology Impact factor: 4.258, year: 2015

  10. Cardioprotective Action of Ginkgo biloba Extract against Sustained β-Adrenergic Stimulation Occurs via Activation of M2/NO Pathway

    Directory of Open Access Journals (Sweden)

    Thássio R. R. Mesquita

    2017-05-01

    Full Text Available Ginkgo biloba is the most popular phytotherapic agent used worldwide for treatment of several human disorders. However, the mechanisms involved in the protective actions of Ginkgo biloba on cardiovascular diseases remain poorly elucidated. Taking into account recent studies showing beneficial actions of cholinergic signaling in the heart and the cholinergic hypothesis of Ginkgo biloba-mediated neuroprotection, we aimed to investigate whether Ginkgo biloba extract (GBE promotes cardioprotection via activation of cholinergic signaling in a model of isoproterenol-induced cardiac hypertrophy. Here, we show that GBE treatment (100 mg/kg/day for 8 days, v.o. reestablished the autonomic imbalance and baroreflex dysfunction caused by chronic β-adrenergic receptor stimulation (β-AR, 4.5 mg/kg/day for 8 days, i.p.. Moreover, GBE prevented the upregulation of muscarinic receptors (M2 and downregulation of β1-AR in isoproterenol treated-hearts. Additionally, we demonstrated that GBE prevents the impaired endothelial nitric oxide synthase activity in the heart. GBE also prevented the pathological cardiac remodeling, electrocardiographic changes and impaired left ventricular contractility that are typical of cardiac hypertrophy. To further investigate the mechanisms involved in GBE cardioprotection in vivo, we performed in vitro studies. By using neonatal cardiomyocyte culture we demonstrated that the antihypertrophic action of GBE was fully abolished by muscarinic receptor antagonist or NOS inhibition. Altogether, our data support the notion that antihypertrophic effect of GBE occurs via activation of M2/NO pathway uncovering a new mechanism involved in the cardioprotective action of Ginkgo biloba.

  11. Iodine-123 labelled Z-(R,R)-IQNP: a potential radioligand for visualization of M{sub 1} and M{sub 2} muscarinic acetylcholine receptors in Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Bergstroem, K.A. [Dept. of Clinical Neuroscience, Psychiatry and Nuclear Medicine Sections, Karolinska Institutet, Karolinska Hospital, Stockholm (Sweden); Clinical Physiology and Nuclear Medicine, Kuopio University Hospital, Kuopio (Finland); Halldin, C.; Okubo, Yoshiro; Nobuhara, Kenji; Swahn, C.G.; Karlsson, P.; Larsson, S.; Schnell, P.O.; Farde, L. [Dept. of Clinical Neuroscience, Psychiatry and Nuclear Medicine Sections, Karolinska Institutet, Karolinska Hospital, Stockholm (Sweden); Savonen, A.; Hiltunen, Jukka [MAP Medical Technologies Oy, Tikkakoski (Finland); McPherson, D.; Knapp, F.F. Jr. [Nuclear Medicine Group, Oak Ridge National Laboratory (ORNL), TN (United States)

    1999-11-01

    Z-(R)-1-Azabicyclo[2.2.2]oct-3-yl (R)-{alpha}-hydroxy-{alpha}-(1-iodo-1-propen-3-yl)-{alpha}-phenylacetate (Z-IQNP) has high affinity to the M{sub 1}and M {sub 2} muscarinic acetylcholine receptor (mAChR) subtypes according to previous in vitro and in vivo studies in rats. In the present study iodine-123 labelled Z-IQNP was prepared for in vivo single-photon emission tomography (SPET) studies in cynomolgus monkeys. SPET studies with Z-[ {sup 123}I]IQNP demonstrated high accumulation in monkey brain (>5% of injected dose at 70 min p.i.) and marked accumulation in brain regions such as the thalamus, the neocortex, the striatum and the cerebellum. Pretreatment with the non-selective mAChR antagonist scopolamine (0.2 mg/kg) inhibited Z-[ {sup 123}I]IQNP binding in all these regions. The percentage of unchanged Z-[ {sup 123}I]IQNP measured in plasma was less than 10% at 10 min after injection, which may be due to rapid hydrolysis, as has been demonstrated previously with the E-isomer of IQNP. Z-[ {sup 123}I]IQNP showed higher uptake in M {sub 2}-rich regions, compared with previously obtained results with E-[ {sup 123}I]IQNP. In conclusion, the radioactivity distribution from Z-[ {sup 123}I]IQNP in monkey brain indicates that Z-[ {sup 123}I]IQNP binds to the M {sub 1}- and M {sub 2}-rich areas and provides a high signal for specific binding, and is thus a potential ligand for mAChR imaging with SPET. (orig.)

  12. Variation in the gene coding for the M5 Muscarinic receptor (CHRM5 influences cigarette dose but is not associated with dependence to drugs of addiction: evidence from a prospective population based cohort study of young adults

    Directory of Open Access Journals (Sweden)

    Olsson Craig A

    2007-07-01

    Full Text Available Abstract Background The mesolimbic structures of the brain are important in the anticipation and perception of reward. Moreover, many drugs of addiction elicit their response in these structures. The M5 muscarinic receptor (M5R is expressed in dopamine-containing neurones of the substantia nigra pars compacta and ventral tegmental area, and regulates the release of mesolimbic dopamine. Mice lacking M5R show a substantial reduction in both reward and withdrawal responses to morphine and cocaine. The CHRM5, the gene that codes for the M5R, is a strong biological candidate for a role in human addiction. We screened the coding and core promoter sequences of CHRM5 using denaturing high performance liquid chromatography to identify common polymorphisms. Additional polymorphisms within the coding and core promoter regions that were identified through dbSNP were validated in the test population. We investigated whether these polymorphisms influence substance dependence and dose in a cohort of 1947 young Australians. Results Analysis was performed on 815 participants of European ancestry who were interviewed at wave 8 of the cohort study and provided DNA. We observed a 26.8% increase in cigarette consumption in carriers of the rs7162140 T-allele, equating to 20.1 cigarettes per week (p=0.01. Carriers of the rs7162140 T-allele were also found to have nearly a 3-fold increased risk of developing cannabis dependence (OR=2.9 (95%CI 1.1-7.4; p=0.03. Conclusion Our data suggest that variation within the CHRM5 locus may play an important role in tobacco and cannabis but not alcohol addiction in European ancestry populations. This is the first study to show an association between CHRM5 and substance use in humans. These data support the further investigation of this gene as a risk factor in substance use and dependence.

  13. Effects of muscarinic M1 and M4 acetylcholine receptor stimulation on extinction and reinstatement of cocaine seeking in male mice, independent of extinction learning

    DEFF Research Database (Denmark)

    Stoll, Kevin; Hart, Rachel; Lindsley, Craig W

    2017-01-01

    seeking, and whether this was mediated via memory consolidation. METHODS: Experimentally naïve C57BL/6J mice were allowed to acquire self-administration of intravenous cocaine (1 mg/kg/infusion) under a fixed-ratio 1 schedule of reinforcement. Then, saline was substituted for cocaine until responding...... sessions (7.5 and 6.4 sessions). Xanomeline-treated mice showed no cocaine-induced reinstatement. CONCLUSIONS: These findings show that M1/M4 receptor stimulation can decrease cocaine seeking in mice. The effect lasted beyond treatment duration and was not dependent upon extinction learning. This suggests...

  14. Proceedings of the International Symposium on Subtypes of Muscarinic Receptors 2 (2nd) Held in Boston, Massachusetts on August 22-24 1985

    Science.gov (United States)

    1986-04-30

    Uiversity ’ Hospital. Walter Reed Army Institute Of Research Lund &-22185 Building 40 MEWashington, D.C. 20307-5100 Pm Mau i~bers~, .D.Paul Bianckhi, M.D...acetyl- 6 Yamada, S., Yarmamura, H. 1. and Roeske, W. Rt. (1982) choline? (We suspect, for example, that the consistently Life Sci. 31, 1161-1170 lower...regulation of 9 Hammer, R., Giralo, E., Schiavi. G. B., Monferini. E. and receptor number be studied under in-vivo conditions? Can Ladinsky, H. Life

  15. Specific binding component of the 'inactive' stereoisomer (S,S)-[125I]IQNB to rat brain muscarinic receptors in vivo

    International Nuclear Information System (INIS)

    Boulay, Sheila F.; McRee, R. Carter; Cohen, Victor I.; Sood, Virendar K.; Zeeberg, Barry R.; Reba, Richard C.

    1996-01-01

    In vivo nonspecific binding can be estimated using the inactive stereoisomer of a receptor radioligand. However, the binding of the inactive stereoisomer may be partially specific. Specific binding of the inactive (S,S)-[ 125 I]IQNB was estimated from the inhibition induced by a competing nonradioactive ligand. This technique differed from the usual approach, since it was used to study the inactive rather than the active stereoisomer. The results indicate that there is substantial specific binding for (S,S)-[ 125 I]IQNB

  16. Heterotic M2-branes

    Directory of Open Access Journals (Sweden)

    Neil Lambert

    2015-10-01

    Full Text Available We construct the action for N M2-branes on S1/Z2. The resulting theory has a gauge anomaly but this can be cancelled if the two fixed point planes each support 8 chiral Fermions in the fundamental of U(N. Taking the low energy limit leads to the worldsheet theory of N free heterotic strings whose quantization induces an E8 spacetime gauge symmetry on each fixed point plane. Thus this paper presents a non-abelian worldvolume analogue of the classic Hořava–Witten analysis.

  17. The role of muscarinic receptor subtypes on carbachol-induced contraction of normal human detrusor and overactive detrusor associated with benign prostatic hyperplasia

    Directory of Open Access Journals (Sweden)

    Tomonori Yamanishi

    2015-06-01

    Full Text Available The aim of this study was to compare the effect of antimuscarinic antagonists on carbachol-induced contraction of normal human bladder and detrusor overactivity associated with benign prostatic hyperplasia (DO/BPH. Samples of human bladder muscle were obtained from patients undergoing total cystectomy for bladder cancer (normal bladder, and those undergoing retropubic prostatectomy for BPH. All of the patients with DO/BPH had detrusor overactivity according to urodynamic studies. Detrusor muscle strips were mounted in 10-ml organ baths containing Krebs solution, and concentration–response curves for carbachol were obtained in the presence of antimuscarinic antagonists (4-DAMP, methoctramine, pirenzepine, tolterodine, solifenacin, trospium, propiverine, oxybutynin, and imidafenacin or vehicle. All antagonists competitively antagonized concentration–response curves to carbachol with high affinities in normal bladder. The rank order of mean pA2 values was as follows: trospium (10.1 > 4-DAMP (9.87, imidafenacin (9.3 > solifenacin (8.8 > tolterodine (8.6 > oxybutynin (8.3 > propiverine (7.7 > pirenzepine (7.4 > methoctramine (6.6. The effects of these antimuscarinic antagonists did not change when tested with DO/BPH bladder, suggesting that each antimuscarinic antagonist has a similar effect in this condition. Schild plots showed a slope corresponding to unity, except for propiverine with DO/BPH detrusor. In conclusion, M3-receptors mainly mediate contractions in human bladder strips with normal state and DO/BPH.

  18. Neuroimmune interactions in Sjögren's syndrome: relationship of exocrine gland dysfunction with autoantibodies to muscarinic acetylcholine receptor-3 and mental health status parameters.

    Science.gov (United States)

    Deák, Magdolna; Szvetnik, Attila; Balog, Attila; Sohár, Nicolette; Varga, Renáta; Pokorny, Gyula; Tóth, Gábor; Kiss, Mária; Kovács, László

    2013-01-01

    Antimuscarinic acetylcholine receptor-3 (m3AChR) autoantibodies have been described in primary Sjögren's syndrome (pSS). The aim of this study was to compare various methods for their detection and to assess the contributions of anti-m3AChR and other immunological and psychosocial factors to the pathomechanism of secondary SS (sSS). Sixty-five rheumatoid arthritis (RA) patients, 103 systemic lupus erythematosus (SLE) patients, 76 pSS patients and 50 controls were compared. Three immunodominant epitopes of m3AChR were synthesized and used in ELISA. Two extracellular epitopes were also prepared in fusion with glutathione-S-transferase and one in conjugation with bovine serum albumin. Mental health status was assessed with the 36-item Short-Form Health Survey and Functional Assessment of Chronic Illness Therapy fatigue scale. Correlations were evaluated between glandular function and anti-m3AChR positivities and specificities, features of SLE and RA, and mental health parameters. Fourteen RA and 27 SLE patients had sSS. The autoantibody levels to all epitopes of m3AChR were significantly higher in pSS and SLE patients than in the controls. The fusion protein forms discriminated RA from pSS and SLE; furthermore, the YNIP fusion protein also distinguished pSS from SLE. The prevalence and the mean levels of all autoantibodies did not differ statistically between sicca and non-sicca SLE or RA patients. Glandular dysfunction correlated with higher age in SLE and RA and an impaired health-related quality of life in SLE. The second and third extracellular loops of m3AChR are antigenic in pSS. Immunoassays with antigens as fusion peptides demonstrate the best performance. Sicca SLE patients have worse mental health status. Anti-m3AChR antibodies represent a peculiar example of neuroimmune interactions. Copyright © 2012 S. Karger AG, Basel.

  19. Urtica dioica leaves modulates muscarinic cholinergic system in the hippocampus of streptozotocin-induced diabetic mice.

    Science.gov (United States)

    Patel, Sita Sharan; Parashar, Arun; Udayabanu, Malairaman

    2015-06-01

    Diabetes mellitus is a chronic metabolic disorder and has been associated with cognitive dysfunction. In our earlier study, chronic Urtica dioica (UD) treatment significantly ameliorated diabetes induced associative and spatial memory deficit in mice. The present study was designed to explore the effect of UD leaves extract on muscarinic cholinergic system, which has long been known to be involved in cognition. Streptozotocin (STZ) (50 mg/kg, i.p., consecutively for 5 days) was used to induce diabetes followed by treatment with UD extract (50 mg/kg, oral) or rosiglitazone (5 mg/kg, oral) for 8 weeks. STZ-induced diabetic mice showed significant reduction in hippocampal muscarinic acetylcholine receptor-1 and choline acetyltransferase expressions. Chronic diabetes significantly up-regulated the protein expression of acetylcholinesterase associated with oxidative stress in hippocampus. Besides, STZ-induced diabetic mice showed hypolocomotion with up-regulation of muscarinic acetylcholine receptor-4 expression in striatum. Chronic UD treatment significantly attenuated the cholinergic dysfunction and oxidative stress in the hippocampus of diabetic mice. UD had no effect on locomotor activity and muscarinic acetylcholine receptor-4 expression in striatum. In conclusion, UD leaves extract has potential to reverse diabetes mediated alteration in muscarinic cholinergic system in hippocampus and thereby improve memory functions.

  20. Homogeneous M2 duals

    International Nuclear Information System (INIS)

    Figueroa-O’Farrill, José; Ungureanu, Mara

    2016-01-01

    Motivated by the search for new gravity duals to M2 branes with N>4 supersymmetry — equivalently, M-theory backgrounds with Killing superalgebra osp(N|4) for N>4 — we classify (except for a small gap) homogeneous M-theory backgrounds with symmetry Lie algebra so(n)⊕so(3,2) for n=5,6,7. We find that there are no new backgrounds with n=6,7 but we do find a number of new (to us) backgrounds with n=5. All backgrounds are metrically products of the form AdS 4 ×P 7 , with P riemannian and homogeneous under the action of SO(5), or S 4 ×Q 7 with Q lorentzian and homogeneous under the action of SO(3,2). At least one of the new backgrounds is supersymmetric (albeit with only N=2) and we show that it can be constructed from a supersymmetric Freund-Rubin background via a Wick rotation. Two of the new backgrounds have only been approximated numerically.

  1. Homogeneous M2 duals

    Energy Technology Data Exchange (ETDEWEB)

    Figueroa-O’Farrill, José [School of Mathematics and Maxwell Institute for Mathematical Sciences,The University of Edinburgh,James Clerk Maxwell Building, The King’s Buildings, Peter Guthrie Tait Road,Edinburgh EH9 3FD, Scotland (United Kingdom); Ungureanu, Mara [Humboldt-Universität zu Berlin, Institut für Mathematik,Unter den Linden 6, 10099 Berlin (Germany)

    2016-01-25

    Motivated by the search for new gravity duals to M2 branes with N>4 supersymmetry — equivalently, M-theory backgrounds with Killing superalgebra osp(N|4) for N>4 — we classify (except for a small gap) homogeneous M-theory backgrounds with symmetry Lie algebra so(n)⊕so(3,2) for n=5,6,7. We find that there are no new backgrounds with n=6,7 but we do find a number of new (to us) backgrounds with n=5. All backgrounds are metrically products of the form AdS{sub 4}×P{sup 7}, with P riemannian and homogeneous under the action of SO(5), or S{sup 4}×Q{sup 7} with Q lorentzian and homogeneous under the action of SO(3,2). At least one of the new backgrounds is supersymmetric (albeit with only N=2) and we show that it can be constructed from a supersymmetric Freund-Rubin background via a Wick rotation. Two of the new backgrounds have only been approximated numerically.

  2. Myotropic Effects of Cholinergic Muscarinic Agonists and Antagonists in the Beetle Tenebrio molitor L.

    Science.gov (United States)

    Chowanski, Szymon; Rosinski, Grzegorz

    2017-01-01

    In mammals, the cholinergic nervous system plays a crucial role in neuronal regulation of physiological processes. It acts on cells by two types of receptors - nicotinic and muscarinic receptors. Both signal transmission pathways also operate in the central and peripheral cholinergic nervous system of insects. In our pharmacological experiments, we studied the effects of two muscarinic agonists (carbachol, pilocarpine) and two muscarinic antagonists (atropine, scopolamine) on the muscle contractile activity of visceral organs in the beetle, Tenebrio molitor. Both antagonists, when injected to haemolymph at concentration 10-5 M, caused delayed and prolonged cardioinhibitory effects on heart contractility in ortho- and antidromic phases of heart activity in T. molitor pupa what was observed as negative chrono- and inotropic effects. Agonist of muscarinic receptors - carbachol evoked opposite effect and increased contraction rate but only in antidromic phase. Pilocarpine, the second agonist induced weak negative chronotropic effects in the antiand orthodromic phases of heart activity. However, neither agonists had an effect on semi-isolated beetle heart in vitro. Only atropine at the highest tested concentrations slightly decreased the frequency of myocardial contractions. These suggest the regulation of heart activity by muscarinic system indirectly. The tested compounds also affected the contractility of the oviduct and hindgut, but the responses of these organs were varied and depended on the concentration of the applied compounds. These pharmacological experiments suggest the possible modulation of insect visceral muscle contractility by the cholinergic nervous system and indirectly indicate the presence of muscarinic receptor(s) in the visceral organs of the beetle T. molitor. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  3. Importance of M2-M3 loop in governing properties of genistein at the α7 nicotinic acetylcholine receptor inferred from α7/5-HT3A chimera.

    Science.gov (United States)

    Grønlien, Jens Halvard; Ween, Hilde; Thorin-Hagene, Kirsten; Cassar, Steven; Li, Jinhe; Briggs, Clark A; Gopalakrishnan, Murali; Malysz, John

    2010-11-25

    Genistein and 5-hydroxyindole (5-HI) potentiate the α7 nicotinic acetylcholine receptor current by primarily increasing peak amplitude, a property of type I α7 positive allosteric modulation. In this study, the effects of these two compounds were investigated at two different α7/5-HT(3) chimeras (chimera 1, comprising of extracellular α7 N-terminus fused to the remainder of 5-HT(3A), and chimera 2 containing an additional α7 encoded M2-M3 loop), and wild-type α7 and 5-HT(3A) receptors. Agonist-evoked responses, examined by expression of the chimeras in Xenopus laevis oocytes or HEK-293 cells, revealed that currents decayed slower and compounds {rank order: N-[(3R)-1-azabicyclo[2.2.2]oct-3-yl]-4-chlorobenzamide hydrochloride (PNU-282987)~2-(1,4-diazabicyclo[3.2.2]nonan-4-yl)-5-phenyl-1,3,4-oxadiazole (NS6784)>acetylcholine>choline} were more potent in chimera 2 than chimera 1 or α7 receptors. In chimera 2, genistein and 5-HI potentiated agonist-evoked responses (EC(50): 4-5 μM for genistein and 300-500 μM for 5-HI) and at higher concentrations evoked current directly consistent with ago-allosteric modulation. At chimera 1 and 5-HT(3A) receptors, neither compound directly evoked any current and 5-HI, only at chimera 1, was able to potentiate agonist-evoked responses. Genistein and 5-HI did not inhibit the binding of the α7 agonist [(3)H](1S,4S)-2,2-dimethyl-5-(6-phenylpyridazin-3-yl)-5-aza-2-azoniabicyclo[2.2.1] heptane ([(3)H]A-585539) to rat brain or chimera 2. In summary, this study supports the role of the M2-M3 loop being critical for the positive allosteric effect of genistein, but not 5-HI, and in agonist-evoked response fine-tuning. The identification of distinct α7 receptor modulatory sites offers unique opportunities for developing CNS therapeutics and understanding its pharmacology. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. Individual receptor profiling as a novel tool to support diagnosis of bladder pain syndrome/interstitial cystitis (BPS/IC).

    Science.gov (United States)

    Neuhaus, Jochen; Schulte-Baukloh, Heinrich; Stolzenburg, Jens-Uwe; Speroni di Fenizio, Pietro; Horn, Lars-Christian; Rüffert, Henrik; Hartenstein, Siegurd; Burger, Maximilian; Schulze, Matthias; Schwalenberg, Thilo

    2012-10-01

    Dysregulation of neurotransmitter receptors may contribute to bladder overactivity (OAB) symptoms. To address the question whether specific receptor expression patterns are associated with bladder pain syndrome/interstitial cystitis (BPS/IC), we examined the expression of muscarinic, purinergic and histamine receptors in the detrusor. Detrusor receptor expression was investigated in bladder biopsies of female BPS/IC patients (n = 44; age 60.64 ± 13.78, mean ± SD) and carcinoma patients (n = 11; age 58.91 ± 12.72) undergoing cystectomy. Protein expression of muscarinic (M2, M3), purinergic (P2X1-3) and histamine receptors (H1, H2) was analysed by confocal immunofluorescence, and gene expression was quantified by real-time polymerase chain reaction (qPCR). M2, P2X1, P2X2 and H1 receptor immunoreactivity (-IR) was significantly enhanced in BPS/IC compared to the control group, while there was no difference for M3-, P2X3- and H2-IR. We calculated a score, which separated BPS/IC from control patients with an AUC of 89.46%, showing 84.09% sensitivity and 90.91% specificity. Patients had a 9.25 times enhanced calculated risk for BPS/IC. In addition, two patient subgroups (M2 > M3 and M3 > M2) were observed, which differed in associated purinergic and histamine receptor expression. M2, P2X1, P2X2 and H1 were significantly upregulated in BPS/IC patients, and H2 was occasionally highly overexpressed. There was no significant correlation between receptor protein and gene expression, implying posttranslational mechanisms being responsible for the altered receptor expressions. On the basis of individual receptor profiles, upregulated receptors could be targeted by monotherapy or combination therapy with already approved receptor inhibitors, thereby promoting tailored therapy for patients suffering from BPS/IC-like symptoms.

  5. Angiotensin II potentiates adrenergic and muscarinic modulation of guinea pig intracardiac neurons.

    Science.gov (United States)

    Girasole, Allison E; Palmer, Christopher P; Corrado, Samantha L; Marie Southerland, E; Ardell, Jeffrey L; Hardwick, Jean C

    2011-11-01

    The intrinsic cardiac plexus represents a major peripheral integration site for neuronal, hormonal, and locally produced neuromodulators controlling efferent neuronal output to the heart. This study examined the interdependence of norepinephrine, muscarinic agonists, and ANG II, to modulate intrinsic cardiac neuronal activity. Intracellular voltage recordings from whole-mount preparations of the guinea pig cardiac plexus were used to determine changes in active and passive electrical properties of individual intrinsic cardiac neurons. Application of either adrenergic or muscarinic agonists induced changes in neuronal resting membrane potentials, decreased afterhyperpolarization duration of single action potentials, and increased neuronal excitability. Adrenergic responses were inhibited by removal of extracellular calcium ions, while muscarinic responses were inhibited by application of TEA. The adrenergic responses were heterogeneous, responding to a variety of receptor-specific agonists (phenylephrine, clonidine, dobutamine, and terbutaline), although α-receptor agonists produced the most frequent responses. Application of ANG II alone produced a significant increase in excitability, while application of ANG II in combination with either adrenergic or muscarinic agonists produced a much larger potentiation of excitability. The ANG II-induced modulation of firing was blocked by the angiotensin type 2 (AT(2)) receptor inhibitor PD 123319 and was mimicked by the AT(2) receptor agonist CGP-42112A. AT(1) receptor blockade with telmasartin did not alter neuronal responses to ANG II. These data demonstrate that ANG II potentiates both muscarinically and adrenergically mediated activation of intrinsic cardiac neurons, doing so primarily via AT(2) receptor-dependent mechanisms. These neurohumoral interactions may be fundamental to regulation of neuronal excitability within the intrinsic cardiac nervous system.

  6. Synthesis of N-Substituted Piperidine Salts as Potential Muscarinic Ligands for Alzheimer's Applications

    Czech Academy of Sciences Publication Activity Database

    Boulos, J.; Jakubík, Jan; Randáková, Alena; Avila, C.

    2013-01-01

    Roč. 50, č. 6 (2013), s. 1363-1367 ISSN 0022-152X R&D Projects: GA ČR(CZ) GA305/09/0681 Institutional support: RVO:67985823 Keywords : N-piperidine substituted salts * muscarinic receptor antagonists * selectivity Subject RIV: ED - Physiology Impact factor: 0.873, year: 2013

  7. Effects of muscarinic blockade in perirhinal cortex during visual recognition

    Science.gov (United States)

    Tang, Yi; Mishkin, Mortimer; Aigner, Thomas G.

    1997-01-01

    Stimulus recognition in monkeys is severely impaired by destruction or dysfunction of the perirhinal cortex and also by systemic administration of the cholinergic-muscarinic receptor blocker, scopolamine. These two effects are shown here to be linked: Stimulus recognition was found to be significantly impaired after bilateral microinjection of scopolamine directly into the perirhinal cortex, but not after equivalent injections into the laterally adjacent visual area TE or into the dentate gyrus of the overlying hippocampal formation. The results suggest that the formation of stimulus memories depends critically on cholinergic-muscarinic activation of the perirhinal area, providing a new clue to how stimulus representations are stored. PMID:9356507

  8. 3-(2-Benzofuranyl)quinuclidin-2-ene derivatives: novel muscarinic antagonists.

    Science.gov (United States)

    Nordvall, G; Sundquist, S; Johansson, G; Glas, G; Nilvebrant, L; Hacksell, U

    1996-08-16

    A series of 26 derivatives of the novel muscarinic antagonist 3-(2-benzofuranyl)quinuclidin-2-ene (1) has been synthesized and evaluated for muscarinic and antimuscarinic properties. The affinity of the compounds was determined by competition experiments in homogenates of cerebral cortex, heart, parotid gland, and urinary bladder from guinea pigs using (-)-[3H]-3-quinuclidinyl benzilate as the radioligand, and the antimuscarinic-potency was determined in a functional assay on isolated guinea pig urinary bladder using carbachol as the agonist. The 5-fluorobenzofuranyl derivative was slightly more potent than 1. The 7-bromo-substituted 8 displayed a 14-fold tissue selectivity ratio for muscarinic receptors in the cortex versus the parotid gland. Comparative molecular field analysis and quantitative structure-activity relationship models were developed for this series of substituted benzofuranyl derivatives.

  9. Synthesis of novel and functionally selective non‐competitive muscarinic antagonists as chemical probes

    Czech Academy of Sciences Publication Activity Database

    Boulos, J. F.; Jakubík, Jan; Boulos, J. M.; Randáková, Alena; Momirov, J.

    2018-01-01

    Roč. 91, č. 1 (2018), s. 93-104 ISSN 1747-0277 R&D Projects: GA ČR(CZ) GA14-05696S; GA ČR(CZ) GBP304/12/G069 Institutional support: RVO:67985823 Keywords : G- protein -coupled receptor * muscarinic acetylcholine receptor * N-methylscopolamine * Parkinson's disease * positive allosteric modulator Subject RIV: ED - Physiology OBOR OECD: Physiology (including cytology) Impact factor: 2.396, year: 2016

  10. Effects of presynaptic muscarinic cholinoreceptor blockade on neuromuscular transmission as assessed by the train-of-four and the tetanic fade response to rocuronium.

    Science.gov (United States)

    Kim, Yong Beom; Lee, Sangseok; Lee, Kyeong Chun; Kim, Ha Jung; Ro, Young Jin; Yang, Hong-Seuk

    2017-07-01

    This study investigated the effect of muscarinic M 1 and M 2 receptor antagonists on the rocuronium-induced train of four (TOF) fade and tetanic fade, respectively. Ex-vivo phrenic nerves and diaphragms were obtained from adult Sprague-Dawley rats and stabilized in Krebs buffer; the nerve-stimulated muscle TOF fade was observed at 20 s intervals. For the TOF study, phrenic nerves and diaphragms were incubated with pirenzepine (an M 1 blocker) at concentrations of 0 nmol L -1 (control), 10 nmol L -1 (PZP10), or 100 nmol L -1 (PZP100). Rocuronium was then administered incrementally until the first twitch tension had depressed by >95% during TOF stimulation. The mean TOF ratios were compared when the first twitch tensions were depressed by 40%-50%. For the tetanic fade study, 50 Hz/5 s tetani was applied initially, 30 min after the administration of a loading dose of rocuronium and methoctramine (an M 2 receptor blocker, loaded at 0 μmol L -1 [control], 1 μmol L -1 [MET1], or 10 μmol L -1 [MET10]). The EC 95 of rocuronium was significantly lower in the PZP10 group than in the control group. In the PZP10 group, the TOF ratios at 50% and first twitch tension depression were significantly lower than those in the control group (P=.02). During tetanic stimulation, the tetanic fade was significantly enhanced in the MET10 group compared to the other groups. This study shows that antagonists of muscarinic M 1 and M 2 receptors affect the rocuronium-induced neuromuscular block as demonstrated by the reduced EC 95 and TOF ratios (M 1 antagonist, pirenzepine) or the enhanced 50-Hz tetanic fade (M 2 antagonist, methoctramine). © 2017 The Authors. Clinical and Experimental Pharmacology and Physiology Published by John Wiley & Sons Australia, Ltd.

  11. Manipulation of Very Few Receptor Discriminator Residues Greatly Enhances Receptor Specificity of Non-visual Arrestins*

    Science.gov (United States)

    Gimenez, Luis E.; Vishnivetskiy, Sergey A.; Baameur, Faiza; Gurevich, Vsevolod V.

    2012-01-01

    Based on the identification of residues that determine receptor selectivity of arrestins and the analysis of the evolution in the arrestin family, we introduced 10 mutations of “receptor discriminator” residues in arrestin-3. The recruitment of these mutants to M2 muscarinic (M2R), D1 (D1R) and D2 (D2R) dopamine, and β2-adrenergic receptors (β2AR) was assessed using bioluminescence resonance energy transfer-based assays in cells. Seven of 10 mutations differentially affected arrestin-3 binding to individual receptors. D260K and Q262P reduced the binding to β2AR, much more than to other receptors. The combination D260K/Q262P virtually eliminated β2AR binding while preserving the interactions with M2R, D1R, and D2R. Conversely, Y239T enhanced arrestin-3 binding to β2AR and reduced the binding to M2R, D1R, and D2R, whereas Q256Y selectively reduced recruitment to D2R. The Y239T/Q256Y combination virtually eliminated the binding to D2R and reduced the binding to β2AR and M2R, yielding a mutant with high selectivity for D1R. Eleven of 12 mutations significantly changed the binding to light-activated phosphorhodopsin. Thus, manipulation of key residues on the receptor-binding surface modifies receptor preference, enabling the construction of non-visual arrestins specific for particular receptor subtypes. These findings pave the way to the construction of signaling-biased arrestins targeting the receptor of choice for research or therapeutic purposes. PMID:22787152

  12. Manipulation of very few receptor discriminator residues greatly enhances receptor specificity of non-visual arrestins.

    Science.gov (United States)

    Gimenez, Luis E; Vishnivetskiy, Sergey A; Baameur, Faiza; Gurevich, Vsevolod V

    2012-08-24

    Based on the identification of residues that determine receptor selectivity of arrestins and the analysis of the evolution in the arrestin family, we introduced 10 mutations of "receptor discriminator" residues in arrestin-3. The recruitment of these mutants to M2 muscarinic (M2R), D1 (D1R) and D2 (D2R) dopamine, and β(2)-adrenergic receptors (β(2)AR) was assessed using bioluminescence resonance energy transfer-based assays in cells. Seven of 10 mutations differentially affected arrestin-3 binding to individual receptors. D260K and Q262P reduced the binding to β(2)AR, much more than to other receptors. The combination D260K/Q262P virtually eliminated β(2)AR binding while preserving the interactions with M2R, D1R, and D2R. Conversely, Y239T enhanced arrestin-3 binding to β(2)AR and reduced the binding to M2R, D1R, and D2R, whereas Q256Y selectively reduced recruitment to D2R. The Y239T/Q256Y combination virtually eliminated the binding to D2R and reduced the binding to β(2)AR and M2R, yielding a mutant with high selectivity for D1R. Eleven of 12 mutations significantly changed the binding to light-activated phosphorhodopsin. Thus, manipulation of key residues on the receptor-binding surface modifies receptor preference, enabling the construction of non-visual arrestins specific for particular receptor subtypes. These findings pave the way to the construction of signaling-biased arrestins targeting the receptor of choice for research or therapeutic purposes.

  13. Impairment of muscarinic transmission in transgenic APPswe/PS1dE9 mice

    Czech Academy of Sciences Publication Activity Database

    Machová, Eva; Jakubík, Jan; Michal, Pavel; Oksman, M.; Iivonen, H.; Tanila, H.; Doležal, Vladimír

    2008-01-01

    Roč. 29, č. 3 (2008), s. 368-378 ISSN 0197-4580 R&D Projects: GA MŠk(CZ) LC554; GA AV ČR(CZ) IAA5011206 Grant - others:EC(XE) QLK1-CT-2002-00172 Institutional research plan: CEZ:AV0Z50110509 Keywords : Alzheimer ´s disease * muscarinic receptors * cholinergic neurotransmission Subject RIV: FH - Neurology Impact factor: 5.959, year: 2008

  14. M2 to D2

    International Nuclear Information System (INIS)

    Mukhi, Sunil; Papageorgakis, Constantinos

    2008-01-01

    We examine the recently proposed ''3-algebra'' field theory for multiple M2-branes and show that when a scalar field valued in the 3-algebra develops a vacuum expectation value, the resulting Higgs mechanism has the novel effect of promoting topological (Chern-Simons) to dynamical (Yang-Mills) gauge fields. This leads to a precise derivation of the maximally supersymmetric Yang-Mills theory on multiple D2-branes and thereby provides a relationship between 3-algebras and Yang-Mills theories. We discuss the physical interpretation of this result.

  15. Muscarinic contribution to the acute cortical effects of vagus nerve stimulation

    Science.gov (United States)

    Nichols, Justin A.

    2011-12-01

    Electrical stimulation of the vagus nerve (VNS) has been used to treat more than 60,000 patients with drug-resistant epilepsy and is under investigation as a treatment for several other neurological disorders and conditions. Among these, VNS increases memory performance and enhances recovery of motor and cognitive function in animal models of traumatic brain injury. Recent research indicates that pairing brief VNS with tones multiple-times a day for several weeks induces long-term, input specific cortical plasticity, which can be used to re-normalize the pathological cortical reorganization and eliminate a behavioral correlate of chronic tinnitus in noise exposed rats. Despite the therapeutic potential, the mechanisms of action of VNS remain speculative. In chapter 2 of this dissertation, the acute effects of VNS on cortical synchrony, excitability, and temporal processing are examined. In anesthetized rats implanted with multi-electrode arrays, VNS increased and decorrelated spontaneous multi-unit activity, and suppressed entrainment to repetitive noise burst stimulation at 6 to 8 Hz, but not after systemic administration of the muscarinic antagonist scopolamine. Chapter 3 focuses on VNS-tone pairing induced cortical plasticity. Pairing VNS with a tone one hundred times in anesthetized rats resulted in frequency specific plasticity in 31% of the auditory cortex sites. Half of these sites exhibited a frequency specific increase in firing rate and half exhibited a frequency specific decrease. Muscarinic receptor blockade with scopolamine almost entirely prevented the frequency specific increases, but not decreases. Collectively, these experiments demonstrate the capacity for VNS to not only acutely influence cortical synchrony, and excitability, but to also influence temporal and spectral tuning via muscarinic receptor activation. These results strengthen the hypothesis that acetylcholine and muscarinic receptors are involved in the mechanisms of action of VNS and

  16. Muscarinic supersensibility of anterior pituitary ACTH and beta-endorphin release in major depressive illness

    International Nuclear Information System (INIS)

    Risch, S.C.; Gillin, J.C.; Janowsky, D.S.

    1986-01-01

    Since numerious physiological systems display muscarinic receptor supersensitivity in major depressive illnesses, the authors have hypothesize that anterior pituitary release of ACTH and beta-Endorphin immunoreactivity may also be muscarinically supersensitive in depression. The studies were conducted under FDA-approved IND and with local human subjects committee approval. Plasma ACTH concentrations were determined as follows: samples were assayed in duplicate using equilibrium radioimmunoassay utilizing a rabbit anti-porcine ACTH antibody. Significance ofchanges in plasma cortisol, ACTH and beta-endorphin immunoreactivity after physostigmine and saline were determined by repeated measures analysis of variance. In all subject groups, physostigmine (relative to placebo) caused significant increases in plasma concentrations of cortisol, ACTH, and beta-endorphin immonoreactivity

  17. The Efficacy of LY293558 in Blocking Seizures and Associated Morphological, and Behavioral Alterations Induced by Soman in Immature Male Rats and the Role of the M1 Muscarinic Acetylcholine Receptor in Organophosphate Induced Seizures

    Science.gov (United States)

    2015-01-30

    including seizures or status epilepticus (SE), and if left untreated results in long-term brain damage and neuropsychiatric symptoms or death. OPs...118 Abstract Exposure to nerve agents induces prolonged status epilepticus (SE), causing brain damage or death. Diazepam (DZP) is the presently...inhibition in the brain produces convulsive seizures and status epilepticus (SE), initiated by the excessive stimulation of cholinergic receptors. If

  18. Fluoxetine induces vasodilatation of cerebral arterioles by co-modulating NO/muscarinic signalling

    Science.gov (United States)

    Ofek, Keren; Schoknecht, Karl; Melamed-Book, Naomi; Heinemann, Uwe; Friedman, Alon; Soreq, Hermona

    2012-01-01

    Ischaemic stroke patients treated with Selective Serotonin Reuptake Inhibitors (SSRI) show improved motor, cognitive and executive functions, but the underlying mechanism(s) are incompletely understood. Here, we report that cerebral arterioles in the rat brain superfused with therapeutically effective doses of the SSRI fluoxetine showed consistent, dose-dependent vasodilatation (by 1.2 to 1.6-fold), suppressible by muscarinic and nitric oxide synthase (NOS) antagonists [atropine, NG-nitro-l-arginine methyl ester (l-NAME)] but resistant to nicotinic and serotoninergic antagonists (mecamylamine, methylsergide). Fluoxetine administered 10–30 min. following experimental vascular photo-thrombosis increased arterial diameter (1.3–1.6), inducing partial, but lasting reperfusion of the ischaemic brain. In brain endothelial b.End.3 cells, fluoxetine induced rapid muscarinic receptor-dependent increases in intracellular [Ca2+] and promoted albumin- and eNOS-dependent nitric oxide (NO) production and HSP90 interaction. In vitro, fluoxetine suppressed recombinant human acetylcholinesterase (rhAChE) activity only in the presence of albumin. That fluoxetine induces vasodilatation of cerebral arterioles suggests co-promotion of endothelial muscarinic and nitric oxide signalling, facilitated by albumin-dependent inhibition of serum AChE. PMID:22697296

  19. TNF Counterbalances the Emergence of M2 Tumor Macrophages

    Directory of Open Access Journals (Sweden)

    Franz Kratochvill

    2015-09-01

    Full Text Available Cancer can involve non-resolving, persistent inflammation where varying numbers of tumor-associated macrophages (TAMs infiltrate and adopt different activation states between anti-tumor M1 and pro-tumor M2 phenotypes. Here, we resolve a cascade causing differential macrophage phenotypes in the tumor microenvironment. Reduction in TNF mRNA production or loss of type I TNF receptor signaling resulted in a striking pattern of enhanced M2 mRNA expression. M2 gene expression was driven in part by IL-13 from eosinophils co-recruited with inflammatory monocytes, a pathway that was suppressed by TNF. Our data define regulatory nodes within the tumor microenvironment that balance M1 and M2 populations. Our results show macrophage polarization in cancer is dynamic and dependent on the balance between TNF and IL-13, thus providing a strategy for manipulating TAMs.

  20. Acetylcholine receptors in the human retina

    International Nuclear Information System (INIS)

    Hutchins, J.B.; Hollyfield, J.G.

    1985-01-01

    Evidence for a population of acetylcholine (ACh) receptors in the human retina is presented. The authors have used the irreversible ligand 3 H-propylbenzilylcholine mustard ( 3 H-PrBCM) to label muscarinic receptors. 3 H- or 125 I-alpha-bungarotoxin (alpha-BTx) was used to label putative nicotinic receptors. Muscarinic receptors are apparently present in the inner plexiform layer of the retina. Autoradiographic grain densities are reduced in the presence of saturating concentrations of atropine, quinuclidinyl benzilate or scopolamine; this indicates that 3 H-PrBCM binding is specific for a population of muscarinic receptors in the human retina. Binding sites for radiolabeled alpha-BTx are found predominantly in the inner plexiform layer of the retina. Grain densities are reduced in the presence of d-tubocurarine, indicating that alpha-BTx may bind to a pharmacologically relevant nicotinic ACh receptor. This study provides evidence for cholinergic neurotransmission in the human retina

  1. Polysaccharide Agaricus blazei Murill stimulates myeloid derived suppressor cell differentiation from M2 to M1 type, which mediates inhibition of tumour immune-evasion via the Toll-like receptor 2 pathway.

    Science.gov (United States)

    Liu, Yi; Zhang, Lingyun; Zhu, Xiangxiang; Wang, Yuehua; Liu, WenWei; Gong, Wei

    2015-11-01

    Gr-1(+) CD11b(+) myeloid-derived suppressor cells (MDSCs) accumulate in tumor-bearing animals and play a critical negative role during tumor immunotherapy. Strategies for inhibition of MDSCs are expected to improve cancer immunotherapy. Polysaccharide Agaricus blazei Murill (pAbM) has been found to have anti-cancer activity, but the underlying mechanism of this is poorly understood. Here, pAbM directly activated the purified MDSCs through inducing the expression of interleukin-6 (IL-6), IL-12, tumour necrosis factor and inducible nitric oxide synthase (iNOS), CD86, MHC II, and pSTAT1 of it, and only affected natural killer and T cells in the presence of Gr-1(+) CD11b(+) monocytic MDSCs. On further analysis, we demonstrated that pAbM could selectively block the Toll-like receptor 2 (TLR2) signal of Gr-1(+) CD11b(+) MDSCs and increased their M1-type macrophage characteristics, such as producing IL-12, lowering expression of Arginase 1 and increasing expression of iNOS. Extensive study showed that Gr-1(+) CD11b(+) MDSCs by pAbM treatment had less ability to convert the CD4(+) CD25(-) cells into CD4(+) CD25(+) phenotype. Moreover, result from selective depletion of specific cell populations in xenograft mice model suggested that the anti-tumour effect of pAbM was dependent on Gr-1(+ ) CD11b(+) monocytes, nether CD8(+) T cells nor CD4(+) T cells. In addition to, pAbM did not inhibit tumour growth in TLR2(-/-) mice. All together, these results suggested that pAbM, a natural product commonly used for cancer treatment, was a specific TLR2 agonist and had potent anti-tumour effects through the opposite of the suppressive function of Gr-1(+) CD11b(+) MDSCs. © 2015 John Wiley & Sons Ltd.

  2. The role of muscarinic cholinergic signaling in cost-benefit decision making

    Science.gov (United States)

    Fobbs, Wambura

    Animals regularly face decisions that affect both their immediate success and long term survival. Such decisions typically involve some form of cost-benefit analysis and engage a number of high level cognitive processes, including learning, memory and motivational influences. While decision making has been a focus of study for over a century, it's only in the last 20 years that researchers have begun to identify functional neural circuits that subserve different forms of cost-benefit decision making. Even though the cholinergic system is both functionally and anatomically positioned to modulate cost-benefit decision circuits, the contribution of the cholinergic system to decision making has been little studied. In this thesis, I investigated the cognitive and neural contribution of muscarinic cholinergic signaling to cost-benefit decision making. I, first, re-examined the effects of systemic administration of 0.3 mg/kg atropine on delay and probability discounting tasks and found that blockade of muscarinic acetylcholine receptors by atropine induced suboptimal choices (impulsive and risky) in both tasks. Since the effect on delay discounting was restricted to the No Cue version of the delay discounting task, I concluded that muscarinic cholinergic signaling mediates both forms of cost-benefit decision making and is selectively engaged when decisions require valuation of reward options whose costs are not externally signified. Second, I assessed the impact of inactivating the nucleus basalis (NBM) on both forms decision making and the effect of injecting atropine locally into the orbitofrontal cortex (OFC), basolateral amygdala (BLA), or nucleus accumbens (NAc) core during the No Cue version of the delay discounting task. I discovered that although NBM inactivation failed to affect delay discounting, it induced risk aversion in the probability discounting task; and blockade of intra- NAc core, but not intra-OFC or intra-BLA, muscarinic cholinergic signaling lead to

  3. Relations between immune and mediator receptors of mouse lymphocytes

    International Nuclear Information System (INIS)

    Ado, A.D.; Alekseeva, T.A.; Kravchenko, S.A.

    1985-01-01

    This paper examines the action of the specific muscarinic antogonist tritium-quinuclidinyl benzilate (tritium-QNB) on immune rosette formation in mice. It is shown that since the specific muscarini antagonist tritium-QNB inhibits immune rosette formation, this process must be regarded as interconnected with muscarinic receptors of lymphocytes. Interaction of immune (antigen-binding) and mediator receptors, however, is an important factor maintaining immune homeostasis at a certain level

  4. Endosulfan and cholinergic (muscarinic) transmission: effect on electroencephalograms and [3H]quinuclidinyl benzilate in pigeon brain

    International Nuclear Information System (INIS)

    Anand, M.; Agrawal, A.K.; Gopal, K.; Sur, R.N.; Seth, P.K.

    1986-01-01

    Single exposure of endosulfan (5 mg/kg) to pigeons (Columbia livia) caused neuronal hyperexcitability as evidence by spike discharges of 200-500 μV in the electroencephalograms (EEG) from the telencephalon and hyperstriatum, but there was not effect on the ectostriatal area. Cholinergic (muscarinic) receptor binding study using [ 3 H]quinuclidinyl benzilate ([ 3 H]QNB) as a specific ligand indicated that a single exposure to 5 mg/kg of endosulfan caused a significant increase in [ 3 H]QNB binding to the striatal membrane. Behavior study further indicated that a single dose of 200 μg/kg of oxotremorine produced a significant induction in the tremor in endosulfan-pretreated pigeons. The results of this behavioral and biochemical study indicate the involvement of a cholinergic (muscarinic) transmitter system in endosulfan-induced neurotoxicity

  5. Understanding the Mysterious M2 Macrophage through Activation Markers and Effector Mechanisms

    Science.gov (United States)

    Rőszer, Tamás

    2015-01-01

    The alternatively activated or M2 macrophages are immune cells with high phenotypic heterogeneity and are governing functions at the interface of immunity, tissue homeostasis, metabolism, and endocrine signaling. Today the M2 macrophages are identified based on the expression pattern of a set of M2 markers. These markers are transmembrane glycoproteins, scavenger receptors, enzymes, growth factors, hormones, cytokines, and cytokine receptors with diverse and often yet unexplored functions. This review discusses whether these M2 markers can be reliably used to identify M2 macrophages and define their functional subdivisions. Also, it provides an update on the novel signals of the tissue environment and the neuroendocrine system which shape the M2 activation. The possible evolutionary roots of the M2 macrophage functions are also discussed. PMID:26089604

  6. G Protein-coupled Receptor Kinases of the GRK4 Protein Subfamily Phosphorylate Inactive G Protein-coupled Receptors (GPCRs).

    Science.gov (United States)

    Li, Lingyong; Homan, Kristoff T; Vishnivetskiy, Sergey A; Manglik, Aashish; Tesmer, John J G; Gurevich, Vsevolod V; Gurevich, Eugenia V

    2015-04-24

    G protein-coupled receptor (GPCR) kinases (GRKs) play a key role in homologous desensitization of GPCRs. It is widely assumed that most GRKs selectively phosphorylate only active GPCRs. Here, we show that although this seems to be the case for the GRK2/3 subfamily, GRK5/6 effectively phosphorylate inactive forms of several GPCRs, including β2-adrenergic and M2 muscarinic receptors, which are commonly used as representative models for GPCRs. Agonist-independent GPCR phosphorylation cannot be explained by constitutive activity of the receptor or membrane association of the GRK, suggesting that it is an inherent ability of GRK5/6. Importantly, phosphorylation of the inactive β2-adrenergic receptor enhanced its interactions with arrestins. Arrestin-3 was able to discriminate between phosphorylation of the same receptor by GRK2 and GRK5, demonstrating preference for the latter. Arrestin recruitment to inactive phosphorylated GPCRs suggests that not only agonist activation but also the complement of GRKs in the cell regulate formation of the arrestin-receptor complex and thereby G protein-independent signaling. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  7. Synthesis of 99mTc-oxybutynin for M3-receptor-mediated imaging of urinary bladder

    International Nuclear Information System (INIS)

    Moustapha, M.E.; Benha University, Benha; Motaleb, M.A.; Ibrahim, I.T.

    2011-01-01

    Radiolabeling of oxybutynin, a muscarinic acetylcholine (mACh) receptor antagonist agent with 99m Tc is of considerable interest for imaging of urinary bladder. This study is aimed to optimize radiolabeling yield of oxybutynin with 99m Tc using SnCl 2 x 2H 2 O as a reducing agent with respect to factors that affect the reaction conditions such as oxybutynin amount, stannous chloride amount, reaction time and pH of the reaction mixture. In vitro stability of the radiolabeled complex was checked and it was found to be stable for up to 8 h. 99m Tc-oxybutynin was injected via subcutaneous and intravenous administration routes into normal Sprague-Dawley rats. Biodistribution studies have revealed that 99m Tc-oxybutynin exhibits high affinity and specificity for the muscarinic M 3 subtype located on the smooth muscle of urinary bladder relative to the M 1 and M 2 subtypes of the G protein coupled receptor (GPCR) superfamily. In vivo uptake of subcutaneous 99m Tc-oxybutynin in urinary bladder was 19.6 ± 0.42% ID at 0.5 h, whereas in intravenous administration route the accumulation in the urinary bladder was found to be 9.4 ± 0.31% ID at 0.5 h post injection. Administration of cold oxybutynin effectively blocked urinary bladder uptake and further confirms the high specificity of this complex for the M 3 receptor. (author)

  8. A proposal for M2-brane-anti-M2-brane action

    International Nuclear Information System (INIS)

    Garousi, Mohammad R.

    2010-01-01

    We propose a manifestly SO(8) invariant BF type Lagrangian for describing the dynamics of M2-brane-anti-M2-brane system in flat spacetime. When one of the scalars which satisfies a free-scalar equation takes a large expectation value, the M2-brane-anti-M2-brane action reduces to the tachyon DBI action of D2-brane-anti-D2-brane system in flat spacetime.

  9. Anti-influenza M2e antibody

    Science.gov (United States)

    Bradbury, Andrew M [Santa Fe, NM

    2011-12-20

    Humanized recombinant and monoclonal antibodies specific for the ectodomain of the influenza virus M2 ion channel protein are disclosed. The antibodies of the invention have anti-viral activity and may be useful as anti-viral therapeutics and/or prophylactic/vaccine agents for inhibiting influenza virus replication and for treating individuals infected with influenza.

  10. Development of radiohalogenated muscarinic ligands for the in vivo imaging of m-AChR by nuclear medicine techniques

    Energy Technology Data Exchange (ETDEWEB)

    McPherson, D.W.; Luo, H.; Knapp, F.F. Jr.

    1994-06-01

    Alterations in the density of acetylcholinergic muscarinic receptors (m-AChR) have been observed in various dementias. This has spurred interest in the development of radiohalogenated ligands which can be used for the non-invasive in vivo detection of m-AChR by nuclear medicine techniques. We have developed a new ligand 1-azabicyclo[2.2.2]oct-3-yl ({alpha}-hydroxy-{alpha}-(1-iodo-1-propen-3-yl)-{alpha}-phenylacetate (IQNP,12) which demonstrates high affinity for the muscarinic receptor. When labeled with radioiodine it has been shown to be selective and specific for m-ACHR. Initial studies on the separation and in vivo evaluation of the various isomers of IQNP have shown that the stereochemistry of the chiral centers and the configuration around the double bond play an important role in m-AChR subtype specificity. In vivo evaluation of these stereoisomers demonstrate that E-(R,R)-IQNP has a high affinity for the M{sub 1} muscarinic subtype while Z-(R,R)-IQNP demonstrate a high affinity for M{sub 1} and M{sub 2} receptor subtypes. These data demonstrate IQNP (12) has potential for use in the non-evasive in vivo detection of m-AChR by single photon emission computed tomography (SPECT). A brominated analogue, ``BrQNP,`` in which the iodine has been replaced by a bromine atom, has also been prepared and was shown to block the in vivo uptake of IQNP in the brain and heart and therefore has potential for positron emission tomographic (PET) studies of m-AChR.

  11. New generic approach to the treatment of organophosphate poisoning : Adenosine receptor mediated inhibition of ACh-release

    NARCIS (Netherlands)

    van Helden, HPM; Moor, E; Westerink, BHC; Bruijnzeel, PLB

    1998-01-01

    Current treatment of acute organophosphate (OP) poisoning includes a combined administration of a cholinesterase reactivator (oxime), a muscarinic receptor antagonist (atropine) and an anticonvulsant (diazepam). This treatment is not adequate since it does not prevent neuronal brain damage and

  12. New generic approach to the treatment of organophosphate poisoning: Adenosine receptor mediated inhibition of ACh-release

    NARCIS (Netherlands)

    Helden, H.P.M. van; Groen, B.; Moor, E.; Westerink, B.H.C.; Bruijnzeel, P.L.B.

    1998-01-01

    Current treatment of acute organophosphate (OP) poisoning includes a combined administration of a cholinesterase reactivator (oxime), a muscarinic receptor antagonist (atropine) and an anticonvulsant (diazepam). This treatment is not adequate since it does not prevent neuronal brain damage and

  13. Presynaptic membrane receptors in acetylcholine release modulation in the neuromuscular synapse.

    Science.gov (United States)

    Tomàs, Josep; Santafé, Manel M; Garcia, Neus; Lanuza, Maria A; Tomàs, Marta; Besalduch, Núria; Obis, Teresa; Priego, Mercedes; Hurtado, Erica

    2014-05-01

    Over the past few years, we have studied, in the mammalian neuromuscular junction (NMJ), the local involvement in transmitter release of the presynaptic muscarinic ACh autoreceptors (mAChRs), purinergic adenosine autoreceptors (P1Rs), and trophic factor receptors (TFRs; for neurotrophins and trophic cytokines) during development and in the adult. At any given moment, the way in which a synapse works is largely the logical outcome of the confluence of these (and other) metabotropic signalling pathways on intracellular kinases, which phosphorylate protein targets and materialize adaptive changes. We propose an integrated interpretation of the complementary function of these receptors in the adult NMJ. The activity of a given receptor group can modulate a given combination of spontaneous, evoked, and activity-dependent release characteristics. For instance, P1Rs can conserve resources by limiting spontaneous quantal leak of ACh (an A1 R action) and protect synapse function, because stimulation with adenosine reduces the magnitude of depression during repetitive activity. The overall outcome of the mAChRs seems to contribute to upkeep of spontaneous quantal output of ACh, save synapse function by decreasing the extent of evoked release (mainly an M2 action), and reduce depression. We have also identified several links among P1Rs, mAChRs, and TFRs. We found a close dependence between mAChR and some TFRs and observed that the muscarinic group has to operate correctly if the tropomyosin-related kinase B receptor (trkB) is also to operate correctly, and vice versa. Likewise, the functional integrity of mAChRs depends on P1Rs operating normally. Copyright © 2014 Wiley Periodicals, Inc.

  14. M2 qualify laser beam propagation

    International Nuclear Information System (INIS)

    Abdelhalim, Bencheikh; Mohamed, Bouafia

    2010-01-01

    One of the most important properties of a laser resonator is the highly collimated or spatially coherent nature of the laser output beam. Laser beam diameter and quality factor M 2 are significant parameters in a wide range of laser applications. This is because the spatial beam quality determines how closely the beam can be focused or how well the beam propagates over long distances without significant dispersion. In the present paper we have used three different methods to qualify the spatial structure of a laser beam propagating in free space, the results are obtained and discussed, and we have found that the Wigner distribution function is a powerful tool which allows a global characterization of any kind of beam

  15. Evolution of the toxins muscarine and psilocybin in a family of mushroom-forming fungi.

    Directory of Open Access Journals (Sweden)

    Pawel Kosentka

    Full Text Available Mushroom-forming fungi produce a wide array of toxic alkaloids. However, evolutionary analyses aimed at exploring the evolution of muscarine, a toxin that stimulates the parasympathetic nervous system, and psilocybin, a hallucinogen, have never been performed. The known taxonomic distribution of muscarine within the Inocybaceae is limited, based only on assays of species from temperate regions of the northern hemisphere. Here, we present a review of muscarine and psilocybin assays performed on species of Inocybaceae during the last fifty years. To supplement these results, we used liquid chromatography-tandem mass spectrometry (LC-MS/MS to determine whether muscarine was present in 30 new samples of Inocybaceae, the majority of which have not been previously assayed or that originated from either the tropics or temperate regions of the southern hemisphere. Our main objective is to test the hypothesis that the presence of muscarine is a shared ancestral feature of the Inocybaceae. In addition, we also test whether species of Inocyabceae that produce psilocybin are monophyletic. Our findings suggest otherwise. Muscarine has evolved independently on several occasions, together with several losses. We also detect at least two independent transitions of muscarine-free lineages to psilocybin-producing states. Although not ancestral for the family as a whole, muscarine is a shared derived trait for an inclusive clade containing three of the seven major lineages of Inocybaceae (the Inocybe, Nothocybe, and Pseudosperma clades, the common ancestor of which may have evolved ca. 60 million years ago. Thus, muscarine represents a conserved trait followed by several recent losses. Transitions to psilocybin from muscarine-producing ancestors occurred more recently between 10-20 million years ago after muscarine loss in two separate lineages. Statistical analyses firmly reject a single origin of muscarine-producing taxa.

  16. Evolution of the toxins muscarine and psilocybin in a family of mushroom-forming fungi.

    Science.gov (United States)

    Kosentka, Pawel; Sprague, Sarah L; Ryberg, Martin; Gartz, Jochen; May, Amanda L; Campagna, Shawn R; Matheny, P Brandon

    2013-01-01

    Mushroom-forming fungi produce a wide array of toxic alkaloids. However, evolutionary analyses aimed at exploring the evolution of muscarine, a toxin that stimulates the parasympathetic nervous system, and psilocybin, a hallucinogen, have never been performed. The known taxonomic distribution of muscarine within the Inocybaceae is limited, based only on assays of species from temperate regions of the northern hemisphere. Here, we present a review of muscarine and psilocybin assays performed on species of Inocybaceae during the last fifty years. To supplement these results, we used liquid chromatography-tandem mass spectrometry (LC-MS/MS) to determine whether muscarine was present in 30 new samples of Inocybaceae, the majority of which have not been previously assayed or that originated from either the tropics or temperate regions of the southern hemisphere. Our main objective is to test the hypothesis that the presence of muscarine is a shared ancestral feature of the Inocybaceae. In addition, we also test whether species of Inocyabceae that produce psilocybin are monophyletic. Our findings suggest otherwise. Muscarine has evolved independently on several occasions, together with several losses. We also detect at least two independent transitions of muscarine-free lineages to psilocybin-producing states. Although not ancestral for the family as a whole, muscarine is a shared derived trait for an inclusive clade containing three of the seven major lineages of Inocybaceae (the Inocybe, Nothocybe, and Pseudosperma clades), the common ancestor of which may have evolved ca. 60 million years ago. Thus, muscarine represents a conserved trait followed by several recent losses. Transitions to psilocybin from muscarine-producing ancestors occurred more recently between 10-20 million years ago after muscarine loss in two separate lineages. Statistical analyses firmly reject a single origin of muscarine-producing taxa.

  17. β-adrenergic-stimulated macrophages: Comprehensive localization in the M1–M2 spectrum

    Science.gov (United States)

    Lamkin, Donald M.; Ho, Hsin-Yun; Ong, Tiffany H.; Kawanishi, Carly K.; Stoffers, Victoria L.; Ahlawat, Nivedita; Ma, Jeffrey C.Y.; Arevalo, Jesusa M. G.; Cole, Steve W.; Sloan, Erica K.

    2016-01-01

    β-adrenergic signaling can regulate macrophage involvement in several diseases and often produces anti-inflammatory properties in macrophages, which are similar to M2 properties in a dichotomous M1 vs. M2 macrophage taxonomy. However, it is not clear that β-adrenergic-stimulated macrophages may be classified strictly as M2. In this in vitro study, we utilized recently published criteria and transcriptome-wide bioinformatics methods to map the relative polarity of murine β-adrenergic-stimulated macrophages within a wider M1–M2 spectrum. Results show that β-adrenergic-stimulated macrophages did not fit entirely into any one predefined category of the M1–M2 spectrum but did express genes that are representative of some M2 side categories. Moreover, transcript origin analysis of genome-wide transcriptional profiles located β-adrenergic-stimulated macrophages firmly on the M2 side of the M1–M2 spectrum and found active suppression of M1 side gene transcripts. The signal transduction pathways involved were mapped through blocking experiments and bioinformatics analysis of transcription factor binding motifs. M2-promoting effects were mediated specifically through β2-adrenergic receptors and were associated with CREB, C/EBPβ, and ATF transcription factor pathways but not with established M1–M2 STAT pathways. Thus, β-adrenergic-signaling induces a macrophage transcriptome that locates on the M2 side of the M1–M2 spectrum but likely accomplishes this effect through a signaling pathway that is atypical for M2-spectrum macrophages. PMID:27485040

  18. An anti-nicotinic cognitive challenge model using mecamylamine in comparison with the anti-muscarinic cognitive challenge using scopolamine.

    Science.gov (United States)

    Baakman, Anne Catrien; Alvarez-Jimenez, Ricardo; Rissmann, Robert; Klaassen, Erica S; Stevens, Jasper; Goulooze, Sebastiaan C; den Burger, Jeroen C G; Swart, Eleonora L; van Gerven, Joop M A; Groeneveld, Geert Jan

    2017-08-01

    The muscarinic acetylcholine receptor antagonist scopolamine is often used for proof-of-pharmacology studies with pro-cognitive compounds. From a pharmacological point of view, it would seem more rational to use a nicotinic rather than a muscarinic anticholinergic challenge to prove pharmacology of a nicotinic acetylcholine receptor agonist. This study aims to characterize a nicotinic anticholinergic challenge model using mecamylamine and to compare it to the scopolamine model. In this double-blind, placebo-controlled, four-way cross-over trial, 12 healthy male subjects received oral mecamylamine 10 and 20 mg, intravenous scopolamine 0.5 mg and placebo. Pharmacokinetics were analysed using non-compartmental analysis. Pharmacodynamic effects were measured with a multidimensional test battery that includes neurophysiological, subjective, (visuo)motor and cognitive measurements. All treatments were safe and well tolerated. Mecamylamine had a t max of 2.5 h and a C max of 64.5 ng ml -1 for the 20 mg dose. Mecamylamine had a dose-dependent effect decreasing the adaptive tracking performance and VAS alertness, and increasing the finger tapping and visual verbal learning task performance time and errors. Scopolamine significantly affected almost all pharmacodynamic tests. This study demonstrated that mecamylamine causes nicotinic receptor specific temporary decline in cognitive functioning. Compared with the scopolamine model, pharmacodynamic effects were less pronounced at the dose levels tested; however, mecamylamine caused less sedation. The cognitive effects of scopolamine might at least partly be caused by sedation. Whether the mecamylamine model can be used for proof-of-pharmacology of nicotinic acetylcholine receptor agonists remains to be established. © 2017 The British Pharmacological Society.

  19. M2M Optimizations in Public Mobile Networks

    NARCIS (Netherlands)

    Norp, A.H.J.; Landais, B.

    2012-01-01

    Many M2M applications use public telecommunications networks to transfer data from M2M devices to an M2M server. These telecommunications networks will have to be adapted to cope with the traffic generated by the projected growth of M2M applications. In the near future, many more devices will be

  20. Muscarinic Long-Term Enhancement of Tonic and Phasic GABAA Inhibition in Rat CA1 Pyramidal Neurons

    Science.gov (United States)

    Domínguez, Soledad; Fernández de Sevilla, David; Buño, Washington

    2016-01-01

    Acetylcholine (ACh) regulates network operation in the hippocampus by controlling excitation and inhibition in rat CA1 pyramidal neurons (PCs), the latter through gamma-aminobutyric acid type-A receptors (GABAARs). Although, the enhancing effects of ACh on GABAARs have been reported (Dominguez et al., 2014, 2015), its role in regulating tonic GABAA inhibition has not been explored in depth. Therefore, we aimed at determining the effects of the activation of ACh receptors on responses mediated by synaptic and extrasynaptic GABAARs. Here, we show that under blockade of ionotropic glutamate receptors ACh, acting through muscarinic type 1 receptors, paired with post-synaptic depolarization induced a long-term enhancement of tonic GABAA currents (tGABAA) and puff-evoked GABAA currents (pGABAA). ACh combined with depolarization also potentiated IPSCs (i.e., phasic inhibition) in the same PCs, without signs of interactions of synaptic responses with pGABAA and tGABAA, suggesting the contribution of two different GABAA receptor pools. The long-term enhancement of GABAA currents and IPSCs reduced the excitability of PCs, possibly regulating plasticity and learning in behaving animals. PMID:27833531

  1. Laminar pattern of cholinergic and adrenergic receptors in rat visual cortex using quantitative receptor autoradiography

    International Nuclear Information System (INIS)

    Schliebs, R.; Walch, C.

    1989-01-01

    The laminar distribution of muscarinic acetylcholine receptors, including the M1-receptor subtype, of beta-adrenergic receptors, and noradrenaline uptake sites, was studied in the adult rat visual, frontal, somatosensory and motor cortex, using quantitative receptor autoradiography. In the visual cortex, the highest density of muscarinic acetylcholine receptors was found in layer I. From layer II/III to layer V binding decreases continueously reaching a constant binding level in layers V and VI. This laminar pattern of muscarinic receptor density differs somewhat from that observed in the non-visual cortical regions examined: layer II/III contained the highest receptor density followed by layer I and IV: lowest density was found in layer V and VI. The binding profile of the muscarinic cholinergic M1-subtype through the visual cortex shows a peak in cortical layer II and in the upper part of layer VI, whereas in the non-visual cortical regions cited the binding level was high in layer II/III, moderate in layer I and IV, and low in layer VI. Layers I to IV of the visual cortex contained the highest beta-adrenergic receptor densities, whereas only low binding levels were observed in the deeper layers. A similar laminar distribution was found also in the frontal, somatosensory and motor cortex. The density of noradrenaline uptake sites was high in all layers of the cortical regions studied, but with noradrenaline uptake sites somewhat more concentrated in the superficial layers than in deeper ones. The distinct laminar pattern of cholinergic and noradrenergic receptor sites indicates a different role for acetylcholine and noradrenaline in the functional anatomy of the cerebral cortex, and in particular, the visual cortex. (author)

  2. Laminar pattern of cholinergic and adrenergic receptors in rat visual cortex using quantitative receptor autoradiography

    Energy Technology Data Exchange (ETDEWEB)

    Schliebs, R; Walch, C [Leipzig Univ. (German Democratic Republic). Bereich Medizin; Stewart, M G [Open Univ., Milton Keynes (UK)

    1989-01-01

    The laminar distribution of muscarinic acetylcholine receptors, including the M1-receptor subtype, of beta-adrenergic receptors, and noradrenaline uptake sites, was studied in the adult rat visual, frontal, somatosensory and motor cortex, using quantitative receptor autoradiography. In the visual cortex, the highest density of muscarinic acetylcholine receptors was found in layer I. From layer II/III to layer V binding decreases continueously reaching a constant binding level in layers V and VI. This laminar pattern of muscarinic receptor density differs somewhat from that observed in the non-visual cortical regions examined: layer II/III contained the highest receptor density followed by layer I and IV: lowest density was found in layer V and VI. The binding profile of the muscarinic cholinergic M1-subtype through the visual cortex shows a peak in cortical layer II and in the upper part of layer VI, whereas in the non-visual cortical regions cited the binding level was high in layer II/III, moderate in layer I and IV, and low in layer VI. Layers I to IV of the visual cortex contained the highest beta-adrenergic receptor densities, whereas only low binding levels were observed in the deeper layers. A similar laminar distribution was found also in the frontal, somatosensory and motor cortex. The density of noradrenaline uptake sites was high in all layers of the cortical regions studied, but with noradrenaline uptake sites somewhat more concentrated in the superficial layers than in deeper ones. The distinct laminar pattern of cholinergic and noradrenergic receptor sites indicates a different role for acetylcholine and noradrenaline in the functional anatomy of the cerebral cortex, and in particular, the visual cortex. (author).

  3. receptores

    Directory of Open Access Journals (Sweden)

    Salete Regina Daronco Benetti

    2006-01-01

    Full Text Available Se trata de un estudio etnográfico, que tuvo lo objetivo de interpretar el sistema de conocimiento y del significado atribuidos a la sangre referente a la transfusión sanguínea por los donadores y receptores de un banco de sangre. Para la colecta de las informaciones se observaron los participantes y la entrevista etnográfica se realizó el análisis de dominio, taxonómicos y temáticos. Los dominios culturales fueron: la sangre es vida: fuente de vida y alimento valioso; creencias religiosas: fuentes simbólicas de apoyos; donación sanguínea: un gesto colaborador que exige cuidarse, gratifica y trae felicidad; donación sanguínea: fuente simbólica de inseguridad; estar enfermo es una condición para realizar transfusión sanguínea; transfusión sanguínea: esperanza de vida; Creencias populares: transfusión sanguínea como riesgo para la salud; donadores de sangre: personas benditas; donar y recibir sangre: como significado de felicidad. Temática: “líquido precioso que origina, sostiene, modifica la vida, provoca miedo e inseguridad”.

  4. Bitopic muscarinic agonists and antagonists and uses thereof: a patent evaluation of US20160136145A1.

    Science.gov (United States)

    Holzgrabe, Ulrike; Decker, Michael

    2017-02-01

    Bitopic M ligands, that is, ligands that interact both with the ortho- and allosteric binding sites of the M receptor subtypes, hold great potential as novel selective for muscarinic acetylcholine (M) ligands for several therapeutic applications. Areas covered: The patent application describes a set of compounds based on the neurotransmitter acetylcholine applying the Schulman-model for M ligands comprising heterocyclic (often quaternary) amines and a benzene ring (often as benzoic acid esters) to act as bitopic ligands. The compounds claimed hold functional selectivity and are supposed to be therapeutically applied as neuromuscular blocking agents, in asthma as well as CNS diseases. In vitro evaluations of selected compounds supported bitopic binding and some degree of functional selectivity was observed - albeit no selectivity was observed in binding studies. Expert opinion: The quaternary amine structure of the compounds claimed will prohibit penetration into the CNS and their ester structure will lead to significant metabolic instability which will hamper therapeutic applications for many indications. Furthermore, high affinity and subtype selectivity with regard to binding affinity which is observed for bitopic and allosteric ligands in the current literature is not observed for the compounds described in the patent.

  5. Rac2 controls tumor growth, metastasis and M1-M2 macrophage differentiation in vivo.

    Directory of Open Access Journals (Sweden)

    Shweta Joshi

    Full Text Available Although it is well-established that the macrophage M1 to M2 transition plays a role in tumor progression, the molecular basis for this process remains incompletely understood. Herein, we demonstrate that the small GTPase, Rac2 controls macrophage M1 to M2 differentiation and the metastatic phenotype in vivo. Using a genetic approach, combined with syngeneic and orthotopic tumor models we demonstrate that Rac2-/- mice display a marked defect in tumor growth, angiogenesis and metastasis. Microarray, RT-PCR and metabolomic analysis on bone marrow derived macrophages isolated from the Rac2-/- mice identify an important role for Rac2 in M2 macrophage differentiation. Furthermore, we define a novel molecular mechanism by which signals transmitted from the extracellular matrix via the α4β1 integrin and MCSF receptor lead to the activation of Rac2 and potentially regulate macrophage M2 differentiation. Collectively, our findings demonstrate a macrophage autonomous process by which the Rac2 GTPase is activated downstream of the α4β1 integrin and the MCSF receptor to control tumor growth, metastasis and macrophage differentiation into the M2 phenotype. Finally, using gene expression and metabolomic data from our Rac2-/- model, and information related to M1-M2 macrophage differentiation curated from the literature we executed a systems biologic analysis of hierarchical protein-protein interaction networks in an effort to develop an iterative interactome map which will predict additional mechanisms by which Rac2 may coordinately control macrophage M1 to M2 differentiation and metastasis.

  6. 26 CFR 1.401(m)-2 - ACP test.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 5 2010-04-01 2010-04-01 false ACP test. 1.401(m)-2 Section 1.401(m)-2 Internal... TAXES Pension, Profit-Sharing, Stock Bonus Plans, Etc. § 1.401(m)-2 ACP test. (a) Actual contribution percentage (ACP) test—(1) In general—(i) ACP test formula. A plan satisfies the ACP test for a plan year only...

  7. Towards Horizontal Architecture for Autonomic M2M Service Networks

    Directory of Open Access Journals (Sweden)

    Juhani Latvakoski

    2014-05-01

    Full Text Available Today, increasing number of industrial application cases rely on the Machine to Machine (M2M services exposed from physical devices. Such M2M services enable interaction of physical world with the core processes of company information systems. However, there are grand challenges related to complexity and “vertical silos” limiting the M2M market scale and interoperability. It is here expected that horizontal approach for the system architecture is required for solving these challenges. Therefore, a set of architectural principles and key enablers for the horizontal architecture have been specified in this work. A selected set of key enablers called as autonomic M2M manager, M2M service capabilities, M2M messaging system, M2M gateways towards energy constrained M2M asset devices and creation of trust to enable end-to-end security for M2M applications have been developed. The developed key enablers have been evaluated separately in different scenarios dealing with smart metering, car sharing and electric bike experiments. The evaluation results shows that the provided architectural principles, and developed key enablers establish a solid ground for future research and seem to enable communication between objects and applications, which are not initially been designed to communicate together. The aim as the next step in this research is to create a combined experimental system to evaluate the system interoperability and performance in a more detailed manner.

  8. Purinergic signaling during macrophage differentiation results in M2 alternative activated macrophages.

    Science.gov (United States)

    Barberà-Cremades, Maria; Baroja-Mazo, Alberto; Pelegrín, Pablo

    2016-02-01

    Macrophages represent a highly heterogenic cell population of the innate immune system, with important roles in the initiation and resolution of the inflammatory response. Purinergic signaling regulates both M1 and M2 macrophage function at different levels by controlling the secretion of cytokines, phagocytosis, and the production of reactive oxygen species. We found that extracellular nucleotides arrest macrophage differentiation from bone marrow precursors via adenosine and P2 receptors. This results in a mature macrophage with increased expression of M2, but not M1, genes. Similar to adenosine and ATP, macrophage growth arrested with LPS treatment resulted in an increase of the M2-related marker Ym1. Recombinant Ym1 was able to affect macrophage proliferation and could, potentially, be involved in the arrest of macrophage growth during hematopoiesis. © Society for Leukocyte Biology.

  9. Pharmacodynamic Study of Interaction of Aqueous Leaf Extract of Psidium Guajava Linn. (Myrtaceae) with Receptor Systems Using Isolated Tissue Preparations.

    Science.gov (United States)

    Mahaseth, R K; Kumar, S; Dutta, Shagun; Sehgal, Ratika; Rajora, Preety; Mathur, Rajani

    2015-01-01

    The present study investigates the interaction of aqueous leaf extract of Psidium guajava with muscarinic, serotonergic and adrenergic receptor system using isolated rat ileum, gastric fundus and trachea, respectively. The concentration-dependent contractile response of aqueous leaf extract of Psidium guajava was parallel and rightward of standard agonists, ACh and 5-HT indicating agonistic activity on muscarinic and serotonergic receptor systems. The inhibition of aqueous leaf extract of Psidium guajava mediated contractions in presence of atropine (10(-7) M) and ketanserin (10(-6) M) confirmed the activity. Relaxant effect of PG (0.2 mg/ml) on carbachol induced pre-contracted rat tracheal chain indicated its agonistic action on adrenergic receptor system. Inhibition (P<0.05) of the action in the presence of propranolol (1 ng/ml) confirmed the activity. It may be concluded that PG possesses agonistic action on muscarinic, serotonergic and adrenergic receptor systems.

  10. Neuropeptide FF increases M2 activation and self-renewal of adipose tissue macrophages

    Science.gov (United States)

    Waqas, Syed F. Hassnain; Hoang, Anh Cuong; Ampem, Grace; Azegrouz, Hind; Balogh, Lajos; Thuróczy, Julianna; Gerling, Ivan C.; Nam, Sorim; Lim, Jong-Seok; Martinez-Ibañez, Juncal; Real, José T.; Paschke, Stephan; Quillet, Raphaëlle; Ayachi, Safia; Simonin, Frédéric; Schneider, E. Marion; Brinkman, Jacqueline A.; Seroogy, Christine M.

    2017-01-01

    The quantity and activation state of adipose tissue macrophages (ATMs) impact the development of obesity-induced metabolic diseases. Appetite-controlling hormones play key roles in obesity; however, our understanding of their effects on ATMs is limited. Here, we have shown that human and mouse ATMs express NPFFR2, a receptor for the appetite-reducing neuropeptide FF (NPFF), and that NPFFR2 expression is upregulated by IL-4, an M2-polarizing cytokine. Plasma levels of NPFF decreased in obese patients and high-fat diet–fed mice and increased following caloric restriction. NPFF promoted M2 activation and increased the proliferation of murine and human ATMs. Both M2 activation and increased ATM proliferation were abolished in NPFFR2-deficient ATMs. Mechanistically, the effects of NPFF involved the suppression of E3 ubiquitin ligase RNF128 expression, resulting in enhanced stability of phosphorylated STAT6 and increased transcription of the M2 macrophage–associated genes IL-4 receptor α (Il4ra), arginase 1 (Arg1), IL-10 (Il10), and alkylglycerol monooxygenase (Agmo). NPFF induced ATM proliferation concomitantly with the increase in N-Myc downstream-regulated gene 2 (Ndrg2) expression and suppressed the transcription of Ifi200 cell-cycle inhibitor family members and MAF bZIP transcription factor B (Mafb), a negative regulator of macrophage proliferation. NPFF thus plays an important role in supporting healthy adipose tissue via the maintenance of metabolically beneficial ATMs. PMID:28581443

  11. Critical illness induces alternative activation of M2 macrophages in adipose tissue.

    Science.gov (United States)

    Langouche, Lies; Marques, Mirna B; Ingels, Catherine; Gunst, Jan; Derde, Sarah; Vander Perre, Sarah; D'Hoore, André; Van den Berghe, Greet

    2011-01-01

    We recently reported macrophage accumulation in adipose tissue of critically ill patients. Classically activated macrophage accumulation in adipose tissue is a known feature of obesity, where it is linked with increasing insulin resistance. However, the characteristics of adipose tissue macrophage accumulation in critical illness remain unknown. We studied macrophage markers with immunostaining and gene expression in visceral and subcutaneous adipose tissue from healthy control subjects (n = 20) and non-surviving prolonged critically ill patients (n = 61). For comparison, also subcutaneous in vivo adipose tissue biopsies were studied from 15 prolonged critically ill patients. Subcutaneous and visceral adipose tissue biopsies from non-surviving prolonged critically ill patients displayed a large increase in macrophage staining. This staining corresponded with elevated gene expression of "alternatively activated" M2 macrophage markers arginase-1, IL-10 and CD163 and low levels of the "classically activated" M1 macrophage markers tumor necrosis factor (TNF)-α and inducible nitric-oxide synthase (iNOS). Immunostaining for CD163 confirmed positive M2 macrophage staining in both visceral and subcutaneous adipose tissue biopsies from critically ill patients. Surprisingly, circulating levels and tissue gene expression of the alternative M2 activators IL-4 and IL-13 were low and not different from controls. In contrast, adipose tissue protein levels of peroxisome proliferator-activated receptor-γ (PPARγ), a nuclear receptor required for M2 differentiation and acting downstream of IL-4, was markedly elevated in illness. In subcutaneous abdominal adipose tissue biopsies from surviving critically ill patients, we could confirm positive macrophage staining with CD68 and CD163. We also could confirm elevated arginase-1 gene expression and elevated PPARγ protein levels. Unlike obesity, critical illness evokes adipose tissue accumulation of alternatively activated M2

  12. Quantitative densitometry of neurotransmitter receptors

    International Nuclear Information System (INIS)

    Rainbow, T.C.; Bleisch, W.V.; Biegon, A.; McEwen, B.S.

    1982-01-01

    An autoradiographic procedure is described that allows the quantitative measurement of neurotransmitter receptors by optical density readings. Frozen brain sections are labeled in vitro with [ 3 H]ligands under conditions that maximize specific binding to neurotransmitter receptors. The labeled sections are then placed against the 3 H-sensitive LKB Ultrofilm to produce the autoradiograms. These autoradiograms resemble those produced by [ 14 C]deoxyglucose autoradiography and are suitable for quantitative analysis with a densitometer. Muscarinic cholinergic receptors in rat and zebra finch brain and 5-HT receptors in rat brain were visualized by this method. When the proper combination of ligand concentration and exposure time are used, the method provides quantitative information about the amount and affinity of neurotransmitter receptors in brain sections. This was established by comparisons of densitometric readings with parallel measurements made by scintillation counting of sections. (Auth.)

  13. The effect of indomethacin on the muscarinic induced contractions in the isolated normal guinea pig urinary bladder.

    Science.gov (United States)

    Rahnama'i, Mohammad S; van Koeveringe, Gommert A; van Kerrebroeck, Philip E V; de Wachter, Stefan G G

    2013-02-07

    To investigate the effect of prostaglandin depletion by means of COX-inhibition on cholinergic enhanced spontaneous contractions. The urethra and bladder of 9 male guinea pigs (weight 270-300 g) were removed and placed in an organ bath with Krebs' solution. A catheter was passed through the urethra through which the intravesical pressure was measured. The muscarinic agonist arecaidine, the non-selective COX inhibitor indomethacin, and PGE2 were subsequently added to the organ bath. The initial average frequency and amplitude of spontaneous contractions in the first 2 minutes after arecaidine application were labelled F(ini) and P(ini), respectively. The steady state frequency (F(steady)) and amplitude (P(steady)) were defined as the average frequency and amplitude during the 5 minutes before the next wash out. Application of 1 μM PGE2 increased the amplitude of spontaneous contractions without affecting frequency. 10 μM of indomethacin reduced amplitude but not frequency.The addition of indomethacin did not alter F(ini) after the first application (p = 0.7665). However, after the second wash, F(ini) was decreased (p = 0.0005). F(steady), P(steady) and P(ini) were not significantly different in any of the conditions. These effects of indomethacin were reversible by PGE2 addition.. Blocking PG synthesis decreased the cholinergically stimulated autonomous contractions in the isolated bladder. This suggests that PG could modify normal cholinergically evoked response. A combination of drugs inhibiting muscarinic receptors and PG function or production can then become an interesting focus of research on a treatment for overactive bladder syndrome.

  14. The effect of indomethacin on the muscarinic induced contractions in the isolated normal guinea pig urinary bladder

    Directory of Open Access Journals (Sweden)

    Rahnama’i Mohammad S

    2013-02-01

    Full Text Available Abstract Background To investigate the effect of prostaglandin depletion by means of COX-inhibition on cholinergic enhanced spontaneous contractions. Methods The urethra and bladder of 9 male guinea pigs (weight 270–300 g were removed and placed in an organ bath with Krebs’ solution. A catheter was passed through the urethra through which the intravesical pressure was measured. The muscarinic agonist arecaidine, the non-selective COX inhibitor indomethacin, and PGE2 were subsequently added to the organ bath. The initial average frequency and amplitude of spontaneous contractions in the first 2 minutes after arecaidine application were labelled Fini and Pini, respectively. The steady state frequency (Fsteady and amplitude (Psteady were defined as the average frequency and amplitude during the 5 minutes before the next wash out. Results Application of 1 μM PGE2 increased the amplitude of spontaneous contractions without affecting frequency. 10 μM of indomethacin reduced amplitude but not frequency. The addition of indomethacin did not alter Fini after the first application (p = 0.7665. However, after the second wash, Fini was decreased (p = 0.0005. Fsteady, Psteady and Pini were not significantly different in any of the conditions. These effects of indomethacin were reversible by PGE2 addition.. Conclusions Blocking PG synthesis decreased the cholinergically stimulated autonomous contractions in the isolated bladder. This suggests that PG could modify normal cholinergically evoked response. A combination of drugs inhibiting muscarinic receptors and PG function or production can then become an interesting focus of research on a treatment for overactive bladder syndrome.

  15. A Survey on M2M Service Networks

    Directory of Open Access Journals (Sweden)

    Juhani Latvakoski

    2014-11-01

    Full Text Available The number of industrial applications relying on the Machine to Machine (M2M services exposed from physical world has been increasing in recent years. Such M2M services enable communication of devices with the core processes of companies. However, there is a big challenge related to complexity and to application-specific M2M systems called “vertical silos”. This paper focuses on reviewing the technologies of M2M service networks and discussing approaches from the perspectives of M2M information and services, M2M communication and M2M security. Finally, a discussion on technologies and approaches potentially enabling future autonomic M2M service networks are provided. According to our conclusions, it is seen that clear definition of the architectural principles is needed to solve the “vertical silo” problem and then, proceeding towards enabling autonomic capabilities for solving complexity problem appears feasible. Several areas of future research have been identified, e.g., autonomic information based services, optimization of communications with limited capability devices, real-time messaging, creation of trust and end to end security, adaptability, reliability, performance, interoperability, and maintenance.

  16. Serotonin-S2 and dopamine-D2 receptors are the same size in membranes

    International Nuclear Information System (INIS)

    Brann, M.R.

    1985-01-01

    Target size analysis was used to compare the sizes of serotonin-S2 and dopamine-D2 receptors in rat brain membranes. The sizes of these receptors were standardized by comparison with the muscarinic receptor, a receptor of known size. The number of serotonin-S2 receptors labeled with (3H)ketanserin or (3H)spiperone in frontal cortex decreased as an exponential function of radiation dose, and receptor affinity was not affected. The number of dopamine-D2 receptors labeled with (3H)spiperone in striatum also decreased as an exponential function of radiation dose, and D2 and S2 receptors were equally sensitive to radiation. In both striatum and frontal cortex, the number of muscarinic receptors labeled with (3H)QNB decreased as an exponential function of radiation dose, and were much less sensitive to radiation than S2 and D2 receptors. These data indicate that in rat brain membranes, S2 and D2 receptors are of similar size, and both molecules are much larger than the muscarinic receptor

  17. M2 polarization enhances silica nanoparticle uptake by macrophages

    Directory of Open Access Journals (Sweden)

    Jessica eHoppstädter

    2015-03-01

    Full Text Available While silica nanoparticles have enabled numerous industrial and medical applications, their toxicological safety requires further evaluation. Macrophages are the major cell population responsible for nanoparticle clearance in vivo. The prevailing macrophage phenotype largely depends on the local immune status of the host. Whereas M1-polarized macrophages are considered as pro-inflammatory macrophages involved in host defense, M2 macrophages exhibit anti-inflammatory and wound-healing properties, but also promote tumor growth.We employed different models of M1 and M2 polarization: GM-CSF/LPS/IFN-gamma was used to generate primary human M1 cells and M-CSF/IL-10 to differentiate M2 monocyte-derived macrophages. PMA-differentiated THP-1 cells were polarized towards an M1 type by LPS/IFN-gamma and towards M2 by IL-10. Uptake of fluorescent silica nanoparticles (Ø 26 and 41 nm and microparticles (Ø 1.75 µm was quantified. At the concentration used (50 µg/ml, silica nanoparticles did not influence cell viability as assessed by MTT assay. Nanoparticle uptake was enhanced in M2-polarized primary human monocyte-derived macrophages compared with M1 cells, as shown by flow cytometric and microscopic approaches. In contrast, the uptake of microparticles did not differ between M1 and M2 phenotypes. M2 polarization was also associated with increased nanoparticle uptake in the macrophage-like THP-1 cell line. In accordance, in vivo polarized M2-like primary human tumor-associated macrophages (TAM obtained from lung tumors took up more nanoparticles than M1-like alveolar macrophages isolated from the surrounding lung tissue.In summary, our data indicate that the M2 polarization of macrophages promotes nanoparticle internalization. Therefore, the phenotypical differences between macrophage subsets should be taken into consideration in future investigations on nanosafety, but might also open up therapeutic perspectives allowing to specifically target M2

  18. Local anesthetic inhibition of G protein-coupled receptor signaling by interference with Galpha(q) protein function

    NARCIS (Netherlands)

    Hollmann, M. W.; Wieczorek, K. S.; Berger, A.; Durieux, M. E.

    2001-01-01

    Although local anesthetics are considered primarily Na(+) channel blockers, previous studies suggest a common intracellular site of action on different G protein-coupled receptors. In the present study, we characterized this site for the LPA, m1 muscarinic, and trypsin receptor. Xenopus laevis

  19. Development of gamma emitting receptor-binding radiotracers for imaging the brain and pancreas. Progress report, February 1983-September 1984

    International Nuclear Information System (INIS)

    Reba, R.C.

    1984-01-01

    The possibility of measuring the change in receptor concentration as a function of disease by external imaging was investigated. The structure-binding-relationship which provides optimal localization of radiolabelled antagonist of the muscarinic acetylcholine receptors in the brain was studied. These relationships were also studied with respect to localization in the pancreas

  20. Adoptive transfer of M2 macrophages reduces neuropathic pain via opioid peptides.

    Science.gov (United States)

    Pannell, Maria; Labuz, Dominika; Celik, Melih Ö; Keye, Jacqueline; Batra, Arvind; Siegmund, Britta; Machelska, Halina

    2016-10-07

    During the inflammation which occurs following nerve damage, macrophages are recruited to the site of injury. Phenotypic diversity is a hallmark of the macrophage lineage and includes pro-inflammatory M1 and anti-inflammatory M2 populations. Our aim in this study was to investigate the ability of polarized M0, M1, and M2 macrophages to secrete opioid peptides and to examine their relative contribution to the modulation of neuropathic pain. Mouse bone marrow-derived cells were cultured as unstimulated M0 macrophages or were stimulated into an M1 phenotype using lipopolysaccharide and interferon-γ or into an M2 phenotype using interleukin-4. The macrophage phenotypes were verified using flow cytometry for surface marker analysis and cytokine bead array for cytokine profile assessment. Opioid peptide levels were measured by radioimmunoassay and enzyme immunoassay. As a model of neuropathic pain, a chronic constriction injury (CCI) of the sciatic nerve was employed. Polarized M0, M1, and M2 macrophages (5 × 10 5 cells) were injected perineurally twice, on days 14 and 15 following CCI or sham surgery. Mechanical and heat sensitivity were measured using the von Frey and Hargreaves tests, respectively. To track the injected macrophages, we also transferred fluorescently stained polarized cells and analyzed the surface marker profile of endogenous and injected cells in the nerves ex vivo. Compared to M0 and M1 cells, M2 macrophages contained and released higher amounts of opioid peptides, including Met-enkephalin, dynorphin A (1-17), and β-endorphin. M2 cells transferred perineurally at the nerve injury site reduced mechanical, but not heat hypersensitivity following the second injection. The analgesic effect was reversed by the perineurally applied opioid receptor antagonist naloxone methiodide. M2 cells did not affect sensitivity following sham surgery. Neither M0 nor M1 cells altered mechanical and heat sensitivity in CCI or sham-operated animals. Tracing the

  1. The MHV68 M2 protein drives IL-10 dependent B cell proliferation and differentiation.

    Directory of Open Access Journals (Sweden)

    Andrea M Siegel

    2008-04-01

    Full Text Available Murine gammaherpesvirus 68 (MHV68 establishes long-term latency in memory B cells similar to the human gammaherpesvirus Epstein Barr Virus (EBV. EBV encodes an interleukin-10 (IL-10 homolog and modulates cellular IL-10 expression; however, the role of IL-10 in the establishment and/or maintenance of chronic EBV infection remains unclear. Notably, MHV68 does not encode an IL-10 homolog, but virus infection has been shown to result in elevated serum IL-10 levels in wild-type mice, and IL-10 deficiency results in decreased establishment of virus latency. Here we show that a unique MHV68 latency-associated gene product, the M2 protein, is required for the elevated serum IL-10 levels observed at 2 weeks post-infection. Furthermore, M2 protein expression in primary murine B cells drives high level IL-10 expression along with increased secretion of IL-2, IL-6, and MIP-1alpha. M2 expression was also shown to significantly augment LPS driven survival and proliferation of primary murine B cells. The latter was dependent on IL-10 expression as demonstrated by the failure of IL10-/- B cells to proliferate in response to M2 protein expression and rescue of M2-associated proliferation by addition of recombinant murine IL-10. M2 protein expression in primary B cells also led to upregulated surface expression of the high affinity IL-2 receptor (CD25 and the activation marker GL7, along with down-regulated surface expression of B220, MHC II, and sIgD. The cells retained CD19 and sIgG expression, suggesting differentiation to a pre-plasma memory B cell phenotype. These observations are consistent with previous analyses of M2-null MHV68 mutants that have suggested a role for the M2 protein in expansion and differentiation of MHV68 latently infected B cells-perhaps facilitating the establishment of virus latency in memory B cells. Thus, while the M2 protein is unique to MHV68, analysis of M2 function has revealed an important role for IL-10 in MHV68 pathogenesis

  2. The MHV68 M2 protein drives IL-10 dependent B cell proliferation and differentiation.

    Science.gov (United States)

    Siegel, Andrea M; Herskowitz, Jeremy H; Speck, Samuel H

    2008-04-04

    Murine gammaherpesvirus 68 (MHV68) establishes long-term latency in memory B cells similar to the human gammaherpesvirus Epstein Barr Virus (EBV). EBV encodes an interleukin-10 (IL-10) homolog and modulates cellular IL-10 expression; however, the role of IL-10 in the establishment and/or maintenance of chronic EBV infection remains unclear. Notably, MHV68 does not encode an IL-10 homolog, but virus infection has been shown to result in elevated serum IL-10 levels in wild-type mice, and IL-10 deficiency results in decreased establishment of virus latency. Here we show that a unique MHV68 latency-associated gene product, the M2 protein, is required for the elevated serum IL-10 levels observed at 2 weeks post-infection. Furthermore, M2 protein expression in primary murine B cells drives high level IL-10 expression along with increased secretion of IL-2, IL-6, and MIP-1alpha. M2 expression was also shown to significantly augment LPS driven survival and proliferation of primary murine B cells. The latter was dependent on IL-10 expression as demonstrated by the failure of IL10-/- B cells to proliferate in response to M2 protein expression and rescue of M2-associated proliferation by addition of recombinant murine IL-10. M2 protein expression in primary B cells also led to upregulated surface expression of the high affinity IL-2 receptor (CD25) and the activation marker GL7, along with down-regulated surface expression of B220, MHC II, and sIgD. The cells retained CD19 and sIgG expression, suggesting differentiation to a pre-plasma memory B cell phenotype. These observations are consistent with previous analyses of M2-null MHV68 mutants that have suggested a role for the M2 protein in expansion and differentiation of MHV68 latently infected B cells-perhaps facilitating the establishment of virus latency in memory B cells. Thus, while the M2 protein is unique to MHV68, analysis of M2 function has revealed an important role for IL-10 in MHV68 pathogenesis-identifying a

  3. Theoretical Assessment of 178m2Hf De-Excitation

    Energy Technology Data Exchange (ETDEWEB)

    Hartouni, E P; Chen, M; Descalle, M A; Escher, J E; Loshak, A; Navratil, P; Ormand, W E; Pruet, J; Thompson, I J; Wang, T F

    2008-10-06

    This document contains a comprehensive literature review in support of the theoretical assessment of the {sup 178m2}Hf de-excitation, as well as a rigorous description of controlled energy release from an isomeric nuclear state.

  4. A distributed approach for secure M2M communications

    OpenAIRE

    BEN SAIED , Yosra; OLIVEREAU , Alexis; LAURENT , Maryline

    2012-01-01

    International audience; A key establishment solution for heterogeneous Machine to Machine (M2M) communications is proposed. Decentralization in M2M environment leads to situations where highly resource-constrained nodes have to establish end-to-end secured contexts with powerful remote servers, which would normally be impossible because of the technological gap between these classes of devices. This paper proposes a novel collaborative session key exchange method, wherein a highly resource-co...

  5. RORα Induces KLF4-Mediated M2 Polarization in the Liver Macrophages that Protect against Nonalcoholic Steatohepatitis

    Directory of Open Access Journals (Sweden)

    Yong-Hyun Han

    2017-07-01

    Full Text Available The regulation of M1/M2 polarization in liver macrophages is closely associated with the progression of nonalcoholic steatohepatitis (NASH; however, the mechanism involved in this process remains unclear. Here, we describe the orphan nuclear receptor retinoic-acid-related orphan receptor α (RORα as a key regulator of M1/M2 polarization in hepatic residential Kupffer cells (KCs and infiltrated monocyte-derived macrophages. RORα enhanced M2 polarization in KCs by inducing the kruppel-like factor 4. M2 polarization was defective in KCs and bone-marrow-derived macrophages of the myeloid-specific RORα null mice, and these mice were susceptible to HFD-induced NASH. We found that IL-10 played an important role in connecting the function of M2 KCs to lipid accumulation and apoptosis in hepatocytes. Importantly, M2 polarization was controlled by a RORα activator, JC1-40, which improved symptoms of NASH. Our results suggest that the M2-promoting effects of RORα in liver macrophages may provide better therapeutic strategies against NASH.

  6. LEU WWR-M2 fuel assemblies burnable test

    International Nuclear Information System (INIS)

    Kirsanov, G.A.; Konoplev, K.A.; Pikulik, R.G.; Sajkov, Yu. P.; Tchmshkyan, D.V.; Tedoradze, L.V.; Zakharov, A.S.

    2000-01-01

    The results of in-pile irradiation tests of LEU WWR-M2 fuel assemblies with reduced enrichment of fuel are submitted in the report. The tests are made according to the Russian Program on Reduced Enrichment for Research and Test Reactors (RERTR). United States Department of Energy and the Ministry of Atomic Energy of Russian Federation jointly fund this Program. The irradiation tests of 5 WWR-M2 experimental assemblies are carried out at WWR-M reactor of the Petersburg Nuclear Physics Institute (PNPI). The information on assembly design and technique of irradiation tests is presented. In the irradiation tests the integrity of fuel assemblies is periodically measured. The report presents the data for the integrity maintained during the burnup of 5 fuel assemblies up to 45%. These results demonstrate the high reliability of the experimental fuel assemblies within the guaranteed burnup limits specified by the manufacturer. The tests are still in progress; it is planned to test and analyze the change in integrity for burnup of up to 70% - 75% or more. LEU WWR-M2 fuel assemblies are to be offered for export by their Novosibirsk manufacturer. Currently, HEU WWR-M2 fuel assemblies are used in Hungary, Ukraine and Vietnam. LEU WWR-M2 fuel assemblies were designed as a possible replacement for the HEU WWR-M2 fuel assemblies in those countries, but their use can be extended to other research reactors. (author)

  7. Alternatively Activated (M2) Macrophage Phenotype Is Inducible by Endothelin-1 in Cultured Human Macrophages.

    Science.gov (United States)

    Soldano, Stefano; Pizzorni, Carmen; Paolino, Sabrina; Trombetta, Amelia Chiara; Montagna, Paola; Brizzolara, Renata; Ruaro, Barbara; Sulli, Alberto; Cutolo, Maurizio

    2016-01-01

    Alternatively activated (M2) macrophages are phenotypically characterized by the expression of specific markers, mainly macrophage scavenger receptors (CD204 and CD163) and mannose receptor-1 (CD206), and participate in the fibrotic process by over-producing pro-fibrotic molecules, such as transforming growth factor-beta1 (TGFbeta1) and metalloproteinase (MMP)-9. Endothelin-1 (ET-1) is implicated in the fibrotic process, exerting its pro-fibrotic effects through the interaction with its receptors (ETA and ETB). The study investigated the possible role of ET-1 in inducing the transition from cultured human macrophages into M2 cells. Cultured human monocytes (THP-1 cell line) were activated into macrophages (M0 macrophages) with phorbol myristate acetate and subsequently maintained in growth medium (M0-controls) or treated with either ET-1 (100nM) or interleukin-4 (IL-4, 10ng/mL, M2 inducer) for 72 hours. Similarly, primary cultures of human peripheral blood monocyte (PBM)-derived macrophages obtained from healthy subjects, were maintained in growth medium (untreated cells) or treated with ET-1 or IL-4 for 6 days. Both M0 and PBM-derived macrophages were pre-treated with ET receptor antagonist (ETA/BRA, bosentan 10-5M) for 1 hour before ET-1 stimulation. Protein and gene expression of CD204, CD206, CD163, TGFbeta1 were analysed by immunocytochemistry, Western blotting and quantitative real time polymerase chain reaction (qRT-PCR). Gene expression of interleukin(IL)-10 and macrophage derived chemokine (CCL-22) was evaluated by qRT-PCR. MMP-9 production was investigated by gel zymography. ET-1 significantly increased the expression of M2 phenotype markers CD204, CD206, CD163, IL-10 and CCL-22, and the production of MMP-9 in both cultures of M0 and PBM-derived macrophages compared to M0-controls and untreated cells. In cultured PBM-derived macrophages, ET-1 increased TGFbeta1 protein and gene expression compared to untreated cells. The ET-1-mediated effects were

  8. M2-like macrophages are responsible for collagen degradation through a mannose receptor–mediated pathway

    Science.gov (United States)

    Madsen, Daniel H.; Leonard, Daniel; Masedunskas, Andrius; Moyer, Amanda; Jürgensen, Henrik Jessen; Peters, Diane E.; Amornphimoltham, Panomwat; Selvaraj, Arul; Yamada, Susan S.; Brenner, David A.; Burgdorf, Sven; Engelholm, Lars H.; Behrendt, Niels; Holmbeck, Kenn; Weigert, Roberto

    2013-01-01

    Tissue remodeling processes critically depend on the timely removal and remodeling of preexisting collagen scaffolds. Nevertheless, many aspects related to the turnover of this abundant extracellular matrix component in vivo are still incompletely understood. We therefore took advantage of recent advances in optical imaging to develop an assay to visualize collagen turnover in situ and identify cell types and molecules involved in this process. Collagen introduced into the dermis of mice underwent cellular endocytosis in a partially matrix metalloproteinase–dependent manner and was subsequently routed to lysosomes for complete degradation. Collagen uptake was predominantly executed by a quantitatively minor population of M2-like macrophages, whereas more abundant Col1a1-expressing fibroblasts and Cx3cr1-expressing macrophages internalized collagen at lower levels. Genetic ablation of the collagen receptors mannose receptor (Mrc1) and urokinase plasminogen activator receptor–associated protein (Endo180 and Mrc2) impaired this intracellular collagen degradation pathway. This study demonstrates the importance of receptor-mediated cellular uptake to collagen turnover in vivo and identifies a key role of M2-like macrophages in this process. PMID:24019537

  9. Muscarinic excitation of parvalbumin-positive interneurons contributes to the severity of pilocarpine-induced seizures

    Science.gov (United States)

    Yi, Feng; DeCan, Evan; Stoll, Kurt; Marceau, Eric; Deisseroth, Karl; Lawrence, J. Josh

    2014-01-01

    SUMMARY Objective A common rodent model in epilepsy research employs the muscarinic acetylcholine receptor (mAChR) agonist pilocarpine, yet the mechanisms underlying the induction of pilocarpine-induced seizures (PISs) remain unclear. Global M1 mAChR (M1R) knockout mice are resistant to PISs, implying that M1R activation disrupts excitation/inhibition balance. Parvalbumin-positive (PV) inhibitory neurons express M1 mAChRs, participate in cholinergically-induced oscillations, and can enter a state of depolarization block (DB) during epileptiform activity. Here, we test the hypothesis that pilocarpine activation of M1Rs expressed on PV cells contributes to PISs. Methods CA1 PV cells in PV-CRE mice were visualized with a floxed YFP or hM3Dq-mCherry adeno-associated virus, or by crossing PV-CRE mice with the RosaYFP reporter line. To eliminate M1Rs from PV cells, we generated PV-M1KO mice by crossing PV-CRE and floxed M1 mice. Action potential (AP) frequency was monitored during application of pilocarpine (200 µM). In behavioral experiments, locomotion and seizure symptoms were recorded in WT or PV-M1KO mice during PISs. Results Pilocarpine significantly increased AP frequency in CA1 PV cells into the gamma range. In the continued presence of pilocarpine, a subset (5/7) of PV cells progressed to DB, which was mimicked by hM3Dq activation of Gq-receptor signaling. Pilocarpine-induced depolarization, AP firing at gamma frequency, and progression to DB were prevented in CA1 PV cells of PV-M1KO mice. Finally, compared to WT mice, PV-M1KO mice were associated with reduced severity of PISs. Significance Pilocarpine can directly depolarize PV+ cells via M1R activation but a subset of these cells progress to DB. Our electrophysiological and behavioral results suggest that this mechanism is active during PISs, contributing to a collapse of PV-mediated GABAergic inhibition, dysregulation of excitation/inhibition balance, and increased susceptibility to PISs. PMID:25495999

  10. Effects of acute administration of nicotinic and muscarinic cholinergic agonists and antagonists on performance in different cost-benefit decision making tasks in rats.

    Science.gov (United States)

    Mendez, Ian A; Gilbert, Ryan J; Bizon, Jennifer L; Setlow, Barry

    2012-12-01

    Alterations in cost-benefit decision making accompany numerous neuropsychiatric conditions, including schizophrenia, attention deficit hyperactivity disorder, and addiction. Central cholinergic systems have been linked to the etiology and/or treatment of many of these conditions, but little is known about the role of cholinergic signaling in cost-benefit decision making. The goal of these experiments was to determine how cholinergic signaling is involved in cost-benefit decision making, using a behavioral pharmacological approach. Male Long-Evans rats were trained in either "probability discounting" or "delay discounting" tasks, in which rats made discrete-trial choices between a small food reward and a large food reward associated with either varying probabilities of omission or varying delays to delivery, respectively. The effects of acute administration of different doses of nicotinic and muscarinic acetylcholine receptor agonists and antagonists were assessed in each task. In the probability discounting task, acute nicotine administration (1.0 mg/kg) significantly increased choice of the large risky reward, and control experiments suggested that this was due to robust nicotine-induced impairments in behavioral flexibility. In the delay discounting task, the muscarinic antagonists scopolamine (0.03, 0.1, and 0.3 mg/kg) and atropine (0.3 mg/kg) both significantly increased choice of the small immediate reward. Neither mecamylamine nor oxotremorine produced reliable effects on either of the decision making tasks. These data suggest that cholinergic receptors play multiple roles in decision making contexts which include consideration of reward delay or probability. These roles should be considered when targeting these receptors for therapeutic purposes.

  11. Effects of acute administration of nicotinic and muscarinic cholinergic agonists and antagonists on performance in different cost–benefit decision making tasks in rats

    Science.gov (United States)

    Mendez, Ian A.; Gilbert, Ryan J.; Bizon, Jennifer L.

    2012-01-01

    Rationale Alterations in cost–benefit decision making accompany numerous neuropsychiatric conditions, including schizophrenia, attention deficit hyperactivity disorder, and addiction. Central cholinergic systems have been linked to the etiology and/or treatment of many of these conditions, but little is known about the role of cholinergic signaling in cost–benefit decision making. Objectives The goal of these experiments was to determine how cholinergic signaling is involved in cost–benefit decision making, using a behavioral pharmacological approach. Methods Male Long-Evans rats were trained in either “probability discounting” or “delay discounting” tasks, in which rats made discrete-trial choices between a small food reward and a large food reward associated with either varying probabilities of omission or varying delays to delivery, respectively. The effects of acute administration of different doses of nicotinic and muscarinic acetylcholine receptor agonists and antagonists were assessed in each task. Results In the probability discounting task, acute nicotine administration (1.0 mg/kg) significantly increased choice of the large risky reward, and control experiments suggested that this was due to robust nicotine-induced impairments in behavioral flexibility. In the delay discounting task, the muscarinic antagonists scopolamine (0.03, 0.1, and 0.3 mg/kg) and atropine (0.3 mg/kg) both significantly increased choice of the small immediate reward. Neither mecamylamine nor oxotremorine produced reliable effects on either of the decision making tasks. Conclusions These data suggest that cholinergic receptors play multiple roles in decision making contexts which include consideration of reward delay or probability. These roles should be considered when targeting these receptors for therapeutic purposes. PMID:22760484

  12. Main: 1M2Q [RPSD[Archive

    Lifescience Database Archive (English)

    Full Text Available 1M2Q トウモロコシ Corn Zea mays L. Casein Kinase Ii, Alpha Chain Name=Ack2; Zea Mays Mole...cule: Casein Kinase Ii, Alpha Chain; Chain: A; Fragment: Catlytic Subunit; Synonym: Ckii; Engineered: Yes Tr...ansferase 2.7.1.37 (Casein Kinase Ii, Alpha Chain) E.De Moliner, S.Sarno, S.Moro, G.Zagotto, G.Zanotti, L.A....=2-326.|PDB; 1M2Q; X-ray; A=2-328.|PDB; 1M2R; X-ray; A=2-328.|PDB; 1OM1; X-ray; A=1-332.|Mai

  13. Polarized M2 macrophages in dogs with visceral leishmaniasis.

    Science.gov (United States)

    Moreira, Pamela Rodrigues Reina; Fernando, Filipe Santos; Montassier, Hélio José; André, Marcos Rogério; de Oliveira Vasconcelos, Rosemeri

    2016-08-15

    The objective of the present study was to analyze the skin (nasal surface and ear regions), lymph nodes (popliteal and pre-scapular), spleen and liver of dogs with visceral leishmaniasis (VL), in order to investigate the relationship between the parasite load measured as DNA copy number of Alpha gene of DNA polymerase of Leishmania infantum by quantitative PCR and the number of M2 macrophages by immunohistochemistry. A set of 29 naturally infected dogs from an endemic area for VL were sampled and another set of six dogs negative for VL and from a non-endemic area were analyzed as the control group (C). The spleen presented the highest number of Leishmania DNA copies, with significant differences between the groups G1 and G2 (with and without skin lesions, respectively). The M2 phenotype immunostaining predominated among the macrophages in granulomas and inflammatory infiltrates of samples from the skin, lymph nodes and spleens examined. The presence of M2 macrophages in dogs from infected group differed significantly from the control group, in all organs analyzed, excepted liver. The highest proportion of M2 macrophages coincided with the highest parasitism loads found in more susceptible organs of VL dogs, even in the skin, considered a more resistant organ, while the liver showed low parasitism load and low immunostaining for M2 macrophages with no significant differences between infected and negative groups. It was concluded that the predominance of M2 phenotype in VL dogs favored the multiplication of Leishmania infantum in organs of dogs that are more susceptible to Leishmania infection, as skin, lymph nodes and spleen. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Characteristics and potential role of M2 macrophages in COPD

    Directory of Open Access Journals (Sweden)

    He S

    2017-10-01

    Full Text Available Shengyang He, Lihua Xie, Junjuan Lu, Shenghua SunDepartment of Respiratory Medicine, The Third Xiangya Hospital of Central South University, Changsha, Hunan, People’s Republic of China Background: COPD is a multi-pathogenesis disease mainly caused by smoking. A further understanding of the mechanism of smoking-related COPD might contribute to preventions and treatments of this disease in the early stages. This study was designed to identify the characteristics of M2 macrophages in COPD for a better understanding about their potential role.Materials and methods: COPD models were built in the C57BL/6 mouse by cigarette smoke (CS exposure combined with intraperitoneal injection of cigarette smoke extract (CSE. The modeling efficiency was evaluated by lung function and hematoxylin and eosin (H&E staining. The number of different macrophage phenotypes was detected by immunohistochemical staining (IHS of CD206, CD86 and CD68 on the lung tissue paraffin section. The RAW264.7 cells were polarized toward the M2 phenotype by interleukin IL-4 and confirmed by a flow cytometer. The gene expression levels of TGF-βRII, Smad2, Smad3 and Smad7 in CSE-treated M2 macrophages were detected by real-time reverse transcription polymerase chain reaction (RT-PCR. The expression levels of TGF-β/Smad pathway-related makers (TGF-βRII, p-Smad2, p-Smad3, Smad7 and TGF-β in alveolar M2 macrophages were detected by two consecutive paraffin section IHS.Results: The COPD model is well established, which is confirmed by the lung function test and lung H&E staining. The whole number of macrophages and the ratio of M2/M1 phenotype are both increased (p<0.05. The level of CD206+ cells in IL-4-stimulated RAW264.7 cells is up to 93.4%, which is confirmed by a flow cytometer. The gene expression of TGF-βRII, Smad2, Smad3 and Smad7 are all enhanced (p<0.05 in CES-treated M2 macrophages, which is detected by RT-PCR. The protein levels of TGF-β/Smad pathway-related markers are

  15. A nonperturbative test of M2-brane theory

    International Nuclear Information System (INIS)

    Hosomichi, Kazuo; Lee, Ki-Myeong; Lee, Sungjay; Yi, Piljin; Lee, Sangmin; Park, Jaemo

    2008-01-01

    We discuss non-perturbative effects in the ABJM model due to monopole instantons. We begin by constructing the instanton solutions in the U(2) x U(2) model, explicitly, and computing the Euclidean action. The Wick-rotated Lagrangian is complex and its BPS monopole instantons are found to be a delicate version of the usual 't Hooft-Polyakov monopole solutions. They are generically 1/3 BPS but become 1/2 BPS at special locus in the moduli space of two M2-branes, yet each instanton carries eight fermionic zero modes, regardless of the vacuum choice. The low energy effective action induced by monopole instantons are quartic order in derivatives. The resulting vertices are nonperturbative in 1/k, as expected, but are rational functions of the vacuum moduli. We also analyze the system of two M2-branes in the supergravity framework and compute the higher order interactions via 11-dimensional supergraviton exchange. The comparison of the two shows that the instanton vertices are precisely reproduced by this M2-brane picture, supporting the proposal that the ABJM model describes multiple M2-branes.

  16. Dimeric Complexes of Tryptophan with M2+ Metal Ions

    NARCIS (Netherlands)

    Dunbar, R. C.; Steill, J. D.; Polfer, N. C.; Oomens, J.

    2009-01-01

    IRMPD spectroscopy using the FELIX free electron laser and a Fourier transform ICR mass spectrometer was used to characterize the structures of electrosprayed dimer complexes M(2+)Trp(2) of tryptophan with a series of eight doubly charged metal ions, including alkaline earths Ca, Sr, and Ba, and

  17. Multiple M2-branes and the embedding tensor

    NARCIS (Netherlands)

    Bergshoeff, Eric A.; de Roo, Mees; Hohm, Olaf

    2008-01-01

    We show that the Bagger-Lambert theory of multiple M2-branes fits into the general construction of maximally supersymmetric gauge theories using the embedding tensor technique. We apply the embedding tensor technique in order to systematically obtain the consistent gaugings of N = 8 superconformal

  18. An N=1 superfield action for M2 branes

    International Nuclear Information System (INIS)

    Mauri, Andrea; Petkou, Anastasios C.

    2008-01-01

    We present an octonionic N=1 superfield action that reproduces in components the action of Bagger and Lambert for M2 branes. By giving an expectation value to one of the scalars we obtain the maximally supersymmetric superfield action for D2 branes

  19. Human Secreted Ly-6/uPAR Related Protein-1 (SLURP-1) Is a Selective Allosteric Antagonist of α7 Nicotinic Acetylcholine Receptor

    DEFF Research Database (Denmark)

    Lyukmanova, Ekaterina N; Shulepko, Mikhail A; Kudryavtsev, Denis

    2016-01-01

    of nicotinic acetylcholine receptors (nAChRs) and muscarinic acetylcholine receptors, respectively, and anti-α7-nAChRs antibodies revealed α7 type nAChRs as an rSLURP-1 target in keratinocytes. Using affinity purification from human cortical extracts, we confirmed that rSLURP-1 binds selectively to the α7-n...

  20. A randomized comparison of daunorubicin 90 mg/m2 vs 60 mg/m2 in AML induction

    DEFF Research Database (Denmark)

    Burnett, A. K.; Russell, N. H.; Hills, R. K.

    2015-01-01

    Modifying induction therapy in acute myeloid leukemia (AML) may improve the remission rate and reduce the risk of relapse, thereby improving survival. Escalation of the daunorubicin dose to 90 mg/m(2) has shown benefit for some patient subgroups when compared with a dose of 45 mg/m(2), and has been...... = .15). In an exploratory subgroup analysis, there was no subgroup that showed significant benefit, although there was a significant interaction by FLT3 ITD mutation. This trial is registered at http://www.isrctn.com as #ISRCTN55675535....

  1. Radiation induced genetic variability studies in M2 and F2M2 generation in chilli (Capsicum annum L.)

    International Nuclear Information System (INIS)

    Rangaiah, S.; Manjunath, A.; Naik, Puttarama; Gangappa, E.

    2002-01-01

    Chilli (Capsicum annum L.) is an important commercial crop in India. Mutation breeding is one of the effective tool to create new variability. Since, yield and its component characters show polygenic inheritance, information on amount of heritable portion of variability created through mutation for these characters is needed to use the induced variability for crop improvement. To harness more variability mutation has been superimposed on hybridization in several crops. The present study is undertaken to estimate the genetic variability induced through gamma irradiation for the polygenically inherited productive traits of chilli in M 2 and F 2 M 2 generation

  2. Membrane Receptor-Induced Changes of the Protein Kinases A and C Activity May Play a Leading Role in Promoting Developmental Synapse Elimination at the Neuromuscular Junction.

    Science.gov (United States)

    Tomàs, Josep M; Garcia, Neus; Lanuza, Maria A; Nadal, Laura; Tomàs, Marta; Hurtado, Erica; Simó, Anna; Cilleros, Víctor

    2017-01-01

    Synapses that are overproduced during histogenesis in the nervous system are eventually lost and connectivity is refined. Membrane receptor signaling leads to activity-dependent mutual influence and competition between axons directly or with the involvement of the postsynaptic cell and the associated glial cell/s. Presynaptic muscarinic acetylcholine (ACh) receptors (subtypes mAChR; M 1 , M 2 and M 4 ), adenosine receptors (AR; A 1 and A 2A ) and the tropomyosin-related kinase B receptor (TrkB), among others, all cooperate in synapse elimination. Between these receptors there are several synergistic, antagonic and modulatory relations that clearly affect synapse elimination. Metabotropic receptors converge in a limited repertoire of intracellular effector kinases, particularly serine protein kinases A and C (PKA and PKC), to phosphorylate protein targets and bring about structural and functional changes leading to axon loss. In most cells A 1 , M 1 and TrkB operate mainly by stimulating PKC whereas A 2A , M 2 and M 4 inhibit PKA. We hypothesize that a membrane receptor-induced shifting in the protein kinases A and C activity (inhibition of PKA and/or stimulation of PKC) in some nerve endings may play an important role in promoting developmental synapse elimination at the neuromuscular junction (NMJ). This hypothesis is supported by: (i) the tonic effect (shown by using selective inhibitors) of several membrane receptors that accelerates axon loss between postnatal days P5-P9; (ii) the synergistic, antagonic and modulatory effects (shown by paired inhibition) of the receptors on axonal loss; (iii) the fact that the coupling of these receptors activates/inhibits the intracellular serine kinases; and (iv) the increase of the PKA activity, the reduction of the PKC activity or, in most cases, both situations simultaneously that presumably occurs in all the situations of singly and paired inhibition of the mAChR, AR and TrkB receptors. The use of transgenic animals and

  3. Membrane Receptor-Induced Changes of the Protein Kinases A and C Activity May Play a Leading Role in Promoting Developmental Synapse Elimination at the Neuromuscular Junction

    Directory of Open Access Journals (Sweden)

    Josep M. Tomàs

    2017-08-01

    Full Text Available Synapses that are overproduced during histogenesis in the nervous system are eventually lost and connectivity is refined. Membrane receptor signaling leads to activity-dependent mutual influence and competition between axons directly or with the involvement of the postsynaptic cell and the associated glial cell/s. Presynaptic muscarinic acetylcholine (ACh receptors (subtypes mAChR; M1, M2 and M4, adenosine receptors (AR; A1 and A2A and the tropomyosin-related kinase B receptor (TrkB, among others, all cooperate in synapse elimination. Between these receptors there are several synergistic, antagonic and modulatory relations that clearly affect synapse elimination. Metabotropic receptors converge in a limited repertoire of intracellular effector kinases, particularly serine protein kinases A and C (PKA and PKC, to phosphorylate protein targets and bring about structural and functional changes leading to axon loss. In most cells A1, M1 and TrkB operate mainly by stimulating PKC whereas A2A, M2 and M4 inhibit PKA. We hypothesize that a membrane receptor-induced shifting in the protein kinases A and C activity (inhibition of PKA and/or stimulation of PKC in some nerve endings may play an important role in promoting developmental synapse elimination at the neuromuscular junction (NMJ. This hypothesis is supported by: (i the tonic effect (shown by using selective inhibitors of several membrane receptors that accelerates axon loss between postnatal days P5–P9; (ii the synergistic, antagonic and modulatory effects (shown by paired inhibition of the receptors on axonal loss; (iii the fact that the coupling of these receptors activates/inhibits the intracellular serine kinases; and (iv the increase of the PKA activity, the reduction of the PKC activity or, in most cases, both situations simultaneously that presumably occurs in all the situations of singly and paired inhibition of the mAChR, AR and TrkB receptors. The use of transgenic animals and various

  4. Human metapneumovirus M2-2 protein inhibits innate immune response in monocyte-derived dendritic cells.

    Directory of Open Access Journals (Sweden)

    Junping Ren

    Full Text Available Human metapneumovirus (hMPV is a leading cause of lower respiratory infection in young children, the elderly and immunocompromised patients. Repeated hMPV infections occur throughout life. However, immune evasion mechanisms of hMPV infection are largely unknown. Recently, our group has demonstrated that hMPV M2-2 protein, an important virulence factor, contributes to immune evasion in airway epithelial cells by targeting the mitochondrial antiviral-signaling protein (MAVS. Whether M2-2 regulates the innate immunity in human dendritic cells (DC, an important family of immune cells controlling antigen presenting, is currently unknown. We found that human DC infected with a virus lacking M2-2 protein expression (rhMPV-ΔM2-2 produced higher levels of cytokines, chemokines and IFNs, compared to cells infected with wild-type virus (rhMPV-WT, suggesting that M2-2 protein inhibits innate immunity in human DC. In parallel, we found that myeloid differentiation primary response gene 88 (MyD88, an essential adaptor for Toll-like receptors (TLRs, plays a critical role in inducing immune response of human DC, as downregulation of MyD88 by siRNA blocked the induction of immune regulatory molecules by hMPV. Since M2-2 is a cytoplasmic protein, we investigated whether M2-2 interferes with MyD88-mediated antiviral signaling. We found that indeed M2-2 protein associated with MyD88 and inhibited MyD88-dependent gene transcription. In this study, we also identified the domains of M2-2 responsible for its immune inhibitory function in human DC. In summary, our results demonstrate that M2-2 contributes to hMPV immune evasion by inhibiting MyD88-dependent cellular responses in human DC.

  5. Tyrosine 129 of the murine gammaherpesvirus M2 protein is critical for M2 function in vivo.

    Science.gov (United States)

    Rangaswamy, Udaya S; O'Flaherty, Brigid M; Speck, Samuel H

    2014-01-01

    A common strategy shared by all known gammaherpesviruses is their ability to establish a latent infection in lymphocytes--predominantly in B cells. In immunocompromised patients, such as transplant recipients or AIDS patients, gammaherpesvirus infections can lead to the development of lymphoproliferative disease and lymphoid malignancies. The human gamma-herpesviruses, EBV and KSHV, encode proteins that are capable of modulating the host immune signaling machinery, thereby subverting host immune responses. Murine gamma-herpesvirus 68 (MHV68) infection of laboratory strains of mice has proven to be useful small-animal model that shares important pathogenic strategies with the human gamma-herpesviruses. The MHV68 M2 protein is known to manipulate B cell signaling and, dependent on route and dose of virus inoculation, plays a role in both the establishment of latency and virus reactivation. M2 contains two tyrosines that are targets for phosphorylation, and have been shown to interact with the B cell signaling machinery. Here we describe in vitro and in vivo studies of M2 mutants which reveals that while both tyrosines Y120 and Y129 are required for M2 induction of IL-10 expression from primary murine B cells in vitro, only Y129 is critical for reactivation from latency and plasma cell differentiation in vivo.

  6. Tyrosine 129 of the murine gammaherpesvirus M2 protein is critical for M2 function in vivo.

    Directory of Open Access Journals (Sweden)

    Udaya S Rangaswamy

    Full Text Available A common strategy shared by all known gammaherpesviruses is their ability to establish a latent infection in lymphocytes--predominantly in B cells. In immunocompromised patients, such as transplant recipients or AIDS patients, gammaherpesvirus infections can lead to the development of lymphoproliferative disease and lymphoid malignancies. The human gamma-herpesviruses, EBV and KSHV, encode proteins that are capable of modulating the host immune signaling machinery, thereby subverting host immune responses. Murine gamma-herpesvirus 68 (MHV68 infection of laboratory strains of mice has proven to be useful small-animal model that shares important pathogenic strategies with the human gamma-herpesviruses. The MHV68 M2 protein is known to manipulate B cell signaling and, dependent on route and dose of virus inoculation, plays a role in both the establishment of latency and virus reactivation. M2 contains two tyrosines that are targets for phosphorylation, and have been shown to interact with the B cell signaling machinery. Here we describe in vitro and in vivo studies of M2 mutants which reveals that while both tyrosines Y120 and Y129 are required for M2 induction of IL-10 expression from primary murine B cells in vitro, only Y129 is critical for reactivation from latency and plasma cell differentiation in vivo.

  7. Once-daily glycopyrronium bromide, a long-acting muscarinic antagonist, for chronic obstructive pulmonary disease

    DEFF Research Database (Denmark)

    Ulrik, Charlotte Suppli

    2012-01-01

    Long-acting bronchodilators are central in the pharmacological management of patients with chronic obstructive pulmonary disease (COPD). The aim of this systematic review is to provide an overview of the studies evaluating the safety and clinical efficacy of inhaled glycopyrronium bromide, a novel...... long-acting muscarinic antagonist, in patients with COPD....

  8. Onset of effect of aclidinium, a novel, long-acting muscarinic antagonist, in patients with COPD

    DEFF Research Database (Denmark)

    Vestbo, Jørgen; Vogelmeier, Claus; Creemers, Jacques

    2010-01-01

    ABSTRACT Aclidinium bromide is a novel, long-acting, inhaled muscarinic antagonist in development for the treatment of chronic obstructive pulmonary disease (COPD). The aim of this study was to assess the rate of onset of bronchodilation with aclidinium compared with placebo and tiotropium. This ...

  9. Analogues of the muscarinic agent 2'-methylspiro[1-azabicyclo[2.2.2]octane-3,4'-[1,3]dioxolane]: synthesis and pharmacology.

    Science.gov (United States)

    Nordvall, G; Sundquist, S; Glas, G; Gogoll, A; Nilvebrant, L; Hacksell, U

    1992-05-01

    A number of tetrahydrofuran analogues of 2'-methylspiro[1-azabicyclo[2.2.2]octane-3,4'-[1,3]dioxolane] (1) have been prepared with the aim to obtain information about the relative importance of each of the oxygens in 1 for efficacy and for selectivity. In addition, the dimethyl and desmethyl analogues of 1 were prepared. The new compounds were compared to cis- and trans-1 with regard to their ability to displace (-)-[3H]-3-quinuclidinyl benzilate ((-)-[3H]QNB) from muscarinic receptors in cerebral cortex, heart, parotid gland, and urinary bladder from guinea pigs. Functional studies were made on isolated guinea pig bladder and ileum. The new compounds exhibited both lower affinity and efficacy than cis-1. A conformational study was performed, and the effects of steric and electronic factors on the biological activity of the compounds are discussed.

  10. Transmitter receptors reveal segregation of the arcopallium/amygdala complex in pigeons (Columba livia).

    Science.gov (United States)

    Herold, Christina; Paulitschek, Christina; Palomero-Gallagher, Nicola; Güntürkün, Onur; Zilles, Karl

    2018-02-15

    At the beginning of the 20th century it was suggested that a complex group of nuclei in the avian posterior ventral telencephalon is comparable to the mammalian amygdala. Subsequent findings, however, revealed that most of these structures share premotor characteristics, while some indeed constitute the avian amygdala. These developments resulted in 2004 in a change of nomenclature of these nuclei, which from then on were named arcopallial or amygdala nuclei and referred to as the arcopallium/amygdala complex. The structural basis for the similarities between avian and mammalian arcopallial and amygdala subregions is poorly understood. Therefore, we analyzed binding site densities for glutamatergic AMPA, NMDA and kainate, GABAergic GABA A , muscarinic M 1 , M 2 and nicotinic acetylcholine (nACh; α 4 β 2 subtype), noradrenergic α 1 and α 2 , serotonergic 5-HT 1A and dopaminergic D 1/5 receptors using quantitative in vitro receptor autoradiography combined with a detailed analysis of the cyto- and myelo-architecture. Our approach supports a segregation of the pigeon's arcopallium/amygdala complex into the following subregions: the arcopallium anterius (AA), the arcopallium ventrale (AV), the arcopallium dorsale (AD), the arcopallium intermedium (AI), the arcopallium mediale (AM), the arcopallium posterius (AP), the nucleus posterioris amygdalopallii pars basalis (PoAb) and pars compacta (PoAc), the nucleus taeniae amgygdalae (TnA) and the area subpallialis amygdalae (SpA). Some of these subregions showed further subnuclei and each region of the arcopallium/amygdala complex are characterized by a distinct multi-receptor density expression. Here we provide a new detailed map of the pigeon's arcopallium/amygdala complex and compare the receptor architecture of the subregions to their possible mammalian counterparts. © 2017 Wiley Periodicals, Inc.

  11. On relating multiple M2 and D2-branes

    International Nuclear Information System (INIS)

    Gran, U.; Nilsson, B.E.W; Petersson, C.

    2008-01-01

    Due to the difficulties of finding superconformal Lagrangian theories for multiple M2-branes, we will in this paper instead focus on the field equations. By relaxing the requirement of a Lagrangian formulation we can explore the possibility of having structure constants f ABC D satisfying the fundamental identity but which are not totally antisymmetric. We exemplify this discussion by making use of an explicit choice of a non-antisymmetric f ABC D constructed from the Lie algebra structure constants f ab c of an arbitrary gauge group. Although this choice of f ABC D does not admit an obvious Lagrangian description, it does reproduce the correct SYM theory for a stack of N D2-branes to leading order in g YM -1 upon reduction and, moreover, it sheds new light on the centre of mass coordinates for multiple M2-branes.

  12. Stimulation of Na+ -K+ -pump currents by epithelial nicotinic receptors in rat colon.

    Science.gov (United States)

    Bader, Sandra; Lottig, Lena; Diener, Martin

    2017-05-01

    Acetylcholine-induced epithelial Cl - secretion is generally thought to be mediated by epithelial muscarinic receptors and nicotinic receptors on secretomotor neurons. However, recent data have shown expression of nicotinic receptors by intestinal epithelium and the stimulation of Cl - secretion by nicotine, in the presence of the neurotoxin, tetrodotoxin. Here, we aimed to identify the transporters activated by epithelial nicotinic receptors and to clarify their role in cholinergic regulation of intestinal ion transport. Ussing chamber experiments were performed, using rat distal colon with intact epithelia. Epithelia were basolaterally depolarized to measure currents across the apical membrane. Apically permeabilized tissue was also used to measure currents across the basolateral membrane in the presence of tetrodotoxin. Nicotine had no effect on currents through Cl - channels in the apical membrane or on currents through K + channels in the apical or the basolateral membrane. Instead, nicotine stimulated the Na + -K + -pump as indicated by Na + -dependency and sensitivity of the nicotine-induced current across the basolateral membrane to cardiac steroids. Effects of nicotine were inhibited by nicotinic receptor antagonists such as hexamethonium and mimicked by dimethyl-4-phenylpiperazinium, a chemically different nicotinic agonist. Simultaneous stimulation of epithelial muscarinic and nicotinic receptors led to a strong potentiation of transepithelial Cl - secretion. These results suggest a novel concept for the cholinergic regulation of transepithelial ion transport by costimulation of muscarinic and nicotinic epithelial receptors and a unique role of nicotinic receptors controlling the activity of the Na + -K + -ATPase. © 2017 The British Pharmacological Society.

  13. Highly retarded M2 transition in 90Nb

    International Nuclear Information System (INIS)

    Sergeev, V.O.

    2006-01-01

    One studied properties of 2.3 keV transition between 124.67 (4 - ) and 122.37 keV (6 + ) in 90 Nb. The mentioned M2-transition is shown to be retarded by approximately 10 4 times and provided explanations of the mentioned extraordinary high factor of deceleration. One evaluated impurity of E3 possible multipolarity constituent in the mentioned transition (δ 2 [ru

  14. Solar thermal barometer. 12 million M2 installed in europe

    International Nuclear Information System (INIS)

    Anon.

    2002-01-01

    European thermal solar has once again reached its zenith. The difficult times of 1985-1995 are now a thing of the past. The best proof is the very good results of 2001 that show figures in significant progression with respect to those of the year 2000. 1480 320 m 2 . This is now the new record to beat in terms of the annual volume of thermal solar collector installation in the European Union. (author)

  15. Autonomic receptors in urinary tract: Sex and age differences

    International Nuclear Information System (INIS)

    Latifpour, J.; Kondo, S.; O'Hollaren, B.; Morita, T.; Weiss, R.M.

    1990-01-01

    As age and sex affect the function of the lower urinary tract, we studied the characteristics of adrenergic and cholinergic receptors in various parts of lower urinary tract smooth muscle of young (6 months) and old (4 1/2-5 years) male and female rabbits. Saturation experiments performed with [3H]prazosin, [3H]yohimbine, [3H]dihydroalprenolol and [3H]quinuclidinyl benzylate in rabbit bladder base, bladder dome and urethra indicate the presence of regional, sex- and age-related differences in the density of alpha-1, alpha-2, and beta adrenergic and muscarinic cholinergic receptors. Alpha-2 adrenergic receptor density is considerably higher in the female than in the male urethra of both age groups, whereas the higher density of beta adrenergic receptors in the female than in the male bladder base is observed only in the younger animals. The density of muscarinic receptors is higher in bladder dome than in bladder base or urethra in young rabbits of both sexes. In the old animals, the density of muscarinic receptors in bladder base increases to the level observed in bladder dome. Inhibition experiments with selective adrenergic agonists and antagonists indicate that the pharmacological profiles of alpha-2 adrenergic receptors in the urethra and beta adrenergic receptors in the bladder dome and bladder base are similar in both sexes and at both ages. Beta-2 adrenergic receptors are shown to be predominant in bladder base and bladder dome of rabbits. Parallel studies in rabbit urethra, adult rat cortex and neonatal rat lung show that the urethral alpha-2 adrenergic receptors are of the alpha-2A subtype

  16. State-of-the-art Model M-2 Maintenance System

    International Nuclear Information System (INIS)

    Herndon, J.N.; Martin, H.L.; Satterlee, P.E. Jr.; Jelatis, D.G.; Jennrich, C.E.

    1984-04-01

    The Model M-2 Maintenance System is part of an ongoing program within the Consolidated Fuel Reprocessing Program (CFRP) at Oak Ridge National Laboratory (ORNL) to improve remote manipulation technology for future nuclear fuel reprocessing and other remote applications. Techniques, equipment, and guidelines which can improve the efficiency of remote maintenance are being developed. The Model M-2 Maintenance System, installed in the Integrated Equipment Test (IET) Facility at ORNL, provides a complete, integrated remote maintenance system for the demonstration and development of remote maintenance techniques. The system comprises a pair of force-reflecting servomanipulator arms, television viewing, lighting, and auxiliary lifting capabilities, thereby allowing manlike maintenance operations to be executed remotely within the remote cell mockup area in the IET. The Model M-2 Maintenance System incorporates an upgraded version of the proven Central Research Laboratories' Model M servomanipulator. Included are state-of-the-art brushless dc servomotors for improved performance, remotely removable wrist assemblies, geared azimuth drive, and a distributed microprocessor-based digital control system. 5 references, 8 figures

  17. Penrose limits, pp waves, and deformed M2-branes

    International Nuclear Information System (INIS)

    Cvetic, M.; Lue, H.; Pope, C.N.

    2004-01-01

    Motivated by the recent discussions of the Penrose limit of AdS 5 xS 5 , we examine a more general class of supersymmetric pp-wave solutions of the type IIB theory, with a larger number of nonvanishing structures in the self-dual 5-form. One of the pp-wave solutions can be obtained as a Penrose limit of a D3-D3 intersection. In addition to 16 standard supersymmetries these backgrounds always allow for supernumerary supersymmetries. The latter are in one-to-one correspondence with the linearly realized world-sheet supersymmetries of the corresponding exactly solvable type IIB string action. The pp-waves provide new examples where supersymmetries will survive in a T-duality transformation on the x + coordinate. The T-dual solutions can be lifted to give supersymmetric deformed M2-branes in D=11. The deformed M2-brane is dual to a three-dimensional field theory whose renormalization group flow runs from the conformal fixed point in the infrared regime to a nonconformal theory as the energy increases. At a certain intermediate energy scale there is a phase transition associated with a naked singularity of the M2-brane. In the ultraviolet limit the theory is related by T duality to an exactly solvable massive type IIB string theory

  18. Identification of M2 macrophages in anterior pituitary glands of normal rats and rats with estrogen-induced prolactinoma.

    Science.gov (United States)

    Fujiwara, Ken; Yatabe, Megumi; Tofrizal, Alimuddin; Jindatip, Depicha; Yashiro, Takashi; Nagai, Ryozo

    2017-05-01

    Macrophages are present throughout the anterior pituitary gland. However, the features and function of macrophages in the gland are poorly understood. Recent studies have indicated that there are two main macrophage classes: M1 (classically activated) and M2 (alternatively activated). In this study, we examine whether both M1 and M2 macrophages are present in the anterior pituitary gland of rats. Our findings indicate that macrophages that are positive for CD68 (a pan-macrophage marker) were localized near capillaries in rat anterior pituitary gland. These macrophages were positive for iNOS or mannose receptor (MR), which are markers of M1 and M2 macrophages, respectively. To determine the morphological characteristics of M2 macrophages under pathological conditions, diethylstilbestrol (DES)-treated rats were used as an animal model of prolactinoma. After 2 weeks of DES treatment, a number of MR-immunopositive cells were present in the gland. Immunoelectron microscopy revealed that MR-immunopositive M2 macrophages had many small vesicles and moderately large vacuoles in cytoplasm. Phagosomes were sometimes present in cytoplasm. Interestingly, M2 macrophages in prolactinoma tissues did not usually exhibit distinct changes or differences during the normal, hyperplasia and adenoma stages. This study is the first to confirm that both M1 and M2 macrophages are present in the anterior pituitary gland of rats. Moreover, the number of M2 macrophages was greatly increased in rats with DES-induced prolactinoma. Future studies should attempt to characterize the functional role of M2 macrophages in the gland.

  19. A new and efficient culture method for porcine bone marrow-derived M1- and M2-polarized macrophages.

    Science.gov (United States)

    Gao, Jiye; Scheenstra, Maaike R; van Dijk, Albert; Veldhuizen, Edwin J A; Haagsman, Henk P

    2018-06-01

    Macrophages play an important role in the innate immune system as part of the mononuclear phagocyte system (MPS). They have a pro-inflammatory signature (M1-polarized macrophages) or anti-inflammatory signature (M2-polarized macrophages) based on expression of surface receptors and secretion of cytokines. However, very little is known about the culture of macrophages from pigs and more specific about the M1 and M2 polarization in vitro. Porcine monocytes or mononuclear bone marrow cells were used to culture M1- and M2-polarized macrophages in the presence of GM-CSF and M-CSF, respectively. Surface receptor expression was measured with flow cytometry and ELISA was used to quantify cytokine secretion in response to LPS and PAM 3 CSK 4 stimulation. Human monocyte-derived macrophages were used as control. Porcine M1- and M2-polarized macrophages were cultured best using porcine GM-CSF and murine M-CSF, respectively. Cultures from bone marrow cells resulted in a higher yield M1- and M2-polarized macrophages which were better comparable to human monocyte-derived macrophages than cultures from porcine monocytes. Porcine M1-polarized macrophages displayed the characteristic fried egg shape morphology, lower CD163 expression and low IL-10 production. Porcine M2-polarized macrophages contained the spindle-like morphology, higher CD163 expression and high IL-10 production. Porcine M1- and M2-polarized macrophages can be most efficiently cultured from mononuclear bone marrow cells using porcine GM-CSF and murine M-CSF. The new culture method facilitates more refined studies of porcine macrophages in vitro, important for both porcine and human health since pigs are increasingly used as model for translational research. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  20. M2-Branes in N = 3 Harmonic Superspace

    Directory of Open Access Journals (Sweden)

    E. Ivanov

    2010-01-01

    Full Text Available We give a brief account of the recently proposed N = 3 superfield formulation of the N = 6, 3D superconformal theory of Aharony et al (ABJM describing a low-energy limit of the system of multiple M2-branes on the AdS4×S7/Zk background. This formulation is given in harmonic N = 3 superspace and reveals a number of surprising new features. In particular, the sextic scalar potential of ABJM arises at the on-shell component level as the result of eliminating appropriate auxiliary fields, while there is no explicit superpotential at the off-shell superfield level.

  1. Cholinergic, opioid and glycine receptor binding sites localized in human spinal cord by in vitro autoradiography

    International Nuclear Information System (INIS)

    Gillberg, P.-G.; Aquilonius, S.-M.

    1985-01-01

    Binding sites for the receptor ligands 3 H-quinuclidinylbenzilate, 3 H-alpha-bungarotoxin ( 3 H-alpha-Btx), 3 H-etorphine and 3 H-strychnine were localized autoradiographically at cervical, thoracic and lumbar levels of spinal cords from post-mortem human control subjects and subjects with amyotrophic lateral sclerosis (ALS). The highest densities of muscarinic binding sites were found in the motor neuron areas and in the substantia gelatinosa, while the grey matter binding was very low within Clarke's column. Both 3 H-alpha-Btx and opioid receptor binding sites were numerous within the substantia gelatinosa, while glycine receptor binding sites were more uniformly distribute within the spinal grey matter. In ALS cases, muscarinic receptor binding sites were markedly reduced in motor neuron areas and slightly reduced in the dorsal horn, while the other binding sites studied were relatively unchanged. (author)

  2. SLiM 2: Flexible, Interactive Forward Genetic Simulations.

    Science.gov (United States)

    Haller, Benjamin C; Messer, Philipp W

    2017-01-01

    Modern population genomic datasets hold immense promise for revealing the evolutionary processes operating in natural populations, but a crucial prerequisite for this goal is the ability to model realistic evolutionary scenarios and predict their expected patterns in genomic data. To that end, we present SLiM 2: an evolutionary simulation framework that combines a powerful, fast engine for forward population genetic simulations with the capability of modeling a wide variety of complex evolutionary scenarios. SLiM achieves this flexibility through scriptability, which provides control over most aspects of the simulated evolutionary scenarios with a simple R-like scripting language called Eidos. An example SLiM simulation is presented to illustrate the power of this approach. SLiM 2 also includes a graphical user interface for simulation construction, interactive runtime control, and dynamic visualization of simulation output, facilitating easy and fast model development with quick prototyping and visual debugging. We conclude with a performance comparison between SLiM and two other popular forward genetic simulation packages. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Effects of muscarinic receptor modulators on ocular biometry of guinea pigs.

    Science.gov (United States)

    Fang, Fang; Huang, Furong; Xie, Ruozhong; Li, Cheng; Liu, Yin; Zhu, Ying; Qu, Jia; Zhou, Xiangtian

    2015-01-01

    This study investigated whether pilocarpine and cyclopentolate induce changes in ocular biometry of guinea pigs, in order to understand if guinea pigs have a similar response to these two agents as humans do. Under general anaesthesia, refraction, axial components and surface curvature in various optical interfaces of the eye were measured in 10 guinea pigs (age of 2 weeks) at baseline (0 min) and different time points (5, 10, 20, 30, 60, 90 min) after topical administration of pilocarpine or cyclopentolate. The interval between the two drug treatments for the same animals was at least 24 h. Eyes treated with pilocarpine developed approximately 6D myopia (p guinea pigs have an accommodative mechanism similar to that in humans. The minimal changes produced by cyclopentolate could be due to the use of general anaesthesia, which may have reduced the susceptibility of the eye to topical cyclopentolate in the induction of cycloplegia. © 2014 The Authors Ophthalmic & Physiological Optics © 2014 The College of Optometrists.

  4. Presynaptic M1 muscarinic receptor modulates spontaneous release of acetylcholine from rat basal forearm slices

    International Nuclear Information System (INIS)

    Suzuki, T.; Fujimoto, LK.; Oohata, H.; Kawashima, K.

    1988-01-01

    Spontaneous release of (ACh) from rat basal forebrain slices in the presence of cholinesterase inhibitor was directly determined using a specific radioimmunoassay for ACh. The release was calcium dependent. A consistent amount of ACh release was observed throughout the experiment. Atropine (10- 8 to 10- 5 M) and pirenzepine (10- 7 to 10- 5 M) enhanced spontaneous ACh release. These findings indicate the presence of an M 1 muscarenic autoreceptor that modulates spontaneous release of ACh in the rat forebrain

  5. Muscarinic receptor activation stimulates B-50/GAP43 phosphorylation in isolated nerve growth cones

    NARCIS (Netherlands)

    Gispen, W.H.; Hooff, C.O.M. van; Graan, P.N.E. de; Oestreicher, A.B.

    1989-01-01

    A characteristic feature of neurite formation is high expression of the phosphoprotein B-50/GAP43. Previous studies with growth cone membranes have indicated that this neuron-specific protein kinase C substrate may be involved in transmembrane signal transduction at the growth cone. We monitored the

  6. Gamma-secretase activity of presenilin 1 regulates acetylcholine muscarinic receptor-mediated signal transduction

    DEFF Research Database (Denmark)

    Popescu, Bogdan O; Cedazo-Minguez, Angel; Benedikz, Eirikur

    2004-01-01

    , we studied the effect of two other FAD PS1 mutants (M146V and L250S) and two dominant negative PS1 mutants (D257A and D385N) on basal and carbachol-stimulated phosphoinositide (PI) hydrolysis and intracellular calcium concentrations ([Ca2+]i) in SH-SY5Y neuroblastoma cells. We found a significant...

  7. Basic and modern concepts on cholinergic receptor: A review

    Directory of Open Access Journals (Sweden)

    Prashant Tiwari

    2013-10-01

    Full Text Available Cholinergic system is an important system and a branch of the autonomic nervous system which plays an important role in memory, digestion, control of heart beat, blood pressure, movement and many other functions. This article serves as both structural and functional sources of information regarding cholinergic receptors and provides a detailed understanding of the determinants governing specificity of muscarinic and nicotinic receptor to researchers. The study helps to give overall information about the fundamentals of the cholinergic system, its receptors and ongoing research in this field.

  8. Labeled receptor ligands for spect

    International Nuclear Information System (INIS)

    Kung, H.F.

    1989-01-01

    Receptor specific imaging agents for single photon emission computed tomography (SPECT) can potentially be useful in the understanding of basic biochemistry and pharmacology of receptors. SPECT images may also provide tools for evaluation of density and binding kinetics of a specific receptor, information important for diagnosis and patient management. Basic requirements for receptor imaging agents are: (a) they are labeled with short-lived isotopes, (b) they show high selectivity and specific uptake, (c) they exhibit high target/background ratio, and (d) they can be modeled to obtain quantitative information. Several good examples of CNS receptor specific ligands labeled with I-123 have been developed, including iodoQNB, iodoestrogen iodobenzadiazepine, iodobenazepine, iodobenzamides for muscarinic, estrogen benzadiazepine, D-1 and D-2 dopamine receptors. With the advent of newer and faster SPECT imaging devices, it may be feasible to quantitate the receptor density by in vivo imaging techniques. These new brain imaging agents can provide unique diagnostic information, which may not be available through other imaging modalities, such as CT and MRI

  9. Supersymmetric states in M5/M2 CFTs

    International Nuclear Information System (INIS)

    Bhattacharyya, Sayantani; Minwalla, Shiraz

    2007-01-01

    We propose an exact, finite N formula for the partition function over 1/4 th BPS states in the conformal field theory on the world volume of N coincident M5 branes, and 1/8 th BPS states in the theory of N conincident M2 branes. We obtain our partition function by performing the radial quantization of the Coulomb Branches of these theories and rederive the same formula from the quantization of supersymmetric giant and dual giant gravitons in AdS 7 x S 4 and AdS 4 x S 7 . Our partition function is qualitatively similar to the analogous quantity in N = 4 Yang Mills. It reduces to the sum over supersymmetric multi gravitons at low energies, but deviates from this supergravity formula at energies that scale like a positive power of N

  10. TREAT experiment M2 post-test examination

    International Nuclear Information System (INIS)

    Holland, J.W.; Teske, G.M.; Florek, J.C.

    1986-01-01

    Transient Reactor Test (TREAT) Facility experiment M2 was performed to evaluate the transient behavior of metal-alloy fuel under accident conditions to investigate the inherent safety features of the fuel in integral fast reactor (IFR) system designs. Objectives were to obtain early information on the key fuel behavior characteristics at transient overpower (TOP) conditions in metal-fueled fast reactors; namely, margin to cladding breach and extent of axial self-extrusion of fuel within intact cladding. The onset of cladding breaching depends on fuel/cladding eutectic formation, as well as cladding pressurization and melting. Driving forces for fuel extrusion are fission gas, liquid sodium, and volatile fission products trapped within the fuel matrix. The post-test examination provided data essential for correctly modeling fuel behavior in accident codes

  11. In vivo and in vitro studies on a muscarinic presynaptic antagonist and postsynaptic agonist: BM-5

    International Nuclear Information System (INIS)

    Nordstrom, O.; Bartafi, T.; Frieder, B.; Grimm, V.; Ladinsky, H.; Unden, A.

    1986-01-01

    This paper reports on in vitro and in vivo studies with compound BM-5 which, at proper dosage, could have great potential since it could enhance cholinergic transmission by being a presynaptic antagonist and postsynaptic agonist. Binding studies are described in which tritium-4-NMPB, a muscarinic antagonist, was displaced by compound BM-5 in membranes from striatum, cerebral cortex, cerebellum and hippocampus. The binding data are summarized, which for each brain area involved 86-92 data points evaluated by means of nonlinear regression methods. Compound BM-5 recognized in each brain region a population of high and a population of low affinity binding sites; both of which were labelled with tritium-4-NMPB. It is shown that compound BM-5 causes muscarinic cholinergic agonist-like effects such as redness of the eye, increased motility in the gut, and impairment of locomotor behavior. It also produces muscarinic super-sensitivity upon chronic treatment, and decreases rat striatial ACh content by acute treatment

  12. Imatinib and Nilotinib Off-Target Effects on Human NK Cells, Monocytes, and M2 Macrophages.

    Science.gov (United States)

    Bellora, Francesca; Dondero, Alessandra; Corrias, Maria Valeria; Casu, Beatrice; Regis, Stefano; Caliendo, Fabio; Moretta, Alessandro; Cazzola, Mario; Elena, Chiara; Vinti, Luciana; Locatelli, Franco; Bottino, Cristina; Castriconi, Roberta

    2017-08-15

    Tyrosine kinase inhibitors (TKIs) are used in the clinical management of hematological neoplasms. Moreover, in solid tumors such as stage 4 neuroblastomas (NB), imatinib showed benefits that might depend on both on-target and immunological off-target effects. We investigated the effects of imatinib and nilotinib on human NK cells, monocytes, and macrophages. High numbers of monocytes died upon exposure to TKI concentrations similar to those achieved in patients. Conversely, NK cells were highly resistant to the TKI cytotoxic effect, were properly activated by immunostimulatory cytokines, and degranulated in the presence of NB cells. In NB, neither drug reduced the expression of ligands for activating NK receptors or upregulated that of HLA class I, B7-H3, PD-L1, and PD-L2, molecules that might limit NK cell function. Interestingly, TKIs modulated the chemokine receptor repertoire of immune cells. Acting at the transcriptional level, they increased the surface expression of CXCR4, an effect observed also in NK cells and monocytes of patients receiving imatinib for chronic myeloid leukemia. Moreover, TKIs reduced the expression of CXCR3 (in NK cells) and CCR1 (in monocytes). Monocytes also decreased the expression of M-CSFR, and low numbers of cells underwent differentiation toward macrophages. M0 and M2 macrophages were highly resistant to TKIs and maintained their phenotypic and functional characteristics. Importantly, also in the presence of TKIs, the M2 immunosuppressive polarization was reverted by TLR engagement, and M1-oriented macrophages fully activated autologous NK cells. Our results contribute to better interpreting the off-target efficacy of TKIs in tumors and to envisaging strategies aimed at facilitating antitumor immune responses. Copyright © 2017 by The American Association of Immunologists, Inc.

  13. (Acanthaceae) on Isolated Guinea Pig Trachea

    African Journals Online (AJOL)

    1Department of Pharmacology, College of Medicine, University of Lagos, PMB 12003, 2Department of Pharmacy,. Lagos University Teaching ..... channels. The degree of muscarinic receptor activation is believed to be important in determining the relaxant potency of isoprenaline; hence, muscarinic. M2 receptor antagonism ...

  14. Nucleus Accumbens Acetylcholine Receptors Modulate Dopamine and Motivation.

    Science.gov (United States)

    Collins, Anne L; Aitken, Tara J; Greenfield, Venuz Y; Ostlund, Sean B; Wassum, Kate M

    2016-11-01

    Environmental reward-predictive cues can motivate reward-seeking behaviors. Although this influence is normally adaptive, it can become maladaptive in disordered states, such as addiction. Dopamine release in the nucleus accumbens core (NAc) is known to mediate the motivational impact of reward-predictive cues, but little is known about how other neuromodulatory systems contribute to cue-motivated behavior. Here, we examined the role of the NAc cholinergic receptor system in cue-motivated behavior using a Pavlovian-to-instrumental transfer task designed to assess the motivating influence of a reward-predictive cue over an independently-trained instrumental action. Disruption of NAc muscarinic acetylcholine receptor activity attenuated, whereas blockade of nicotinic receptors augmented cue-induced invigoration of reward seeking. We next examined a potential dopaminergic mechanism for this behavioral effect by combining fast-scan cyclic voltammetry with local pharmacological acetylcholine receptor manipulation. The data show evidence of opposing modulation of cue-evoked dopamine release, with muscarinic and nicotinic receptor antagonists causing suppression and augmentation, respectively, consistent with the behavioral effects of these manipulations. In addition to demonstrating cholinergic modulation of naturally-evoked and behaviorally-relevant dopamine signaling, these data suggest that NAc cholinergic receptors may gate the expression of cue-motivated behavior through modulation of phasic dopamine release.

  15. A novel muscarinic antagonist R2HBJJ inhibits non-small cell lung cancer cell growth and arrests the cell cycle in G0/G1.

    Directory of Open Access Journals (Sweden)

    Nan Hua

    Full Text Available Lung cancers express the cholinergic autocrine loop, which facilitates the progression of cancer cells. The antagonists of mAChRs have been demonstrated to depress the growth of small cell lung cancers (SCLCs. In this study we intended to investigate the growth inhibitory effect of R2HBJJ, a novel muscarinic antagonist, on non-small cell lung cancer (NSCLC cells and the possible mechanisms. The competitive binding assay revealed that R2HBJJ had a high affinity to M3 and M1 AChRs. R2HBJJ presented a strong anticholinergic activity on carbachol-induced contraction of guinea-pig trachea. R2HBJJ markedly suppressed the growth of NSCLC cells, such as H1299, H460 and H157. In H1299 cells, both R2HBJJ and its leading compound R2-PHC displayed significant anti-proliferative activity as M3 receptor antagonist darifenacin. Exogenous replenish of ACh could attenuate R2HBJJ-induced growth inhibition. Silencing M3 receptor or ChAT by specific-siRNAs resulted in a growth inhibition of 55.5% and 37.9% on H1299 cells 96 h post transfection, respectively. Further studies revealed that treatment with R2HBJJ arrested the cell cycle in G0/G1 by down-regulation of cyclin D1-CDK4/6-Rb. Therefore, the current study reveals that NSCLC cells express an autocrine and paracrine cholinergic system which stimulates the growth of NSCLC cells. R2HBJJ, as a novel mAChRs antagonist, can block the local cholinergic loop by antagonizing predominantly M3 receptors and inhibit NSCLC cell growth, which suggest that M3 receptor antagonist might be a potential chemotherapeutic regimen for NSCLC.

  16. Report ETSI M2M-14bis JTC March 2011 meeting

    NARCIS (Netherlands)

    Keesmaat, N.W.

    2011-01-01

    The ETSI Technical Committee (TC) M2M focuses on the development of a generic M2M architecture and underlying protocols suitable for a wide range of M2M environments. Whereas in the past effort has been put in the development of several use cases, the focus of this M2M 14bis meeting – held in Sophia

  17. Agomelatine or ramelteon as treatment adjuncts in glioblastoma and other M1- or M2-expressing cancers.

    Science.gov (United States)

    Kast, Richard E

    2015-01-01

    The impressive but sad list of over forty clinical studies using various cytotoxic chemotherapies published in the last few years has failed to increase median survival of glioblastoma beyond two years after diagnosis. In view of this apparent brick wall, adjunctive non-cytotoxic growth factor blocking drugs are being tried, as in the CUSP9* protocol. A related theme is searching for agonists at growth inhibiting receptors. One such dataset is that of melatonin agonism at M1 or M2 receptors found on glioblastoma cells, being a negative regulator of these cells' growth. Melatonin itself is an endogenous hormone, but when used as an exogenously administered drug it has many disadvantages. Agomelatine, marketed as an antidepressant, and ramelteon, marketed as a treatment for insomnia, are currently-available melatonin receptor agonists. These melatonin receptor agonists have significant advantages over the natural ligand: longer half-life, better oral absorption, and higher affinity to melatonin receptors. They have an eminently benign side effect profile. As full agonists they should function to inhibit glioblastoma growth, as demonstrated for melatonin. A potentially helpful ancillary attribute of melatonergic agonists in glioblastoma treatment is an increase in interleukin-2 synthesis, expected, at least partially, to reverse some of the immunosuppression associated with glioblastoma.

  18. Detection of Nuclear Protein Profile Changes by Human Metapneumovirus M2-2 Protein Using Quantitative Differential Proteomics

    Directory of Open Access Journals (Sweden)

    Yuping Ren

    2017-12-01

    Full Text Available Human metapneumovirus (hMPV is a leading cause of lower respiratory infection in pediatric populations globally. This study examined proteomic profile changes in A549 cells infected with hMPV and two attenuated mutants with deleted PDZ domain-binding motif(s in the M2-2 protein. These motifs are involved in the interruption of antiviral signaling, namely the interaction between the TNF receptor associated factor (TRAF and mitochondrial antiviral-signaling (MAVS proteins. The aim of this study was to provide insight into the overall and novel impact of M2-2 motifs on cellular responses via an unbiased comparison. Tandem mass tagging, stable isotope labeling, and high-resolution mass spectrometry were used for quantitative proteomic analysis. Using quantitative proteomics and Venn analysis, 1248 common proteins were detected in all infected samples of both technical sets. Hierarchical clustering of the differentiated proteome displayed distinct proteomic signatures that were controlled by the motif(s. Bioinformatics and experimental analysis confirmed the differentiated proteomes, revealed novel cellular biological events, and implicated key pathways controlled by hMPV M2-2 PDZ domain-binding motif(s. This provides further insight for evaluating M2-2 mutants as potent vaccine candidates.

  19. Expression Profiles of Neuropeptides, Neurotransmitters, and Their Receptors in Human Keratocytes In Vitro and In Situ.

    Science.gov (United States)

    Słoniecka, Marta; Le Roux, Sandrine; Boman, Peter; Byström, Berit; Zhou, Qingjun; Danielson, Patrik

    2015-01-01

    Keratocytes, the quiescent cells of the corneal stroma, play a crucial role in corneal wound healing. Neuropeptides and neurotransmitters are usually associated with neuronal signaling, but have recently been shown to be produced also by non-neuronal cells and to be involved in many cellular processes. The aim of this study was to assess the endogenous intracellular and secreted levels of the neuropeptides substance P (SP) and neurokinin A (NKA), and of the neurotransmitters acetylcholine (ACh), catecholamines (adrenaline, noradrenaline and dopamine), and glutamate, as well as the expression profiles of their receptors, in human primary keratocytes in vitro and in keratocytes of human corneal tissue sections in situ. Cultured keratocytes expressed genes encoding for SP and NKA, and for catecholamine and glutamate synthesizing enzymes, as well as genes for neuropeptide, adrenergic and ACh (muscarinic) receptors. Keratocytes in culture produced SP, NKA, catecholamines, ACh, and glutamate, and expressed neurokinin-1 and -2 receptors (NK-1R and NK-2R), dopamine receptor D2, muscarinic ACh receptors, and NDMAR1 glutamate receptor. Human corneal sections expressed SP, NKA, NK-1R, NK-2R, receptor D2, choline acetyl transferase (ChAT), M3, M4 and M5 muscarinic ACh receptors, glutamate, and NMDAR1, but not catecholamine synthesizing enzyme or the α1 and β2 adrenoreceptors, nor M1 receptor. In addition, expression profiles assumed significant differences between keratocytes from the peripheral cornea as compared to those from the central cornea, as well as differences between keratocytes cultured under various serum concentrations. In conclusion, human keratocytes express an array of neuropeptides and neurotransmitters. The cells furthermore express receptors for neuropeptides/neurotransmitters, which suggests that they are susceptible to stimulation by these substances in the cornea, whether of neuronal or non-neuronal origin. As it has been shown that neuropeptides

  20. Venoms of South Asian hump-nosed pit vipers (Genus: Hypnale cause muscarinic effects in BALB/c mice

    Directory of Open Access Journals (Sweden)

    A Silva

    2014-03-01

    Full Text Available Although clinical, in-vivo and in-vitro studies suggest the necrotic, haemorrhagic, pro-coagulant and nephrotoxic effects of South Asian Hump nosed pit vipers, reports on neurotoxic properties are limited to a single in-vitro study. Using BALB/c mice, for the first time, here we demonstrate the signs of envenoming suggestive of possible muscarinic effects of the venoms of all three Hypnale species. Further, we demonstrate that the muscarinic effects are occurred at lower venom doses by H. hypnale venom, compared to H. nepa and H. zara.

  1. Inhibition of allergen-induced basophil activation by ASM-024, a nicotinic receptor ligand.

    Science.gov (United States)

    Watson, Brittany M; Oliveria, John Paul; Nusca, Graeme M; Smith, Steven G; Beaudin, Sue; Dua, Benny; Watson, Rick M; Assayag, Evelynne Israël; Cormier, Yvon F; Sehmi, Roma; Gauvreau, Gail M

    2014-01-01

    Nicotinic acetylcholine receptors (nAChRs) were identified on eosinophils and shown to regulate inflammatory responses, but nAChR expression on basophils has not been explored yet. We investigated surface receptor expression of nAChR α4, α7 and α1/α3/α5 subunits on basophils. Furthermore, we examined the effects of ASM-024, a synthetic nicotinic ligand, on in vitro anti-IgE and in vivo allergen-induced basophil activation. Basophils were enriched from the peripheral blood of allergic donors and the expression of nAChR subunits and muscarinic receptors was determined. Purified basophils were stimulated with anti-IgE in the presence of ASM-024 with or without muscarinic or nicotinic antagonists for the measurement of CD203c expression and histamine release. The effect of 9 days of treatment with 50 and 200 mg ASM-024 on basophil CD203c expression was examined in the blood of mild allergic asthmatics before and after allergen inhalation challenge. nAChR α4, α7 and α1/α3/α5 receptor subunit expression was detected on basophils. Stimulation of basophils with anti-IgE increased CD203c expression and histamine release, which was inhibited by ASM-024 (10(-5) to 10(-)(3) M, p ASM-024 was reversed in the presence of muscarinic and nicotinic antagonists. In subjects with mild asthma, ASM-024 inhalation significantly inhibited basophil CD203c expression measured 24 h after allergen challenge (p = 0.03). This study shows that ASM-024 inhibits IgE- and allergen-induced basophil activation through both nicotinic and muscarinic receptors, and suggests that ASM-024 may be an efficacious agent for modulating allergic asthma responses. © 2015 S. Karger AG, Basel.

  2. Discovery of novel quaternary ammonium derivatives of (3R)-quinuclidinyl amides as potent and long acting muscarinic antagonists.

    Science.gov (United States)

    Prat, Maria; Buil, María Antonia; Fernández, Maria Dolors; Tort, Laia; Monleón, Juan Manuel; Casals, Gaspar; Ferrer, Manuel; Castro, Jordi; Gavaldà, Amadeu; Miralpeix, Montserrat; Ramos, Israel; Vilella, Dolors; Huerta, Josep Maria; Espinosa, Sònia; Hernández, Begoña; Segarra, Victor; Córdoba, Mònica

    2015-04-15

    Novel quaternary ammonium derivatives of (3R)-quinuclidinyl amides have been identified as potent M3 muscarinic antagonists with a long duration of action in an in vivo model of bronchoconstriction. The synthesis, structure-activity relationships and biological evaluation of this series of compounds are reported. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Dual role of YM1+ M2 macrophages in allergic lung inflammation

    NARCIS (Netherlands)

    Draijer, Christina; Robbe, Patricia; Boorsma, Carian E; Hylkema, Machteld N; Melgert, Barbro N

    2018-01-01

    Alternatively activated (M2 or YM1+) macrophages have been associated with the development of asthma but their contribution to disease initiation and progression remains unclear. To assess the therapeutic potential of modulating these M2 macrophages, we have studied inhibition of M2 polarisation

  4. Machine-to-Machine networks: integration of M2M networks into companies' administrative networks

    OpenAIRE

    Pointereau, Romain

    2013-01-01

    This analysis will address the technical, economic and regulatory aspects and will identify the position taken by the various market actors. Integration of M2M Networks into Companies' Administrative Networks. Integración de redes M2M en redes administrativas de las empresas. Integració de xarxes M2M en xarxes administratives de les empreses.

  5. Increased immunogenicity and protective efficacy of influenza M2e fused to a tetramerizing protein

    DEFF Research Database (Denmark)

    Andersson, Anne-Marie Carola; Håkansson, Kjell Ove; Jensen, Benjamin Anderschou Holbech

    2012-01-01

    by diverse influenza A viruses, a vaccine (M2e-NSP4) was constructed linking M2e (in its consensus sequence) to the rotavirus fragment NSP4(98-135); due to its coiled-coil region this fragment is known to form tetramers in aqueous solution and in this manner we hoped to mimick the natural configuration of M2...

  6. Vascular endothelium receptors and transduction mechanisms

    CERN Document Server

    Gillis, C; Ryan, Una; Proceedings of the Advanced Studies Institute on "Vascular Endothelium: Receptors and Transduction Mechanisms"

    1989-01-01

    Beyond their obvious role of a barrier between blood and tissue, vascular endothelial cells are now firmly established as active and essential participants in a host of crucial physiological and pathophysiological functions. Probably the two most important factors responsible for promoting the current knowledge of endothelial functions are 1) observations in the late sixties-early seventies that many non-ventilatory properties of the lung could be attributed to the pulmonary endothelium and 2) the establishment, in the early and mid-seventies of procedures for routine culture of vascular endothelial cells. Many of these endothelial functions require the presence of receptors on the surface of the plasma membrane. There is now evidence for the existence among others of muscarinic, a-and /3-adrenergic, purine, insulin, histamine, bradykinin, lipoprotein, thrombin, paf, fibronectin, vitronectin, interleukin and albumin receptors. For some of these ligands, there is evidence only for the existence of endothelial ...

  7. M1 and M2 Monocytes in Rheumatoid Arthritis: A Contribution of Imbalance of M1/M2 Monocytes to Osteoclastogenesis

    Directory of Open Access Journals (Sweden)

    Shoichi Fukui

    2018-01-01

    Full Text Available ObjectivesWe investigated the relationships among M1 monocytes, M2 monocytes, osteoclast (OC differentiation ability, and clinical characteristics in patients with rheumatoid arthritis (RA.MethodsPeripheral blood mononuclear cells (PBMCs were isolated from RA patients and healthy donors, and we then investigated the number of M1 monocytes or M2 monocytes by fluorescence-activated cell sorting. We also obtained and cultured CD14-positive cells from PBMCs from RA patients and healthy donors to investigate OC differentiation in vitro.ResultsForty RA patients and 20 healthy donors were included. Twenty-two patients (55% were anticitrullinated protein antibody (ACPA positive. The median M1/M2 ratio was 0.59 (0.31–1.11, interquartile range. There were no significant differences between the RA patients and healthy donors. There was a positive correlation between the M1/M2 ratio and the differentiated OC number in vitro in RA patients (ρ = 0.81, p < 0.001. The ACPA-positive patients had significantly higher M1/M2 ratios in vivo (p = 0.028 and significantly greater numbers of OCs in vitro (p = 0.005 than the ACPA-negative patients. Multivariable regression analysis revealed that the M1/M2 ratio was the sole significant contribution factor to in vitro osteoclastogenesis. RA patients with M1/M2 ratios >1 (having relatively more M1 monocytes had higher C-reactive protein and erythrocyte sedimentation rates than RA patients with M1/M2 ratios ≤1. M1-dominant monocytes in vitro produced higher concentrations of interleukin-6 upon stimulation with lipopolysaccharide than M2 monocytes.ConclusionM1/M2 monocytes imbalance strongly contributes to osteoclastogenesis of RA patients. Our findings cast M1 and M2 monocyte subsets in a new light as a new target of treatments for RA to prevent progression of osteoclastic bone destruction.

  8. Reexamination of M2,3 atomic level widths and L1M2,3 transition energies of elements 69≤Z≤95

    Science.gov (United States)

    Fennane, K.; Berset, M.; Dousse, J.-Cl.; Hoszowska, J.; Raboud, P.-A.; Campbell, J. L.

    2013-11-01

    We report on high-resolution measurements of the photoinduced L1M2 and L1M3 x-ray emission lines of 69Tm, 70Yb, 71Lu, 73Ta, 74W, 75Re, 77Ir, 81Tl, 83Bi, and 95Am. From the linewidths of the measured transitions an accurate set of M2 and M3 level widths is determined assuming for the L1 level widths the values reported by Raboud [P.-A. Raboud et al., Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.65.022512 65, 022512 (2002)]. Furthermore, the present experimental M2,3 data set is extended to 80Hg, 90Th, and 92U, using former L1M2,3 high-resolution x-ray emission spectroscopy measurements performed by our group. A detailed comparison of the M2 and M3 level widths determined in the present work with those recommended by Campbell and Papp [J. L. Campbell and T. Papp, At. Data Nucl. Data TablesADNDAT0092-640X10.1006/adnd.2000.0848 77, 1 (2001)] and other available experimental data as well as theoretical predictions is done. The observed abrupt changes of the M2,3 level widths versus atomic number Z can be explained satisfactorily by the cutoffs and onsets of the M2M4N1, respectively M3M4N3,4,5 and M3M5N2,3 Coster-Kronig transitions deduced from the semiempirical (Z+1) approximation. As a spin-off result of this study, precise L1M2 and L1M3 transition energies are obtained for the investigated elements. A very good agreement with transition energies calculated within the many-body perturbation theory is found.

  9. Muscarinic agonists and phorbol esters increase tyrosine phosphorylation of a 40-kilodalton protein in hippocampal slices

    International Nuclear Information System (INIS)

    Stratton, K.R.; Worley, P.F.; Huganir, R.L.; Baraban, J.M.

    1989-01-01

    The authors have used the hippocampal slice preparation to investigate the regulation of protein tyrosine phosphorylation in brain. After pharmacological treatment of intact slices, proteins were separated by electrophoresis, and levels of protein tyrosine phosphorylation were assessed by immunoblotting with specific anti-phosphotyrosine antibodies. Phorbol esters, activators of the serine- and threonine-phosphorylating enzyme protein kinase C, selectively increase tyrosine phosphorylation of a soluble protein with an apparent molecular mass of approximately 40 kilodaltons. Muscarinic agonists such as carbachol and oxotremorine M that strongly activate the inositol phospholipid system also increase tyrosine phosphorylation of this protein. Neurotransmitter activation of the inositol phospholipid system and protein kinase C appears to trigger a cascade leading to increased tyrosine phosphorylation

  10. Dopamine induces growth inhibition and vascular normalization through reprogramming M2-polarized macrophages in rat C6 glioma

    International Nuclear Information System (INIS)

    Qin, Tian; Wang, Chenlong; Chen, Xuewei; Duan, Chenfan; Zhang, Xiaoyan; Zhang, Jing; Chai, Hongyan; Tang, Tian; Chen, Honglei; Yue, Jiang; Li, Ying; Yang, Jing

    2015-01-01

    Dopamine (DA), a monoamine catecholamine neurotransmitter with antiangiogenic activity, stabilizes tumor vessels in colon, prostate and ovarian cancers, thus increases chemotherapeutic efficacy. Here, in the rat C6 glioma models, we investigated the vascular normalization effects of DA and its mechanisms of action. DA (25, 50 mg/kg) inhibited tumor growth, while a precursor of DA (levodopa) prolonged the survival time of rats bearing orthotopic C6 glioma. DA improved tumor perfusion, with significant effects from day 3, and a higher level at days 5 to 7. In addition, DA decreased microvessel density and hypoxia-inducible factor-1α expression in tumor tissues, while increasing the coverage of pericyte. Conversely, an antagonist of dopamine receptor 2 (DR2) (eticlopride) but not DR1 (butaclamol) abrogated DA-induced tumor regression and vascular normalization. Furthermore, DA improved the delivery and efficacy of temozolomide therapy. Importantly, DA increased representative M1 markers (iNOS, CXCL9, etc.), while decreasing M2 markers (CD206, arginase-1, etc.). Depletion of macrophages by clodronate or zoledronic acid attenuated the effects of DA. Notably, DA treatment induced M2-to-M1 polarization in RAW264.7 cells and mouse peritoneal macrophages, and enhanced the migration of pericyte-like cells (10T1/2), which was reversed by eticlopride or DR2-siRNA. Such changes were accompanied by the downregulation of VEGF/VEGFR2 signaling. In summary, DA induces growth inhibition and vascular normalization through reprogramming M2-polarized macrophages. Thus, targeting the tumor microvasculature by DA represents a promising strategy for human glioma therapy. - Highlights: • Dopamine induces tumor growth inhibition and vascular normalization in rat C6 glioma. • Dopamine switches macrophage phenotype from M2 to M1. • Dopamine-induced vascular normalization is mediated by macrophage polarization. • Dopamine is a promising agent targeting the microvasculature in tumor

  11. Dopamine induces growth inhibition and vascular normalization through reprogramming M2-polarized macrophages in rat C6 glioma

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Tian; Wang, Chenlong; Chen, Xuewei; Duan, Chenfan; Zhang, Xiaoyan [Department of Pharmacology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); Zhang, Jing [Animal Experimental Center of Wuhan University, Wuhan 430071 (China); Chai, Hongyan [Center for Gene Diagnosis, Zhongnan Hospital, Wuhan University, Wuhan 430071 (China); Tang, Tian [Department of Oncology, Renmin Hospital of Wuhan University, Wuhan 430060 (China); Chen, Honglei [Department of Pathology and Pathophysiology, School of Medicine, Wuhan University, Wuhan 430071 (China); Yue, Jiang [Department of Pharmacology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); Li, Ying, E-mail: lyying0@163.com [Department of Pharmacology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); Yang, Jing, E-mail: yangjingliu2013@163.com [Department of Pharmacology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China)

    2015-07-15

    Dopamine (DA), a monoamine catecholamine neurotransmitter with antiangiogenic activity, stabilizes tumor vessels in colon, prostate and ovarian cancers, thus increases chemotherapeutic efficacy. Here, in the rat C6 glioma models, we investigated the vascular normalization effects of DA and its mechanisms of action. DA (25, 50 mg/kg) inhibited tumor growth, while a precursor of DA (levodopa) prolonged the survival time of rats bearing orthotopic C6 glioma. DA improved tumor perfusion, with significant effects from day 3, and a higher level at days 5 to 7. In addition, DA decreased microvessel density and hypoxia-inducible factor-1α expression in tumor tissues, while increasing the coverage of pericyte. Conversely, an antagonist of dopamine receptor 2 (DR2) (eticlopride) but not DR1 (butaclamol) abrogated DA-induced tumor regression and vascular normalization. Furthermore, DA improved the delivery and efficacy of temozolomide therapy. Importantly, DA increased representative M1 markers (iNOS, CXCL9, etc.), while decreasing M2 markers (CD206, arginase-1, etc.). Depletion of macrophages by clodronate or zoledronic acid attenuated the effects of DA. Notably, DA treatment induced M2-to-M1 polarization in RAW264.7 cells and mouse peritoneal macrophages, and enhanced the migration of pericyte-like cells (10T1/2), which was reversed by eticlopride or DR2-siRNA. Such changes were accompanied by the downregulation of VEGF/VEGFR2 signaling. In summary, DA induces growth inhibition and vascular normalization through reprogramming M2-polarized macrophages. Thus, targeting the tumor microvasculature by DA represents a promising strategy for human glioma therapy. - Highlights: • Dopamine induces tumor growth inhibition and vascular normalization in rat C6 glioma. • Dopamine switches macrophage phenotype from M2 to M1. • Dopamine-induced vascular normalization is mediated by macrophage polarization. • Dopamine is a promising agent targeting the microvasculature in tumor

  12. Increased immunogenicity and protective efficacy of influenza M2e fused to a tetramerizing protein.

    Directory of Open Access Journals (Sweden)

    Anne-Marie Carola Andersson

    Full Text Available The ectodomain of the matrix 2 protein (M2e of influenza A virus represents an attractive target for developing a universal influenza A vaccine, with its sequence being highly conserved amongst human variants of this virus. With the aim of targeting conformational epitopes presumably shared by diverse influenza A viruses, a vaccine (M2e-NSP4 was constructed linking M2e (in its consensus sequence to the rotavirus fragment NSP4(98-135; due to its coiled-coil region this fragment is known to form tetramers in aqueous solution and in this manner we hoped to mimick the natural configuration of M2e as presented in membranes. M2e-NSP4 was then evaluated side-by-side with synthetic M2e peptide for its immunogenicity and protective efficacy in a murine influenza challenge model. Here we demonstrate that M2e fused to the tetramerizing protein induces an accelerated, augmented and more broadly reactive antibody response than does M2e peptide as measured in two different assays. Most importantly, vaccination with M2e-NSP4 caused a significant decrease in lung virus load early after challenge with influenza A virus and maintained its efficacy against a lethal challenge even at very low vaccine doses. Based on the results presented in this study M2e-NSP4 merits further investigation as a candidate for or as a component of a universal influenza A vaccine.

  13. Comparison of the butyrate effects on neurotransmitter receptors in neurohybrids NG108-15 and NCB-20 cells

    International Nuclear Information System (INIS)

    Zhu, X.Z.; Chuang, D.M.

    1987-01-01

    The authors previous study demonstrated that long term treatment of NCB-20 cells with sodium butyrate resulted in a marked increase in the density of delta-opioid receptors with a much lesser effect on muscarinic cholinergic and no effect on alpha 2 -adrenergic receptors. In the present study the authors investigated the effect of sodium butyrate on these three types of receptors in NG108-15 cells whose neuroblastoma parent is the same as that of NCB-20 cells. Long term treatment of NG108-15 cells with sodium butyrate (0.5 mM) induced a 2-fold increase in the density of the specific binding of 3 H-clonidine. A comparable increase in the number of binding sites was detected when 3 H-yohimbine was used as the receptor ligand. The butyrate-induced increase in the alpha 2 -adrenergic receptor binding could be totally abolished by treatment with a protein synthesis inhibitor, cycloheximide, suggesting that synthesis of receptor protein is involved. The same butyrate treatment had no significant effect on opioid and muscarinic cholinergic receptor bindings. Thus, butyrate effects on the expression of these three types of receptors in NG108-15 and NCB-20 cells are dramatically different. These data suggest that induction by butyrate of neurotransmitter receptors requires concerted action of genetic factors of both parents of the neurohybrids. 22 references, 2 figures, 2 tables

  14. Distributed Energy-Efficient Topology Control Algorithm in Home M2M Networks

    OpenAIRE

    Lee, Chao-Yang; Yang, Chu-Sing

    2012-01-01

    Because machine-to-machine (M2M) technology enables machines to communicate with each other without human intervention, it could play a big role in sensor network systems. Through wireless sensor network (WSN) gateways, various information can be collected by sensors for M2M systems. For home M2M networks, this study proposes a distributed energy-efficient topology control algorithm for both topology construction and topology maintenance. Topology control is an effective method of enhancing e...

  15. Reliable Reporting for Massive M2M Communications with Periodic Resource Pooling

    DEFF Research Database (Denmark)

    Madueño, Germán Corrales; Stefanovic, Cedomir; Popovski, Petar

    2014-01-01

    This letter considers a wireless M2M communication scenario with a massive number of M2M devices. Each device needs to send its reports within a given deadline and with certain reliability, e.g., 99.99%. A pool of resources available to all M2M devices is periodically available for transmission...... to guarantee the desired reliability of the report delivery within the deadline. The fact that the pool of resources is used by a massive number of devices allows to base the dimensioning on the central limit theorem. The results are interpreted in the context of LTE, but they are applicable to any M2M...

  16. A search for presynaptic inhibitory histamine receptors in guinea-pig tissues: Further H3 receptors but no evidence for H4 receptors.

    Science.gov (United States)

    Petri, Doris; Schlicker, Eberhard

    2016-07-01

    The histamine H4 receptor is coupled to Gi/o proteins and expressed on inflammatory cells and lymphoid tissues; it was suggested that this receptor also occurs in the brain or on peripheral neurones. Since many Gi/o protein-coupled receptors, including the H3 receptor, serve as presynaptic inhibitory receptors, we studied whether the sympathetic neurones supplying four peripheral tissues and the cholinergic neurones in the hippocampus from the guinea-pig are equipped with release-modulating H4 and H3 receptors. For this purpose, we preincubated tissue pieces from the aorta, atrium, renal cortex and vas deferens with (3)H-noradrenaline and hippocampal slices with (3)H-choline and determined the electrically evoked tritium overflow. The stimulation-evoked overflow in the five superfused tissues was inhibited by the muscarinic receptor agonist oxotremorine, which served as a positive control, but not affected by the H4 receptor agonist 4-methylhistamine. The H3 receptor agonist R-α-methylhistamine inhibited noradrenaline release in the peripheral tissues without affecting acetylcholine release in the hippocampal slices. Thioperamide shifted the concentration-response curve of histamine in the aorta and the renal cortex to the right, yielding apparent pA2 values of 8.0 and 8.1, respectively, which are close to its affinity at other H3 receptors but higher by one log unit than its pKi at the H4 receptor of the guinea-pig. In conclusion, histamine H4 receptors could not be identified in five experimental models of the guinea-pig that are suited for the detection of presynaptic inhibitory receptors whereas H3 receptors could be shown in the peripheral tissues but not in the hippocampus. This article is part of the Special Issue entitled 'Histamine Receptors'. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Shc adaptor proteins are key transducers of mitogenic signaling mediated by the G protein-coupled thrombin receptor

    DEFF Research Database (Denmark)

    Chen, Y; Grall, D; Salcini, A E

    1996-01-01

    The serine protease thrombin activates G protein signaling systems that lead to Ras activation and, in certain cells, proliferation. Whereas the steps leading to Ras activation by G protein-coupled receptors are not well defined, the mechanisms of Ras activation by receptor tyrosine kinases have......-insensitive proteins appear to mediate this effect, since (i) pertussis toxin pre-treatment of cells does not blunt the action of thrombin and (ii) Shc phosphorylation on tyrosine can be stimulated by the muscarinic m1 receptor. Shc phosphorylation does not appear to involve protein kinase C, since the addition of 4...

  18. Brain cortex muscarinic transmission is impaired in young adult transgenic Appswe/Ps1de9 female mice

    Czech Academy of Sciences Publication Activity Database

    Machová, Eva; Jakubík, Jan; Michal, Pavel; Oksman, M.; Iivonen, H.; Tanila, H.; Doležal, Vladimír

    2007-01-01

    Roč. 4, Suppl.1 (2007), s. 281-281 ISSN 1660-2854. [International conference Alzheimer ´s diseases/Parkinson´s diseases /8./. 14.03.2007-18.03.2007, Salzburg] R&D Projects: GA AV ČR(CZ) IAA5011206; GA MŠk(CZ) LC554 Institutional research plan: CEZ:AV0Z50110509 Keywords : cpr1 * brain cortex * muscarinic transmission * Alzheimer ´s disease Subject RIV: FH - Neurology

  19. Properties of M1-M2-Si-Al-O-N glasses (M1 = La or Nd, M2 = Y or Er)

    Energy Technology Data Exchange (ETDEWEB)

    Pomeroy, M.J.; Nestor, E.; Hampshire, S. [Limerick Univ. (Ireland). Materials and Surface Science Inst.; Ramesh, R. [Littelfuse Ireland, Dundalk, Co. Louth (Ireland)

    2002-07-01

    Mixed lanthanide cation oxynitride glasses have been prepared in the M1 - M2 - Si-Al-O-N systems where M1 = La or Nd and M2 = Y or Er. The densities ({rho}), Young's moduli (E), microhardnesses (H{sub v}), glass transition temperatures (T{sub g}), dilatometric softening temperatures (T{sub dil}) and coefficients of thermal expansion (CTE) of 13 glasses were determined. The molar volume values (MV) calculated from density data, E, H{sub v}, T{sub g}, T{sub dil} and CTE values were all found to vary linearly with the effective cation field strength arising from the M1 and M2 modifier cations. Least squares intercept and slope values are presented which correlate each property to effective cation field strength together with error values which arise from glass and specimen preparation and measurement inconsistencies. These linear correlations clearly indicate that the overall glass structure remains the same for each of the thirteen glasses with only the modifier cation(s) having any influence. This influence appears to be a cross-linking effect, the strength of which increases as the effective cation field strength of the M1, M2 modifiers increases. (orig.)

  20. Models for financial crisis detection in Indonesia based on M1, M2 per foreign exchange reverse, and M2 multiplier indicators

    Science.gov (United States)

    Sugiyanto; Zukhronah, Etik; Pratiwi, Esteti Sophia

    2017-12-01

    Indonesia has been hit by financial crisis in the middle of 1997. The financial crisis that has occurred gives a severe impact to the economy of Indonesia resulting the needs for a detection system of financial crisis. Crisis can be detected based on several indicators such as M1, M2 per foreign exchange reserves, and M2 multiplier. These three indicators can affect the exchange rate stability and may further affect the financial stability so that it can be one of the causes of the financial crisis. This research aims to determine the appropriate model that can detect the financial crisis in Indonesia. Markov switching is an alternative model that can be approach and used often for detecting financial crisis. We can determine the combination of volatility and Markov switching model with AR and volatility model are determined first. The results of this research are that M1 can be modelled by SWARCH (3, 1) while M2 per foreign research exchange reserves and M2 multiplier can be modelled by SWARCH(3,2).

  1. 12 CFR Appendix M2 to Part 226 - Actual Repayment Disclosures

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Actual Repayment Disclosures M2 Appendix M2 to Part 226 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL RESERVE... nearest whole year if the estimate contains a fractional year less than 0.5, and rounded up to the nearest...

  2. Establishing a Research Center: The Minority Male Community College Collaborative (M2C3)

    Science.gov (United States)

    Wood, J. Luke; Urias, Marissa Vasquez; Harris, Frank, III

    2016-01-01

    This chapter describes the establishment of the Minority Male Community College Collaborative (M2C3), a research and practice center at San Diego State University. M2C3 partners with community colleges across the United States to enhance access, achievement, and success among men of color. This chapter begins with a description of the national…

  3. M2- and M5-branes in E11 current algebra formulation of M-theory

    Science.gov (United States)

    Shiba, Shotaro; Sugawara, Hirotaka

    2018-03-01

    Equations of motion for M2- and M5-branes are written down in the E11 current algebra formulation of M-theory. These branes correspond to currents of the second and the fifth rank antisymmetric tensors in the E11 representation, whereas the electric and magnetic fields (coupled to M2- and M5-branes) correspond to currents of the third and the sixth rank antisymmetric tensors, respectively. We show that these equations of motion have solutions in terms of the coordinates on M2- and M5-branes. We also discuss the geometric equations, and show that there are static solutions when M2- or M5-brane exists alone and also when M5-brane wraps around M2-brane. This situation is realized because our Einstein-like equation contains an extra term which can be interpreted as gravitational energy contributing to the curvature, thus avoiding the usual intersection rule.

  4. Reliable Radio Access for Massive Machine-to-Machine (M2M) Communication

    DEFF Research Database (Denmark)

    Madueño, Germán Corrales

    the service requirements can range from massive number of devices to ultra-reliable. This PhD thesis focuses on novel mechanisms to meet these requirements in a variety of wireless systems, from well-established technologies such as cellular networks, to emerging technologies like IEEE 802.11ah. Today...... an overwhelming 89% of the deployed M2M modules are GPRS-based. This motivates us to investigate the potential of GPRS as a dedicated M2M network. We show that by introducing minimal modifications to GPRS operation, a large number of devices can be reliably supported. Surprisingly, even though LTE is seen...... as the preferable solution for M2M, no mechanisms are in place to guarantee reliable M2M access. Contrary to mainstream solutions that focus on preventing overload, we introduce mechanisms to provide reliable M2M service. We also investigate what cellular networks can do about upcoming smart metering traffic...

  5. Evaluation of secure capability-based access control in the M2M local cloud platform

    DEFF Research Database (Denmark)

    Anggorojati, Bayu; Prasad, Neeli R.; Prasad, Ramjee

    2016-01-01

    delegation. Recently, the capability based access control has been considered as method to manage access in the Internet of Things (IoT) or M2M domain. In this paper, the implementation and evaluation of a proposed secure capability based access control in the M2M local cloud platform is presented......Managing access to and protecting resources is one of the important aspect in managing security, especially in a distributed computing system such as Machine-to-Machine (M2M). One such platform known as the M2M local cloud platform, referring to BETaaS architecture [1], which conceptually consists...... of multiple distributed M2M gateways, creating new challenges in the access control. Some existing access control systems lack in scalability and flexibility to manage access from users or entity that belong to different authorization domains, or fails to provide fine grained and flexible access right...

  6. Evidence That Ly6C(hi) Monocytes are Protective in Acute Ischemic Stroke by Promoting M2 Macrophage Polarization.

    Science.gov (United States)

    Chu, Hannah X; Broughton, Brad R S; Kim, Hyun Ah; Lee, Seyoung; Drummond, Grant R; Sobey, Christopher G

    2015-07-01

    Ly6C(hi) monocytes are generally thought to exert a proinflammatory role in acute tissue injury, although their impact after injuries to the central nervous system is poorly defined. CC chemokine receptor 2 is expressed on Ly6C(hi) monocytes and plays an essential role in their extravasation and transmigration into the brain after cerebral ischemia. We used a selective CC chemokine receptor 2 antagonist, INCB3344, to assess the effect of Ly6C(hi) monocytes recruited into the brain early after ischemic stroke. Male C57Bl/6J mice underwent occlusion of the middle cerebral artery for 1 hour followed by 23 hours of reperfusion. Mice were administered either vehicle (dimethyl sulfoxide/carboxymethylcellulose) or INCB3344 (10, 30 or 100 mg/kg IP) 1 hour before ischemia and at 2 and 6 hours after ischemia. At 24 hours, we assessed functional outcomes, infarct volume, and quantified the immune cells in blood and brain by flow cytometry or immunofluorescence. Gene expression of selected inflammatory markers was assessed by quantitative polymerase chain reaction. Ly6C(hi) monocytes were increased 3-fold in the blood and 10-fold in the brain after stroke, and these increases were selectively prevented by INCB3344 in a dose-dependent manner. Mice treated with INCB3344 exhibited markedly worse functional outcomes and larger infarct volumes, in association with reduced M2 polarization and increased peroxynitrite production in macrophages, compared with vehicle-treated mice. Our data suggest that Ly6C(hi) monocytes exert an acute protective effect after ischemic stroke to limit brain injury and functional deficit that involves promotion of M2 macrophage polarization. © 2015 American Heart Association, Inc.

  7. Insulin receptors

    International Nuclear Information System (INIS)

    Kahn, C.R.; Harrison, L.C.

    1988-01-01

    This book contains the proceedings on insulin receptors. Part A: Methods for the study of structure and function. Topics covered include: Method for purification and labeling of insulin receptors, the insulin receptor kinase, and insulin receptors on special tissues

  8. Pharmacological receptors of nematoda as target points for action of antiparasitic drugs

    Directory of Open Access Journals (Sweden)

    Trailović Saša M.

    2010-01-01

    Full Text Available Cholinergic receptors of parasitic nematodes are one of the most important possible sites of action of antiparasitic drugs. This paper presents some of our own results of electrophysiological and pharamcological examinations of nicotinic and muscarinic receptors of nematodes, as well as data from literature on a new class of anthelmintics that act precisely on cholinergic receptors. The nicotinic acetylcholine receptor (nAChR is located on somatic muscle cells of nematodes and it is responsible for the coordination of parasite movement. Cholinomimetic anthelmintics act on this receptor, as well as acetylcholine, an endogenic neurotransmitter, but they are not sensitive to enzyme acetylcholineesterase which dissolves acetylcholine. As opposed to the nicotinic receptor of vertebra, whose structure has been examined thoroughly, the stoichiometry of the nicotinic receptor of nematodes is not completely known. However, on the grounds of knowledge acquired so far, a model has been constructed recently of the potential composition of a type of nematodes nicotinic receptor, as the site of action of anthelmintics. Based on earlier investigations, it is supposed that a conventional muscarinic receptor exists in nematodes as well, so that it can also be a new pharamocological target for the development of antinematode drugs. The latest class of synthesized anthelmintics, named aminoacetonitriles (AAD, act via the nicotinic receptor. Monepantel is the first drug from the AAD group as a most significant candidate for registration in veterinary medicine. Even though several groups of cholinomimetic anthelmintics (imiodazothiazoles, tetrahydropyrimidines, organophosphat anthelmintics have been in use in veterinary practice for many years now, it is evident that cholinergic receptors of nematodes still present an attractive place in the examinations and development of new antinematode drugs. .

  9. Respiratory syncytial virus M2-1 protein induces the activation of nuclear factor kappa B

    Energy Technology Data Exchange (ETDEWEB)

    Reimers, Kerstin [Klinik fuer Plastische, Hand-und Wiederherstellungschirurgie, Podbielskistrasse 380, D-30659 Hannover (Germany); Buchholz, Katja [Institut fuer Medizinische Mikrobiologie, Otto-von-Guericke-Universitaet Magdeburg, Leipzigerstrasse 44, D-39120 Magdeburg (Germany); Werchau, Hermann [Institut fuer Medizinische Mikrobiologie, Otto-von-Guericke-Universitaet Magdeburg, Leipzigerstrasse 44, D-39120 Magdeburg (Germany)

    2005-01-20

    Respiratory syncytial virus (RSV) induces the production of a number of cytokines and chemokines by activation of nuclear factor kappa B (NF-{kappa}B). The activation of NF-{kappa}B has been shown to depend on viral replication in the infected cells. In this study, we demonstrate that expression of RSV M2-1 protein, a transcriptional processivity and anti-termination factor, is sufficient to activate NF-{kappa}B in A549 cells. Electromobility shift assays show increased NF-{kappa}B complexes in the nuclei of M2-1-expressing cells. M2-1 protein is found in nuclei of M2-1-expressing cells and in RSV-infected cells. Co-immunoprecipitations of nuclear extracts of M2-1-expressing cells and of RSV-infected cells revealed an association of M2-1 with Rel A protein. Furthermore, the activation of NF-{kappa}B depends on the C-terminus of the RSV M2-1 protein, as shown by NF-{kappa}B-induced gene expression of a reporter gene construct.

  10. All Trans Retinoic Acid, Transforming Growth Factor β and Prostaglandin E2 in Mouse Plasma Synergize with Basophil-Secreted Interleukin-4 to M2 Polarize Murine Macrophages.

    Directory of Open Access Journals (Sweden)

    Victor W Ho

    Full Text Available In previous studies we found that macrophages (MФs from SH2-containing inositol-5'-phosphatase (SHIP deficient mice are M2 polarized while their wild type (WT counterparts are M1 polarized and that this difference in MФ phenotype can be recapitulated during in vitro derivation from bone marrow if mouse plasma (MP, but not fetal calf serum, is added to standard M-CSF-containing cultures. In the current study we investigated the mechanism by which MP skews SHIP-/- but not +/+ MФs to an M2 phenotype. Our results suggest that SHIP-/- basophils constitutively secrete higher levels of IL-4 than SHIP+/+ basophils and this higher level of IL-4 is sufficient to skew both SHIP+/+ and SHIP-/- MФs to an M2 phenotype, but only when MP is present to increase the sensitivity of the MФs to this level of IL-4. MP increases the IL-4 sensitivity of both SHIP+/+ and -/- MФs not by increasing cell surface IL-4 or CD36 receptor levels, but by triggering the activation of Erk and Akt and the production of ROS, all of which play a critical role in sensitizing MФs to IL-4-induced M2 skewing. Studies to identify the factor(s in MP responsible for promoting IL-4-induced M2 skewing suggests that all-trans retinoic acid (ATRA, TGFβ and prostaglandin E2 (PGE2 all play a role. Taken together, these results indicate that basophil-secreted IL-4 plays an essential role in M2 skewing and that ATRA, TGFβ and PGE2 within MP collaborate to dramatically promote M2 skewing by acting directly on MФs to increase their sensitivity to IL-4.

  11. A humanized anti-M2 scFv shows protective in vitro activity against influenza

    Energy Technology Data Exchange (ETDEWEB)

    Bradbury, Andrew M [Los Alamos National Laboratory; Velappan, Nileena [Los Alamos National Laboratory; Schmidt, Jurgen G [Los Alamos National Laboratory

    2008-01-01

    M2 is one of the most conserved influenza proteins, and has been widely prospected as a potential universal vaccine target, with protection predominantly mediated by antibodies. In this paper we describe the creation of a humanized single chain Fv from 14C2, a potent monoclonal antibody against M2. We show that the humanized scFv demonstrates similar activity to the parental mAb: it is able to recognize M2 in its native context on cell surfaces and is able to show protective in vitro activity against influenza, and so represents a potential lead antibody candidate for universal prophylactic or therapeutic intervention in influenza.

  12. Phosphorylation of Human Metapneumovirus M2-1 Protein Upregulates Viral Replication and Pathogenesis.

    Science.gov (United States)

    Cai, Hui; Zhang, Yu; Lu, Mijia; Liang, Xueya; Jennings, Ryan; Niewiesk, Stefan; Li, Jianrong

    2016-08-15

    Human metapneumovirus (hMPV) is a major causative agent of upper- and lower-respiratory-tract infections in infants, the elderly, and immunocompromised individuals worldwide. Like all pneumoviruses, hMPV encodes the zinc binding protein M2-1, which plays important regulatory roles in RNA synthesis. The M2-1 protein is phosphorylated, but the specific role(s) of the phosphorylation in viral replication and pathogenesis remains unknown. In this study, we found that hMPV M2-1 is phosphorylated at amino acid residues S57 and S60. Subsequent mutagenesis found that phosphorylation is not essential for zinc binding activity and oligomerization, whereas inhibition of zinc binding activity abolished the phosphorylation and oligomerization of the M2-1 protein. Using a reverse genetics system, recombinant hMPVs (rhMPVs) lacking either one or both phosphorylation sites in the M