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Sample records for selective mu-opioid agonist

  1. Regulation of ventilation and oxygen consumption by delta- and mu-opioid receptor agonists.

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    Schaeffer, J I; Haddad, G G

    1985-09-01

    To study the effect of endorphins on metabolic rate and on the relationship between O2 consumption (VO2) and ventilation, we administered enkephalin analogues (relatively selective delta-receptor agonists) and a morphiceptin analogue (a highly selective mu-receptor agonist) intracisternally in nine unanesthetized chronically instrumented adult dogs. Both delta- and mu-agonists decreased VO2 by 40-60%. delta-Agonists induced a dose-dependent decrease in mean instantaneous minute ventilation (VT/TT) associated with periodic breathing. The decrease in VT/TT started and resolved prior to the decrease and returned to baseline of VO2, respectively. In contrast, the mu-agonists induced an increase in VT/TT associated with rapid shallow breathing. Arterial PCO2 increased and arterial PO2 decreased after both delta- and mu-agonists. Low doses of intracisternal naloxone (0.002-2.0 micrograms/kg) reversed the opioid effect on VT/TT but not on VO2; higher doses of naloxone (5-25 micrograms/kg) reversed both. Naloxone administered alone had no effect on VT/TT or VO2. These data suggest that 1) both delta- and mu-agonists induce alveolar hypoventilation despite a decrease in VO2, 2) this hypoventilation results from a decrease in VT/TT after delta-agonists but an increase in dead space ventilation after mu-agonists, and 3) endorphins do not modulate ventilation and metabolic rate tonically, but we speculate that they may do so in response to stressful stimulation.

  2. Wheel running reduces high-fat diet intake, preference and mu-opioid agonist stimulated intake

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    Liang, Nu-Chu; Bello, Nicholas T.; Moran, Timothy H.

    2015-01-01

    The ranges of mechanisms by which exercise affects energy balance remain unclear. One potential mechanism may be that exercise reduces intake and preference for highly palatable, energy dense fatty foods. The current study used a rodent wheel running model to determine whether and how physical activity affects HF diet intake/preference and reward signaling. Experiment 1 examined whether wheel running affected the ability of intracerebroventricular (ICV) µ opioid receptor agonist D-Ala2, NMe-Phe4, Glyol5-enkephalin (DAMGO) to increase HF diet intake. Experiment 2 examined the effects of wheel running on the intake of and preference for a previously preferred HF diet. We also assessed the effects of wheel running and diet choice on mesolimbic dopaminergic and opioidergic gene expression. Experiment 1 revealed that wheel running decreased the ability of ICV DAMGO administration to stimulate HF diet intake. Experiment 2 showed that wheel running suppressed weight gain and reduced intake and preference for a previously preferred HF diet. Furthermore, the mesolimbic gene expression profile of wheel running rats was different from that of their sedentary paired-fed controls but similar to that of sedentary rats with large HF diet consumption. These data suggest that alterations in preference for palatable, energy dense foods play a role in the effects of exercise on energy homeostasis. The gene expression results also suggest that the hedonic effects of exercise may substitute for food reward to limit food intake and suppress weight gain. PMID:25668514

  3. General, kappa, delta and mu opioid receptor antagonists mediate feeding elicited by the GABA-B agonist baclofen in the ventral tegmental area and nucleus accumbens shell in rats: reciprocal and regional interactions.

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    Miner, Patricia; Shimonova, Lyudmila; Khaimov, Arthur; Borukhova, Yaffa; Ilyayeva, Ester; Ranaldi, Robert; Bodnar, Richard J

    2012-03-14

    Food intake is significantly increased following administration of agonists of GABA and opioid receptors into the nucleus accumbens shell (NACs) and ventral tegmental area (VTA). GABA-A or GABA-B receptor antagonist pretreatment within the VTA or NACs differentially affects mu-opioid agonist-induced feeding elicited from the same site. Correspondingly, general or selective opioid receptor antagonist pretreatment within the VTA or NACs differentially affects GABA agonist-induced feeding elicited from the same site. Regional interactions have been evaluated in feeding studies by administering antagonists in one site prior to agonist administration in a second site. Thus, opioid antagonist-opioid agonist and GABA antagonist-GABA agonist feeding interactions have been identified between the VTA and NACs. However, pretreatment with GABA-A or GABA-B receptor antagonists in the VTA failed to affect mu opioid agonist-induced feeding elicited from the NACs, and correspondingly, these antagonists administered in the NACs failed to affect mu opioid-induced feeding elicited from the VTA. To evaluate whether regional and reciprocal VTA and NACs feeding interactions occur for opioid receptor modulation of GABA agonist-mediated feeding, the present study examined whether feeding elicited by the GABA-B agonist, baclofen microinjected into the NACs was dose-dependently blocked by pretreatment with general (naltrexone: NTX), mu (beta-funaltrexamine: BFNA), kappa (nor-binaltorphamine: NBNI) or delta (naltrindole: NTI) opioid antagonists in the VTA, and correspondingly, whether VTA baclofen-induced feeding was dose-dependently blocked by NACs pretreatment with NTX, BFNA, NBNI or NTI in rats. Bilateral pairs of cannulae aimed at the VTA and NACs were stereotaxically implanted in rats, and their food intakes were assessed following vehicle and baclofen (200 ng) in each site. Baclofen produced similar magnitudes of increased food intake following VTA and NACs treatment. Baclofen

  4. Adrenergic Agonists Bind to Adrenergic-Receptor-Like Regions of the Mu Opioid Receptor, Enhancing Morphine and Methionine-Enkephalin Binding: A New Approach to "Biased Opioids"?

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    Root-Bernstein, Robert; Turke, Miah; Subhramanyam, Udaya K Tiruttani; Churchill, Beth; Labahn, Joerg

    2018-01-17

    Extensive evidence demonstrates functional interactions between the adrenergic and opioid systems in a diversity of tissues and organs. While some effects are due to receptor and second messenger cross-talk, recent research has revealed an extracellular, allosteric opioid binding site on adrenergic receptors that enhances adrenergic activity and its duration. The present research addresses whether opioid receptors may have an equivalent extracellular, allosteric adrenergic binding site that has similar enhancing effects on opioid binding. Comparison of adrenergic and opioid receptor sequences revealed that these receptors share very significant regions of similarity, particularly in some of the extracellular and transmembrane regions associated with adrenergic binding in the adrenergic receptors. Five of these shared regions from the mu opioid receptor (muOPR) were synthesized as peptides and tested for binding to adrenergic, opioid and control compounds using ultraviolet spectroscopy. Adrenergic compounds bound to several of these muOPR peptides with low micromolar affinity while acetylcholine, histamine and various adrenergic antagonists did not. Similar studies were then conducted with purified, intact muOPR with similar results. Combinations of epinephrine with methionine enkephalin or morphine increased the binding of both by about half a log unit. These results suggest that muOPR may be allosterically enhanced by adrenergic agonists.

  5. ERK1/2 activation in rat ventral tegmental area by the mu-opioid agonist fentanyl : An in vitro study

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    Lesscher, HMB; Burbach, JPH; Van Ree, JM; Gerrits, MAFM

    2003-01-01

    Opioid receptors in the ventral tegmental area, predominantly the mu-opioid receptors, have been suggested to modulate reinforcement sensitivity for both opioid and non-opioid drugs of abuse. The present study was conducted to study signal transduction proteins, which may mediate the functioning of

  6. Antinociceptive action of DBO 17 and DBO 11 in mice: two 3,8 diazabicyclo (3.2.1.) octane derivates with selective mu opioid receptor affinity.

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    Fadda, P; Barlocco, D; Tronci, S; Cignarella, G; Fratta, W

    1997-11-01

    Two 3,8 diazabicyclo (3.2.1.) octane derivates, namely DBO 17 and DBO 11, were studied for the opioid-like activity. In the rat brain membrane preparation binding studies, DBO 17 and DBO 11 showed a high affinity and selectivity for the mu opioid receptor (Ki's: 5.1 and 25 nM, respectively). DBO 17 and DBO 11 inhibited the nociceptive response in the hot-plate test of mice with ED50 values of 0.16 mg/kg and 0.44 mg/kg, respectively. The antinociceptive action of both DBO 17 and DBO 11 was blocked by naloxone. Tolerance to the antinociceptive action of DBO 17 and DBO 11 was present after 13 and 7 days of repeated treatment, respectively. Both DBO 17 and DBO 11 were ineffective in morphine-tolerant mice and vice versa. Chronic treatments (three times daily for seven consecutive days) of DBO 17 and DBO 11 induced a naloxone-precipitated withdrawal syndrome in DBO 17 treated mice similar to that in morphine treated mice, whereas in DBO 11 treated mice abstinence signs were virtually absent. These results indicate an interesting pharmacological profile that suggests these compounds as possible new candidates for the clinical treatment of pain.

  7. Mu opioid receptor binding sites in human brain

    International Nuclear Information System (INIS)

    Pilapil, C.; Welner, S.; Magnan, J.; Zamir, N.; Quirion, R.

    1986-01-01

    Our experiments focused on the examination of the distribution of mu opioid receptor binding sites in normal human brain using the highly selective ligand [ 3 H]DAGO, in both membrane binding assay and in vitro receptor autoradiography. Mu opioid binding sites are very discretely distributed in human brain with high densities of sites found in the posterior amygdala, caudate, putamen, hypothalamus and certain cortical areas. Moreover the autoradiographic distribution of [ 3 H]DAGO binding sites clearly reveals the discrete lamination (layers I and III-IV) of mu sites in cortical areas

  8. Adrenergic Agonists Bind to Adrenergic-Receptor-Like Regions of the Mu Opioid Receptor, Enhancing Morphine and Methionine-Enkephalin Binding: A New Approach to “Biased Opioids”?

    Science.gov (United States)

    Turke, Miah; Subhramanyam, Udaya K. Tiruttani; Churchill, Beth; Labahn, Joerg

    2018-01-01

    Extensive evidence demonstrates functional interactions between the adrenergic and opioid systems in a diversity of tissues and organs. While some effects are due to receptor and second messenger cross-talk, recent research has revealed an extracellular, allosteric opioid binding site on adrenergic receptors that enhances adrenergic activity and its duration. The present research addresses whether opioid receptors may have an equivalent extracellular, allosteric adrenergic binding site that has similar enhancing effects on opioid binding. Comparison of adrenergic and opioid receptor sequences revealed that these receptors share very significant regions of similarity, particularly in some of the extracellular and transmembrane regions associated with adrenergic binding in the adrenergic receptors. Five of these shared regions from the mu opioid receptor (muOPR) were synthesized as peptides and tested for binding to adrenergic, opioid and control compounds using ultraviolet spectroscopy. Adrenergic compounds bound to several of these muOPR peptides with low micromolar affinity while acetylcholine, histamine and various adrenergic antagonists did not. Similar studies were then conducted with purified, intact muOPR with similar results. Combinations of epinephrine with methionine enkephalin or morphine increased the binding of both by about half a log unit. These results suggest that muOPR may be allosterically enhanced by adrenergic agonists. PMID:29342106

  9. Adrenergic Agonists Bind to Adrenergic-Receptor-Like Regions of the Mu Opioid Receptor, Enhancing Morphine and Methionine-Enkephalin Binding: A New Approach to “Biased Opioids”?

    Directory of Open Access Journals (Sweden)

    Robert Root-Bernstein

    2018-01-01

    Full Text Available Extensive evidence demonstrates functional interactions between the adrenergic and opioid systems in a diversity of tissues and organs. While some effects are due to receptor and second messenger cross-talk, recent research has revealed an extracellular, allosteric opioid binding site on adrenergic receptors that enhances adrenergic activity and its duration. The present research addresses whether opioid receptors may have an equivalent extracellular, allosteric adrenergic binding site that has similar enhancing effects on opioid binding. Comparison of adrenergic and opioid receptor sequences revealed that these receptors share very significant regions of similarity, particularly in some of the extracellular and transmembrane regions associated with adrenergic binding in the adrenergic receptors. Five of these shared regions from the mu opioid receptor (muOPR were synthesized as peptides and tested for binding to adrenergic, opioid and control compounds using ultraviolet spectroscopy. Adrenergic compounds bound to several of these muOPR peptides with low micromolar affinity while acetylcholine, histamine and various adrenergic antagonists did not. Similar studies were then conducted with purified, intact muOPR with similar results. Combinations of epinephrine with methionine enkephalin or morphine increased the binding of both by about half a log unit. These results suggest that muOPR may be allosterically enhanced by adrenergic agonists.

  10. 14-O-Methylmorphine: A Novel Selective Mu-Opioid Receptor Agonist with High Efficacy and Affinity.

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    Zádor, Ferenc; Balogh, Mihály; Váradi, András; Zádori, Zoltán S; Király, Kornél; Szűcs, Edina; Varga, Bence; Lázár, Bernadette; Hosztafi, Sándor; Riba, Pál; Benyhe, Sándor; Fürst, Susanna; Al-Khrasani, Mahmoud

    2017-11-05

    14-O-methyl (14-O-Me) group in morphine-6-O-sulfate (M6SU) or oxymorphone has been reported to be essential for enhanced affinity, potency and antinociceptive effect of these opioids. Herein we report on the pharmacological properties (potency, affinity and efficacy) of the new compound, 14-O-methylmorphine (14-O-MeM) in in vitro. Additionally, we also investigated the antinociceptive effect of the novel compound, as well as its inhibitory action on gastrointestinal transit in in vivo. The potency and efficacy of test compound were measured by [ 35 S]GTPγS binding, isolated mouse vas deferens (MVD) and rat vas deferens (RVD) assays. The affinity of 14-O-MeM for opioid receptors was assessed by radioligand binding and MVD assays. The antinociceptive and gastrointestinal effects of the novel compound were evaluated in the rat tail-flick test and charcoal meal test, respectively. Morphine, DAMGO, Ile 5,6 deltorphin II, deltorphin II and U-69593 were used as reference compounds. 14-O-MeM showed higher efficacy (E max ) and potency (EC 50 ) than morphine in MVD, RVD or [ 35 S]GTPγS binding. In addition, 14-O-MeM compared to morphine showed higher affinity for μ-opioid receptor (MOR). In vivo, in rat tail-flick test 14-O-MeM proved to be stronger antinociceptive agent than morphine after peripheral or central administration. Additionally, both compounds inhibited the gastrointestinal peristalsis. However, when the antinociceptive and antitransit doses for each test compound are compared, 14-O-MeM proved to have slightly more favorable pharmacological profile. Our results affirm that 14-O-MeM, an opioid of high efficacy and affinity for MOR can be considered as a novel analgesic agent of potential clinical value. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. The effect of benfotiamine on mu-opioid receptor mediated antinociception in experimental diabetes.

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    Nacitarhan, C; Minareci, E; Sadan, G

    2014-03-01

    Diabetic neuropathy is a prevalent, disabling disorder. Currently, the only treatments available to patients with diabetic neuropathy are glucose control and pain management. B vitamin present neuroprotective effects, which are suggested to be related to their analgesic action in various models of neuropathic pain. According to our literature knowledge there is no report about antinociceptive effects of thiamine as benfotiamine and opioids together in diabetic mice. The purpose of this study was to determine the effects of benfotiamine on the antinociception produced by mu-opioid receptor agonist fentanyl in diabetic mice. The effects of benfotiamine on antinociception produced by fentanyl in diabetic mice were studied in 4 groups. Antinociceptive effect was determined with tail flick, hot plate and formalin test. Our results showed that, mu-opioid agonist fentanyl in benfotiamine applied diabetic group caused more potent antinociceptive effect than in diabetic group without benfotiamine treatment. In brief benfotiamine supplement in diet did not bring out antinociceptive effect itself, but during development of STZ diabetes, benfotiamine replacement increased the antinociceptive effect of fentanyl in mice tail-flick test. This effect is probably due to the replacement of benfotiamine efficiency occurring in diabetes mellitus. Finally, we suppose that oral benfotiamine replacement therapy may be useful to ameliorate analgesic effect of mu-opioid agonists on neuropathic pain in diabetic case. © J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart · New York.

  12. Cell-Autonomous Regulation of Mu-Opioid Receptor Recycling by Substance P

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    Shanna L. Bowman

    2015-03-01

    Full Text Available How neurons coordinate and reprogram multiple neurotransmitter signals is an area of broad interest. Here, we show that substance P (SP, a neuropeptide associated with inflammatory pain, reprograms opioid receptor recycling and signaling. SP, through activation of the neurokinin 1 (NK1R receptor, increases the post-endocytic recycling of the mu-opioid receptor (MOR in trigeminal ganglion (TG neurons in an agonist-selective manner. SP-mediated protein kinase C (PKC activation is both required and sufficient for increasing recycling of exogenous and endogenous MOR in TG neurons. The target of this cross-regulation is MOR itself, given that mutation of either of two PKC phosphorylation sites on MOR abolishes the SP-induced increase in recycling and resensitization. Furthermore, SP enhances the resensitization of fentanyl-induced, but not morphine-induced, antinociception in mice. Our results define a physiological pathway that cross-regulates opioid receptor recycling via direct modification of MOR and suggest a mode of homeostatic interaction between the pain and analgesic systems.

  13. Amygdala mu-opioid receptors mediate the motivating influence of cue-triggered reward expectations.

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    Lichtenberg, Nina T; Wassum, Kate M

    2017-02-01

    Environmental reward-predictive stimuli can retrieve from memory a specific reward expectation that allows them to motivate action and guide choice. This process requires the basolateral amygdala (BLA), but little is known about the signaling systems necessary within this structure. Here we examined the role of the neuromodulatory opioid receptor system in the BLA in such cue-directed action using the outcome-specific Pavlovian-to-instrumental transfer (PIT) test in rats. Inactivation of BLA mu-, but not delta-opioid receptors was found to dose-dependently attenuate the ability of a reward-predictive cue to selectively invigorate the performance of actions directed at the same unique predicted reward (i.e. to express outcome-specific PIT). BLA mu-opioid receptor inactivation did not affect the ability of a reward itself to similarly motivate action (outcome-specific reinstatement), suggesting a more selective role for the BLA mu-opioid receptor in the motivating influence of currently unobservable rewarding events. These data reveal a new role for BLA mu-opioid receptor activation in the cued recall of precise reward memories and the use of this information to motivate specific action plans. © 2016 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  14. Dermorphin-related peptides from the skin of Phyllomedusa bicolor and their amidated analogs activate two mu opioid receptor subtypes that modulate antinociception and catalepsy in the rat.

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    Negri, L; Erspamer, G F; Severini, C; Potenza, R L; Melchiorri, P; Erspamer, V

    1992-08-01

    Three naturally occurring dermorphin-like peptides from the skin of the frog Phyllomedusa bicolor, the related carboxyl-terminal amides, and some substituted analogs were synthesized, their binding profiles to opioid receptors were determined, and their biological activities were studied in isolated organ preparations and intact animals. The opioid binding profile revealed a very high selectivity of these peptides for mu sites and suggested the existence of two receptor subtypes, of high and low affinity. The peptides tested acted as potent mu opioid agonists on isolated organ preparations. They were several times more active in inhibiting electrically evoked contractions in guinea pig ileum than in mouse vas deferens. When injected into the lateral brain ventricle or peritoneum of rats, the high-affinity-site-preferring ligand, [Lys7-NH2]dermorphin, behaved as a potent analgesic agent. By contrast, the low-affinity-site-preferring ligand, [Trp4,Asn7-NH2]dermorphin, produced a weak antinociception but an intense catalepsy.

  15. Mu Opioid Receptor Gene: New Point Mutations in Opioid Addicts

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    Amin Dinarvand

    2014-02-01

    Full Text Available Introduction: Association between single-nucleotide polymorphisms (SNPs in mu opioid receptor gene and drug addiction has been shown in various studies. Here, we have evaluated the existence of polymorphisms in exon 3 of this gene in Iranian population and investigated the possible association between these mutations and opioid addiction.  Methods: 79 opioid-dependent subjects (55 males, 24 females and 134 non-addict or control individuals (74 males, 60 females participated in the study. Genomic DNA was extracted from volunteers’ peripheral blood and exon 3 of the mu opioid receptor gene was amplified by polymerase chain reaction (PCR whose products were then sequenced.  Results: Three different heterozygote polymorphisms were observed in 3 male individuals: 759T>C and 877G>A mutations were found in 2 control volunteers and 1043G>C substitution was observed in an opioid-addicted subject. Association between genotype and opioid addiction for each mutation was not statistically significant.  Discussion: It seems that the sample size used in our study is not enough to confirm or reject any association between 759T>C, 877G>A and 1043G>C substitutions in exon 3 of the mu opioid receptor gene and opioid addiction susceptibility in Iranian population.

  16. Quantitative immunolocalization of {mu} opioid receptors: regulation by naltrexone

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    Evans, C.J.; Lam, H.; To, T.; Anton, B. [Department of Psychiatry and Biobehavioral Sciences, Neuropsychiatric Institute, University of California, Los Angeles, CA (United States); Unterwald, E.M. [Department of Psychiatry, New York University Medical Center, New York, NY (United States)

    1998-04-24

    The present study utilized a newly developed quantitative immunohistochemical assay to measure changes in {mu} opioid receptor abundance following chronic administration of the opioid receptor antagonist naltrexone. These data were compared with those obtained from {mu} receptor radioligand binding on adjacent tissue sections, in order to determine whether the characteristic antagonist-induced increase in radioligand binding is due to an increase in the total number of {mu} receptors and/or to an increase in the proportion of receptors that are in an active binding conformation in the absence of a change in the total number of receptors. Adult male Sprague-Dawley rats were administered naltrexone, 7-8 mg/kg per day, or saline continuously for seven days by osmotic minipumps, after which time their brains were processed for immunohistochemistry and receptor autoradiography on adjacent fresh frozen tissue sections. Semiquantitative immunohistochemistry was performed using a radiolabelled secondary antibody for autoradiographic determination and a set of radioactive standards. Results demonstrate an overall concordance between the distribution of {mu} opioid receptors as measured by the two different methods with a few exceptions. Following naltrexone administration, {mu} receptor immunoreactivity was significantly higher in the amygdala, thalamus, hippocampus, and interpeduncular nucleus as compared with the saline-treated control animals. [{sup 3}H]D-Ala{sup 2},N-Me-Phe{sup 4},Gly-ol{sup 5}-enkephalin binding to {mu} opioid receptors was significantly higher in the globus pallidus, amygdala, thalamus, hypothalamus, hippocampus, substantia nigra, ventral tegmental area, central gray, and interpeduncular nucleus of the naltrexone-treated rats.These findings indicate that in some brain regions chronic naltrexone exposure increases the total number of {mu} opioid receptors, while in other regions there is an increase in the percent of active receptors without an

  17. /sup 3/H)-(H-D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2) ((/sup 3/H)CTOP), a potent and highly selective peptide for mu opioid receptors in rat brain

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    Hawkins, K.N.; Knapp, R.J.; Lui, G.K.; Gulya, K.; Kazmierski, W.; Wan, Y.P.; Pelton, J.T.; Hruby, V.J.; Yamamura, H.I.

    1989-01-01

    The cyclic, conformationally restricted octapeptide (3H)-(H-D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2) ((3H)CTOP) was synthesized and its binding to mu opioid receptors was characterized in rat brain membrane preparations. Association rates (k+1) of 1.25 x 10(8) M-1 min-1 and 2.49 x 10(8) M-1 min-1 at 25 and 37 degrees C, respectively, were obtained, whereas dissociation rates (k-1) at the same temperatures were 1.93 x 10(-2) min-1 and 1.03 x 10(-1) min-1 at 25 and 37 degrees C, respectively. Saturation isotherms of (3H)CTOP binding to rat brain membranes gave apparent Kd values of 0.16 and 0.41 nM at 25 and 37 degrees C, respectively. Maximal number of binding sites in rat brain membranes were found to be 94 and 81 fmol/mg of protein at 25 and 37 degrees C, respectively. (3H)CTOP binding over a concentration range of 0.1 to 10 nM was best fit by a one site model consistent with binding to a single site. The general effect of different metal ions and guanyl-5'-yl-imidodiphosphate on (3H)CTOP binding was to reduce its affinity. High concentrations (100 mM) of sodium also produced a reduction of the apparent mu receptor density. Utilizing the delta opioid receptor specific peptide (3H)-(D-Pen2,D-Pen5)enkephalin, CTOP appeared to be about 2000-fold more specific for mu vs. delta opioid receptor than naloxone. Specific (3H)CTOP binding was inhibited by a large number of opioid or opiate ligands.

  18. Affinity of the enantiomers of. alpha. - and. beta. -cyclazocine for binding to the phencyclidine and. mu. opioid receptors

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    Todd, S.L.; Balster, R.L.; Martin, B.R. (Virginia Commonwealth Univ., Richmond (USA))

    1990-01-01

    The enantiomers in the {alpha} and {beta} series of cyclazocine were evaluated for their ability to bind to phencyclidine (PCP) and {mu}-opioid receptors in order to determine their receptor selectivity. The affinity of (-)-{beta}-cyclazocine for the PCP receptor was 1.5 greater than PCP itself. In contrast, (-)-{alpha}-cyclazocine, (+)-{alpha}-cyclazocine, and (+)-{beta}-cyclazocine were 3-, 5- and 138-fold less potent than PCP, respectively. Scatchard analysis of saturable binding of ({sup 3}H)Tyr-D-Ala-Gly-N-MePhe-Gly-ol (DAMGO) also exhibited a homogeneous population of binding sites with an apparent K{sub D} of 1.9 nM and an estimated Bmax of 117 pM. (3H)Tyr-D-Ala-Gly-N-MePhe-Gly-ol (DAMGO) binding studies revealed that (-)-{alpha}-cyclazocine (K{sub D} = 0.48 nM) was 31-, 1020- and 12,600-fold more potent than (-)-{beta}-cyclazocine, (+)-{alpha}-cyclazocine and (+)-{beta}-cyclazocine, respectively, for binding to the {mu}-opioid receptor. These data show that, although (-)-{beta}-cyclazocine is a potent PCP receptor ligand consistent with its potent PCP-like discriminative stimulus effects, it shows little selectivity for PCP receptor since it also potently displaces {mu}-opioid binding. However, these cyclazocine isomers, due to their extraordinary degree of stereoselectivity, may be useful in characterizing the structural requirements for benzomorphans having activity at the PCP receptor.

  19. Mu-opioid receptor knockout mice show diminished food-anticipatory activity

    NARCIS (Netherlands)

    Kas, Martien J H; van den Bos, Ruud; Baars, Annemarie M; Lubbers, Marianne; Lesscher, Heidi M B; Hillebrand, Jacquelien J G; Schuller, Alwin G; Pintar, John E; Spruijt, Berry M

    We have previously suggested that during or prior to activation of anticipatory behaviour to a coming reward, mu-opioid receptors are activated. To test this hypothesis schedule induced food-anticipatory activity in mu-opioid receptor knockout mice was measured using running wheels. We hypothesized

  20. Chronic ethanol consumption in rats produces opioid antinociceptive tolerance through inhibition of mu opioid receptor endocytosis.

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    Li He

    Full Text Available It is well known that the mu-opioid receptor (MOR plays an important role in the rewarding properties of ethanol. However, it is less clear how chronic ethanol consumption affects MOR signaling. Here, we demonstrate that rats with prolonged voluntary ethanol consumption develop antinociceptive tolerance to opioids. Signaling through the MOR is controlled at many levels, including via the process of endocytosis. Importantly, agonists at the MOR that promote receptor endocytosis, such as the endogenous peptides enkephalin and β-endorphin, show a reduced propensity to promote antinociceptive tolerance than do agonists, like morphine, which do not promote receptor endocytosis. These observations led us to examine whether chronic ethanol consumption produced opioid tolerance by interfering with MOR endocytosis. Indeed, here we show that chronic ethanol consumption inhibits the endocytosis of MOR in response to opioid peptide. This loss of endocytosis was accompanied by a dramatic decrease in G protein coupled receptor kinase 2 (GRK2 protein levels after chronic drinking, suggesting that loss of this component of the trafficking machinery could be a mechanism by which endocytosis is lost. We also found that MOR coupling to G-protein was decreased in ethanol-drinking rats, providing a functional explanation for loss of opioid antinociception. Together, these results suggest that chronic ethanol drinking alters the ability of MOR to endocytose in response to opioid peptides, and consequently, promotes tolerance to the effects of opioids.

  1. Desensitization and Tolerance of Mu Opioid Receptors on Pontine Kölliker-Fuse Neurons.

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    Levitt, Erica S; Williams, John T

    2018-01-01

    Acute desensitization of mu opioid receptors is thought to be an initial step in the development of tolerance to opioids. Given the resistance of the respiratory system to develop tolerance, desensitization of neurons in the Kölliker-Fuse (KF), a key area in the respiratory circuit, was examined. The activation of G protein-coupled inwardly rectifying potassium current was measured using whole-cell voltage-clamp recordings from KF and locus coeruleus (LC) neurons contained in acute rat brain slices. A saturating concentration of the opioid agonist [Met 5 ]-enkephalin (ME) caused significantly less desensitization in KF neurons compared with LC neurons. In contrast to LC, desensitization in KF neurons was not enhanced by activation of protein kinase C or in slices from morphine-treated rats. Cellular tolerance to ME and morphine was also lacking in KF neurons from morphine-treated rats. The lack of cellular tolerance in KF neurons correlates with the relative lack of tolerance to the respiratory depressant effect of opioids. Copyright © 2018 by The American Society for Pharmacology and Experimental Therapeutics.

  2. Preparation and biodistribution in mice of ( sup 11 C)carfentanil; A radiopharmaceutical for studying brain. mu. -opioid receptors by positron emission tomography

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    Saji, Hideo; Tsutsumi, Daisuke; Iida, Yasuhiko; Yokoyama, Akira (Kyoto Univ. (Japan). Faculty of Pharmaceutical Science); Magata, Yasuhiro; Konishi, Junji

    1992-02-01

    A potent {mu}-opioid agonist, ({sup 11}C)carfentanil, was prepared by the methylation of carfentanil carboxylic acid with ({sup 11}C)methyl iodide in order to study brain {mu}-opioid receptors by positron emission tomography. Synthesis (including purification) was completed within 25 min and the radiochemical yield was approximately 40%. The radiochemical purity of the product was more than 99% and its specific activity was 3.7-7.4 GBq/{mu}mol. Biodistribution studies performed in mice after intravenous injection showed a high brain uptake and rapid blood clearance, so a high brain/blood ratio of 1.5-1.8 was found from 5 to 30 min. Regional cerebral distribution studies in the mouse showed a significantly higher uptake of ({sup 11}C)carfentanil by the thalamus and striatum than by the cerebellum, with the radioactivity in the striatum disappearing more rapidly than that in the thalamus. Treatment with naloxone significantly reduced the uptake of ({sup 11}C)carfentanil by the thalamus and striatum. These results indicate that ({sup 11}C)carfentanil binds specifically to brain {mu}-opioid receptors. (author).

  3. Identification in the mu-opioid receptor of cysteine residues responsible for inactivation of ligand binding by thiol alkylating and reducing agents.

    Science.gov (United States)

    Gaibelet, G; Capeyrou, R; Dietrich, G; Emorine, L J

    1997-05-19

    Inactivation by thiol reducing and alkylating agents of ligand binding to the human mu-opioid receptor was examined. Dithiothreitol reduced the number of [3H]diprenorphine binding sites. Replacement by seryl residues of either C142 or C219 in extracellular loops 1 and 2 of the mu receptor resulted in a complete loss of opioid binding. A disulfide bound linking C142 to C219 may thus be essential to maintain a functional conformation of the receptor. We also demonstrated that inactivation of ligand binding upon alkylation by N-ethylmaleimide occurred at two sites. Alteration of the more sensitive (IC50 = 20 microM) did not modify antagonists binding but decreased agonist affinity almost 10-fold. Modification of the less reactive site (IC50 = 2 mM) decreased the number of both agonist and antagonist binding sites. The alkylation site of higher sensitivity to N-ethylmaleimide was shown by mutagenesis experiments to be constituted of both C81 and C332 in transmembrane domains 1 and 7 of the mu-opioid receptor.

  4. Mu-opioid receptor inhibition decreases voluntary wheel running in a dopamine-dependent manner in rats bred for high voluntary running.

    Science.gov (United States)

    Ruegsegger, Gregory N; Brown, Jacob D; Kovarik, M Cathleen; Miller, Dennis K; Booth, Frank W

    2016-12-17

    The mesolimbic dopamine and opioid systems are postulated to influence the central control of physical activity motivation. We utilized selectively bred rats for high (HVR) or low (LVR) voluntary running behavior to examine (1) inherent differences in mu-opioid receptor (Oprm1) expression and function in the nucleus accumbens (NAc), (2) if dopamine-related mRNAs, wheel-running, and food intake are differently influenced by intraperitoneal (i.p.) naltrexone injection in HVR and LVR rats, and (3) if dopamine is required for naltrexone-induced changes in running and feeding behavior in HVR rats. Oprm1 mRNA and protein expression were greater in the NAc of HVR rats, and application of the Oprm1 agonist [D-Ala2, N-MePhe4, Gly-ol]-enkephalin (DAMGO) to dissociated NAc neurons produced greater depolarizing responses in neurons from HVR versus LVR rats. Naltrexone injection dose-dependently decreased wheel running and food intake in HVR, but not LVR, rats. Naltrexone (20mg/kg) decreased tyrosine hydroxylase mRNA in the ventral tegmental area and Fos and Drd5 mRNA in NAc shell of HVR, but not LVR, rats. Additionally, lesion of dopaminergic neurons in the NAc with 6-hydroxydopamine (6-OHDA) ablated the decrease in running, but not food intake, in HVR rats following i.p. naltrexone administration. Collectively, these data suggest the higher levels of running observed in HVR rats, compared to LVR rats, are mediated, in part, by increased mesolimbic opioidergic signaling that requires downstream dopaminergic activity to influence voluntary running, but not food intake. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  5. Human Mu Opioid Receptor (OPRM1A118G) polymorphism is associated with brain mu- opioid receptor binding potential in smokers

    Energy Technology Data Exchange (ETDEWEB)

    Ray, R.; Logan, J.; Ray, R.; Ruparel, K.; Newberg, A.; Wileyto, E.P.; Loughead, J.W.; Divgi, C.; Blendy, J.A.; Logan, J.; Zubieta, J.-K.; Lerman, C.

    2011-04-15

    Evidence points to the endogenous opioid system, and the mu-opioid receptor (MOR) in particular, in mediating the rewarding effects of drugs of abuse, including nicotine. A single nucleotide polymorphism (SNP) in the human MOR gene (OPRM1 A118G) has been shown to alter receptor protein level in preclinical models and smoking behavior in humans. To clarify the underlying mechanisms for these associations, we conducted an in vivo investigation of the effects of OPRM1 A118G genotype on MOR binding potential (BP{sub ND} or receptor availability). Twenty-two smokers prescreened for genotype (12 A/A, 10 */G) completed two [{sup 11}C] carfentanil positron emission tomography (PET) imaging sessions following overnight abstinence and exposure to a nicotine-containing cigarette and a denicotinized cigarette. Independent of session, smokers homozygous for the wild-type OPRM1 A allele exhibited significantly higher levels of MOR BP{sub ND} than smokers carrying the G allele in bilateral amygdala, left thalamus, and left anterior cingulate cortex. Among G allele carriers, the extent of subjective reward difference (denicotinized versus nicotine cigarette) was associated significantly with MOR BP{sub ND} difference in right amygdala, caudate, anterior cingulate cortex, and thalamus. Future translational investigations can elucidate the role of MORs in nicotine addiction, which may lead to development of novel therapeutics.

  6. Human Mu Opioid Receptor (OPRM1A118G) polymorphism is associated with brain mu- opioid receptor binding potential in smokers

    International Nuclear Information System (INIS)

    Ray, R.; Logan, J.; Ruparel, K.; Newberg, A.; Wileyto, E.P.; Loughead, J.W.; Divgi, C.; Blendy, J.A.; Logan, J.; Zubieta, J.-K.; Lerman, C.

    2011-01-01

    Evidence points to the endogenous opioid system, and the mu-opioid receptor (MOR) in particular, in mediating the rewarding effects of drugs of abuse, including nicotine. A single nucleotide polymorphism (SNP) in the human MOR gene (OPRM1 A118G) has been shown to alter receptor protein level in preclinical models and smoking behavior in humans. To clarify the underlying mechanisms for these associations, we conducted an in vivo investigation of the effects of OPRM1 A118G genotype on MOR binding potential (BP ND or receptor availability). Twenty-two smokers prescreened for genotype (12 A/A, 10 */G) completed two [ 11 C] carfentanil positron emission tomography (PET) imaging sessions following overnight abstinence and exposure to a nicotine-containing cigarette and a denicotinized cigarette. Independent of session, smokers homozygous for the wild-type OPRM1 A allele exhibited significantly higher levels of MOR BP ND than smokers carrying the G allele in bilateral amygdala, left thalamus, and left anterior cingulate cortex. Among G allele carriers, the extent of subjective reward difference (denicotinized versus nicotine cigarette) was associated significantly with MOR BP ND difference in right amygdala, caudate, anterior cingulate cortex, and thalamus. Future translational investigations can elucidate the role of MORs in nicotine addiction, which may lead to development of novel therapeutics.

  7. A Potential Role for mu-Opioids in Mediating the Positive Effects of Gratitude.

    Science.gov (United States)

    Henning, Max; Fox, Glenn R; Kaplan, Jonas; Damasio, Hanna; Damasio, Antonio

    2017-01-01

    Gratitude is a complex emotional feeling associated with universally desirable positive effects in personal, social, and physiological domains. Why or how gratitude achieves these functional outcomes is not clear. Toward the goal of identifying its' underlying physiological processes, we recently investigated the neural correlates of gratitude. In our study, participants were exposed to gratitude-inducing stimuli, and rated each according to how much gratitude it provoked. As expected, self-reported gratitude intensity correlated with brain activity in distinct regions of the medial pre-frontal cortex associated with social reward and moral cognition. Here we draw from our data and existing literature to offer a theoretical foundation for the physiological correlates of gratitude. We propose that mu-opioid signaling (1) accompanies the mental experience of gratitude, and (2) may account for the positive effects of gratitude on social relationships, subjective wellbeing, and physiological health.

  8. Crystal structure of the[mu]-opioid receptor bound to a morphinan antagonist

    Energy Technology Data Exchange (ETDEWEB)

    Manglik, Aashish; Kruse, Andrew C.; Kobilka, Tong Sun; Thian, Foon Sun; Mathiesen, Jesper M.; Sunahara, Roger K.; Pardo, Leonardo; Weis, William I.; Kobilka, Brian K.; Granier, Sébastien (Michigan-Med); (Stanford-MED); (UAB, Spain)

    2012-06-27

    Opium is one of the world's oldest drugs, and its derivatives morphine and codeine are among the most used clinical drugs to relieve severe pain. These prototypical opioids produce analgesia as well as many undesirable side effects (sedation, apnoea and dependence) by binding to and activating the G-protein-coupled {mu}-opioid receptor ({mu}-OR) in the central nervous system. Here we describe the 2.8 {angstrom} crystal structure of the mouse {mu}-OR in complex with an irreversible morphinan antagonist. Compared to the buried binding pocket observed in most G-protein-coupled receptors published so far, the morphinan ligand binds deeply within a large solvent-exposed pocket. Of particular interest, the {mu}-OR crystallizes as a two-fold symmetrical dimer through a four-helix bundle motif formed by transmembrane segments 5 and 6. These high-resolution insights into opioid receptor structure will enable the application of structure-based approaches to develop better drugs for the management of pain and addiction.

  9. Expression and purification of functional human mu opioid receptor from E.coli.

    Directory of Open Access Journals (Sweden)

    Yanbin Ma

    Full Text Available N-terminally his-tagged human mu opioid receptor, a G protein-coupled receptor was produced in E.coli employing synthetic codon-usage optimized constructs. The receptor was expressed in inclusion bodies and membrane-inserted in different E.coli strains. By optimizing the expression conditions the expression level for the membrane-integrated receptor was raised to 0.3-0.5 mg per liter of culture. Milligram quantities of receptor could be enriched by affinity chromatography from IPTG induced cultures grown at 18°C. By size exclusion chromatography the protein fraction with the fraction of alpha-helical secondary structure expected for a 7-TM receptor was isolated, by CD-spectroscopy an alpha-helical content of ca. 45% was found for protein solubilised in the detergent Fos-12. Receptor in Fos-12 micelles was shown to bind endomorphin-1 with a K(D of 61 nM. A final yield of 0.17 mg functional protein per liter of culture was obtained.

  10. Changes in mu-opioid receptor expression and function in the mesolimbic system after long-term access to a palatable diet.

    Science.gov (United States)

    Pitman, Kimberley A; Borgland, Stephanie L

    2015-10-01

    The incidence of obesity in both adults and children is rising. In order to develop effective treatments for obesity, it is important to understand how diet can induce changes in the brain that could promote excessive intake of high-calorie foods and alter the efficacy of therapeutic targets. The mu-opioid receptor is involved in regulating the motivation for and hedonic reaction to food. Here, we review the literature examining changes in the expression and function of mu-opioid receptors in the mesolimbic system of rodents after extended access to a high-fat diet. We also review how maternal diet can induce long-term changes in the expression or function of mu-opioid receptors in the mesolimbic system of offspring. Understanding the behavioural and therapeutic implications of these changes requires further study. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Cell-Autonomous Regulation of Mu-Opioid Receptor Recycling by Substance P

    Science.gov (United States)

    Bowman, Shanna L.; Soohoo, Amanda L.; Shiwarski, Daniel J.; Schulz, Stefan; Pradhan, Amynah A.; Puthenveedu, Manojkumar A.

    2015-01-01

    SUMMARY How neurons coordinate and reprogram multiple neurotransmitter signals is an area of broad interest. Here, we show that substance P (SP), a neuropep-tide associated with inflammatory pain, reprograms opioid receptor recycling and signaling. SP, through activation of the neurokinin 1 (NK1R) receptor, increases the post-endocytic recycling of the muopioid receptor (MOR) in trigeminal ganglion (TG) neurons in an agonist-selective manner. SP-mediated protein kinase C (PKC) activation is both required and sufficient for increasing recycling of exogenous and endogenous MOR in TG neurons. The target of this cross-regulation is MOR itself, given that mutation of either of two PKC phosphorylation sites on MOR abolishes the SP-induced increase in recycling and resensitization. Furthermore, SP enhances the resensitization of fentanyl-induced, but not morphine-induced, antinociception in mice. Our results define a physiological pathway that cross-regulates opioid receptor recycling via direct modification of MOR and suggest a mode of homeo-static interaction between the pain and analgesic systems. PMID:25801029

  12. Binge eating disorder and morbid obesity are associated with lowered mu-opioid receptor availability in the brain.

    Science.gov (United States)

    Joutsa, Juho; Karlsson, Henry K; Majuri, Joonas; Nuutila, Pirjo; Helin, Semi; Kaasinen, Valtteri; Nummenmaa, Lauri

    2018-03-09

    Both morbid obesity and binge eating disorder (BED) have previously been linked with aberrant brain opioid function. Behaviorally these two conditions are however different suggesting also differences in neurotransmitter function. Here we directly compared mu-opioid receptor (MOR) availability between morbidly obese and BED subjects. Seven BED and nineteen morbidly obese (non-BED) patients, and thirty matched control subjects underwent positron emission tomography (PET) with MOR-specific ligand [ 11 C]carfentanil. Both subjects with morbid obesity and BED had widespread reduction in [ 11 C]carfentanil binding compared to control subjects. However, there was no significant difference in brain MOR binding between subjects with morbid obesity and BED. Thus, our results indicate that there is common brain opioid abnormality in behaviorally different eating disorders involving obesity. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Mu opioid receptor availability in people with psychiatric disorders who died by suicide: a case control study

    Directory of Open Access Journals (Sweden)

    Scarr Elizabeth

    2012-08-01

    Full Text Available Abstract Background Mu opioid receptors have previously been shown to be altered in people with affective disorders who died as a result of suicide. We wished to determine whether these changes were more widespread and independent of psychiatric diagnoses. Methods Mu receptor levels were determined using [3 H]DAMGO binding in BA24 from 51 control subjects; 38 people with schizophrenia (12 suicides; 20 people with major depressive disorder (15 suicides; 13 people with bipolar disorder (5 suicides and 9 people who had no history of psychiatric disorders but who died as a result of suicide. Mu receptor levels were further determined in BA9 and caudate-putamen from 38 people with schizophrenia and 20 control subjects using [3 H]DAMGO binding and, in all three regions, using Western blots. Data was analysed using one-way ANOVAs with Bonferroni’s Multiple Comparison Test or, where data either didn’t approximate to a binomial distribution or the sample size was too small to determine distribution, a Kruskal-Wallis test with Dunn’s Multiple Comparison Test. Results [3 H]DAMGO binding density was lower in people who had died as a result of suicide (p3 H]DAMGO binding densities, but not mu protein levels, were significantly decreased in BA9 from people with schizophrenia who died as a result of suicide (p Conclusions Overall these data suggest that mu opioid receptor availability is decreased in the brains of people with schizophrenia who died as a result of suicide, which would be consistent with increased levels of endogenous ligands occupying these receptors.

  14. Subtype selective kainic acid receptor agonists

    DEFF Research Database (Denmark)

    Bunch, Lennart; Krogsgaard-Larsen, Povl

    2009-01-01

    (S)-Glutamic acid (Glu) is the major excitatory neurotransmitter in the mammalian central nervous system, activating the plethora of glutamate receptors (GluRs). In broad lines, the GluRs are divided into two major classes: the ionotropic Glu receptors (iGluRs) and the metabotropic Glu receptors (m......GluRs). Within the iGluRs, five subtypes (KA1, KA2, iGluR5-7) show high affinity and express full agonist activity upon binding of the naturally occurring amino acid kainic acid (KA). Thus these receptors have been named the KA receptors. This review describes all-to our knowledge-published KA receptor agonists...

  15. Analgesic tone conferred by constitutively active mu opioid receptors in mice lacking β-arrestin 2

    Directory of Open Access Journals (Sweden)

    Hales Tim G

    2011-04-01

    Full Text Available Abstract Hedonic reward, dependence and addiction are unwanted effects of opioid analgesics, linked to the phasic cycle of μ opioid receptor activation, tolerance and withdrawal. In vitro studies of recombinant G protein coupled receptors (GPCRs over expressed in cell lines reveal an alternative tonic signaling mechanism that is independent of agonist. Such studies demonstrate that constitutive GPCR signaling can be inhibited by inverse agonists but not by neutral antagonists. However, ligand-independent activity has been difficult to examine in vivo, at the systems level, due to relatively low levels of constitutive activity of most GPCRs including μ receptors, often necessitating mutagenesis or pharmacological manipulation to enhance basal signaling. We previously demonstrated that the absence of β-arrestin 2 (β-arr2 augments the constitutive coupling of μ receptors to voltage-activated Ca2+ channels in primary afferent dorsal root ganglion neurons from β-arr2-/- mice. We used this in vitro approach to characterize neutral competitive antagonists and inverse agonists of the constitutively active wild type μ receptors in neurons. We administered these agents to β-arr2-/- mice to explore the role of constitutive μ receptor activity in nociception and hedonic tone. This study demonstrates that the induction of constitutive μ receptor activity in vivo in β-arr2-/- mice prolongs tail withdrawal from noxious heat, a phenomenon that was reversed by inverse agonists, but not by antagonists that lack negative efficacy. By contrast, the aversive effects of inverse agonists were similar in β-arr2-/- and β-arr2+/+ mice, suggesting that hedonic tone was unaffected.

  16. Acute stimulation of brain mu opioid receptors inhibits glucose-stimulated insulin secretion via sympathetic innervation.

    Science.gov (United States)

    Tudurí, Eva; Beiroa, Daniel; Stegbauer, Johannes; Fernø, Johan; López, Miguel; Diéguez, Carlos; Nogueiras, Rubén

    2016-11-01

    Pancreatic insulin-secreting β-cells express opioid receptors, whose activation by opioid peptides modulates hormone secretion. Opioid receptors are also expressed in multiple brain regions including the hypothalamus, where they play a role in feeding behavior and energy homeostasis, but their potential role in central regulation of glucose metabolism is unknown. Here, we investigate whether central opioid receptors participate in the regulation of insulin secretion and glucose homeostasis in vivo. C57BL/6J mice were acutely treated by intracerebroventricular (i.c.v.) injection with specific agonists for the three main opioid receptors, kappa (KOR), delta (DOR) and mu (MOR) opioid receptors: activation of KOR and DOR did not alter glucose tolerance, whereas activation of brain MOR with the specific agonist DAMGO blunted glucose-stimulated insulin secretion (GSIS), reduced insulin sensitivity, increased the expression of gluconeogenic genes in the liver and, consequently, impaired glucose tolerance. Pharmacological blockade of α2A-adrenergic receptors prevented DAMGO-induced glucose intolerance and gluconeogenesis. Accordingly, DAMGO failed to inhibit GSIS and to impair glucose tolerance in α2A-adrenoceptor knockout mice, indicating that the effects of central MOR activation on β-cells are mediated via sympathetic innervation. Our results show for the first time a new role of the central opioid system, specifically the MOR, in the regulation of insulin secretion and glucose metabolism. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Anti-nociceptive effect of patchouli alcohol: Involving attenuation of cyclooxygenase 2 and modulation of mu-opioid receptor.

    Science.gov (United States)

    Yu, Xuan; Wang, Xin-Pei; Yan, Xiao-Jin; Jiang, Jing-Fei; Lei, Fan; Xing, Dong-Ming; Guo, Yue-Ying; Du, Li-Jun

    2017-08-09

    To explore the anti-nociceptive effect of patchouli alcohol (PA), the essential oil isolated from Pogostemon cablin (Blanco) Bent, and determine the mechanism in molecular levels. The acetic acid-induced writhing test and formalin-induced plantar injection test in mice were employed to confifirm the effect in vivo. Intracellular calcium ion was imaged to verify PA on mu-opioid receptor (MOR). Cyclooxygenase 2 (COX2) and MOR of mouse brain were expressed for determination of PA's target. Cellular experiments were carried out to find out COX2 and MOR expression induced by PA. PA significantly reduced latency period of visceral pain and writhing induced by acetic acid saline solution (Peffect of PA. A decrease in the intracellular calcium level (Peffect. PA showed the characters of enhancing the MOR expression and reducing the intracellular calcium ion similar to opioid effect. Both COX2 and MOR are involved in the mechanism of PA's anti-nociceptive effect, and the up-regulation of the receptor expression and the inhibition of intracellular calcium are a new perspective to PA's effect on MOR.

  18. Mu opioid receptor availability in people with psychiatric disorders who died by suicide: a case control study.

    Science.gov (United States)

    Scarr, Elizabeth; Money, Tammie Terese; Pavey, Geoffrey; Neo, Jaclyn; Dean, Brian

    2012-08-28

    Mu opioid receptors have previously been shown to be altered in people with affective disorders who died as a result of suicide. We wished to determine whether these changes were more widespread and independent of psychiatric diagnoses. Mu receptor levels were determined using [3 H]DAMGO binding in BA24 from 51 control subjects; 38 people with schizophrenia (12 suicides); 20 people with major depressive disorder (15 suicides); 13 people with bipolar disorder (5 suicides) and 9 people who had no history of psychiatric disorders but who died as a result of suicide. Mu receptor levels were further determined in BA9 and caudate-putamen from 38 people with schizophrenia and 20 control subjects using [3 H]DAMGO binding and, in all three regions, using Western blots. Data was analysed using one-way ANOVAs with Bonferroni's Multiple Comparison Test or, where data either didn't approximate to a binomial distribution or the sample size was too small to determine distribution, a Kruskal-Wallis test with Dunn's Multiple Comparison Test. [3 H]DAMGO binding density was lower in people who had died as a result of suicide (pendogenous ligands occupying these receptors.

  19. The influences of reproductive status and acute stress on the levels of phosphorylated mu opioid receptor immunoreactivity in rat hippocampus

    Directory of Open Access Journals (Sweden)

    Keith L. Gonzales

    2011-08-01

    Full Text Available Opioids play a critical role in hippocampally dependent behavior and plasticity. In the hippocampal formation, mu opioid receptors (MOR are prominent in parvalbumin (PARV containing interneurons. Previously we found that gonadal hormones modulate the trafficking of MORs in PARV interneurons. Although sex differences in response to stress are well documented, the point at which opioids, sex and stress interact to influence hippocampal function remains elusive. Thus, we used quantitative immunocytochemistry in combination with light and electron microscopy for the phosphorylated MOR at the SER375 carboxy-terminal residue (pMOR in male and female rats to assess these interactions. In both sexes, pMOR-immunoreactivity (ir was prominent in axons and terminals and in a few neuronal somata and dendrites, some of which contained PARV in the mossy fiber pathway region of the dentate gyrus (DG hilus and CA3 stratum lucidum. In unstressed rats, the levels of pMOR-ir in the DG or CA3 were not affected by sex or estrous cycle stage. However, immediately following 30 minutes of acute immobilization stress (AIS, males had higher levels of pMOR-ir whereas females at proestrus and estrus (high estrogen stages had lower levels of pMOR-ir within the DG. In contrast, the number and types of neuronal profiles with pMOR-ir were not altered by AIS in either males or proestrus females. These data demonstrate that although gonadal steroids do not affect pMOR levels at resting conditions, they are differentially activated both pre- and post-synaptic MORs following stress. These interactions may contribute to the reported sex differences in hippocampally dependent behaviors in stressed animals.

  20. Discovery of a potent and selective GPR120 agonist

    DEFF Research Database (Denmark)

    Shimpukade, Bharat; Hudson, Brian D; Hovgaard, Christine Kiel

    2012-01-01

    GPR120 is a receptor of unsaturated long-chain fatty acids reported to mediate GLP-1 secretion, insulin sensitization, anti-inflammatory, and anti-obesity effects and is therefore emerging as a new potential target for treatment of type 2 diabetes and metabolic diseases. Further investigation...... is however hindered by the lack of suitable receptor modulators. Screening of FFA1 ligands provided a lead with moderate activity on GPR120 and moderate selectivity over FFA1. Optimization led to the discovery of the first potent and selective GPR120 agonist....

  1. Internalisation of the mu-opioid receptor by endomorphin-1 and leu-enkephalin is dependant on aromatic amino acid residues.

    Science.gov (United States)

    Del Borgo, Mark P; Blanchfield, Joanne T; Toth, Istvan

    2008-04-15

    The opioid receptor system in the central nervous system controls a number of physiological processes, most notably pain. However, most opioids currently available have a variety of side-effects as well as exhibiting tolerance. Tolerance is most likely to be a complex phenomenon, however, the role of receptor internalisation is thought to play a crucial role. In this study, we examined the role of aromaticity in ligand-mediated receptor internalisation of the mu-opioid receptor (MOPR). These studies show that the amount of receptor internalisation may be dependant on the amphiphilicity of the ligand. Specifically, deletion of the C-terminus aromatic residues of endomorphin 1, particularly tryptophan reduces receptor-mediated internalisation whilst the addition of tryptophan within the enkephalin sequence increases receptor internalisation and decreases tolerance.

  2. Prolonging survival of corneal transplantation by selective sphingosine-1-phosphate receptor 1 agonist.

    Directory of Open Access Journals (Sweden)

    Min Gao

    Full Text Available Corneal transplantation is the most used therapy for eye disorders. Although the cornea is somewhat an immune privileged organ, immune rejection is still the major problem that reduces the success rate. Therefore, effective chemical drugs that regulate immunoreactions are needed to improve the outcome of corneal transplantations. Here, a sphingosine-1-phosphate receptor 1 (S1P1 selective agonist was systematically evaluated in mouse allogeneic corneal transplantation and compared with the commonly used immunosuppressive agents. Compared with CsA and the non-selective sphingosine 1-phosphate (S1P receptor agonist FTY720, the S1P1 selective agonist can prolong the survival corneal transplantation for more than 30 days with a low immune response. More importantly, the optimal dose of the S1P1 selective agonist was much less than non-selective S1P receptor agonist FTY720, which would reduce the dose-dependent toxicity in drug application. Then we analyzed the mechanisms of the selected S1P1 selective agonist on the immunosuppression. The results shown that the S1P1 selective agonist could regulate the distribution of the immune cells with less CD4+ T cells and enhanced Treg cells in the allograft, moreover the expression of anti-inflammatory cytokines TGF-β1 and IL-10 unregulated which can reduce the immunoreactions. These findings suggest that S1P1 selective agonist may be a more appropriate immunosuppressive compound to effectively prolong mouse allogeneic corneal grafts survival.

  3. Constitutive cannabinoid 1 and mu opioid receptor activity in the ventral tegmental area: occurrence, function and therapeutic relevance

    NARCIS (Netherlands)

    Meye, F.J.

    2012-01-01

    Cannabinoid 1 receptors (CB1Rs) play a crucial role in regulating systems dedicated to processing rewards and emotions. It was known that in artificial systems, CB1Rs can exhibit activity that is independent of the typical agonist-driven form. However, it remained largely unclear whether this

  4. The Effect of the [mu]-Opioid Receptor Antagonist Naloxone on Extinction of Conditioned Fear in the Developing Rat

    Science.gov (United States)

    Kim, Jee Hyun; Richardson, Rick

    2009-01-01

    Several recent studies report that neurotransmitters that are critically involved in extinction in adult rats are not important for extinction in young rats. Specifically, pretest injection of the [gamma]-aminobutryic acid (GABA) receptor inverse agonist FG7142 has no effect on extinction in postnatal day (P)17 rats, although it reverses…

  5. The Mu opioid receptor promotes opioid and growth factor-induced proliferation, migration and Epithelial Mesenchymal Transition (EMT in human lung cancer.

    Directory of Open Access Journals (Sweden)

    Frances E Lennon

    Full Text Available Recent epidemiologic studies implying differences in cancer recurrence based on anesthetic regimens raise the possibility that the mu opioid receptor (MOR can influence cancer progression. Based on our previous observations that overexpression of MOR in human non-small cell lung cancer (NSCLC cells increased tumor growth and metastasis, this study examined whether MOR regulates growth factor receptor signaling and epithelial mesenchymal transition (EMT in human NSCLC cells. We utilized specific siRNA, shRNA, chemical inhibitors and overexpression vectors in human H358 NSCLC cells that were either untreated or treated with various concentrations of DAMGO, morphine, fentanyl, EGF or IGF. Cell function assays, immunoblot and immunoprecipitation assays were then performed. Our results indicate MOR regulates opioid and growth factor-induced EGF receptor signaling (Src, Gab-1, PI3K, Akt and STAT3 activation which is crucial for consequent human NSCLC cell proliferation and migration. In addition, human NSCLC cells treated with opioids, growth factors or MOR overexpression exhibited an increase in snail, slug and vimentin and decrease ZO-1 and claudin-1 protein levels, results consistent with an EMT phenotype. Further, these effects were reversed with silencing (shRNA or chemical inhibition of MOR, Src, Gab-1, PI3K, Akt and STAT3 (p<0.05. Our data suggest a possible direct effect of MOR on opioid and growth factor-signaling and consequent proliferation, migration and EMT transition during lung cancer progression. Such an effect provides a plausible explanation for the epidemiologic findings.

  6. Sex and age-dependent effects of a maternal junk food diet on the mu-opioid receptor in rat offspring.

    Science.gov (United States)

    Gugusheff, Jessica R; Bae, Sung Eun; Rao, Alexandra; Clarke, Iain J; Poston, Lucilla; Taylor, Paul D; Coen, Clive W; Muhlhausler, Beverly S

    2016-03-15

    Perinatal junk food exposure increases the preference for palatable diets in juvenile and adult rat offspring. Previous studies have implicated reduced sensitivity of the opioid pathway in the programming of food preferences; however it is not known when during development these changes in opioid signalling first emerge. This study aimed to determine the impact of a maternal junk food (JF) diet on mu-opioid receptor (MuR) expression and ligand binding in two key regions of the reward pathway, the nucleus accumbens (NAc) and the ventral tegmental area (VTA) in rats during the early suckling (postnatal day (PND) 1 and 7) and late suckling/early post-weaning (PND 21 and 28) periods. Female rats were fed either a JF or a control diet for two weeks prior to mating and throughout pregnancy and lactation. MuR expression in the VTA was significantly reduced in female JF offspring on PND 21 and 28 (by 32% and 57% respectively, Pjunk food exposure on MuR mRNA expression or binding were detected at these time points in male offspring. These findings provide evidence that the opioid signalling system is a target of developmental programming by the end of the third postnatal week in females, but not in males. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. β3-adrenoceptor mediates β3-selective agonist-induced effects on ...

    African Journals Online (AJOL)

    β3-adrenoceptor mediates β3-selective agonist-induced effects on energy expenditure, insulin secrtion and food ... Journal of the Ghana Science Association ... is usually associated with obesity, also involves defective energy expenditure, ...

  8. Discovery of novel acetanilide derivatives as potent and selective beta3-adrenergic receptor agonists.

    Science.gov (United States)

    Maruyama, Tatsuya; Onda, Kenichi; Hayakawa, Masahiko; Matsui, Tetsuo; Takasu, Toshiyuki; Ohta, Mitsuaki

    2009-06-01

    In the search for potent and selective human beta3-adrenergic receptor (AR) agonists as potential drugs for the treatment of obesity and noninsulin-dependent (type II) diabetes, a novel series of acetanilide-based analogues were prepared and their biological activities were evaluated at the human beta3-, beta2-, and beta1-ARs. Among these compounds, 2-pyridylacetanilide (2f), pyrimidin-2-ylacetanilide (2u), and pyrazin-2-ylacetanilide (2v) derivatives exhibited potent agonistic activity at the beta3-AR with functional selectivity over the beta1- and beta2-ARs. In particular, compound 2u was found to be the most potent and selective beta3-AR agonist with an EC(50) value of 0.11 microM and no agonistic activity for either the beta1- or beta2-AR. In addition, 2f, 2u, and 2v showed significant hypoglycemic activity in a rodent diabetic model.

  9. Optimisation of in silico derived 2-aminobenzimidazole hits as unprecedented selective kappa opioid receptor agonists

    DEFF Research Database (Denmark)

    Sasmal, Pradip K; Krishna, C Vamsee; Sudheerkumar Adabala, S

    2015-01-01

    Kappa opioid receptor (KOR) is an important mediator of pain signaling and it is targeted for the treatment of various pains. Pharmacophore based mining of databases led to the identification of 2-aminobenzimidazole derivative as KOR agonists with selectivity over the other opioid receptors DOR a...... of novel benzimidazole derivatives as KOR agonists are described. The in vivo proof of principle for anti-nociceptive effect with a lead compound from this series is exemplified....

  10. Acute inflammation induces segmental, bilateral, supraspinally mediated opioid release in the rat spinal cord, as measured by mu-opioid receptor internalization.

    Science.gov (United States)

    Chen, W; Marvizón, J C G

    2009-06-16

    The objective of this study was to measure opioid release in the spinal cord during acute and long-term inflammation using mu-opioid receptor (MOR) internalization. In particular, we determined whether opioid release occurs in the segments receiving the noxious signals or in the entire spinal cord, and whether it involves supraspinal signals. Internalization of neurokinin 1 receptors (NK1Rs) was measured to track the intensity of the noxious stimulus. Rats received peptidase inhibitors intrathecally to protect opioids from degradation. Acute inflammation of the hind paw with formalin induced moderate MOR internalization in the L5 segment bilaterally, whereas NK1R internalization occurred only ipsilaterally. MOR internalization was restricted to the lumbar spinal cord, regardless of whether the peptidase inhibitors were injected in a lumbar or thoracic site. Formalin-induced MOR internalization was substantially reduced by isoflurane anesthesia. It was also markedly reduced by a lidocaine block of the cervical-thoracic spinal cord (which did not affect the evoked NK1R internalization) indicating that spinal opioid release is mediated supraspinally. In the absence of peptidase inhibitors, formalin and hind paw clamp induced a small amount of MOR internalization, which was significantly higher than in controls. To study spinal opioid release during chronic inflammation, we injected complete Freund's adjuvant (CFA) in the hind paw and peptidase inhibitors intrathecally. Two days later, no MOR or NK1R internalization was detected. Furthermore, CFA inflammation decreased MOR internalization induced by clamping the inflamed hind paw. These results show that acute inflammation, but not chronic inflammation, induces segmental opioid release in the spinal cord that involves supraspinal signals.

  11. Increased serum IL-6 level time-dependently regulates hyperalgesia and spinal mu opioid receptor expression during CFA-induced arthritis.

    Science.gov (United States)

    Tekieh, E; Zaringhalam, Jalal; Manaheji, H; Maghsoudi, N; Alani, B; Zardooz, H

    2011-01-01

    Interleukin (IL)-6 is known to cause pro- and anti-inflammatory effects during different stages of inflammation. Recent therapeutic investigations have focused on treatment of various inflammatory disorders with anti-cytokine substances. As a result, the aim of this study was to further elucidate the influence of IL-6 in hyperalgesia and edema during different stages of Complete Freund's Adjuvant (CFA)-induced arthritis (AA) in male Wistar rats. AA was induced by a single subcutaneous injection of CFA into the rats' hindpaw. Anti-IL-6 was administered either daily or weekly during the 21 days of study. Spinal mu opioid receptor (mOR) expression was detected by Western blotting. Daily and weekly treatment with an anti-IL-6 antibody significantly decreased paw edema in the AA group compared to the AA control group. Additionally, daily and weekly anti-IL-6 administration significantly reduced hyperalgesia on day 7 in the AA group compared to the AA control group; however, there were significant increases in hyperalgesia in the antibody-treated group on days 14 and 21 compared to the AA control group. IL-6 antibody-induced increases in hyperalgesia on the 14 th and 21 st days after CFA injection correlated with a time-dependent, significant reduction in spinal mOR expression during anti-IL-6 treatment. Our study confirmed the important time-dependent relationship between serum IL-6 levels and hyperalgesia during AA. These results suggest that the stages of inflammation in AA must be considered for anti-hyperalgesic and anti-inflammatory interventions via anti-IL-6 antibody treatment.

  12. Antagonist-agonist combinations as therapies for heroin addiction: back to the future?

    Science.gov (United States)

    Nutt, David J

    2010-02-01

    Psychopharmacology is a powerful approach to the treatment of many psychiatric disorders. In this article I discuss the conceptual and practical issues in relation to the use of mu opioid receptor agonist, antagonist and partial agonist drugs in the treatment of opioid addiction, as this is one therapeutic area where all three types of agents are currently available. The choice of pharmacological agent is largely determined by patient profile, existence of ongoing drug misuse, and the kinetics of the drugs available. These principles, however, can be applied to other disorders as and when other pharmacological approaches become refined in these areas.

  13. Identification of novel selective V2 receptor non-peptide agonists.

    Science.gov (United States)

    Del Tredici, Andria L; Vanover, Kim E; Knapp, Anne E; Bertozzi, Sine M; Nash, Norman R; Burstein, Ethan S; Lameh, Jelveh; Currier, Erika A; Davis, Robert E; Brann, Mark R; Mohell, Nina; Olsson, Roger; Piu, Fabrice

    2008-10-30

    Peptides with agonist activity at the vasopressin V(2) receptor are used clinically to treat fluid homeostasis disorders such as polyuria and central diabetes insipidus. Of these peptides, the most commonly used is desmopressin, which displays poor bioavailability as well as potent activity at the V(1b) receptor, with possible stress-related adverse effects. Thus, there is a strong need for the development of small molecule chemistries with selective V(2) receptor agonist activity. Using the functional cell-based assay Receptor Selection and Amplification Technology (R-SAT((R))), a screening effort identified three small molecule chemotypes (AC-94544, AC-88324, and AC-110484) with selective agonist activity at the V(2) receptor. One of these compounds, AC-94544, displayed over 180-fold selectivity at the V(2) receptor compared to related vasopressin and oxytocin receptors and no activity at 28 other G protein-coupled receptors (GPCRs). All three compounds also showed partial agonist activity at the V(2) receptor in a cAMP accumulation assay. In addition, in a rat model of central diabetes insipidus, AC-94544 was able to significantly reduce urine output in a dose-dependent manner. Thus, AC-94544, AC-88324, and AC-110484 represent novel opportunities for the treatment of disorders associated with V(2) receptor agonist deficiency.

  14. Imidazopyridine CB2 agonists: optimization of CB2/CB1 selectivity and implications for in vivo analgesic efficacy.

    Science.gov (United States)

    Trotter, B Wesley; Nanda, Kausik K; Burgey, Christopher S; Potteiger, Craig M; Deng, James Z; Green, Ahren I; Hartnett, John C; Kett, Nathan R; Wu, Zhicai; Henze, Darrell A; Della Penna, Kimberly; Desai, Reshma; Leitl, Michael D; Lemaire, Wei; White, Rebecca B; Yeh, Suzie; Urban, Mark O; Kane, Stefanie A; Hartman, George D; Bilodeau, Mark T

    2011-04-15

    A new series of imidazopyridine CB2 agonists is described. Structural optimization improved CB2/CB1 selectivity in this series and conferred physical properties that facilitated high in vivo exposure, both centrally and peripherally. Administration of a highly selective CB2 agonist in a rat model of analgesia was ineffective despite substantial CNS exposure, while administration of a moderately selective CB2/CB1 agonist exhibited significant analgesic effects. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Alterations in food intake elicited by GABA and opioid agonists and antagonists administered into the ventral tegmental area region of rats.

    Science.gov (United States)

    Echo, Joyce A; Lamonte, Nicole; Ackerman, Tsippa F; Bodnar, Richard J

    2002-05-01

    Food intake is significantly increased following administration of mu-selective opioid agonists into the ventral tegmental area (VTA) region acting through multiple local opioid receptor subtypes. Since GABA receptor agonists in the VTA region are capable of eliciting feeding, the present study investigated whether feeding elicited by the mu-selective opioid agonist [D-Ala(2), NMe(4), Gly-ol(5)]-enkephalin (DAMGO) in the VTA region was altered by pretreatment into the same site with equimolar doses of either GABA(A) (bicuculline) or GABA(B) (saclofen) antagonists, and further, whether pretreatment with either general opioid or selective GABA receptor antagonists decreased feeding elicited by GABA(A) (muscimol) or GABA(B) (baclofen) agonists in the VTA region. DAMGO-induced feeding in the VTA region was dose-dependently decreased following pretreatment with either GABA(A) or GABA(B) antagonists in the absence of significant alterations in food intake by the antagonists per se. However, the presence of short-lived seizures following bicuculline in the VTA region suggests that this ingestive effect was caused by nonspecific actions. In contrast, GABA(B) receptors are involved in the full expression of mu-opioid agonist-induced feeding in this region since saclofen failed to elicit either seizure activity or a conditioned taste aversion. Pretreatment with naltrexone in the VTA region reduced intake elicited by baclofen, but not muscimol. Finally, baclofen-induced feeding was significantly reduced by saclofen, but not bicuculline, pretreatment in the VTA region. Therefore, possible coregulation between GABA(B) and opioid receptors in the VTA region, as suggested by immunocytochemical evidence, is supported by these behavioral effects upon ingestion.

  16. Design and Discovery of Functionally Selective Serotonin 2C (5-HT2C) Receptor Agonists.

    Science.gov (United States)

    Cheng, Jianjun; McCorvy, John D; Giguere, Patrick M; Zhu, Hu; Kenakin, Terry; Roth, Bryan L; Kozikowski, Alan P

    2016-11-10

    On the basis of the structural similarity of our previous 5-HT 2C agonists with the melatonin receptor agonist tasimelteon and the putative biological cross-talk between serotonergic and melatonergic systems, a series of new (2,3-dihydro)benzofuran-based compounds were designed and synthesized. The compounds were evaluated for their selectivity toward 5-HT 2A , 5-HT 2B , and 5-HT 2C receptors in the calcium flux assay with the ultimate goal to generate selective 5-HT 2C agonists. Selected compounds were studied for their functional selectivity by comparing their transduction efficiency at the G protein signaling pathway versus β-arrestin recruitment. The most functionally selective compound (+)-7e produced weak β-arrestin recruitment and also demonstrated less receptor desensitization compared to serotonin in both calcium flux and phosphoinositide (PI) hydrolysis assays. We report for the first time that selective 5-HT 2C agonists possessing weak β-arrestin recruitment can produce distinct receptor desensitization properties.

  17. Partial agonists and subunit selectivity at NMDA receptors

    DEFF Research Database (Denmark)

    Risgaard, Rune; Hansen, Kasper Bø; Clausen, Rasmus Prætorius

    2010-01-01

    Subunit-selective ligands for glutamate receptors remains an area of interest as glutamate is the major excitatory neurotransmitter in the brain and involved in a number of diseased states in the central nervous system (CNS). Few subtype-selective ligands are known, especially among the N...

  18. Immunohistochemical localization of mu opioid receptor in the marginal division with comparison to patches in the neostriatum of the rat brain

    Directory of Open Access Journals (Sweden)

    Wu Bingyi

    2011-06-01

    Full Text Available Abstract Background Mu opioid receptor (MOR, which plays key roles in analgesia and also has effects on learning and memory, was reported to distribute abundantly in the patches of the neostriatum. The marginal division (MrD of the neostriatum, which located at the caudomedial border of the neostriatum, was found to stain for enkephalin and substance P immunoreactivities and this region was found to be involved in learning and memory in our previous study. However, whether MOR also exists in the MrD has not yet been determined. Methods In this study, we used western blot analysis and immunoperoxidase histochemical methods with glucose oxidase-DAB-nickel staining to investigate the expression of MOR in the MrD by comparison to the patches in the neostriatum. Results The results from western blot analyses revealed that the antibody to MOR detected a 53 kDa protein band, which corresponded directly to the molecular weight of MOR. Immunohistochemical results showed that punctate MOR-immunoreacted fibers were observed in the "patch" areas in the rostrodorsal part of the neostriatum but these previous studies showed neither labelled neuronal cell bodies, nor were they shown in the caudal part of the neostriatum. Dorsoventrally oriented dark MOR-immunoreactive nerve fibers with individual labelled fusiform cell bodies were firstly observed in the band at the caudomedial border, the MrD, of the neostriatum. The location of the MOR-immunoreactivity was in the caudomedial border of the neostriatum. The morphology of the labelled fusiform neuronal somatas and the dorsoventrally oriented MOR-immunoreacted fibers in the MrD was distinct from the punctate MOR-immunoreactive diffuse mosaic-patterned patches in the neostriatum. Conclusions The results indicated that MOR was expressed in the MrD as well as in patches in the neostriatum of the rat brain, but with different morphological characteristics. The punctate MOR-immunoreactive and diffuse mosaic

  19. Xamoterol, a new selective beta-1-adrenoceptor partial agonist, in the treatment of postural hypotension

    DEFF Research Database (Denmark)

    Mehlsen, J; Trap-Jensen, J

    1986-01-01

    Three patients severely disabled from postural hypotension were treated with xamoterol, a selective beta-1-adrenoceptor antagonist with a high degree of partial agonist activity. Oral treatment (200 mg b.i.d.) was chosen on the basis of the effects of acute intravenous administration of xamoterol...... and pindolol, a non-selective beta-adrenoceptor antagonist with partial agonist activity. In these patients pindolol had a predominantly antagonist effect, whereas xamoterol had a predominantly agonist effect after intravenous administration. Oral treatment was carried out with placebo control in a single......, supine). During the placebo period (2 weeks) heart rate decreased to pretreatment levels and mean blood pressure was reduced by only 14 mmHg. The patients reported substantial improvement in their condition during active medication. Xamoterol seems to be a useful alternative in the treatment of postural...

  20. NeuroD Modulates Opioid Agonist-Selective Regulation of Adult Neurogenesis and Contextual Memory Extinction

    OpenAIRE

    Zheng, Hui; Zhang, Yue; Li, Wen; Loh, Horace H; Law, Ping-Yee

    2013-01-01

    Addictive drugs, including opioids, modulate adult neurogenesis. In order to delineate the probable implications of neurogenesis on contextual memory associated with addiction, we investigated opioid agonist-selective regulation of neurogenic differentiation 1 (NeuroD) activities under the conditioned place preference (CPP) paradigm. Training mice with equivalent doses of morphine and fentanyl produced different CPP extinction rates without measurable differences in the CPP acquisition rate o...

  1. Allosteric activation of the follicle-stimulating hormone (FSH) receptor by selective, nonpeptide agonists.

    Science.gov (United States)

    Yanofsky, Stephen D; Shen, Emily S; Holden, Frank; Whitehorn, Erik; Aguilar, Barbara; Tate, Emily; Holmes, Christopher P; Scheuerman, Randall; MacLean, Derek; Wu, May M; Frail, Donald E; López, Francisco J; Winneker, Richard; Arey, Brian J; Barrett, Ronald W

    2006-05-12

    The pituitary glycoprotein hormones, luteinizing hormone and follicle-stimulating hormone (FSH), act through their cognate receptors to initiate a series of coordinated physiological events that results in germ cell maturation. Given the importance of FSH in regulating folliculogenesis and fertility, the development of FSH mimetics has been sought to treat infertility. Currently, purified and recombinant human FSH are the only FSH receptor (FSH-R) agonists available for infertility treatment. By screening unbiased combinatorial chemistry libraries, using a cAMP-responsive luciferase reporter assay, we discovered thiazolidinone agonists (EC50's = 20 microm) of the human FSH-R. Subsequent analog library screening and parallel synthesis optimization resulted in the identification of a potent agonist (EC50 = 2 nm) with full efficacy compared with FSH that was FSH-R-selective and -dependent. The compound mediated progesterone production in Y1 cells transfected with the human FSH-R (EC50 = 980 nm) and estradiol production from primary rat ovarian granulosa cells (EC50 = 10.5 nm). This and related compounds did not compete with FSH for binding to the FSH-R. Use of human FSH/thyroid-stimulating hormone (TSH) receptor chimeras suggested a novel mechanism for receptor activation through a binding site independent of the natural hormone binding site. This study is the first report of a high affinity small molecule agonist that activates a glycoprotein hormone receptor through an allosteric mechanism. The small molecule FSH receptor agonists described here could lead to an oral alternative to the current parenteral FSH treatments used clinically to induce ovarian stimulation for both in vivo and in vitro fertilization therapy.

  2. Prediction of selective estrogen receptor beta agonist using open data and machine learning approach.

    Science.gov (United States)

    Niu, Ai-Qin; Xie, Liang-Jun; Wang, Hui; Zhu, Bing; Wang, Sheng-Qi

    2016-01-01

    Estrogen receptors (ERs) are nuclear transcription factors that are involved in the regulation of many complex physiological processes in humans. ERs have been validated as important drug targets for the treatment of various diseases, including breast cancer, ovarian cancer, osteoporosis, and cardiovascular disease. ERs have two subtypes, ER-α and ER-β. Emerging data suggest that the development of subtype-selective ligands that specifically target ER-β could be a more optimal approach to elicit beneficial estrogen-like activities and reduce side effects. Herein, we focused on ER-β and developed its in silico quantitative structure-activity relationship models using machine learning (ML) methods. The chemical structures and ER-β bioactivity data were extracted from public chemogenomics databases. Four types of popular fingerprint generation methods including MACCS fingerprint, PubChem fingerprint, 2D atom pairs, and Chemistry Development Kit extended fingerprint were used as descriptors. Four ML methods including Naïve Bayesian classifier, k-nearest neighbor, random forest, and support vector machine were used to train the models. The range of classification accuracies was 77.10% to 88.34%, and the range of area under the ROC (receiver operating characteristic) curve values was 0.8151 to 0.9475, evaluated by the 5-fold cross-validation. Comparison analysis suggests that both the random forest and the support vector machine are superior for the classification of selective ER-β agonists. Chemistry Development Kit extended fingerprints and MACCS fingerprint performed better in structural representation between active and inactive agonists. These results demonstrate that combining the fingerprint and ML approaches leads to robust ER-β agonist prediction models, which are potentially applicable to the identification of selective ER-β agonists.

  3. Sphingosine-1-Phosphate Receptor-1 Selective Agonist Enhances Collateral Growth and Protects against Subsequent Stroke.

    Directory of Open Access Journals (Sweden)

    Masahiko Ichijo

    Full Text Available Collateral growth after acute occlusion of an intracranial artery is triggered by increasing shear stress in preexisting collateral pathways. Recently, sphingosine-1-phosphate receptor-1 (S1PR1 on endothelial cells was reported to be essential in sensing fluid shear stress. Here, we evaluated the expression of S1PR1 in the hypoperfused mouse brain and investigated the effect of a selective S1PR1 agonist on leptomeningeal collateral growth and subsequent ischemic damage after focal ischemia.In C57Bl/6 mice (n = 133 subjected to unilateral common carotid occlusion (CCAO and sham surgery. The first series examined the time course of collateral growth, cell proliferation, and S1PR1 expression in the leptomeningeal arteries after CCAO. The second series examined the relationship between pharmacological regulation of S1PR1 and collateral growth of leptomeningeal anastomoses. Animals were randomly assigned to one of the following groups: LtCCAO and daily intraperitoneal (i.p. injection for 7 days of an S1PR1 selective agonist (SEW2871, 5 mg/kg/day; sham surgery and daily i.p. injection for 7 days of SEW2871 after surgery; LtCCAO and daily i.p. injection for 7 days of SEW2871 and an S1PR1 inverse agonist (VPC23019, 0.5 mg/kg; LtCCAO and daily i.p. injection of DMSO for 7 days after surgery; and sham surgery and daily i.p. injection of DMSO for 7 days. Leptomeningeal anastomoses were visualized 14 days after LtCCAO by latex perfusion method, and a set of animals underwent subsequent permanent middle cerebral artery occlusion (pMCAO 7 days after the treatment termination. Neurological functions 1 hour, 1, 4, and 7 days and infarction volume 7 days after pMCAO were evaluated.In parallel with the increase in S1PR1 mRNA levels, S1PR1 expression colocalized with endothelial cell markers in the leptomeningeal arteries, increased markedly on the side of the CCAO, and peaked 7 days after CCAO. Mitotic cell numbers in the leptomeningeal arteries increased after

  4. Detection and Quantization of the Expression of Two mu-Opioid Receptor Splice Variants mRNA (hMOR-1A and hMOR-1O in Peripheral Blood Lymphocytes of Long-Term Abstinent Former Opioid Addicts

    Directory of Open Access Journals (Sweden)

    N Vousooghi, Pharm

    2012-05-01

    Full Text Available

    Background and Objectives

    The mu-Opioid receptor (MOR exerts a critical role on effects of opiodis. The objective of this study is to find a peripheral bio-marker in addiction studies through quantization of the expression of two MOR splice variants mRNA (hMOR-1A and hMOR-1O in peripheral blood lymphocytes (PBLs of long-term abstinent former opioids addicts.

    Methods

    In this case-control study, case and control people were male and divided in two groups: people who gave up addiction to opioids (case and healthy individuals without history of addiction (control. The mRNA expression in PBLs of participants was detected and measured by real-time Polymerase Chain Reaction (PCR using SYBR Green Dye.

    Results

    The hMOR-1A mRNA expression in PBLs of abstinent group was significantly reduced and reached to 0.33 of the control group (p<0.001. Similar results were obtained for the other splice variant with the mRNA expression of hMOR-1O in PBLs of abstinent group reaching to 0.38 of that of the control group (p < 0.001.

    Conclusion

    mRNA expression deficiency of two mu-opioid receptor splice variants, hMOR-1A and nMOR-1O, seams to be a risk factor making individuals vulnerable to drug addiction. Based on this analysis measuring the amount of mRNA expression of these two splice variants in PBLs can serve as a peripheral bio-marker for detecting people at risk.

  5. Prediction of selective estrogen receptor beta agonist using open data and machine learning approach

    Directory of Open Access Journals (Sweden)

    Niu AQ

    2016-07-01

    for the classification of selective ER-β agonists. Chemistry Development Kit extended fingerprints and MACCS fingerprint performed better in structural representation between active and inactive agonists. Conclusion: These results demonstrate that combining the fingerprint and ML approaches leads to robust ER-β agonist prediction models, which are potentially applicable to the identification of selective ER-β agonists. Keywords: estrogen receptor subtype β, selective estrogen receptor modulators, quantitative structure-activity relationship models, machine learning approach

  6. A highly selective CCR2 chemokine agonist encoded by human herpesvirus 6

    DEFF Research Database (Denmark)

    Lüttichau, Hans R; Clark-Lewis, Ian; Jensen, Peter Østrup

    2003-01-01

    The chemokine-like, secreted protein product of the U83 gene from human herpesvirus 6, here named vCCL4, was chemically synthesized to be characterized in a complete library of the 18 known human chemokine receptors expressed individually in stably transfected cell lines. vCCL4 was found to cause...... being equally or more efficacious in causing cell migration than CCL2 and CCL7 and considerably more efficacious than CCL8 and CCL13. It is concluded that human herpesvirus 6 encodes a highly selective and efficacious CCR2 agonist, which will attract CCR2 expressing cells, for example macrophages...

  7. Anxiogenic properties of an inverse agonist selective for α3 subunit-containing GABAA receptors

    OpenAIRE

    Atack, John R; Hutson, Peter H; Collinson, Neil; Marshall, George; Bentley, Graham; Moyes, Christopher; Cook, Susan M; Collins, Ian; Wafford, Keith; McKernan, Ruth M; Dawson, Gerard R

    2005-01-01

    α3IA (6-(4-pyridyl)-5-(4-methoxyphenyl)-3-carbomethoxy-1-methyl-1H-pyridin-2-one) is a pyridone with higher binding and functional affinity and greater inverse agonist efficacy for GABAA receptors containing an α3 rather than an α1, α2 or α5 subunit. If doses are selected that minimise the occupancy at these latter subtypes, then the in vivo effects of α3IA are most probably mediated by the α3 subtype.α3IA has good CNS penetration in rats and mice as measured using a [3H]Ro 15-1788 in vivo bi...

  8. Drug and cell type-specific regulation of genes with different classes of estrogen receptor beta-selective agonists.

    Directory of Open Access Journals (Sweden)

    Sreenivasan Paruthiyil

    2009-07-01

    Full Text Available Estrogens produce biological effects by interacting with two estrogen receptors, ERalpha and ERbeta. Drugs that selectively target ERalpha or ERbeta might be safer for conditions that have been traditionally treated with non-selective estrogens. Several synthetic and natural ERbeta-selective compounds have been identified. One class of ERbeta-selective agonists is represented by ERB-041 (WAY-202041 which binds to ERbeta much greater than ERalpha. A second class of ERbeta-selective agonists derived from plants include MF101, nyasol and liquiritigenin that bind similarly to both ERs, but only activate transcription with ERbeta. Diarylpropionitrile represents a third class of ERbeta-selective compounds because its selectivity is due to a combination of greater binding to ERbeta and transcriptional activity. However, it is unclear if these three classes of ERbeta-selective compounds produce similar biological activities. The goals of these studies were to determine the relative ERbeta selectivity and pattern of gene expression of these three classes of ERbeta-selective compounds compared to estradiol (E(2, which is a non-selective ER agonist. U2OS cells stably transfected with ERalpha or ERbeta were treated with E(2 or the ERbeta-selective compounds for 6 h. Microarray data demonstrated that ERB-041, MF101 and liquiritigenin were the most ERbeta-selective agonists compared to estradiol, followed by nyasol and then diarylpropionitrile. FRET analysis showed that all compounds induced a similar conformation of ERbeta, which is consistent with the finding that most genes regulated by the ERbeta-selective compounds were similar to each other and E(2. However, there were some classes of genes differentially regulated by the ERbeta agonists and E(2. Two ERbeta-selective compounds, MF101 and liquiritigenin had cell type-specific effects as they regulated different genes in HeLa, Caco-2 and Ishikawa cell lines expressing ERbeta. Our gene profiling studies

  9. Identification of Eupatilin from Artemisia argyi as a Selective PPARα Agonist Using Affinity Selection Ultrafiltration LC-MS

    Directory of Open Access Journals (Sweden)

    Yongsoo Choi

    2015-07-01

    Full Text Available Peroxisome proliferator-activated receptors (PPARs are key nuclear receptors and therapeutic targets for the treatment of metabolic diseases through the regulation of insulin resistance, diabetes, and dyslipidemia. Although a few drugs that target PPARs have been approved, more diverse and novel PPAR ligands are necessary to improve the safety and efficacy of available drugs. To expedite the search for new natural agonists of PPARs, we developed a screening assay based on ultrafiltration liquid chromatography-mass spectrometry (LC-MS that is compatible with complex samples such as dietary foods or botanical extracts. The known PPARα and/or PPARγ ligands resveratrol and rosiglitazone were used as positive controls to validate the developed method. When applied to the screening of an Artemisia argyi extract, eupatilin was identified as a selective PPARα ligand. A PPAR competitive binding assay based on FRET detection also confirmed eupatilin as a selective PPARα agonist exhibiting a binding affinity of 1.18 μM (IC50. Furthermore, eupatilin activation of the transcriptional activity of PPARα was confirmed using a cell-based transactivation assay. Thus, ultrafiltration LC-MS is a suitable assay for the identification of PPAR ligands in complex matrixes such as extracts of dietary foods and botanicals.

  10. A selective cannabinoid CB2 agonist attenuates damage and improves memory retention following stroke in mice.

    Science.gov (United States)

    Ronca, Richard D; Myers, Alyssa M; Ganea, Doina; Tuma, Ronald F; Walker, Ellen A; Ward, Sara Jane

    2015-10-01

    We have recently demonstrated that treatment with a cannabinoid CB2 agonist was protective in a mouse middle cerebral artery occlusion model of cerebral ischemia/reperfusion injury. The present study aimed to determine whether these protective effects of CB2 agonism would extend to a mouse photoinjury model of permanent ischemia and determine associated alterations in cognition and infarct size. Mice received three injections of the CB2 selective agonist O-1966 or vehicle 1h prior to and 2 and 5days following induction of stroke. Infarct size was assessed at 1, 3, or 7days post-injury and learning and memory effects of injury and O-1966 treatment were assessed on days 6 and 7 using a novel object recognition task and an operant acquisition and retention procedure. O-1966 treated mice had significantly smaller infarct volumes compared with vehicle treated mice. Photoinjury was also associated with a significant memory impairment on day 7 post-injury, and this deficit was reversed with O-1966 treatment. Surprisingly, sham-operated mice receiving O-1966 treatment showed a significant learning deficit in both the recognition and operant tasks compared with vehicle treated sham mice. We conclude that CB2 activation is protective against cognitive deficits and tissue damage following permanent ischemia, but may dysregulate glial or neuronal function of learning and memory circuits in the absence of injury and/or inflammation. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Agonistic activity of tamoxifen, a selective estrogen-receptor modulator (SERM), on arthritic ovariectomized mice

    Science.gov (United States)

    Silva, L.A.S.; Felix, F.B.; Araujo, J.M.D.; Souza, E.V.; Camargo, E.A.; Grespan, R.

    2017-01-01

    Arthritis is positively associated with the decline of sex hormones, especially estrogen. Tamoxifen (TMX) is a selective estrogen receptor modulator, possessing agonist or antagonistic activity in different tissues. Thus, the objective of this study was to investigate the effect of TMX on the zymosan-induced arthritis model. Female Swiss normal and ovariectomized (OVX) mice were divided into groups and treated for five days with TMX (0.3, 0.9 or 2.7 mg/kg) or 17-β-estradiol (E2, 50 µg/kg). On the fifth day, arthritis was induced and 4 h later, leukocyte migration into joint cavities was evaluated. The neutrophil migration in OVX animals, but not in normal mice, treated with TMX (all tested doses) was significantly decreased compared with mice that received the vehicle (P≤0.05). Similarly, this effect was also demonstrated in the E2-treated group. Therefore, the present study demonstrates that TMX presented agonist effects in inhibiting neutrophil migration and preventing arthritis progression in OVX mice. PMID:29160416

  12. An Oral Selective Alpha-1A Adrenergic Receptor Agonist Prevents Doxorubicin Cardiotoxicity

    Directory of Open Access Journals (Sweden)

    Ju Youn Beak, PhD

    2017-02-01

    Full Text Available Summary: Alpha-1 adrenergic receptors (α1-ARs play adaptive and protective roles in the heart. Dabuzalgron is an oral selective α1A-AR agonist that was well tolerated in multiple clinical trials of treatment for urinary incontinence, but has never been used to treat heart disease in humans or animal models. In this study, the authors administered dabuzalgron to mice treated with doxorubicin (DOX, a widely used chemotherapeutic agent with dose-limiting cardiotoxicity that can lead to heart failure (HF. Dabuzalgron protected against DOX-induced cardiotoxicity, likely by preserving mitochondrial function. These results suggest that activating cardiac α1A-ARs with dabuzalgron, a well-tolerated oral agent, might represent a novel approach to treating HF. Key Words: alpha adrenergic receptors, anthracyclines, cardioprotection, catecholamines, heart failure

  13. Novel sst2-selective somatostatin agonists. Three-dimensional consensus structure by NMR

    Science.gov (United States)

    Grace, Christy Rani R.; Erchegyi, Judit; Koerber, Steven C.; Reubi, Jean Claude; Rivier, Jean; Riek, Roland

    2008-01-01

    The three-dimensional NMR structures of six octapeptide agonist analogues of somatostatin (SRIF) in the free form are described. These analogues, with the basic sequence H-DPhe/Phe2-c[Cys3-Xxx7-DTrp8-Lys9-Thr10-Cys14]-Thr-NH2 (the numbering refers to the position in native SRIF), with Xxx7 being Ala/Aph, exhibit potent and highly selective binding to human SRIF type 2 (sst2) receptors. The backbone of these sst2-selective analogues have the usual type-II’ β-turn reported in the literature for sst2/3/5-subtype-selective analogues. Correlating biological results and NMR studies led to the identification of the side chains of DPhe2, DTrp8 and Lys9 as the necessary components of the sst2 pharmacophore. This is the first study to show that the aromatic ring at position 7 (Phe7) is not critical for sst2 binding and that it plays an important role in sst3 and sst5 binding. This pharmacophore is therefore different from that proposed by others for sst2/3/5 analogues. PMID:16854054

  14. NeuroD modulates opioid agonist-selective regulation of adult neurogenesis and contextual memory extinction.

    Science.gov (United States)

    Zheng, Hui; Zhang, Yue; Li, Wen; Loh, Horace H; Law, Ping-Yee

    2013-04-01

    Addictive drugs, including opioids, modulate adult neurogenesis. In order to delineate the probable implications of neurogenesis on contextual memory associated with addiction, we investigated opioid agonist-selective regulation of neurogenic differentiation 1 (NeuroD) activities under the conditioned place preference (CPP) paradigm. Training mice with equivalent doses of morphine and fentanyl produced different CPP extinction rates without measurable differences in the CPP acquisition rate or magnitude. Fentanyl-induced CPP required much longer time for extinction than morphine-induced CPP. We observed a parallel decrease in NeuroD activities and neurogenesis after morphine-induced CPP, but not after fentanyl-induced CPP. Increasing NeuroD activities with NeuroD-lentivirus (nd-vir) injection at the dentate gyrus before CPP training reversed morphine-induced decreases in NeuroD activities and neurogenesis, and prolonged the time required for extinction of morphine-induced CPP. On the other hand, decreasing NeuroD activities via injection of miRNA-190-virus (190-vir) reversed the fentanyl effect on NeuroD and neurogenesis and shortened the time required for extinction of fentanyl-induced CPP. Another contextual memory task, the Morris Water Maze (MWM), was affected similarly by alteration of NeuroD activities. The reduction in NeuroD activities either by morphine treatment or 190-vir injection decreased MWM task retention, while the increase in NeuroD activities by nd-vir prolonged MWM task retention. Thus, by controlling NeuroD activities, opioid agonists differentially regulate adult neurogenesis and subsequent contextual memory retention. Such drug-related memory regulation could have implications in eventual context-associated relapse.

  15. 24(S)-Saringosterol from edible marine seaweed Sargassum fusiforme is a novel selective LXRβ agonist.

    Science.gov (United States)

    Chen, Zhen; Liu, Jiao; Fu, Zhifei; Ye, Cheng; Zhang, Renshuai; Song, Yiyun; Zhang, Ying; Li, Haihua; Ying, Hao; Liu, Hongbing

    2014-07-02

    Dietary phytosterols have been successfully used for lowering cholesterol levels, which correlates with the fact that some phytosterols are able to act as liver X receptor (LXR) agonists. Sargassum fusiforme is an edible marine seaweed well-known for its antiatherosclerotic function in traditional Chinese medicine. In this study, seven phytosterols including fucosterol (1), saringosterol (2), 24-hydroperoxy-24-vinyl-cholesterol (3), 29-hydroperoxy-stigmasta-5,24(28)-dien-3β-ol (4), 24-methylene-cholesterol (5), 24-keto-cholesterol (6), and 5α,8α-epidioxyergosta-6,22-dien-3β-ol (7) were purified and evaluated for their actions on LXR-mediated transcription using a reporter assay. Among these phytosterols, 2 was the most potent compound in stimulating the transcriptional activities of LXRα by (3.81±0.15)-fold and LXRβ by (14.40±1.10)-fold, respectively. Two epimers of 2, 24(S)-saringosterol (2a) and 24(R)-saringosterol (2b), were subsequently separated by semipreparative high-performance liquid chromatography. Interestingly, 2a was more potent than 2b in LXRβ-mediated transactivation ((3.50±0.17)-fold vs (1.63±0.12)-fold) compared with control. Consistently, 2a induced higher expression levels of LXR target genes including key players in reverse cholesterol transport in six cell lines. These data along with molecular modeling suggested that 2a acts as a selective LXRβ agonist and is a potent natural cholesterol-lowering agent. This study also demonstrated that phytosterols in S. fusiforme contributed to the well-known antiatherosclerotic function.

  16. Prevention of diabetic nephropathy by compound 21, selective agonist of angiotensin type 2 receptors, in Zucker diabetic fatty rats

    DEFF Research Database (Denmark)

    Castoldi, Giovanna; di Gioia, Cira Rt; Bombardi, Camila

    2014-01-01

    Aim of the study was to evaluate the effect of compound 21 (C21), selective AT2 receptor agonist, in diabetic nephropathy and the potential additive effect of C21, when associated to losartan treatment, on the development of albuminuria and renal fibrosis in Zucker diabetic fatty (ZDF) rats. The ...

  17. Randomised controlled trial for emphysema with a selective agonist of the γ-type retinoic acid receptor

    DEFF Research Database (Denmark)

    Stolk, Jan; Stockley, Robert A; Stoel, Berend C

    2012-01-01

    Palovarotene is an oral γ-selective retinoid agonist. In animal emphysema models, palovarotene reduced inflammation, promoted structural repair and functional improvement. REPAIR (Retinoid treatment of Emphysema in Patients on the α(1)-antitrypsin International Registry), was an investigator-init...

  18. Stereochemistry and molecular pharmacology of (S)-thio-ATPA, a new potent and selective GluR5 agonist

    DEFF Research Database (Denmark)

    Stensbøl, T B; Jensen, H S; Nielsen, B

    2001-01-01

    )-Glu) receptors (EC(50)=14 microM), comparable in potency with ATPA (EC(50)=34 microM). Recent findings, that (S)-ATPA is a potent (EC(50)=0.48 microM) and selective agonist at homomerically expressed ionotropic GluR5, prompted us to resolve thio-ATPA using chiral chromatography and pharmacologically characterize...

  19. Responses to cholinergic agonists of rats selectively bred for differential sensitivity to ethanol.

    Science.gov (United States)

    de Fiebre, C M; Romm, E; Collins, J T; Draski, L J; Deitrich, R A; Collins, A C

    1991-03-01

    Alcoholics are almost invariably heavy users of tobacco. Both alcoholism and smoking appear to be influenced by genetic factors but it is not known whether the same or different genes regulate the abuse of ethanol and nicotine. Recent studies have demonstrated that the long-sleep (LS) and short-sleep (SS) mouse lines, which were selectively bred for differences in ethanol-induced anesthesia ("sleep-time"), also differ in several effects of nicotine and the muscarinic agonist, oxotremorine. In order to determine whether or not these differences are due to chance, the relative sensitivities of rat lines which were selectively bred for differences in ethanol-induced sleep-time were determined. The high alcohol sensitivity (HAS) rat line was more sensitive to the locomotor and body temperature depressant effects of nicotine than was the low alcohol sensitivity (LAS) rat line. The control line (CAS) was intermediate in sensitivity. The rat lines did not differ in sensitivity to oxotremorine's hypothermia-producing effects. The numbers and affinities of two classes of brain nicotinic receptors were measured in eight brain regions. No differences among the rat lines were detected. These results suggest that ethanol elicits some of its depressant actions via an effect on brain nicotinic systems, but the differences in sensitivity to ethanol and nicotine are probably not due to differences in the number of brain nicotinic receptors. Perhaps this interaction explains the high correlation between alcoholism and smoking in humans.

  20. Visual selective attention is impaired in children prenatally exposed to opioid agonist medication.

    Science.gov (United States)

    Konijnenberg, Carolien; Melinder, Annika

    2015-01-01

    To examine whether prenatal exposure to opioid agonist medication is associated with visual selective attention and general attention problems in early childhood. Twenty-two children (mean age = 52.17 months, SD = 1.81) prenatally exposed to methadone, 9 children (mean age = 52.41 months, SD = 1.42) prenatally exposed to buprenorphine and 25 nonexposed comparison children (mean age = 51.44 months, SD = 1.31) were tested. Visual selective attention was measured with a Tobii 1750 Eye Tracker using a spatial negative priming paradigm. Attention problems were measured using the Child Behavior Checklist. The comparison group demonstrated a larger spatial negative priming effect (mean = 23.50, SD = 45.50) than the exposed group [mean = -6.84, SD = 86.39, F(1,50) = 5.91, p = 0.019, η(2) = 0.11]. No difference in reported attention problems was found [F(1,51) = 1.63, p = 0.21, η(2) = 0.03]. Neonatal abstinence syndrome and prenatal exposure to marijuana were found to predict slower saccade latencies in the exposed group (b = 54.55, SE = 23.56, p = 0.03 and b = 88.86, SE = 32.07, p = 0.01, respectively). Although exposed children did not appear to have attention deficits in daily life, lower performance on the SNP task indicates subtle alteration in the attention system. © 2014 S. Karger AG, Basel.

  1. Trialkyltin rexinoid-X receptor agonists selectively potentiate thyroid hormone induced programs of xenopus laevis metamorphosis

    NARCIS (Netherlands)

    Mengeling, Brenda J.; Murk, Albertinka J.; Furlow, J.D.

    2016-01-01

    The trialkyltins tributyltin (TBT) and triphenyltin (TPT) can function as rexinoid-X receptor (RXR) agonists. We recently showed that RXR agonists can alter thyroid hormone (TH) signaling in a mammalian pituitary TH-responsive reporter cell line, GH3.TRE-Luc. The prevalence of TBT and TPT in the

  2. Click-Chemistry-Mediated Synthesis of Selective Melanocortin Receptor 4 Agonists

    DEFF Research Database (Denmark)

    Palmer, Daniel; Gonçalves, Juliana P.L.; Hansen, Louise V.

    2017-01-01

    The melanocortin receptor 4 (MC4R) subtype of the melanocortin receptor family is a target for therapeutics to ameliorate metabolic dysfunction. Endogenous MC4R agonists possess a critical pharmacophore (HFRW), and cyclization of peptide agonists often enhances potency. Thus, 17 cyclized peptides...

  3. BOLD Imaging in Awake Wild-Type and Mu-Opioid Receptor Knock-Out Mice Reveals On-Target Activation Maps in Response to Oxycodone

    Directory of Open Access Journals (Sweden)

    Kelsey Moore

    2016-11-01

    brain signature that should, in the future, be compared to other µ opioid agonists.

  4. Knockdown of ventral tegmental area mu-opioid receptors in rats prevents effects of social defeat stress: Implications for amphetamine cross-sensitization, social avoidance, weight regulation and expression of brain-derived neurotrophic factor

    Science.gov (United States)

    Johnston, Caitlin E.; Herschel, Daniel; Lasek, Amy W.; Hammer, Ronald P.; Nikulina, Ella M.

    2014-01-01

    Social defeat stress causes social avoidance and long-lasting cross-sensitization to psychostimulants, both of which are associated with increased brain-derived neurotrophic factor (BDNF) expression in the ventral tegmental area (VTA). Moreover, social stress upregulates VTA mu-opioid receptor (MOR) mRNA. In the VTA, MOR activation inhibits GABA neurons to disinhibit VTA dopamine neurons, thus providing a role for VTA MORs in the regulation of psychostimulant sensitization. The present study determined the effect of lentivirus-mediated MOR knockdown in the VTA on the consequences of intermittent social defeat stress, a salient and profound stressor in humans and rodents. Social stress exposure induced social avoidance and attenuated weight gain in animals with non-manipulated VTA MORs, but both these effects were prevented by VTA MOR knockdown. Rats with non-manipulated VTA MOR expression exhibited cross-sensitization to amphetamine challenge (1.0 mg/kg, i.p.), evidenced by a significant augmentation of locomotion. By contrast, knockdown of VTA MORs prevented stress-induced cross-sensitization without blunting the locomotor-activating effects of amphetamine. At the time point corresponding to amphetamine challenge, immunohistochemical analysis was performed to examine the effect of stress on VTA BDNF expression. Prior stress exposure increased VTA BDNF expression in rats with non-manipulated VTA MOR expression, while VTA MOR knockdown prevented stress-induced expression of VTA BDNF. Taken together, these results suggest that upregulation of VTA MOR is necessary for the behavioral and biochemical changes induced by social defeat stress. Elucidating VTA MOR regulation of stress effects on the mesolimbic system may provide new therapeutic targets for treating stress-induced vulnerability to substance abuse. PMID:25446676

  5. Adaptability and selectivity of human peroxisome proliferator-activated receptor (PPAR) pan agonists revealed from crystal structures

    International Nuclear Information System (INIS)

    Oyama, Takuji; Toyota, Kenji; Waku, Tsuyoshi; Hirakawa, Yuko; Nagasawa, Naoko; Kasuga, Jun-ichi; Hashimoto, Yuichi; Miyachi, Hiroyuki; Morikawa, Kosuke

    2009-01-01

    The structures of the ligand-binding domains (LBDs) of human peroxisome proliferator-activated receptors (PPARα, PPARγ and PPARδ) in complexes with a pan agonist, an α/δ dual agonist and a PPARδ-specific agonist were determined. The results explain how each ligand is recognized by the PPAR LBDs at an atomic level. Peroxisome proliferator-activated receptors (PPARs) belong to the nuclear hormone receptor family, which is defined as transcriptional factors that are activated by the binding of ligands to their ligand-binding domains (LBDs). Although the three PPAR subtypes display different tissue distribution patterns and distinct pharmacological profiles, they all are essentially related to fatty-acid and glucose metabolism. Since the PPARs share similar three-dimensional structures within the LBDs, synthetic ligands which simultaneously activate two or all of the PPARs could be potent candidates in terms of drugs for the treatment of abnormal metabolic homeostasis. The structures of several PPAR LBDs were determined in complex with synthetic ligands, derivatives of 3-(4-alkoxyphenyl)propanoic acid, which exhibit unique agonistic activities. The PPARα and PPARγ LBDs were complexed with the same pan agonist, TIPP-703, which activates all three PPARs and their crystal structures were determined. The two LBD–ligand complex structures revealed how the pan agonist is adapted to the similar, but significantly different, ligand-binding pockets of the PPARs. The structures of the PPARδ LBD in complex with an α/δ-selective ligand, TIPP-401, and with a related δ-specific ligand, TIPP-204, were also determined. The comparison between the two PPARδ complexes revealed how each ligand exhibits either a ‘dual selective’ or ‘single specific’ binding mode

  6. Dermorphin-related peptides from the skin of Phyllomedusa bicolor and their amidated analogs activate two mu opioid receptor subtypes that modulate antinociception and catalepsy in the rat.

    OpenAIRE

    Negri, L; Erspamer, G F; Severini, C; Potenza, R L; Melchiorri, P; Erspamer, V

    1992-01-01

    Three naturally occurring dermorphin-like peptides from the skin of the frog Phyllomedusa bicolor, the related carboxyl-terminal amides, and some substituted analogs were synthesized, their binding profiles to opioid receptors were determined, and their biological activities were studied in isolated organ preparations and intact animals. The opioid binding profile revealed a very high selectivity of these peptides for mu sites and suggested the existence of two receptor subtypes, of high and ...

  7. Minimal_Set_of_In_Vitro_ER_Agonist_Assays_Selection_RegToxPharm_Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — A dataset for the manuscript which demonstrates that it is possible to achieve levels of performance equivalent to the full 16 assay ER agonist model against both in...

  8. Selective serotonin reuptake inhibitors potentiate the rapid antidepressant-like effects of serotonin4 receptor agonists in the rat.

    Directory of Open Access Journals (Sweden)

    Guillaume Lucas

    2010-02-01

    Full Text Available We have recently reported that serotonin(4 (5-HT(4 receptor agonists have a promising potential as fast-acting antidepressants. Here, we assess the extent to which this property may be optimized by the concomitant use of conventional antidepressants.We found that, in acute conditions, the 5-HT(4 agonist prucalopride was able to counteract the inhibitory effect of the selective serotonin reuptake inhibitors (SSRI fluvoxamine and citalopram on 5-HT neuron impulse flow, in Dorsal Raphé Nucleus (DRN cells selected for their high (>1.8 Hz basal discharge. The co-administration of both prucalopride and RS 67333 with citalopram for 3 days elicited an enhancement of DRN 5-HT neuron average firing rate, very similar to what was observed with either 5-HT(4 agonist alone. At the postsynaptic level, this translated into the manifestation of a tonus on hippocampal postsynaptic 5-HT(1A receptors, that was two to three times stronger when the 5-HT(4 agonist was combined with citalopram. Similarly, co-administration of citalopram synergistically potentiated the enhancing effect of RS 67333 on CREB protein phosphorylation within the hippocampus. Finally, in the Forced Swimming Test, the combination of RS 67333 with various SSRIs (fluvoxamine, citalopram and fluoxetine was more effective to reduce time of immobility than the separate administration of each compound.These findings strongly suggest that the adjunction of an SSRI to a 5-HT(4 agonist may help to optimize the fast-acting antidepressant efficacy of the latter.

  9. Synthesis, modelling, and mu-opioid receptor affinity of N-3(9)-arylpropenyl-N-9(3)-propionyl-3,9-diazabicycl.

    Science.gov (United States)

    Pinna, G A; Murineddu, G; Curzu, M M; Villa, S; Vianello, P; Borea, P A; Gessi, S; Toma, L; Colombo, D; Cignarella, G

    2000-08-01

    A series of N-3-arylpropenyl-N-9-propionyl-3,9-diazabicyclo[3.3.1]nonanes (1a-g) and of reverted N-3-propionyl-N-9-arylpropenyl isomers (2a-g), as homologues of the previously reported analgesic 3,8-diazabicyclo[3.2.1]octanes (I-II), were synthesized and evaluated for the binding affinity towards opioid receptor subtypes mu, delta and kappa. Compounds 1a-g and 2a-g exhibited a strong selective mu-affinity with Ki values in the nanomolar range, which favourably compared with those of I and II. In addition, contrary to the trend observed for DBO-I, II, the mu-affinity of series 2 is markedly higher than that of the isomeric series 1. This aspect was discussed on the basis of the conformational studies performed on DBN which allowed hypotheses on the mode of interaction of these compounds with the mu receptor.

  10. A neurokinin 3 receptor-selective agonist accelerates pulsatile luteinizing hormone secretion in lactating cattle.

    Science.gov (United States)

    Nakamura, Sho; Wakabayashi, Yoshihiro; Yamamura, Takashi; Ohkura, Satoshi; Matsuyama, Shuichi

    2017-07-01

    Pulsatile gonadotropin-releasing hormone (GnRH) secretion, which is indispensable for follicular development, is suppressed in lactating dairy and beef cattle. Neurokinin B (NKB) neurons in the arcuate nucleus of the hypothalamus are considered to play an essential role in generating the pulsatile mode of GnRH/luteinizing hormone (LH) secretion. The present study aimed to clarify the role of NKB-neurokinin 3 receptor (NK3R) signaling in the pulsatile pattern of GnRH/gonadotropin secretion in postpartum lactating cattle. We examined the effects of the administration of an NK3R-selective agonist, senktide, on gonadotropin secretion in lactating cattle. The lactating cattle, at approximately 7 days postpartum, were intravenously infused with senktide (30 or 300 nmol/min) or vehicle for 24 h. The administration of 30 or 300 nmol/min senktide significantly increased LH pulse frequency compared to in the control group during 0-4 or 20-24 h after infusion, respectively. Moreover, LH and follicle-stimulating hormone levels were gradually increased by 300 nmol/min administration of senktide during the 0-4-h sampling period. Ultrasonography of the ovaries was performed to identify the first postpartum ovulation in senktide-administered lactating cattle. The interval from calving to first postpartum ovulation was significantly shorter in the 300 nmol/min senktide-administered group than in the control group. Taken together, these findings suggest that senktide infusion elicits an increase in LH pulse frequency that may stimulate follicular development and, in turn, induce the first postpartum ovulation in lactating cattle. © The Authors 2017. Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. Varenicline: a selective alpha4beta2 nicotinic acetylcholine receptor partial agonist approved for smoking cessation.

    Science.gov (United States)

    Lam, Sum; Patel, Priti N

    2007-01-01

    Tobacco smoking remains a significant health problem in the United States. It has been associated with staggering morbidity and mortality, specifically due to malignancies and cardiovascular disease. Smoking cessation can be difficult and frequently requires pharmacologic interventions in addition to nonpharmacologic measures. Previously available agents are nicotine replacement products and bupropion, which increased quit rates by about 2-fold compared with placebo. Varenicline is the first drug in a new class known as the selective alpha4beta2 nicotinic receptor partial agonists. In several randomized, double-blind, 52-week clinical trials involving healthy chronic smokers, varenicline demonstrated superiority to placebo and bupropion in terms of efficacy measures. Additionally, it improved tobacco withdrawal symptoms and reinforcing effects of smoking in relapsed patients. Patients should start therapy in combination with tobacco cessation counseling 1 week before quit date and continue the regimen for 12 weeks. The dose of varenicline should be titrated to minimize nausea. The recommended dosage is 0.5 mg once daily (QD) on days 1-3; titrate to 0.5 mg twice daily (BID) on days 4-7; and 1 mg BID starting on day 8. An additional 12-week maintenance therapy may be considered for those who achieve abstinence. The most common side effects are nausea (30%), insomnia (18%), headache (15%), abnormal dreams (13%), constipation (8%), and abdominal pain (7%). Overall, varenicline is a breakthrough in the management of tobacco addiction and has demonstrated good efficacy in motivated quitters. It also provides an option for smokers who cannot tolerate other pharmacologic interventions.

  12. Electrochemical sensor based on a carbon nanotube-modified imprinted sol–gel for selective and sensitive determination of β2-agonists

    International Nuclear Information System (INIS)

    Xu, Wei; Liu, Ping; Guo, Chunhui; Dong, Chao; Zhang, Xiuhua; Wang, Shengfu

    2013-01-01

    We describe a molecularly imprinted electrochemical sensor for selective and sensitive determination of β2-agonists. It is making use of a combination of single-wall carbon nanotubes (SWNTs) with a molecularly imprinted sol–gel. The SWNTs were introduced in order to enhance electron transport and sensitivity. The imprinted sol–gel film with its specific binding sites acts as a selective recognition element and as a preconcentrator for β 2 -agonists. The morphology of the imprinted film was characterized by scanning electron microscopy. The optimized sensor displays high sensitivity and excellent selectivity for the β 2 -agonists as shown for their determination in human serum samples. (author)

  13. Estrogen receptor beta-selective agonists stimulate calcium oscillations in human and mouse embryonic stem cell-derived neurons.

    Directory of Open Access Journals (Sweden)

    Lili Zhang

    2010-07-01

    Full Text Available Estrogens are used extensively to treat hot flashes in menopausal women. Some of the beneficial effects of estrogens in hormone therapy on the brain might be due to nongenomic effects in neurons such as the rapid stimulation of calcium oscillations. Most studies have examined the nongenomic effects of estrogen receptors (ER in primary neurons or brain slices from the rodent brain. However, these cells can not be maintained continuously in culture because neurons are post-mitotic. Neurons derived from embryonic stem cells could be a potential continuous, cell-based model to study nongenomic actions of estrogens in neurons if they are responsive to estrogens after differentiation. In this study ER-subtype specific estrogens were used to examine the role of ERalpha and ERbeta on calcium oscillations in neurons derived from human (hES and mouse embryonic stem cells. Unlike the undifferentiated hES cells the differentiated cells expressed neuronal markers, ERbeta, but not ERalpha. The non-selective ER agonist 17beta-estradiol (E(2 rapidly increased [Ca2+]i oscillations and synchronizations within a few minutes. No change in calcium oscillations was observed with the selective ERalpha agonist 4,4',4''-(4-Propyl-[1H]-pyrazole-1,3,5-triyltrisphenol (PPT. In contrast, the selective ERbeta agonists, 2,3-bis(4-Hydroxyphenyl-propionitrile (DPN, MF101, and 2-(3-fluoro-4-hydroxyphenyl-7-vinyl-1,3 benzoxazol-5-ol (ERB-041; WAY-202041 stimulated calcium oscillations similar to E(2. The ERbeta agonists also increased calcium oscillations and phosphorylated PKC, AKT and ERK1/2 in neurons derived from mouse ES cells, which was inhibited by nifedipine demonstrating that ERbeta activates L-type voltage gated calcium channels to regulate neuronal activity. Our results demonstrate that ERbeta signaling regulates nongenomic pathways in neurons derived from ES cells, and suggest that these cells might be useful to study the nongenomic mechanisms of estrogenic compounds.

  14. Medium chain fatty acids are selective peroxisome proliferator activated receptor (PPAR γ activators and pan-PPAR partial agonists.

    Directory of Open Access Journals (Sweden)

    Marcelo Vizoná Liberato

    Full Text Available Thiazolidinediones (TZDs act through peroxisome proliferator activated receptor (PPAR γ to increase insulin sensitivity in type 2 diabetes (T2DM, but deleterious effects of these ligands mean that selective modulators with improved clinical profiles are needed. We obtained a crystal structure of PPARγ ligand binding domain (LBD and found that the ligand binding pocket (LBP is occupied by bacterial medium chain fatty acids (MCFAs. We verified that MCFAs (C8-C10 bind the PPARγ LBD in vitro and showed that they are low-potency partial agonists that display assay-specific actions relative to TZDs; they act as very weak partial agonists in transfections with PPARγ LBD, stronger partial agonists with full length PPARγ and exhibit full blockade of PPARγ phosphorylation by cyclin-dependent kinase 5 (cdk5, linked to reversal of adipose tissue insulin resistance. MCFAs that bind PPARγ also antagonize TZD-dependent adipogenesis in vitro. X-ray structure B-factor analysis and molecular dynamics (MD simulations suggest that MCFAs weakly stabilize C-terminal activation helix (H 12 relative to TZDs and this effect is highly dependent on chain length. By contrast, MCFAs preferentially stabilize the H2-H3/β-sheet region and the helix (H 11-H12 loop relative to TZDs and we propose that MCFA assay-specific actions are linked to their unique binding mode and suggest that it may be possible to identify selective PPARγ modulators with useful clinical profiles among natural products.

  15. Novel 2-aminotetralin and 3-aminochroman derivatives as selective serotonin 5-HT7 receptor agonists and antagonists.

    Science.gov (United States)

    Holmberg, Pär; Sohn, Daniel; Leideborg, Robert; Caldirola, Patrizia; Zlatoidsky, Pavel; Hanson, Sverker; Mohell, Nina; Rosqvist, Susanne; Nordvall, Gunnar; Johansson, Anette M; Johansson, Rolf

    2004-07-29

    The understanding of the physiological role of the G-protein coupled serotonin 5-HT(7) receptor is largely rudimentary. Therefore, selective and potent pharmacological tools will add to the understanding of serotonergic effects mediated through this receptor. In this report, we describe two compound classes, chromans and tetralins, encompassing compounds with nanomolar affinity for the 5-HT(7) receptor and with good selectivity. Within theses classes, we have discovered both agonists and antagonists that can be used for further understanding of the pharmacology of the 5-HT(7) receptor.

  16. Selective adenosine A2A receptor agonists and antagonists protect against spinal cord injury through peripheral and central effects

    Directory of Open Access Journals (Sweden)

    Esposito Emanuela

    2011-04-01

    Full Text Available Abstract Background Permanent functional deficits following spinal cord injury (SCI arise both from mechanical injury and from secondary tissue reactions involving inflammation. Enhanced release of adenosine and glutamate soon after SCI represents a component in the sequelae that may be responsible for resulting functional deficits. The role of adenosine A2A receptor in central ischemia/trauma is still to be elucidated. In our previous studies we have demonstrated that the adenosine A2A receptor-selective agonist CGS21680, systemically administered after SCI, protects from tissue damage, locomotor dysfunction and different inflammatory readouts. In this work we studied the effect of the adenosine A2A receptor antagonist SCH58261, systemically administered after SCI, on the same parameters. We investigated the hypothesis that the main action mechanism of agonists and antagonists is at peripheral or central sites. Methods Spinal trauma was induced by extradural compression of SC exposed via a four-level T5-T8 laminectomy in mouse. Three drug-dosing protocols were utilized: a short-term systemic administration by intraperitoneal injection, a chronic administration via osmotic minipump, and direct injection into the spinal cord. Results SCH58261, systemically administered (0.01 mg/kg intraperitoneal. 1, 6 and 10 hours after SCI, reduced demyelination and levels of TNF-α, Fas-L, PAR, Bax expression and activation of JNK mitogen-activated protein kinase (MAPK 24 hours after SCI. Chronic SCH58261 administration, by mini-osmotic pump delivery for 10 days, improved the neurological deficit up to 10 days after SCI. Adenosine A2A receptors are physiologically expressed in the spinal cord by astrocytes, microglia and oligodendrocytes. Soon after SCI (24 hours, these receptors showed enhanced expression in neurons. Both the A2A agonist and antagonist, administered intraperitoneally, reduced expression of the A2A receptor, ruling out the possibility that the

  17. β-agonists selectively modulate proinflammatory gene expression in skeletal muscle cells via non-canonical nuclear crosstalk mechanisms.

    Directory of Open Access Journals (Sweden)

    Krzysztof Kolmus

    Full Text Available The proinflammatory cytokine Tumour Necrosis Factor (TNF-α is implicated in a variety of skeletal muscle pathologies. Here, we have investigated how in vitro cotreatment of skeletal muscle C2C12 cells with β-agonists modulates the TNF-α-induced inflammatory program. We observed that C2C12 myotubes express functional TNF receptor 1 (TNF-R1 and β2-adrenoreceptors (β2-ARs. TNF-α activated the canonical Nuclear Factor-κB (NF-κB pathway and Mitogen-Activated Protein Kinases (MAPKs, culminating in potent induction of NF-κB-dependent proinflammatory genes. Cotreatment with the β-agonist isoproterenol potentiated the expression of inflammatory mediators, including Interleukin-6 (IL-6 and several chemokines. The enhanced production of chemotactic factors upon TNF-α/isoproterenol cotreatment was also suggested by the results from migrational analysis. Whereas we could not explain our observations by cytoplasmic crosstalk, we found that TNF-R1-and β2-AR-induced signalling cascades cooperate in the nucleus. Using the IL-6 promoter as a model, we demonstrated that TNF-α/isoproterenol cotreatment provoked phosphorylation of histone H3 at serine 10, concomitant with enhanced promoter accessibility and recruitment of the NF-κB p65 subunit, cAMP-response element-binding protein (CREB, CREB-binding protein (CBP and RNA polymerase II. In summary, we show that β-agonists potentiate TNF-α action, via nuclear crosstalk, that promotes chromatin relaxation at selected gene promoters. Our data warrant further study into the mode of action of β-agonists and urge for caution in their use as therapeutic agents for muscular disorders.

  18. Nonsteroidal Selective Androgen Receptor Modulators and Selective Estrogen Receptor β Agonists Moderate Cognitive Deficits and Amyloid-β Levels in a Mouse Model of Alzheimer’s Disease

    Science.gov (United States)

    2013-01-01

    Decreases of the sex steroids, testosterone and estrogen, are associated with increased risk of Alzheimer’s disease. Testosterone and estrogen supplementation improves cognitive deficits in animal models of Alzheimer’s disease. Sex hormones play a role in the regulation of amyloid-β via induction of the amyloid-β degrading enzymes neprilysin and insulin-degrading enzyme. To mimic the effect of dihydrotestosterone (DHT), we administered a selective androgen receptor agonist, ACP-105, alone and in combination with the selective estrogen receptor β (ERβ) agonist AC-186 to male gonadectomized triple transgenic mice. We assessed long-term spatial memory in the Morris water maze, spontaneous locomotion, and anxiety-like behavior in the open field and in the elevated plus maze. We found that ACP-105 given alone decreases anxiety-like behavior. Furthermore, when ACP-105 is administered in combination with AC-186, they increase the amyloid-β degrading enzymes neprilysin and insulin-degrading enzyme and decrease amyloid-β levels in the brain as well as improve cognition. Interestingly, the androgen receptor level in the brain was increased by chronic treatment with the same combination treatment, ACP-105 and AC-186, not seen with DHT or ACP-105 alone. Based on these results, the beneficial effect of the selective ERβ agonist as a potential therapeutic for Alzheimer’s disease warrants further investigation. PMID:24020966

  19. Role of dopamine D4 receptors in copulatory behavior: Studies with selective D4 agonists and antagonists in male rats.

    Science.gov (United States)

    Sanna, Fabrizio; Contini, Andrea; Melis, Maria Rosaria; Argiolas, Antonio

    2015-10-01

    Dopamine influences the anticipatory and consummatory phases of sexual behavior, by acting on receptors of the D2 family (D2, D3 and D4) and in particular of the D2 subtype, although evidence for a role of D4 receptors in erectile function and copulatory behavior is also available. In order to clarify such a role of D4 receptors, the effect of selective D4 receptor agonists and antagonists on copulatory behavior of sexually potent male rats in classic copulation tests with a receptive female, was compared with that of apomorphine and haloperidol, a classic dopamine receptor agonist and antagonist, respectively. PD-168,077 (0.05-0.2mg/kg) and ABT-724 (0.01-0.04mg/kg), two selective D4 receptor agonists, given subcutaneously, improved dose-dependently copulatory behavior as shown by the decrease of mount frequency and post ejaculatory interval induced by PD-168,077, and of mount frequency, ejaculation latency, post ejaculatory and inter intromission intervals induced by ABT-724, and by the increase of ejaculation frequency and copulatory efficacy induced by both drugs. Conversely, L-745,870 (1-5mg/kg), a selective D4 receptor antagonist, given intraperitoneally, impaired dose-dependently copulatory behavior, as shown by the increase in intromission and ejaculation latencies, mount frequency, post ejaculatory interval and the decrease in ejaculation frequency and copulatory efficacy induced by this drug. L-745,870 (5mg/kg) administered before PD-168,077 (0.2mg/kg) or ABT-724 (0.04mg/kg), also abolished completely the facilitatory effects of both PD-168,077 and ABT-724 on sexual behavior. These results confirm the involvement of D4 receptors in specific aspects of male rat copulatory behavior that overlap only partially with those influenced by apomorphine and haloperidol. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Studies To Examine Potential Tolerability Differences between the 5-HT2C Receptor Selective Agonists Lorcaserin and CP-809101.

    Science.gov (United States)

    Higgins, Guy A; Silenieks, Leonardo B; Patrick, Amy; De Lannoy, Ines A M; Fletcher, Paul J; Parker, Linda A; MacLusky, Neil J; Sullivan, Laura C; Chavera, Teresa A; Berg, Kelly A

    2017-05-17

    Lorcaserin (LOR) is a selective 5-HT 2C receptor agonist that has been FDA approved as a treatment for obesity. The most frequently reported side-effects of LOR include nausea and headache, which can be dose limiting. We have previously reported that in the rat, while LOR produced unconditioned signs characteristic of nausea/malaise, the highly selective 5-HT 2C agonist CP-809101 (CP) produced fewer equivalent signs. Because this may indicate a subclass of 5-HT 2C agonists having better tolerability, the present studies were designed to further investigate this apparent difference. In a conditioned gaping model, a rodent test of nausea, LOR produced significantly higher gapes compared to CP consistent with it having higher emetogenic properties. Subsequent studies were designed to identify features of each drug that may account for such differences. In rats trained to discriminate CP-809101 from saline, both CP and LOR produced full generalization suggesting a similar interoceptive cue. In vitro tests of functional selectivity designed to examine signaling pathways activated by both drugs in CHO (Chinese hamster ovary) cells expressing h5-HT 2C receptors failed to identify evidence for biased signaling differences between LOR and CP. Thus, both drugs showed similar profiles across PLC, PLA 2 , and ERK signaling pathways. In studies designed to examine pharmacokinetic differences between LOR and CP, while drug plasma levels correlated with increasing dose, CSF levels did not. CSF levels of LOR increased proportionally with dose; however CSF levels of CP plateaued from 6 to 12 mg/kg. Thus, the apparently improved tolerability of CP likely reflects a limit to CNS levels attained at relatively high doses.

  1. The selective alpha7 nicotinic acetylcholine receptor agonist A-582941 activates immediate early genes in limbic regions of the forebrain

    DEFF Research Database (Denmark)

    Thomsen, M S; Mikkelsen, J D; Timmermann, D B

    2008-01-01

    to study whether alpha7 nAChR stimulation activates brain regions involved in cognition in juvenile as well as adult individuals. Here, we compared the effects of the novel and selective alpha7 nAChR agonist 2-methyl-5-(6-phenyl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyrrole (A-582941) in the juvenile...... regions critically involved in working memory and attention. Furthermore, this effect is more pronounced in juvenile than adult rats, indicating that the juvenile forebrain is more responsive to alpha7 nAChR stimulation. This observation may be relevant in the treatment of juvenile-onset schizophrenia....

  2. Differential Regulation of Receptor Activation and Agonist Selectivity by Highly Conserved Tryptophans in the Nicotinic Acetylcholine Receptor Binding Site

    OpenAIRE

    Williams, Dustin K.; Stokes, Clare; Horenstein, Nicole A.; Papke, Roger L.

    2009-01-01

    We have shown previously that a highly conserved Tyr in the nicotinic acetylcholine receptor (nAChR) ligand-binding domain (LBD) (α7 Tyr188 or α4 Tyr195) differentially regulates the activity of acetylcholine (ACh) and the α7-selective agonist 3-(4-hydroxy,2-methoxybenzylidene)anabaseine (4OH-GTS-21) in α4β2 and α7 nAChR. In this study, we mutated two highly conserved LBD Trp residues in human α7 and α4β2 and expressed the receptors in Xenopus laevis oocytes. α7 Re...

  3. Labeling and preliminary in vivo evaluation of the 5-HT7 receptor selective agonist [(11)C]E-55888

    DEFF Research Database (Denmark)

    Hansen, Hanne D; Andersen, Valdemar L; Lehel, Szabolcs

    2015-01-01

    E-55888 has been identified as a selective serotonin 7 (5-HT7) receptor agonist. In this study, we describe the synthesis, radiolabeling and in vivo evaluation of [(11)C]E-55888 as a radioligand for positron emission tomography (PET) imaging. [(11)C]E-55888 was obtained by N-methylation of an app...... neither be displaced by the structurally different 5-HT7 receptor ligand SB-269970 nor by self-block with unlabeled E-55888. Based on these data, [(11)C]E-55888 does not show promise as a PET radioligand for imaging the 5-HT7 receptor in vivo....

  4. Structural optimization and structure-functional selectivity relationship studies of G protein-biased EP2 receptor agonists.

    Science.gov (United States)

    Ogawa, Seiji; Watanabe, Toshihide; Moriyuki, Kazumi; Goto, Yoshikazu; Yamane, Shinsaku; Watanabe, Akio; Tsuboi, Kazuma; Kinoshita, Atsushi; Okada, Takuya; Takeda, Hiroyuki; Tani, Kousuke; Maruyama, Toru

    2016-05-15

    The modification of the novel G protein-biased EP2 agonist 1 has been investigated to improve its G protein activity and develop a better understanding of its structure-functional selectivity relationship (SFSR). The optimization of the substituents on the phenyl ring of 1, followed by the inversion of the hydroxyl group on the cyclopentane moiety led to compound 9, which showed a 100-fold increase in its G protein activity compared with 1 without any increase in β-arrestin recruitment. Furthermore, SFSR studies revealed that the combination of meta and para substituents on the phenyl moiety was crucial to the functional selectivity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Delta/mu opioid receptor interactions in operant conditioning assays of pain-depressed responding and drug-induced rate suppression: assessment of therapeutic index in male Sprague Dawley rats.

    Science.gov (United States)

    Cone, Katherine; Lanpher, Janell; Kinens, Abigail; Richard, Philomena; Couture, Sarah; Brackin, Rebecca; Payne, Emily; Harrington, Kylee; Rice, Kenner C; Stevenson, Glenn W

    2018-05-01

    Although delta/mu receptor interactions vary as a function of behavioral endpoint, there have been no assessments of these interactions using assays of pain-depressed responding. This is the first report of delta/mu interactions using an assay of pain-depressed behavior. A mult-cycle FR10 operant schedule was utilized in the presence of (nociception) and in the absence of (rate suppression) a lactic acid inflammatory pain-like manipulation. SNC80 and methadone were used as selective/high efficacy delta and mu agonists, respectively. Both SNC80 and methadone alone produced a dose-dependent restoration of pain-depressed responding and dose-dependent response rate suppression. Three fixed ratio mixtures, based on the relative potencies of the drugs in the nociception assay, also produced dose-dependent antinociception and sedation. Isobolographic analysis indicated that all three mixtures produced supra-additive antinociceptive effects and simply additive sedation effects. The therapeutic index (TI) inversely varied as a function of amount of SNC80 in the mixture, such that lower amounts of SNC80 produced a higher TI, and larger amounts produced a lower TI. Compared to literature using standard pain-elicited assays, the orderly relationship between SNC80 and TI reported here may be a unique function of assessing pain-depressed behavior.

  6. Nalfurafine hydrochloride, a selective κ opioid receptor agonist, has no reinforcing effect on intravenous self-administration in rhesus monkeys

    Directory of Open Access Journals (Sweden)

    Kaoru Nakao

    2016-01-01

    Full Text Available Nalfurafine hydrochloride [(E-N-[17-(cyclopropylmethyl-4,5α-epoxy-3,14-dihydroxymorphinan-6β-yl]-3-(furan-3-yl-N-methylprop-2-enamide monohydrochloride; nalfurafine] is used in Japan as an antipruritic for the treatment of intractable pruritus in patients undergoing hemodialysis or with chronic liver disease. It is a potent and selective agonist at the κ opioid receptor, but also has weak and partial agonist activity at μ opioid receptors. Opioids, especially those acting at μ receptors, carry a risk of abuse. This is an important factor in the consideration of therapeutic risk vs. benefit in clinical use and the potential for misuse as a public health problem. It is therefore necessary to carefully evaluate the reinforcing effects of nalfurafine. To this end, we investigated intravenous self-administration of nalfurafine in rhesus monkeys. The number of self-administration of nalfurafine at doses of 0.0625, 0.125 and 0.25 μg/kg/infusion was not higher than that of saline in rhesus monkeys that frequently self-administered pentazocine (0.25 mg/kg/infusion. These results indicate that nalfurafine has no reinforcing effect in rhesus monkeys in the intravenous self-administration paradigm.

  7. Selepressin, a novel selective vasopressin V1A agonist, is an effective substitute for norepinephrine in a phase IIa randomized, placebo-controlled trial in septic shock patients

    DEFF Research Database (Denmark)

    Russell, James A; Vincent, Jean-Louis; Kjølbye, Anne Louise

    2017-01-01

    BACKGROUND: Vasopressin is widely used for vasopressor support in septic shock patients, but experimental evidence suggests that selective V1A agonists are superior. The initial pharmacodynamic effects, pharmacokinetics, and safety of selepressin, a novel V1A-selective vasopressin analogue, was e...

  8. The pharmacology of TD-8954, a potent and selective 5-HT4 receptor agonist with gastrointestinal prokinetic properties

    Directory of Open Access Journals (Sweden)

    David T Beattie

    2011-05-01

    Full Text Available This study evaluated the in vitro and in vivo pharmacological properties of TD-8954, a potent and selective 5-HT4 receptor agonist. TD-8954 had high affinity (pKi = 9.4 for human recombinant 5-HT4(c (h5-HT4(c receptors, and selectivity (> 2,000-fold over all other 5-HT receptors and non-5-HT receptors, ion channels, enzymes and transporters tested (n = 78. TD-8954 produced an elevation of cAMP in HEK-293 cells expressing the h5-HT4(c receptor (pEC50 = 9.3, and contracted the guinea pig colonic longitudinal muscle/myenteric plexus (LMMP preparation (pEC50 = 8.6. TD-8954 had moderate intrinsic activity (IA in the in vitro assays. In conscious guinea pigs, subcutaneous (s.c. administration of TD 8954 (0.03 - 3 mg/kg increased the colonic transit of carmine red dye, reducing the time taken for its excretion. Following intraduodenal (i.d. dosing to anesthetized rats, TD 8954 (0.03 - 10 mg/kg evoked a dose-dependent relaxation of the esophagus. Following oral administration to conscious dogs, TD 8954 (10 and 30 µg/kg produced an increase in contractility of the antrum, duodenum and jejunum. In a single ascending oral dose study in healthy human subjects, TD-8954 (0.1 - 20 mg increased bowel movement frequency and reduced the time to first stool. It is concluded that TD-8954 is a potent and selective 5-HT4 receptor agonist in vitro, with robust in vivo stimulatory activity in the gastrointestinal (GI tract of guinea pigs, rats, dogs and humans. TD-8954 may have clinical utility in patients with disorders of reduced GI motility.

  9. Identification of a potent and selective free fatty acid receptor 1 (FFA1/GPR40) agonist with favorable physicochemical and in vitro ADME properties

    DEFF Research Database (Denmark)

    Christiansen, Elisabeth; Urban, Christian; Grundmann, Manuel

    2011-01-01

    The free fatty acid receptor 1 (FFA1, also known as GPR40) enhances glucose-stimulated insulin secretion from pancreatic ß-cells and is recognized as an interesting new target for treatment of type 2 diabetes. Several series of selective FFA1 agonists are already known. Most of these are derived...... from free fatty acids (FFAs) or glitazones, and are relatively lipophilic. Aiming at the development of potent, selective and less lipophilic FFA1 agonists, the terminal phenyl of a known compound series was replaced by nitrogen containing heterocycles. This resulted in the identification of 37......, a selective FFA1 agonist with potent activity on recombinant human FFA1 receptors and on the rat insulinoma cell line INS-1E, optimal lipophilicity and excellent in vitro permeability and metabolic stability....

  10. Identification and in Vivo Evaluation of Liver X Receptor β-Selective Agonists for the Potential Treatment of Alzheimer’s Disease

    Energy Technology Data Exchange (ETDEWEB)

    Stachel, Shawn J.; Zerbinatti, Celina; Rudd, Michael T.; Cosden, Mali; Suon, Sokreine; Nanda, Kausik K.; Wessner, Keith; DiMuzio, Jillian; Maxwell, Jill; Wu, Zhenhua; Uslaner, Jason M.; Michener, Maria S.; Szczerba, Peter; Brnardic, Edward; Rada, Vanessa; Kim, Yuntae; Meissner, Robert; Wuelfing, Peter; Yuan, Yang; Ballard, Jeanine; Holahan, Marie; Klein, Daniel J.; Lu, Jun; Fradera, Xavier; Parthasarathy, Gopal; Uebele, Victor N.; Chen, Zhongguo; Li, Yingjie; Li, Jian; Cooke, Andrew J.; Bennett, D. Jonathan; Bilodeau, Mark T.; Renger, John (Merck); (WuXi App Tec)

    2016-04-14

    Herein, we describe the development of a functionally selective liver X receptor β (LXRβ) agonist series optimized for Emax selectivity, solubility, and physical properties to allow efficacy and safety studies in vivo. Compound 9 showed central pharmacodynamic effects in rodent models, evidenced by statistically significant increases in apolipoprotein E (apoE) and ATP-binding cassette transporter levels in the brain, along with a greatly improved peripheral lipid safety profile when compared to those of full dual agonists. These findings were replicated by subchronic dosing studies in non-human primates, where cerebrospinal fluid levels of apoE and amyloid-β peptides were increased concomitantly with an improved peripheral lipid profile relative to that of nonselective compounds. These results suggest that optimization of LXR agonists for Emax selectivity may have the potential to circumvent the adverse lipid-related effects of hepatic LXR activity.

  11. Mechanisms of anorexia-cachexia syndrome and rational for treatment with selective ghrelin receptor agonist.

    Science.gov (United States)

    Esposito, Angela; Criscitiello, Carmen; Gelao, Lucia; Pravettoni, Gabriella; Locatelli, Marzia; Minchella, Ida; Di Leo, Maria; Liuzzi, Rita; Milani, Alessandra; Massaro, Mariangela; Curigliano, Giuseppe

    2015-11-01

    Cancer cachexia is a multi-organ, multifactorial and often irreversible syndrome affecting many patients with cancer. Cancer cachexia is invariably associated with weight loss, mainly from loss of skeletal muscle and body fat, conditioning a reduced quality of life due to asthenia, anorexia, anaemia and fatigue. Treatment options for treating cancer cachexia are limited. The approach is multimodal and may include: treatment of secondary gastrointestinal symptoms, nutritional treatments, drug, and non-drug treatments. Nutritional counselling and physical training may be beneficial in delaying or preventing the development of anorexia-cachexia. However, these interventions are limited in their effect, and no definitive pharmacological treatment is available to address the relevant components of the syndrome. Anamorelin is a first-in-class, orally active ghrelin receptor agonist that binds and stimulates the growth hormone secretagogue receptor centrally, thereby mimicking the appetite-enhancing and anabolic effects of ghrelin. It represents a new class of drug and an additional treatment option for this patient group, whose therapeutic options are currently limited. In this review we examine the mechanisms of anamorelin by which it contrasts catabolic states, its role in regulation of metabolism and energy homeostasis, the data of recent trials in the setting of cancer cachexia and its safety profile. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. PARTIAL AGONISTS, FULL AGONISTS, ANTAGONISTS - DILEMMAS OF DEFINITION

    NARCIS (Netherlands)

    HOYER, D; BODDEKE, HWGM

    The absence of selective antagonists makes receptor characterization difficult, and largely dependent on the use of agonists. However, there has been considerable debate as to whether certain drugs acting at G protein-coupled receptors are better described as agonists, partial agonists or

  13. Stereochemical studies of the monocyclic agouti-related protein (103-122) Arg-Phe-Phe residues: conversion of a melanocortin-4 receptor antagonist into an agonist and results in the discovery of a potent and selective melanocortin-1 agonist.

    Science.gov (United States)

    Joseph, Christine G; Wang, Xiang S; Scott, Joseph W; Bauzo, Rayna M; Xiang, Zhimin; Richards, Nigel G; Haskell-Luevano, Carrie

    2004-12-30

    The agouti-related protein (AGRP) is an endogenous antagonist of the centrally expressed melanocortin receptors. The melanocortin-4 receptor (MC4R) is involved in energy homeostasis, food intake, sexual function, and obesity. The endogenous hAGRP protein is 132 amino acids in length, possesses five disulfide bridges at the C-terminus of the molecule, and is expressed in the hypothalamus of the brain. We have previously reported that a monocyclic hAGRP(103-122) peptide is an antagonist at the melanocortin receptors expressed in the brain. Stereochemical inversion from the endogenous l- to d-isomers of single or multiple amino acid modifications in this monocyclic truncated hAGRP sequence resulted in molecules that are converted from melanocortin receptor antagonists into melanocortin receptor agonists. The Asp-Pro-Ala-Ala-Thr-Ala-Tyr-cyclo[Cys-Arg-DPhe-DPhe-Asn-Ala-Phe-Cys]-Tyr-Ala-Arg-Lys-Leu peptide resulted in a 60 nM melanocortin-1 receptor agonist that is 100-fold selective versus the mMC4R, 1000-fold selective versus the mMC3R, and ca. 180-fold selective versus the mMC5R. In attempts to identify putative ligand-receptor interactions that may be participating in the agonist induced stimulation of the MC4R, selected ligands were docked into a homology molecular model of the mMC4R. These modeling studies have putatively identified hAGRP ligand DArg111-mMC4RAsn115 (TM3) and the hAGRP DPhe113-mMC4RPhe176 (TM4) interactions as important for agonist activity.

  14. Role of estrogen receptor β selective agonist in ameliorating portal hypertension in rats with CCl4-induced liver cirrhosis.

    Science.gov (United States)

    Zhang, Cheng-Gang; Zhang, Bin; Deng, Wen-Sheng; Duan, Ming; Chen, Wei; Wu, Zhi-Yong

    2016-05-14

    To investigate the role of diarylpropionitrile (DPN), a selective agonist of estrogen receptor β (ERβ), in liver cirrhosis with portal hypertension (PHT) and isolated hepatic stellate cells (HSCs). Female Sprague-Dawley rats were ovariectomized (OVX), and liver cirrhosis with PHT was induced by CCl4 injection. DPN and PHTPP, the selective ERβ agonist and antagonist, were used as drug interventions. Liver fibrosis was assessed by hematoxylin and eosin (HE) and Masson's trichrome staining and by analyzing smooth muscle actin expression. Hemodynamic parameters were determined in vivo using colored microspheres technique. Protein expression and phosphorylation were determined by immunohistochemical staining and Western blot analysis. Messenger RNA levels were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). Collagen gel contraction assay was performed using gel lattices containing HSCs treated with DPN, PHTPP, or Y-27632 prior to ET-1 addition. Treatment with DPN in vivo greatly lowered portal pressure and improved hemodynamic parameters without affecting mean arterial pressure, which was associated with the attenuation of liver fibrosis and intrahepatic vascular resistance (IHVR). In CCl4-treated rat livers, DPN significantly decreased the expression of RhoA and ROCK II, and even suppressed ROCK II activity. Moreover, DPN remarkedly increased the levels of endothelial nitric oxide synthase (eNOS) and phosphorylated eNOS, and promoted the activities of protein kinase G (PKG), which is an NO effector in the liver. Furthermore, DPN reduced the contractility of activated HSCs in the 3-dimensional stress-relaxed collagen lattices, and decreased the ROCK II activity in activated HSCs. Finally, in vivo/in vitro experiments demonstrated that MLC activity was inhibited by DPN. For OVX rats with liver cirrhosis, DPN suppressed liver RhoA/ROCK signal, facilitated NO/PKG pathways, and decreased IHVR, giving rise to reduced portal pressure. Therefore, DPN

  15. A Novel Selective Inverse Agonist of the CB2 Receptor as a Radiolabeled Tool Compound for Kinetic Binding Studies.

    Science.gov (United States)

    Martella, Andrea; Sijben, Huub; Rufer, Arne C; Grether, Uwe; Fingerle, Juergen; Ullmer, Christoph; Hartung, Thomas; IJzerman, Adriaan P; van der Stelt, Mario; Heitman, Laura H

    2017-10-01

    The endocannabinoid system, and in particular the cannabinoid type 2 receptor (CB2R), raised the interest of many medicinal chemistry programs for its therapeutic relevance in several (patho)physiologic processes. However, the physico-chemical properties of tool compounds for CB2R (e.g., the radioligand [ 3 H]CP55,940) are not optimal, despite the research efforts in developing effective drugs to target this system. At the same time, the importance of drug-target binding kinetics is growing since the kinetic binding profile of a ligand may provide important insights for the resulting in vivo efficacy. In this context we synthesized and characterized [ 3 H]RO6957022, a highly selective CB2R inverse agonist, as a radiolabeled tool compound. In equilibrium and kinetic binding experiments [ 3 H]RO6957022 showed high affinity for human CB2R with fast association ( k on ) and moderate dissociation ( k off ) kinetics. To demonstrate the robustness of [ 3 H]RO6957022 binding, affinity studies were carried out for a wide range of CB2R reference ligands, spanning the range of full, partial, and inverse agonists. Finally, we used [ 3 H]RO6957022 to study the kinetic binding profiles (i.e., k on and k off values) of selected synthetic and endogenous (i.e., 2-arachidonoylglycerol, anandamide, and noladin ether) CB2R ligands by competition association experiments. All tested ligands, and in particular the endocannabinoids, displayed distinct kinetic profiles, shedding more light on their mechanism of action and the importance of association rates in the determination of CB2R affinity. Altogether, this study shows that the use of a novel tool compound, i.e., [ 3 H]RO6957022, can support the development of novel ligands with a repertoire of kinetic binding profiles for CB2R. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

  16. Spinal antinociceptive effects of [D-Ala2]deltorphin II, a novel and highly selective delta-opioid receptor agonist.

    Science.gov (United States)

    Improta, G; Broccardo, M

    1992-01-01

    Pharmacological assays in isolated tissues and binding tests have recently shown that two peptides, with the sequence Tyr-D-Ala-Phe-Asp-(or Glu)- Val-Val-Gly-NH2, isolated from skin extracts of Phyllomedusa bicolor and named [D-Ala2]deltorphin I and II, respectively, possess a higher affinity and selectivity for delta-opioid receptors than any other known natural compound. Since much evidence supports the role of spinal delta-opioid sites in producing antinociceptive effects, we investigated whether analgesia might be detected by direct spinal cord administration of [D-Ala2]deltorphin II (DADELT II) in the rat. The thermal antinociceptive effects of intrathecal DADELT II and dermorphin, a potent mu-selective agonist, were compared at different postinjection times by means of the tail-flick test. The DADELT II produced a dose-related inhibition of the tail-flick response, which lasted 10-60 min depending on the dose and appeared to be of shorter duration than the analgesia produced in rats after intrathecal injection of dermorphin (20-120 min). The analgesic effect of infused or injected DADELT II was completely abolished by naltrindole, the highly selective delta antagonist. These results confirm the involvement of delta receptors in spinal analgesic activity in the rat.

  17. Comparative Structural Analysis of ERa and ERb Bound to Selective Estrogen Agonists and Antagonists

    National Research Council Canada - National Science Library

    Greene, Geoffrey

    2001-01-01

    ...) complexed with receptor-selective estrogens and antiestrogens (SERMs) The crystallographic structures of ERalpha and ERbeta ligand binding domains complexed with cis-R,R-diethyl-tetrahydrochrysene-2,8-diol (R,R-THC...

  18. Comparative Structural Analysis of ERa and ERb Bound to Selective Estrogen Agonists and Antagonists

    National Research Council Canada - National Science Library

    Greene, Geoggrey

    2000-01-01

    ...) complexed with receptor-selective estrogens and antiestrogens (SERMs). The crystallographic structures of ERalpha and ERbeta ligand binding domains complexed with cis- R,R-diethyl-tetrahydrochrysene-2, 8 -diol (R,R-THC...

  19. [3H]CGS 21680, a selective A2 adenosine receptor agonist directly labels A2 receptors in rat brain

    International Nuclear Information System (INIS)

    Jarvis, M.F.; Schulz, R.; Hutchison, A.J.; Do, U.H.; Sills, M.A.; Williams, M.

    1989-01-01

    In the present study, the binding of a highly A2-selective agonist radioligand, [3H]CGS 21680 (2-[p-(2-carboxyethyl)-phenethylamino]-5'-N-ethylcarboxamido adenosine) is described. [3H]CGS 21680 specific binding to rat striatal membranes was saturable, reversible and dependent upon protein concentration. Saturation studies revealed that [3H]CGS 21680 bound with high affinity (Kd = 15.5 nM) and limited capacity (apparent Bmax = 375 fmol/mg of protein) to a single class of recognition sites. Estimates of ligand affinity (16 nM) determined from association and dissociation kinetic experiments were in close agreement with the results from the saturation studies. [3H]CGS 21680 binding was greatest in striatal membranes with negligible specific binding obtained in rat cortical membranes. Adenosine agonists ligands competed for the binding of 5 nM [3H]CGS 21680 to striatal membranes with the following order of activity; CGS 21680 = 5'-N-ethylcarboxamidoadenosine greater than 2-phenylaminoadenosine (CV-1808) = 5'-N-methylcarboxamidoadenosine = 2-chloroadenosine greater than R-phenylisopropyladenosine greater than N6-cyclohexyladenosine greater than N6cyclopentyltheophylline greater than S-phenylisopropyladenosine. The nonxanthine adenosine antagonist, CGS 15943A, was the most active compound in inhibiting the binding of [3H]CGS 21680. Other adenosine antagonists inhibited binding in the following order; xanthine amine congener = 1,3-dipropyl-8-(2-amino-4-chloro)phenylxanthine greater than 1,3-dipropyl-8-cyclopentylxanthine greater than 1,3-diethyl-8-phenylxanthine greater than 8-phenyltheophylline greater than 8-cyclopentyltheophylline = xanthine carboxylic acid congener greater than 8-parasulfophenyltheophylline greater than theophylline greater than caffeine

  20. Functional investigation of β-adrenoceptors in human isolated detrusor focusing on the novel selective β3-adrenoceptor agonist KUC-7322

    NARCIS (Netherlands)

    Igawa, Yasuhiko; Schneider, Tim; Yamazaki, Yoshinobu; Tatemichi, Satoshi; Homma, Yukio; Nishizawa, Osamu; Michel, Martin C.

    2012-01-01

    This study aimed to characterize the β-adrenoceptor (β-AR) subtype mediating relaxation of isolated human bladder strips and to explore relaxation by the novel β3-AR-selective agonist KUC-7322 for its relaxant effect on the human isolated detrusor and for its effect on the carbachol (CCh)-induced

  1. In vitro pharmacological characterization of a novel selective alpha7 neuronal nicotinic acetylcholine receptor agonist ABT-107.

    Science.gov (United States)

    Malysz, John; Anderson, David J; Grønlien, Jens H; Ji, Jianguo; Bunnelle, William H; Håkerud, Monika; Thorin-Hagene, Kirten; Ween, Hilde; Helfrich, Rosalind; Hu, Min; Gubbins, Earl; Gopalakrishnan, Sujatha; Puttfarcken, Pamela S; Briggs, Clark A; Li, Jinhe; Meyer, Michael D; Dyhring, Tino; Ahring, Philip K; Nielsen, Elsebet Ø; Peters, Dan; Timmermann, Daniel B; Gopalakrishnan, Murali

    2010-09-01

    Enhancement of alpha7 nicotinic acetylcholine receptor (nAChR) activity is considered a therapeutic approach for ameliorating cognitive deficits present in Alzheimer's disease and schizophrenia. In this study, we describe the in vitro profile of a novel selective alpha7 nAChR agonist, 5-(6-[(3R)-1-azabicyclo[2,2,2]oct-3-yloxy]pyridazin-3-yl)-1H-indole (ABT-107). ABT-107 displayed high affinity binding to alpha7 nAChRs [rat or human cortex, [(3)H](1S,4S)-2,2-dimethyl-5-(6-phenylpyridazin-3-yl)-5-aza-2-azoniabicyclo[2.2.1]heptane (A-585539), K(i) = 0.2-0.6 nM or [(3)H]methyllycaconitine (MLA), 7 nM] that was at least 100-fold selective versus non-alpha7 nAChRs and other receptors. Functionally, ABT-107 did not evoke detectible currents in Xenopus oocytes expressing human or nonhuman alpha3beta4, chimeric (alpha6/alpha3)beta4, or 5-HT(3A) receptors, and weak or negligible Ca(2+) responses in human neuroblastoma IMR-32 cells (alpha3* function) and human alpha4beta2 and alpha4beta4 nAChRs expressed in human embryonic kidney 293 cells. ABT-107 potently evoked human and rat alpha7 nAChR current responses in oocytes (EC(50), 50-90 nM total charge, approximately 80% normalized to acetylcholine) that were enhanced by the positive allosteric modulator (PAM) 4-[5-(4-chloro-phenyl)-2-methyl-3-propionyl-pyrrol-1-yl]-benzenesulfonamide (A-867744). In rat hippocampus, ABT-107 alone evoked alpha7-like currents, which were inhibited by the alpha7 antagonist MLA. In dentate gyrus granule cells, ABT-107 enhanced spontaneous inhibitory postsynaptic current activity when coapplied with A-867744. In the presence of an alpha7 PAM [A-867744 or N-[(3R)-1-azabicyclo[2.2.2]oct-3-yl]-4-chlorobenzamide hydrochloride (PNU-120596)], the addition of ABT-107 elicited MLA-sensitive alpha7 nAChR-mediated Ca(2+) signals in IMR-32 cells and rat cortical cultures and enhanced extracellular signal-regulated kinase phosphorylation in differentiated PC-12 cells. ABT-107 was also effective in protecting rat

  2. Interaction between Mu and Delta Opioid Receptor Agonists in an Assay of Capsaicin-Induced Thermal Allodynia in Rhesus Monkeys

    Directory of Open Access Journals (Sweden)

    S. Stevens Negus

    2012-01-01

    Full Text Available Delta opioid agonists enhance antinociceptive effects of mu-opioid agonists in many preclinical assays of acute nociception, but delta/mu interactions in preclinical models of inflammation-associated pain have not been examined. This study examined interactions between the delta agonist SNC80 [(+-4-[(αR-α-((2S,5R-4-allyl-2,5-dimethyl-1-piperazinyl-3-methoxybenzyl]-N,N-diethylbenzamide] and the mu agonist analgesics methadone, morphine, and nalbuphine in an assay of capsaicin-induced thermal allodynia in rhesus monkeys. Thermal allodynia was produced by topical application of capsaicin to the tail. Antiallodynic effects of methadone, morphine, and nalbuphine were evaluated alone or in combination with fixed proportions of SNC80 identical to proportions previously shown to enhance acute thermal antinociceptive effects of these mu agonists in rhesus monkeys (0.9 : 1 SNC80/methadone; 0.29 : 1 SNC80/morphine; 3.6 : 1 SNC80/nalbuphine. Methadone, morphine, and nalbuphine each produced dose-dependent antiallodynia. SNC80 produced partial antiallodynia up to the highest dose tested (5.6 mg/kg. SNC80 produced a modest, enantioselective, and naltrindole-reversible enhancement of methadone-induced antiallodynia. However, SNC80 did not enhance morphine antiallodynia and only weakly enhanced nalbuphine antiallodynia. Overall, SNC80 produced modest or no enhancement of the antiallodynic effects of the three mu agonists evaluated. These results suggest that delta agonist-induced enhancement of mu agonist antiallodynia may be weaker and less reliable than previously demonstrated enhancement of mu agonist acute thermal nociception.

  3. Ethylphenidate as a selective dopaminergic agonist and methylphenidate-ethanol transesterification biomarker.

    Science.gov (United States)

    Patrick, Kennerly S; Corbin, Timothy R; Murphy, Cristina E

    2014-12-01

    We review the pharmaceutical science of ethylphenidate (EPH) in the contexts of drug discovery, drug interactions, biomarker for dl-methylphenidate (MPH)-ethanol exposure, potentiation of dl-MPH abuse liability, contemporary "designer drug," pertinence to the newer transdermal and chiral switch MPH formulations, as well as problematic internal standard. d-EPH selectively targets the dopamine transporter, whereas d-MPH exhibits equipotent actions at dopamine and norepinephrine transporters. This selectivity carries implications for the advancement of tailored attention-deficit/hyperactivity disorder (ADHD) pharmacotherapy in the era of genome-based diagnostics. Abuse of dl-MPH often involves ethanol coabuse. Carboxylesterase 1 enantioselectively transesterifies l-MPH with ethanol to yield l-EPH accompanied by significantly increased early exposure to d-MPH and rapid potentiation of euphoria. The pharmacokinetic component of this drug interaction can largely be avoided using dexmethylphenidate (dexMPH). This notwithstanding, maximal potentiated euphoria occurs following dexMPH-ethanol. C57BL/6 mice model dl-MPH-ethanol interactions: an otherwise depressive dose of ethanol synergistically increases dl-MPH stimulation; a substimulatory dose of dl-MPH potentiates a low, stimulatory dose of ethanol; ethanol elevates blood, brain, and urinary d-MPH concentrations while forming l-EPH. Integration of EPH preclinical neuropharmacology with clinical studies of MPH-ethanol interactions provides a translational approach toward advancement of ADHD personalized medicine and management of comorbid alcohol use disorder. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  4. Discovery of a potent and selective free fatty acid receptor 1 agonist with low lipophilicity and high oral bioavailability

    DEFF Research Database (Denmark)

    Christiansen, Elisabeth; Due-Hansen, Maria E; Urban, Christian

    2013-01-01

    The free fatty acid receptor 1 (FFA1, also known as GPR40) mediates enhancement of glucose-stimulated insulin secretion and is emerging as a new target for the treatment of type 2 diabetes. Several FFA1 agonists are known, but the majority of these suffer from high lipophilicity. We have previously...... reported the FFA1 agonist 3 (TUG-424). We here describe the continued structure-activity exploration and optimization of this compound series, leading to the discovery of the more potent agonist 40, a compound with low lipophilicity, excellent in vitro metabolic stability and permeability, complete oral...

  5. Selective kappa-opioid agonists: synthesis and structure-activity relationships of piperidines incorporating on oxo-containing acyl group.

    Science.gov (United States)

    Giardina, G; Clarke, G D; Dondio, G; Petrone, G; Sbacchi, M; Vecchietti, V

    1994-10-14

    This study describes the synthesis and the structure-activity relationships (SARs) of the (S)-(-)-enantiomers of a novel class of 2-(aminomethyl)piperidine derivatives, using kappa-opioid binding affinity and antinociceptive potency as the indices of biological activity. Compounds incorporating the 1-tetralon-6-ylacetyl residue (30 and 34-45) demonstrated an in vivo antinociceptive activity greater than predicted on the basis of their kappa-binding affinities. In particular, (2S)-2-[(dimethylamino)methyl]-1-[(5,6,7,8-tetrahydro-5-oxo-2- naphthyl)acetyl]piperidine (34) was found to have a potency similar to spiradoline in animal models of antinociception after subcutaneous administration, with ED50s of 0.47 and 0.73 mumol/kg in the mouse and in the rat abdominal constriction tests, respectively. Further in vivo studies in mice and/or rats revealed that compound 34, compared to other selective kappa-agonists, has a reduced propensity to cause a number of kappa-related side effects, including locomotor impairment/sedation and diuresis, at antinociceptive doses. For example, it has an ED50 of 26.5 mumol/kg sc in the rat rotarod model, exhibiting a ratio of locomotor impairment/sedation vs analgesia of 36. Possible reasons for this differential activity and its clinical consequence are discussed.

  6. Investigational hormone receptor agonists as ongoing female contraception: a focus on selective progesterone receptor modulators in early clinical development.

    Science.gov (United States)

    Nelson, Anita L

    2015-01-01

    As efforts are made to continue to increase the safety of contraceptive methods, those without estrogen have attracted new attention. Progestin-only options are available in many delivery systems, but most cause disturbed bleeding patterns. For gynecologic patients, selective progesterone receptor modulators (SPRMs) have been approved for medical abortion, for ovulation suppression in emergency contraception, and for the treatment of heavy menstrual bleeding due to leiomyoma. This article discusses the role of SPRMs in controlling fertility on an ongoing basis with particular emphasis on mifepristone and ulipristal acetate (UPA), since none of the other compounds has progressed out of early Phase I - II testing. It also discusses important information about the mechanisms of action and safety of these two SPRMs. Of all the investigational hormone agonist/antagonists, SPRMs have demonstrated the greatest potential as ongoing female contraceptives. They have the ability to suppress ovulation after initiation of the luteinizing hormone (LH) surge without affecting ovarian production of estrogen or inducing any significant metabolic changes. SPRMs may well be able to provide longer term contraception as oral agents, vaginal rings, and perhaps even intrauterine devices. UPA has the greatest promise. Current research needs to be expanded.

  7. Synthesis of [11C]-ohmefentanyl, a novel, highly potent and selective agonist for opiate μ-receptors

    International Nuclear Information System (INIS)

    Zhu, Y.C.; Academia Sinica, Shangha, SH; Prenant, C.; Crouzel, C.; Comar, D.; Chi, Z.Q.

    1992-01-01

    We describe the synthesis of 11 C-ohmefentanyl, a novel, highly potent and selective agonist for opiate μ-receptors, to be visualized by Positron Emission Tomography (PET). The unlabelled cis-A-ohmefentanyl was prepared in a nine-step synthesis and two-step fractional crystallization, and the OH-precursor for [ 11 C]-ohmefentanyl labelling was obtained by hydrolysis of the 4-N-propionyl group of cis-A-ohmefentanyl in 6 N hydrochloric acid. The [ 11 C]-propionyl chloride was prepared by carbonation of ethylmagnesium bromide with cyclotron-produced [ 11 C]-carbon dioxide followed by direct treatment of the intermediate complex with phthaloyl dichloride and 2,6-di-t-butylpyridine. Reaction of the OH-precursor with [ 11 C]-propionyl chloride yields [ 11 C]-ohmefentanyl separated by HPLC, with a high specific activity of 300-400 mCi μmol -1 . The keto-precursor prepared by hydrolysis of the 4-N-propionyl group of cis-10 in 8 N hydrochloric acid, was also used for [ 11 C]-ohmefentanyl labelling. Reaction of the [ 11 C]-propionyl chloride with keto-precursor, followed by addition of sodium borohydride, yields [ 11 C]-ohmefentanyl. The [ 11 C]-labelled ohmefentanyl obtained using the OH-precursor is a cis-A form, while that obtained using the keto-precursor is a mixture of cis-A and cis-B forms. (author)

  8. Experience affects the outcome of agonistic contests without affecting the selective advantage of size.

    Science.gov (United States)

    Kasumovic, Michael M; Elias, Damian O; Punzalan, David; Mason, Andrew C; Andrade, Maydianne C B

    2009-06-01

    In the field, phenotypic determinants of competitive success are not always absolute. For example, contest experience may alter future competitive performance. As future contests are not determined solely on phenotypic attributes, prior experience could also potentially alter phenotype-fitness associations. In this study, we examined the influence of single and multiple experiences on contest outcomes in the jumping spider Phidippus clarus. We also examined whether phenotype-fitness associations altered as individuals gained more experience. Using both size-matched contests and a tournament design, we found that both winning and losing experience affected future contest success; males with prior winning experience were more likely to win subsequent contests. Although experience was a significant determinant of success in future contests, male weight was approximately 1.3 times more important than experience in predicting contest outcomes. Despite the importance of experience in determining contest outcomes, patterns of selection did not change between rounds. Overall, our results show that experience can be an important determinant in contest outcomes, even in short-lived invertebrates, and that experience alone is unlikely to alter phenotype-fitness associations.

  9. Effects of a selective cannabinoid CB2 agonist and antagonist on intravenous nicotine self administration and reinstatement of nicotine seeking.

    Directory of Open Access Journals (Sweden)

    Islam Gamaleddin

    Full Text Available Over the last decade there have been significant advances in the discovery and understanding of the cannabinoid system along with the development of pharmacologic tools that modulate its function. Characterization of the crosstalk between nicotine addiction and the cannabinoid system may have significant implications on our understanding of the neurobiological mechanisms underlying nicotine dependence. Two types of cannabinoid receptors (CB1 and CB2 have been identified. CB1 receptors are expressed in the brain and modulate drug taking and drug seeking for various drugs of abuse, including nicotine. CB2 receptors have been recently identified in the brain and have been proposed to play a functional role in mental disorders and drug addiction. Our objective was to explore the role of CB2 receptors on intravenous nicotine self administration under two schedules of reinforcement (fixed and progressive ratio and on nicotine seeking induced by nicotine priming or by nicotine associated cues. For this, we evaluated the effects of various doses of the selective CB2 antagonist AM630 (1.25 to 5 mg/kg and CB2 agonist AM1241 (1 to 10 mg/kg on these behavioral responses in rats. Different groups of male Long Evans rats were trained to lever press for nicotine at a unit dose of 30 µg/kg/infusion. Subsequently, animals were randomized using a Latin-square design and injected with either AM1241 or AM630 using a counterbalanced within subject design. Administration of the CB2 ligands did not affect either nicotine-taking nicotine-seeking behavior. Our results do not support the involvement of CB2 receptors in nicotine-taking or nicotine-seeking behavior.

  10. Mapracorat, a selective glucocorticoid receptor agonist, causes apoptosis of eosinophils infiltrating the conjunctiva in late-phase experimental ocular allergy

    Directory of Open Access Journals (Sweden)

    Baiula M

    2014-06-01

    Full Text Available Monica Baiula,1 Andrea Bedini,1 Jacopo Baldi,1 Megan E Cavet,2 Paolo Govoni,3 Santi Spampinato11Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy; 2Global Pharmaceutical R&D, Bausch & Lomb Inc., Rochester, NY, USA; 3Department of Biomedical, Biotechnological and Translational Sciences, University of Parma, Parma, ItalyBackground: Mapracorat, a novel nonsteroidal selective glucocorticoid receptor agonist, has been proposed for the topical treatment of inflammatory disorders as it binds with high affinity and selectivity to the human glucocorticoid receptor and displays a potent anti-inflammatory activity, but seems to be less effective in transactivation of a number of genes, resulting in a lower potential for side effects. Contrary to classical glucocorticoids, mapracorat displays a reduced ability to increase intraocular pressure and in inducing myocilin, a protein linked to intraocular pressure elevation. Allergic conjunctivitis is the most common form of ocular allergy and can be divided into an early phase, developing immediately after allergen exposure and driven primarily by mast cell degranulation, and a late phase, developing from 6–10 hours after the antigen challenge, and characterized by conjunctival infiltration of eosinophils and other immune cells as well as by the production of cytokines and chemokines.Methods: In this study, mapracorat was administered into the conjunctival sac of ovalbumin (OVA-sensitized guinea pigs 2 hours after the induction of allergic conjunctivitis, with the aim of investigating its activity in reducing clinical signs of the late-phase ocular reaction and to determine its mechanism of anti-allergic effects with respect to apoptosis of conjunctival eosinophils and expression of the chemokines C-C motif ligand 5 (CCL5, C-C motif ligand 11 (CCL11, and interleukin-8 (IL-8 and the proinflammatory cytokines interleukin-1β (IL-1β and tumor necrosis factor-α (TNF

  11. SGLT2 inhibitors or GLP-1 receptor agonists as second-line therapy in type 2 diabetes: patient selection and perspectives.

    Science.gov (United States)

    Gurgle, Holly E; White, Karen; McAdam-Marx, Carrie

    2016-01-01

    Controversy exists regarding the selection of second-line therapy for patients with type 2 diabetes mellitus (T2DM) who are unable to achieve glycemic control with metformin therapy alone. Newer pharmacologic treatments for T2DM include glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter 2 inhibitors. Both the classes of medication are efficacious, exhibit positive effects on weight, and are associated with minimal risk of hypoglycemia. The purpose of this review is to compare the clinical trial and real-world effectiveness data of glucagon-like peptide-1 receptor agonists versus sodium-glucose cotransporter 2 inhibitors related to A1c reduction, weight loss, cost-effectiveness, cardiovascular outcomes, and safety in patients with T2DM. This review summarizes comparative evidence for providers who are determining which of the two classes may be the most appropriate for a specific patient.

  12. Obeticholic acid, a selective farnesoid X receptor agonist, regulates bile acid homeostasis in sandwich-cultured human hepatocytes.

    Science.gov (United States)

    Zhang, Yuanyuan; Jackson, Jonathan P; St Claire, Robert L; Freeman, Kimberly; Brouwer, Kenneth R; Edwards, Jeffrey E

    2017-08-01

    Farnesoid X receptor (FXR) is a master regulator of bile acid homeostasis through transcriptional regulation of genes involved in bile acid synthesis and cellular membrane transport. Impairment of bile acid efflux due to cholangiopathies results in chronic cholestasis leading to abnormal elevation of intrahepatic and systemic bile acid levels. Obeticholic acid (OCA) is a potent and selective FXR agonist that is 100-fold more potent than the endogenous ligand chenodeoxycholic acid (CDCA). The effects of OCA on genes involved in bile acid homeostasis were investigated using sandwich-cultured human hepatocytes. Gene expression was determined by measuring mRNA levels. OCA dose-dependently increased fibroblast growth factor-19 (FGF-19) and small heterodimer partner (SHP) which, in turn, suppress mRNA levels of cholesterol 7-alpha-hydroxylase (CYP7A1), the rate-limiting enzyme for de novo synthesis of bile acids. Consistent with CYP7A1 suppression, total bile acid content was decreased by OCA (1 μmol/L) to 42.7 ± 20.5% relative to control. In addition to suppressing de novo bile acids synthesis, OCA significantly increased the mRNA levels of transporters involved in bile acid homeostasis. The bile salt excretory pump (BSEP), a canalicular efflux transporter, increased by 6.4 ± 0.8-fold, and the basolateral efflux heterodimer transporters, organic solute transporter α (OST α ) and OST β increased by 6.4 ± 0.2-fold and 42.9 ± 7.9-fold, respectively. The upregulation of BSEP and OST α and OST β, by OCA reduced the intracellular concentrations of d 8 -TCA, a model bile acid, to 39.6 ± 8.9% relative to control. These data demonstrate that OCA does suppress bile acid synthesis and reduce hepatocellular bile acid levels, supporting the use of OCA to treat bile acid-induced toxicity observed in cholestatic diseases. © 2017 Intercept Pharmaceuticals. Pharmacology Research & Perspectives published by John Wiley & Sons Ltd, British Pharmacological Society and

  13. Evidence available on the use of the selective β3-adrenoceptor agonist mirabegron for the treatment of overactive bladder.

    Science.gov (United States)

    Angulo, J C; Khullar, V; Nitti, V W; Siddiqui, E

    2013-01-01

    Mirabegron, the selective β3-adrenoceptor agonist, heralds the latest development for the treatment of overactive bladder (OAB). To present the evidence available on the efficacy and tolerability of mirabegron and to discuss this treatment's potential in our setting. We reviewed 11 studies conducted with mirabegron in patients with OAB (2 phase II, 9 phase III), all studies were compared to placebo with 6 studies also including tolterodine as an additional arm. Greater emphasis shall be given to the main phase III trials performed in Europe, the USA and Australia evaluating efficacy and safety after 12 weeks (NCT00662909, NCT00689104, NCT00912964) and safety after 12 months (NCT00688688). The combined analyses of these 12 week studies is also available, with emphasis on global efficacy (FAS), efficacy with regard to incontinence (FAS i) and safety (SAF). More than 50% of patients had previously discontinued anticholinergics medication for OAB, thus allowing us to obtain data on the effectiveness of mirabegron in patients already treated with anticholinergics. Mirabegron is an efficacious drug which presents a statistically significant reduction in the number of incontinence episodes and in urinary frequency as of 4 weeks, with a higher percentage of dry patients and a higher percentage of patients with reduction ≥50% in the number of incontinence episodes than placebo. The efficacy of mirabegron 50 and 100mg in the reduction of incontinence episodes occurs in de novo patients and who have received antimuscarinics, with adjusted mean difference and improvement in urinary frequency greater in treated patients. Its tolerability is very similar to placebo particularly for the adverse effects of the antimuscarinics (dry mouth, constipation and blurred vision). A minimal, non-clinically significant change is observed in systolic and diastolic blood pressure and pulse. Its efficacy is long-term. Mirabegron at the doses of 50 and 100mg presents an improvement versus

  14. SGLT2 inhibitors or GLP-1 receptor agonists as second-line therapy in type 2 diabetes: patient selection and perspectives

    Directory of Open Access Journals (Sweden)

    Gurgle HE

    2016-06-01

    Full Text Available Holly E Gurgle, Karen White, Carrie McAdam-Marx Department of Pharmacotherapy, University of Utah College of Pharmacy, Salt Lake City, UT, USA Abstract: Controversy exists regarding the selection of second-line therapy for patients with type 2 diabetes mellitus (T2DM who are unable to achieve glycemic control with metformin therapy alone. Newer pharmacologic treatments for T2DM include glucagon-like peptide-1 receptor agonists and sodium–glucose cotransporter 2 inhibitors. Both the classes of medication are efficacious, exhibit positive effects on weight, and are associated with minimal risk of hypoglycemia. The purpose of this review is to compare the clinical trial and real-world effectiveness data of glucagon-like peptide-1 receptor agonists versus sodium–glucose cotransporter 2 inhibitors related to A1c reduction, weight loss, cost-effectiveness, cardiovascular outcomes, and safety in patients with T2DM. This review summarizes comparative evidence for providers who are determining which of the two classes may be the most appropriate for a specific patient. Keywords: type 2 diabetes mellitus, GLP-1 receptor agonist, SGLT2 inhibitor, A1c, weight loss, adverse effect

  15. Boehringer Ingleheim's selective glucocorticoid receptor agonist development candidate: evaluation of WO2010141331, WO2010141332 and WO2010141333.

    Science.gov (United States)

    Norman, Peter

    2011-07-01

    Three applications from Boehringer Ingelheim all relate to the preparation of non-steroidal glucocorticoid receptor agonists useful in the treatment of inflammatory respiratory diseases. The first two applications claim chiral processes for the preparation of these compounds or intermediates useful therein. These provide two alternative routes, respectively, using achiral and chiral reagents. The third application relates to the preparation of a crystalline salt of the preferred compound on a multi-kilogram scale in micronised form.

  16. The α4β2 nicotine acetylcholine receptor agonist ispronicline induces c-Fos expression in selective regions of the rat forebrain

    DEFF Research Database (Denmark)

    Jacobsen, Julie; Hansen, Henrik H; Kiss, Alexander

    2012-01-01

    The dominant nicotine acetylcholine receptor (nAChR) subtype in the brain is the pentameric receptor containing both α4 and β2 subunits (α4β2). Due to the lack of selective agonists it has not been ruled out what neuronal circuits that are stimulated after systemic administration with nicotine. We...... or indirectly involved in acute stress regulation after a single dose of ispronicline, supports earlier studies that the α4β2 receptors are strongly involved in nicotine-dependent activation of the hypothalamo-pituitary adrenocortical axis....

  17. The selective vitamin D receptor agonist, elocalcitol, reduces endometriosis development in a mouse model by inhibiting peritoneal inflammation.

    Science.gov (United States)

    Mariani, Margherita; Viganò, Paola; Gentilini, Davide; Camisa, Barbara; Caporizzo, Elvira; Di Lucia, Pietro; Monno, Antonella; Candiani, Massimo; Somigliana, Edgardo; Panina-Bordignon, Paola

    2012-07-01

    Endometriosis, which is characterized by the growth of endometrial tissue at ectopic locations as well as vascular development and inflammation, is still an unmet clinical need since an optimal drug that allows for both pain and infertility management does not exist. Since both the eutopic and the ectopic endometrium express the vitamin D receptor (VDR), and VDR agonists are endowed with anti-proliferative and anti-inflammatory properties, we evaluated the effect of elocalcitol, a VDR agonist with low calcaemic liability, in a mouse model of experimentally induced endometriosis. Endometriosis was induced by injection of syngeneic endometrial tissue fragments into adult Balb/c female mice. After having confirmed by immunohistochemistry that endometriotic lesions developing in mice expressed VDR, the mice were administered with elocalcitol (100 μg/kg) or vehicle orally, once a day, for various durations of time. In this model, elocalcitol was able to reduce total lesion weight up to 70% upon treatment for 1 week before and 2 weeks after disease induction. Interestingly, a therapeutic effect was also observed on already established lesions. Elocalcitol was shown to reduce the capacity of mouse endometrial cells to adhere to collagen. In addition in treated mice, a decreased state of peritoneal inflammation was demonstrated by the inhibition of macrophage recruitment and inflammatory cytokine secretion. The VDR agonist elocalcitol inhibits lesion development in a validated mouse model of endometriosis, and exerts a protective effect on both the implantation and organization of transferred endometrial tissue. These preliminary data in mice provide a sound rationale for further testing in primate models and eventually in humans.

  18. Effect of Selective Prostaglandin E2 EP2 Receptor Agonist CP-533,536 on Voiding Efficiency in Rats with Midodrine-Induced Functional Urethral Obstruction.

    Science.gov (United States)

    Kurihara, Ryoko; Imazumi, Katsunori; Takamatsu, Hajime; Ishizu, Kenichiro; Yoshino, Taiji; Masuda, Noriyuki

    2016-05-01

    We investigated the effect of the selective prostaglandin E2 EP2 receptor agonist CP-533,536 on voiding efficiency in rats with midodrine-induced functional urethral obstruction. The effect of CP-533,536 (0.03-0.3 mg/kg, intravenous [i.v.]) on urethral perfusion pressure (UPP) was investigated in anesthetized rats pre-treated with midodrine (1 mg/kg, i.v.), which forms an active metabolite that acts as an α1 -adrenoceptor agonist. The effect of CP-533,536 (0.03-0.3 mg/kg, i.v.) on cystometric parameters was also investigated in anesthetized rats. In addition, the effect of CP-533,536 (0.03-0.3 mg/kg, i.v.) on residual urine volume (RV) and voiding efficiency (VE) was investigated in conscious rats treated with midodrine (1 mg/kg, i.v.). CP-533,536 dose-dependently decreased UPP elevated by midodrine in anesthetized rats. In contrast, CP-533,536 did not affect maximum voiding pressure, intercontraction interval, or intravesical threshold pressure. In conscious rats, midodrine (1 mg/kg, i.v.) markedly increased RV and reduced VE. CP-533,536 dose-dependently ameliorated increases in RV and decreases in VE induced by midodrine. These results suggest that a selective EP2 receptor agonist could ameliorate the elevation of RV and improve the reduction of VE in rats with functional urethral obstruction caused by stimulation of α1 -adrenoceptors. The mechanism of action might be not potentiation of bladder contraction but rather preferential relief of urethral constriction. © 2014 Wiley Publishing Asia Pty Ltd.

  19. Effects of selective Imidazolin-1 (I1 receptor agonists vs ACE-Is/ARBs on metabolic parameters in patients of hypertension: A Meta-analysis of RCTs

    Directory of Open Access Journals (Sweden)

    Sharan Hiremath

    2016-05-01

    Full Text Available Objectives:  Co-existence of metabolic syndrome in hypertensive patients is associated with the higher risk for development of various complications including type 2 diabetes mellitus and hence highlights the need for selecting an anti-hypertensive with favorable effect on metabolic parameters. Present study aims at analyzing the efficacies of selective imidazolin-1 (I1 receptor agonists vs ACE-Is/ARBs on blood pressure, indicators of insulin resistance and plasma lipids concentration.Methods: Electronic data search in PUBMED, Cochrane library and EMBASE was conducted. Eligible studies were analyzed by random and fixed effects model for the effect size measures. RevMan 5.2 software was used for statistical analysisResults: There was significant difference in the level of decrease in total cholesterol and triglyceride in imidazolins group. However, the decrease in systolic and diastolic blood pressure was significantly more in ACE-Is/ARBs. However among these significant findings found in fixed effect model, the only significant change present in random effect model was the decrease in triglycerides by imidazolins.Conclusion: Efficacy of I1-agonists on plasma lipids and decreasing blood pressure appears to be non-inferior to ACE-Is/ARBs at short term treatment.  

  20. Discovery of isoxazole analogues of sazetidine-A as selective α4β2-nicotinic acetylcholine receptor partial agonists for the treatment of depression.

    Science.gov (United States)

    Liu, Jianhua; Yu, Li-Fang; Eaton, J Brek; Caldarone, Barbara; Cavino, Katie; Ruiz, Christina; Terry, Matthew; Fedolak, Allison; Wang, Daguang; Ghavami, Afshin; Lowe, David A; Brunner, Dani; Lukas, Ronald J; Kozikowski, Alan P

    2011-10-27

    Depression, a common neurological condition, is one of the leading causes of disability and suicide worldwide. Standard treatment, targeting monoamine transporters selective for the neurotransmitters serotonin and noradrenaline, is not able to help many patients that are poor responders. This study advances the development of sazetidine-A analogues that interact with α4β2 nicotinic acetylcholine receptors (nAChRs) as partial agonists and that possess favorable antidepressant profiles. The resulting compounds that are highly selective for the α4β2 subtype of nAChR over α3β4-nAChRs are partial agonists at the α4β2 subtype and have excellent antidepressant behavioral profiles as measured by the mouse forced swim test. Preliminary absorption, distribution, metabolism, excretion, and toxicity (ADMET) studies for one promising ligand revealed an excellent plasma protein binding (PPB) profile, low CYP450-related metabolism, and low cardiovascular toxicity, suggesting it is a promising lead as well as a drug candidate to be advanced through the drug discovery pipeline.

  1. Synergistic action of octopamine receptor agonists on the activity of selected novel insecticides for control of dengue vector Aedes aegypti (Diptera: Culicidae) mosquito.

    Science.gov (United States)

    Ahmed, Mohamed Ahmed Ibrahim; Vogel, Christoph Franz Adam

    2015-05-01

    Studying insecticide resistance in mosquitoes has attracted the attention of many scientists to elucidate the pathways of resistance development and to design novel strategies in order to prevent or minimize the spread and evolution of resistance. Here, we tested the synergistic action of piperonyl butoxide (PBO) and two octopamine receptor (OR) agonists, amitraz (AMZ) and chlordimeform (CDM) on selected novel insecticides to increase their lethal action on the fourth instar larvae of Aedes aegypti L. However, chlorfenapyr was the most toxic insecticide (LC50 = 193, 102, and 48 ng/ml, after 24, 48, and 72 h exposure, respectively) tested. Further, PBO synergized all insecticides and the most toxic combinatorial insecticide was nitenpyram even after 48 and 72 h exposure. In addition, OR agonists significantly synergized most of the selected insecticides especially after 48 and 72 h exposure. The results imply that the synergistic effects of amitraz are a promising approach in increasing the potency of certain insecticides in controlling the dengue vector Ae. aegypti mosquito. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Human fat cell alpha-2 adrenoceptors. I. Functional exploration and pharmacological definition with selected alpha-2 agonists and antagonists

    International Nuclear Information System (INIS)

    Galitzky, J.; Mauriege, P.; Berlan, M.; Lafontan, M.

    1989-01-01

    This study was undertaken to investigate more fully the pharmacological characteristics of the human fat cell alpha-2 adrenoceptor. Biological assays were performed on intact isolated fat cells while radioligand binding studies were carried out with [ 3 H]yohimbine in membranes. These pharmacological studies brought: (1) a critical definition of the limits of the experimental conditions required for the exploration of alpha-2 adrenergic responsiveness on human fat cells and membranes; (2) an improvement in the pharmacological definition of the human fat cell postsynaptic alpha-2 adrenoceptor. Among alpha-2 agonists, UK-14,304 was the most potent and the relative order of potency was: UK-14,304 greater than p-aminoclonidine greater than clonidine = B-HT 920 greater than rilmenidine. For alpha-2 antagonists, the potency order was: yohimbine greater than idazoxan greater than SK ampersand F-86,466 much greater than benextramine; (3) a description of the impact of benextramine (irreversible alpha-1/alpha-2 antagonist) on human fat cell alpha-2 adrenergic receptors and on human fat cell function; the drug inactivates the alpha-2 adrenergic receptors with a minor impact on beta adrenergic receptors and without noticeable alterations of fat cell function as assessed by preservation of beta adrenergic and Al-adenosine receptor-mediated lipolytic responses; and (4) a definition of the relationship existing between alpha-2 adrenergic receptor occupancy, inhibition of adenylate cyclase activity and antilipolysis with full and partial agonists. The existence of a receptor reserve must be taken into account when evaluating alpha-2 adrenergic receptor distribution and regulation of human fat cells

  3. Selecting GLP-1 agonists in the management of type 2 diabetes: differential pharmacology and therapeutic benefits of liraglutide and exenatide

    Directory of Open Access Journals (Sweden)

    Jonathan Pinkney

    2010-08-01

    Full Text Available Jonathan Pinkney1, Thomas Fox1, Lakshminarayan Ranganath21Department of Diabetes and Endocrinology, Peninsula College of Medicine and Dentistry, Plymouth, United Kingdom; 2Department of Clinical Biochemistry and Metabolic Medicine, Royal Liverpool University Hospital, Liverpool, United KingdomAbstract: Failure of secretion of the incretin hormone glucagon-like peptide-1 (GLP-1 plays a prominent role in type 2 diabetes, and restoration of GLP-1 action is an important therapeutic objective. Although the short duration of action of GLP-1 renders it unsuited to therapeutic use, 2 long-acting GLP-1 receptor agonists, exenatide and liraglutide, represent a significant advance in treatment. In controlled trials, both produce short-term glucose-lowering effects, with the reduction in hemoglobin A1c of up to 1.3%. These responses are often superior to those observed with additional oral agents. However, unlike sulfonylureas, thiazolidinediones, or insulin, all of which lead to significant weight gain, GLP-1 receptor agonists uniquely result in long-term weight loss of around 5 kg, and higher doses may enhance this further. Reduction in blood pressure of 2–7 mm Hg also has been observed. Both drugs produce transient mild gastrointestinal side effects; although mild hypoglycemia can occur, this is usually in combination with other hypoglycemic therapies. However, serious hypoglycemia and acute pancreatitis are rare. The once-daily dosage of liraglutide makes it more convenient than twice-daily dosage of prandial exenatide, and a superior glucose-lowering effect was observed in the only head-to-head comparison reported so far. Besides cost, these considerations currently favor liraglutide over exenatide. Further studies are needed to confirm long-term safety, and most importantly, that short-term benefits translate into long-term reductions of diabetes-related cardiovascular events and other complications.Keywords: diabetes, weight loss, glycemic control

  4. A-C Estrogens as Potent and Selective Estrogen Receptor-Beta Agonists (SERBAs) to Enhance Memory Consolidation under Low-Estrogen Conditions.

    Science.gov (United States)

    Hanson, Alicia M; Perera, K L Iresha Sampathi; Kim, Jaekyoon; Pandey, Rajesh K; Sweeney, Noreena; Lu, Xingyun; Imhoff, Andrea; Mackinnon, Alexander Craig; Wargolet, Adam J; Van Hart, Rochelle M; Frick, Karyn M; Donaldson, William A; Sem, Daniel S

    2018-06-04

    Estrogen receptor-beta (ERβ) is a drug target for memory consolidation in postmenopausal women. Herein is reported a series of potent and selective ERβ agonists (SERBAs) with in vivo efficacy that are A-C estrogens, lacking the B and D estrogen rings. The most potent and selective A-C estrogen is selective for activating ER relative to seven other nuclear hormone receptors, with a surprising 750-fold selectivity for the β over α isoform and with EC 50 s of 20-30 nM in cell-based and direct binding assays. Comparison of potency in different assays suggests that the ER isoform selectivity is related to the compound's ability to drive the productive conformational change needed to activate transcription. The compound also shows in vivo efficacy after microinfusion into the dorsal hippocampus and after intraperitoneal injection (0.5 mg/kg) or oral gavage (0.5 mg/kg). This simple yet novel A-C estrogen is selective, brain penetrant, and facilitates memory consolidation.

  5. Induction of selective blood-tumor barrier permeability and macromolecular transport by a biostable kinin B1 receptor agonist in a glioma rat model.

    Science.gov (United States)

    Côté, Jérôme; Bovenzi, Veronica; Savard, Martin; Dubuc, Céléna; Fortier, Audrey; Neugebauer, Witold; Tremblay, Luc; Müller-Esterl, Werner; Tsanaclis, Ana-Maria; Lepage, Martin; Fortin, David; Gobeil, Fernand

    2012-01-01

    Treatment of malignant glioma with chemotherapy is limited mostly because of delivery impediment related to the blood-brain tumor barrier (BTB). B1 receptors (B1R), inducible prototypical G-protein coupled receptors (GPCR) can regulate permeability of vessels including possibly that of brain tumors. Here, we determine the extent of BTB permeability induced by the natural and synthetic peptide B1R agonists, LysdesArg(9)BK (LDBK) and SarLys[dPhe(8)]desArg(9)BK (NG29), in syngeneic F98 glioma-implanted Fischer rats. Ten days after tumor inoculation, we detected the presence of B1R on tumor cells and associated vasculature. NG29 infusion increased brain distribution volume and uptake profiles of paramagnetic probes (Magnevist and Gadomer) at tumoral sites (T(1)-weighted imaging). These effects were blocked by B1R antagonist and non-selective cyclooxygenase inhibitors, but not by B2R antagonist and non-selective nitric oxide synthase inhibitors. Consistent with MRI data, systemic co-administration of NG29 improved brain tumor delivery of Carboplatin chemotherapy (ICP-Mass spectrometry). We also detected elevated B1R expression in clinical samples of high-grade glioma. Our results documented a novel GPCR-signaling mechanism for promoting transient BTB disruption, involving activation of B1R and ensuing production of COX metabolites. They also underlined the potential value of synthetic biostable B1R agonists as selective BTB modulators for local delivery of different sized-therapeutics at (peri)tumoral sites.

  6. Induction of selective blood-tumor barrier permeability and macromolecular transport by a biostable kinin B1 receptor agonist in a glioma rat model.

    Directory of Open Access Journals (Sweden)

    Jérôme Côté

    Full Text Available Treatment of malignant glioma with chemotherapy is limited mostly because of delivery impediment related to the blood-brain tumor barrier (BTB. B1 receptors (B1R, inducible prototypical G-protein coupled receptors (GPCR can regulate permeability of vessels including possibly that of brain tumors. Here, we determine the extent of BTB permeability induced by the natural and synthetic peptide B1R agonists, LysdesArg(9BK (LDBK and SarLys[dPhe(8]desArg(9BK (NG29, in syngeneic F98 glioma-implanted Fischer rats. Ten days after tumor inoculation, we detected the presence of B1R on tumor cells and associated vasculature. NG29 infusion increased brain distribution volume and uptake profiles of paramagnetic probes (Magnevist and Gadomer at tumoral sites (T(1-weighted imaging. These effects were blocked by B1R antagonist and non-selective cyclooxygenase inhibitors, but not by B2R antagonist and non-selective nitric oxide synthase inhibitors. Consistent with MRI data, systemic co-administration of NG29 improved brain tumor delivery of Carboplatin chemotherapy (ICP-Mass spectrometry. We also detected elevated B1R expression in clinical samples of high-grade glioma. Our results documented a novel GPCR-signaling mechanism for promoting transient BTB disruption, involving activation of B1R and ensuing production of COX metabolites. They also underlined the potential value of synthetic biostable B1R agonists as selective BTB modulators for local delivery of different sized-therapeutics at (peritumoral sites.

  7. EVP-6124, a novel and selective α7 nicotinic acetylcholine receptor partial agonist, improves memory performance by potentiating the acetylcholine response of α7 nicotinic acetylcholine receptors.

    Science.gov (United States)

    Prickaerts, Jos; van Goethem, Nick P; Chesworth, Richard; Shapiro, Gideon; Boess, Frank G; Methfessel, Christoph; Reneerkens, Olga A H; Flood, Dorothy G; Hilt, Dana; Gawryl, Maria; Bertrand, Sonia; Bertrand, Daniel; König, Gerhard

    2012-02-01

    EVP-6124, (R)-7-chloro-N-quinuclidin-3-yl)benzo[b]thiophene-2-carboxamide, is a novel partial agonist of α7 neuronal nicotinic acetylcholine receptors (nAChRs) that was evaluated here in vitro and in vivo. In binding and functional experiments, EVP-6124 showed selectivity for α7 nAChRs and did not activate or inhibit heteromeric α4β2 nAChRs. EVP-6124 had good brain penetration and an adequate exposure time. EVP-6124 (0.3 mg/kg, p.o.) significantly restored memory function in scopolamine-treated rats (0.1 mg/kg, i.p.) in an object recognition task (ORT). Although donepezil at 0.1 mg/kg, p.o. or EVP-6124 at 0.03 mg/kg, p.o. did not improve memory in this task, co-administration of these sub-efficacious doses fully restored memory. In a natural forgetting test, an ORT with a 24 h retention time, EVP-6124 improved memory at 0.3 mg/kg, p.o. This improvement was blocked by the selective α7 nAChR antagonist methyllycaconitine (0.3 mg/kg, i.p. or 10 μg, i.c.v.). In co-application experiments of EVP-6124 with acetylcholine, sustained exposure to EVP-6124 in functional investigations in oocytes caused desensitization at concentrations greater than 3 nM, while lower concentrations (0.3-1 nM) caused an increase in the acetylcholine-evoked response. These actions were interpreted as representing a co-agonist activity of EVP-6124 with acetylcholine on α7 nAChRs. The concentrations of EVP-6124 that resulted in physiological potentiation were consistent with the free drug concentrations in brain that improved memory performance in the ORT. These data suggest that the selective partial agonist EVP-6124 improves memory performance by potentiating the acetylcholine response of α7 nAChRs and support new therapeutic strategies for the treatment of cognitive impairment. This article is part of a Special Issue entitled 'Post-Traumatic Stress Disorder'. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Anticonvulsant activity of a mGlu(4alpha) receptor selective agonist, (1S,3R,4S)-1-aminocyclopentane-1,2,4-tricarboxylic acid.

    Science.gov (United States)

    Chapman, A G; Talebi, A; Yip, P K; Meldrum, B S

    2001-07-20

    The metabotropic Group III agonist, (1S,3R,4S)-1-aminocyclopentane-1,2,4-tricarboxylic acid (ACPT-1), selective for the mGlu(4alpha) receptor, suppresses sound-induced seizures in DBA/2 mice following its intracerebroventricular (i.c.v.) administration (ED(50) 5.6 [2.9-10.7], nmol i.c.v., 15 min, clonic phase) and in genetically epilepsy-prone (GEP) rats following focal administration into the inferior colliculus (ED(50) 0.08 [0.01-0.50], nmol, 60 min, clonic phase). ACPT-1 also protects against clonic seizures induced in DBA/2 mice by the Group I agonist, (RS)-3,5-dihydroxyphenylglycine (3,5-DHPG) (ED(50) 0.60 [0.29-1.2], nmol i.c.v.) and by the Group III antagonist, (RS)-alpha-methylserine-O-phosphate (MSOP) (ED(50) 49.3 [37.9-64.1], nmol i.c.v.). Another Group III agonist, (RS)-4-phosphonophenyl-glycine (PPG), preferentially activating the mGlu(8) receptor, previously shown to protect against sound-induced seizures in DBA/2 mice and GEP rats, also protects against seizures induced in DBA/2 by 3,5-DHPG (ED(50) 3.7 [2.4-5.7], nmol i.c.v.) and by the Group III antagonist, MSOP (ED(50) 40.2 [21.0-77.0], nmol i.c.v.). At very high doses (500 nmol i.c.v. and above), Group III antagonists have pro-convulsant and convulsant activity. The anticonvulsant protection against sound-induced seizures in DBA/2 mice provided by a fully protective dose (20 nmol, i.c.v.) of the mGlu(4) receptor agonist ACPT-1, is partially reversed by the co-administration of the Group III antagonists, MSOP, (RS)-alpha-methyl-4-phosphonophenylglycine (MPPG) or (S)-2-amino-2-methyl-4-phosphonobutanoic acid (MAP4), in the 20-50 nmol dose range. At doses of 50-200 nmol, MPPG and MAP4 cause further reversal of the ACPT-1 anticonvulsant protection, while the MSOP effect on ACPT-1 protection is abolished at higher doses. In contrast, the anticonvulsant protection against sound-induced seizures in DBA/2 mice provided by a fully protective dose (20 nmol, i.c.v.) of the mGlu(8) receptor agonist PPG, is not

  9. Rational design, synthesis, and pharmacological properties of new 1,8-naphthyridin-2(1H)-on-3-carboxamide derivatives as highly selective cannabinoid-2 receptor agonists

    DEFF Research Database (Denmark)

    Manera, Clementina; Saccomanni, Giuseppe; Adinolfi, Barbara

    2009-01-01

    The CB(2) receptor activation can be exploited for the treatment of diseases such as chronic pain and tumors of immune origin, devoid of psychotropic activity. On the basis of our already reported 1,8-naphthyridin-4(1H)-on-3-carboxamide derivatives, new 1,8-naphthyridin-2(1H)-on-3-carboxamide......-dependent decrease of cell viability. The obtained results suggest that 1,8-naphthyridin-2(1H)-on-3-carboxamides represent a new scaffold very suitable for the development of new promising CB(2) agonists....... derivatives were designed, synthesized, and tested for their affinities toward the human CB(1) and CB(2) cannabinoid receptors. Some of the reported compounds showed a subnanomolar CB(2) affinity with a CB(1)/CB(2) selectivity ratio greater than 200 (compounds 6, 12, cis-12, 13, and cis-13). Further studies...

  10. Changes in proliferating and apoptotic markers of leiomyoma following treatment with a selective progesterone receptor modulator or gonadotropin-releasing hormone agonist.

    Science.gov (United States)

    Yun, Bo Seong; Seong, Seok Ju; Cha, Dong Hyun; Kim, Ji Yeon; Kim, Mi-La; Shim, Jeong Yun; Park, Ji Eun

    2015-08-01

    To evaluate changes in proliferating and apoptotic markers of myoma tissue from patients treated with a selective progesterone receptor modulator (SPRM) or GnRH agonist by measuring expression of PDGF-A mRNA, IGF-1 mRNA, bcl-2 mRNA, and PCNA and caspase-3 protein. Between December 2013 and July 2014, women with symptomatic leiomyoma were divided into control (no treatment before surgery), SPRM (treatment with ulipristal acetate [SPRM] for 3 months before surgery), and GnRHa (treatment with leuprolide acetate [GnRH agonist] for 3 months before surgery) groups. Tissue specimens were collected from the myoma core and normal myometrium of all patients. The expression of mRNA and protein was assessed by quantitative real-time reverse transcriptase-polymerase chain reaction and Western blot. A total of 38 patients were enrolled (control group, n=14; SPRM group, n=13; GnRHa group, n=11). PDGF-A mRNA expression was lower in both the myoma core and normal myometrium tissues of the SPRM compared with the control group, but there was no difference between the control and GnRHa group. There were also no group differences in bcl-2 mRNA or IGF-1 mRNA expression. Both PCNA and caspase-3 protein expression were higher in the leiomyoma tissue of the SPRM compared with the control group, but there was no difference between the control and GnRHa groups in the expression of either protein. Both proliferation and apoptosis were increased in the leiomyoma of patients after SPRM treatment, but there was no change following GnRH agonist treatment, in vivo. However, PDGF-A mRNA was decreased after SPRM treatment, indicating a dual effect of progesterone on the regulation of growth factors. Furthermore, there was an increase in caspase-3 protein, but not bcl-2 mRNA, expression in the SPRM group suggesting that SPRM may exert its effects in pathways other than the bcl-2 apoptotic pathway. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  11. On the role of subtype selective adenosine receptor agonists during proliferation and osteogenic differentiation of human primary bone marrow stromal cells.

    Science.gov (United States)

    Costa, M Adelina; Barbosa, A; Neto, E; Sá-e-Sousa, A; Freitas, R; Neves, J M; Magalhães-Cardoso, T; Ferreirinha, F; Correia-de-Sá, P

    2011-05-01

    Purines are important modulators of bone cell biology. ATP is metabolized into adenosine by human primary osteoblast cells (HPOC); due to very low activity of adenosine deaminase, the nucleoside is the end product of the ecto-nucleotidase cascade. We, therefore, investigated the expression and function of adenosine receptor subtypes (A(1) , A(2A) , A(2B) , and A(3) ) during proliferation and osteogenic differentiation of HPOC. Adenosine A(1) (CPA), A(2A) (CGS21680C), A(2B) (NECA), and A(3) (2-Cl-IB-MECA) receptor agonists concentration-dependently increased HPOC proliferation. Agonist-induced HPOC proliferation was prevented by their selective antagonists, DPCPX, SCH442416, PSB603, and MRS1191. CPA and NECA facilitated osteogenic differentiation measured by increases in alkaline phosphatase (ALP) activity. This contrasts with the effect of CGS21680C which delayed HPOC differentiation; 2-Cl-IB-MECA was devoid of effect. Blockade of the A(2B) receptor with PSB603 prevented osteogenic differentiation by NECA. In the presence of the A(1) antagonist, DPCPX, CPA reduced ALP activity at 21 and 28 days in culture. At the same time points, blockade of A(2A) receptors with SCH442416 transformed the inhibitory effect of CGS21680C into facilitation. Inhibition of adenosine uptake with dipyridamole caused a net increase in osteogenic differentiation. The presence of all subtypes of adenosine receptors on HPOC was confirmed by immunocytochemistry. Data show that adenosine is an important regulator of osteogenic cell differentiation through the activation of subtype-specific receptors. The most abundant A(2B) receptor seems to have a consistent role in cell differentiation, which may be balanced through the relative strengths of A(1) or A(2A) receptors determining whether osteoblasts are driven into proliferation or differentiation. Copyright © 2010 Wiley-Liss, Inc.

  12. Zolpidem, a selective GABA(A) receptor alpha1 subunit agonist, induces comparable Fos expression in oxytocinergic neurons of the hypothalamic paraventricular and accessory but not supraoptic nuclei in the rat

    DEFF Research Database (Denmark)

    Kiss, Alexander; Søderman, Andreas; Bundzikova, Jana

    2006-01-01

    Functional activation of oxytocinergic (OXY) cells in the hypothalamic paraventricular (PVN), supraoptic (SON), and accessory (ACC) nuclei was investigated in response to acute treatment with Zolpidem (a GABA(A) receptor agonist with selectivity for alpha(1) subunits) utilizing dual Fos/OXY immun...

  13. An investigation into the receptor-regulating effects of the acute administration of opioid agonists and an antagonist on beta adrenergic receptors in the rat cerebral cortex

    International Nuclear Information System (INIS)

    Roper, I.

    1987-01-01

    Past and current research indicated that biochemical deviations which might be involved in the etiology and pathophysiology of depression, included abnormalities or imbalances in the noradrenergic, serotonergic, hormonal and possibly in the endogenous opioid, dopaminergic, histaminergic, cholinergic and trace amine systems. In order to investigate a possible link between the noradrenergic system and opioids, it was decided to test the acute effects of opioid administration on cortical beta adrenoceptor numbers and affinity. As these receptors have been most consistently downregulated by antidepressant treatment, they may be involved in the mechanism of antidepressant action of these agents. It was decided to investigate beta adrenoceptor-regulatory effects of opioid treatment. Naloxone was tested alone, with a view to suppressing any possible endogenous opioid influences upon beta receptor status and revealing an effect which would possibly be the opposite of that brought about by the administration of opioid agonists. Naloxone was administered together with morphine to demonstrate that any beta receptor up- or downregulation which might be measured, had indeed been opioid-receptor mediated. It was found that the acute administration of four different mu opioid agonists, naloxone and naloxone plus morphine, did not cause any statistically significant alterations in cortical beta adrenergic receptor numbers or affinity in the rat. A radioactive ligand, the beta adrenoceptor-labelling compound referred to as DHA (L-dihydroalprenolol HCI) was used in this study

  14. Medium chain fatty acids are selective peroxisome proliferator activated receptor (PPAR) γ activators and pan-PPAR partial agonists

    NARCIS (Netherlands)

    Liberato, Marcelo Vizoná; Nascimento, Alessandro S; Ayers, Steven D; Lin, Jean Z; Cvoro, Aleksandra; Silveira, Rodrigo L; Martínez, Leandro; Souza, Paulo C T; Saidemberg, Daniel; Deng, Tuo; Amato, Angela Angelica; Togashi, Marie; Hsueh, Willa A; Phillips, Kevin; Palma, Mário Sérgio; Neves, Francisco A R; Skaf, Munir S; Webb, Paul; Polikarpov, Igor

    2012-01-01

    Thiazolidinediones (TZDs) act through peroxisome proliferator activated receptor (PPAR) γ to increase insulin sensitivity in type 2 diabetes (T2DM), but deleterious effects of these ligands mean that selective modulators with improved clinical profiles are needed. We obtained a crystal structure of

  15. Discovery of a novel selective PPARγ ligand with partial agonist binding properties by integrated in silico / in vitro work flow

    DEFF Research Database (Denmark)

    Kouskoumvekaki, Irene; Petersen, Rasmus K.; Fratev, Filip Filipov

    2013-01-01

    that control glucose and lipid metabolism and is an important target for drugs against type 2 diabetes, dyslipidemia, atherosclerosis, and cardiovascular disease. In an effort to identify novel PPARγ ligands with an improved pharmacological profile, emphasis has shifted to selective ligands with partial...

  16. Characterization of the 1H-cyclopentapyrimidine-2,4(1H,3H)-dione derivative (S)-CPW399 as a novel, potent, and subtype-selective AMPA receptor full agonist with partial desensitization properties

    DEFF Research Database (Denmark)

    Campiani, G; Morelli, E; Nacci, V

    2001-01-01

    (S)-CPW399 (2b) is a novel, potent, and subtype-selective AMPA receptor full agonist that, unlike (S)-willardiine and related compounds, in mouse cerebellar granule cells, stimulated an increase in [Ca(2+)](i), and induced neuronal cell death in a time- and concentration-dependent manner. Compound...... 2b appears to be a weakly desensitizing, full agonist at AMPA receptors and therefore represents a new pharmacological tool to investigate the role of AMPA receptors in excitotoxicity and their molecular mechanisms of desensitization....

  17. Carbetocin is a Functional Selective Gq Agonist That Does Not Promote Oxytocin Receptor Recycling After Inducing β-Arrestin-Independent Internalisation.

    Science.gov (United States)

    Passoni, I; Leonzino, M; Gigliucci, V; Chini, B; Busnelli, M

    2016-04-01

    Carbetocin, a long-acting oxytocin analogue, has been reported to elicit interesting and peculiar behavioural effects. The present study investigated the molecular pharmacology of carbetocin, aiming to better understand the molecular basis of its action in the brain. Using bioluminescence resonance energy transfer biosensors, we characterised the effects of carbetocin on the three human oxytocin/vasopressin receptors expressed in the nervous system: the oxytocin receptor (OXTR) and the vasopressin V1a (V1aR) and V1b (V1bR) receptors. Our results indicate that (i) carbetocin activates the OXTR but not the V1aR and V1bR at which it may act as an antagonist; (ii) carbetocin selectively activates only the OXTR/Gq pathway displaying a strong functional selectivity; (iii) carbetocin is a partial agonist at the OXTR/Gq coupling; (iv) carbetocin promotes OXTR internalisation via a previously unreported β-arrestin-independent pathway; and (v) carbetocin does not induce OXTR recycling to the plasma membrane. Altogether, these molecular pharmacology features identify carbetocin as a substantially different analogue compared to the endogenous oxytocin and, consequently, carbetocin is not expected to mimic oxytocin in the brain. Whether these unique features of carbetocin could be exploited therapeutically remains to be established. © 2016 The Authors. Journal of Neuroendocrinology published by John Wiley & Sons Ltd on behalf of British Society for Neuroendocrinology.

  18. Identification and in vitro pharmacological characterization of a novel and selective α7 nicotinic acetylcholine receptor agonist, Br-IQ17B.

    Science.gov (United States)

    Tang, Jing-shu; Xie, Bing-xue; Bian, Xi-ling; Xue, Yu; Wei, Ning-ning; Zhou, Jing-heng; Hao, Yu-chen; Li, Gang; Zhang, Liang-ren; Wang, Ke-wei

    2015-07-01

    Alpha7-nicotinic acetylcholine receptor (α7 nAChR) is a ligand-gated Ca(2+)-permeable ion channel implicated in cognition and neuropsychiatric disorders. Activation of α7 nAChR improves learning, memory, and sensory gating in animal models. To identify novel α7 nAChR agonists, we synthesized a series of small molecules and characterized a representative compound, Br-IQ17B, N-[(3R)-1-azabicyclo[2,2,2]oct-3-yl]-5-bromoindolizine-2-carboxamide, which specifically activates α7 nAChR. Two-electrode voltage clamp (TEVC) recordings were primarily used for screening in Xenopus oocytes expressing human α7 nAChR. Assays, including radioisotope ligand binding, Western blots, whole-cell recordings of hippocampal culture neurons, and spontaneous IPSC recordings of brain slices, were also utilized to evaluate and confirm the specific activation of α7 nAChR by Br-IQ17B. Br-IQ17B potently activates α7 nAChR with an EC50 of 1.8±0.2 μmol/L. Br-IQ17B is selective over other subtypes such as α4β2 and α3β4, but it blocks 5-HT3A receptors. Br-IQ17B displaced binding of the α7 blocker [(3)H]-MLA to hippocampal crude membranes with a Ki of 14.9±3.2 nmol/L. In hippocampal neurons, Br-IQ17B evoked α7-like currents that were inhibited by MLA and enhanced in the presence of the α7 PAM PNU-120596. In brain slice recordings, Br-IQ17B enhanced GABAergic synaptic transmission in CA1 neurons. Mechanistically, Br-IQ17B increased ERK1/2 phosphorylation that was MLA-sensitive. We identified the novel, potent, and selective α7 agonist Br-IQ17B, which enhances synaptic transmission. Br-IQ17B may be a helpful tool to understand new aspects of α7 nAChR function, and it also has potential for being developed as therapy for schizophrenia and cognitive deficits.

  19. Selective orthosteric free fatty acid receptor 2 (FFA2) agonists: identification of the structural and chemical requirements for selective activation of FFA2 versus FFA3

    DEFF Research Database (Denmark)

    Schmidt, Johannes; Smith, Nicola J; Christiansen, Elisabeth

    2011-01-01

    given its size. Propionate, however, does not discriminate between FFA2 and the closely related receptor FFA3 (GPR41). To identify FFA2 selective ligands and understand the molecular basis for FFA2 selectivity, a targeted library of small carboxylic acids (SCAs) was examined using holistic, label...

  20. A new highly selective metabotropic excitatory amino acid agonist: 2-amino-4-(3-hydroxy-5-methylisoxazol-4-yl)butyric acid

    DEFF Research Database (Denmark)

    Bräuner-Osborne, Hans; Sløk, F A; Skjaerbaek, N

    1996-01-01

    The homologous series of acidic amino acids, ranging from aspartic acid (1) to 2-aminosuberic acid (5), and the corresponding series of 3-isoxazolol bioisosteres of these amino acids, ranging from (RS)-2-amino-2-(3-hydroxy-5-methylisoxazol-4-yl)acetic acid (AMAA, 6) to (RS)-2-amino-6-(3-hydroxy-5......-methylisoxazol-4-yl)hexanoic acid (10), were tested as ligands for metabotropic excitatory amino acid receptors (mGlu1 alpha, mGlu2, mGlu4a, and mGlu6). Whereas AMAA (6) and (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propinoic acid (AMPA, 7) are potent and highly selective agonists at N......-methyl-D-aspartic acid (NMDA) and AMPA receptors, respectively, the higher homologue of AMPA (7), (RS)-2-amino-4-(3-hydroxy-5-methylisoxazol-4-yl)butyric acid (homo-AMPA, 8), is inactive at ionotropic excitatory amino acid receptors. Homo-AMPA (8), which is a 3-isoxazolol bioisostere of 2-aminoadipic acid (3), was...

  1. A kinetic analysis of kappa-opioid agonist binding using the selective radioligand (/sup 3/H)U69593

    Energy Technology Data Exchange (ETDEWEB)

    Smith, J.A.; Hunter, J.C.; Hill, R.G.; Hughes, J.

    1989-07-01

    The interaction of the nonselective opioid ligand (3H)bremazocine and of the kappa-opioid (3H)U69593 with the kappa-receptor was investigated in guinea-pig cortical membranes. Each radioligand bound to a single population of high-affinity sites, although (3H)U69593 apparently recognised only 70% of those sites labelled by (3H)bremazocine. Naloxone and the kappa-selective ligands U69593 and PD117302 exhibited full inhibition of the binding of both radioligands. Kinetic analysis demonstrated biphasic rates of association and dissociation for both (3H)bremazocine and (3H)U69593. Detailed analysis of the binding of (3H)U69593 revealed that the fast rate of association was dependent on radioligand concentration, in contrast to the slow rate, which was independent of ligand concentration. Guanylyl-5'-imidodiphosphate (GppNHp) inhibited binding of (3H)U69593; saturation analysis demonstrated that the inhibitory effects of GppNHp resulted in a decrease in affinity without any significant change in binding capacity. GppNHp attenuated the formation of the slow component of (3H)U69593 binding, while accelerating the fast component. The data are consistent with the formation of a high-affinity complex between the kappa-receptor and a guanine nucleotide binding protein. Guanine nucleotides promote the dissociation of this ternary complex and the stabilisation of a lower-affinity state of the receptor.

  2. Radioiodination and biological evaluation of levalbuterol as a new selective radiotracer. A β{sub 2}-adrenoceptor agonist

    Energy Technology Data Exchange (ETDEWEB)

    Sanad, Mahmoud Hamdi; Abelrahman, Mohamed Abdelmotelb; Marzook, Fawzy Mohamed Abdelmaged [Atomic Energy Authority, Cairo (Egypt). Radioisotopes Production and Radioactive Sources Div.

    2016-08-01

    Levalbuterol was successfully radiolabeled with iodine using chloramine-T as an oxidizing agent via an electrophilic substitution reaction. The reaction parameters that affecting the labeling yield such as levalbuterol concentration, chloramine-T concentration, pH of the reaction medium and reaction time were studied in details. The radiochemical yield was 97.5 ± 0.5% and the radioiodinated compound was separated by HPLC. In vitro studies showed that the iodinated levalbuterol was stable for up to 24 h. The biodistribution in experimental animals showed that the lung uptake was 68.18 ± 0.17% at 5 min post injection which decreased with time until reached to 18.7 ± 0.12% at 2 h which was higher than other recent developed radiopharmaceuticals for lung imaging. The clearance pathways from the mice appear to proceed via both hepatobiliary and renal pathways. Predosing the mice with cold levalbuterol reduced the lung uptake to 20 ± 1.3% and further confirms the high specificity and selectivity of {sup 125}I-levalbuterol for the lung.

  3. CBirTox is a selective antigen-specific agonist of the Treg-IgA-microbiota homeostatic pathway.

    Directory of Open Access Journals (Sweden)

    Katie L Alexander

    Full Text Available Cultivating an environment of mutualism between host cells and the microbiota is vital, and dysregulation of this relationship is associated with multiple immune disorders including metabolic and skin diseases, asthma, allergy, and Inflammatory Bowel Disease (IBD. One prominent mechanism for maintaining homeostasis is the protective regulatory T cell (Treg- Immunoglobulin A (IgA pathway toward microbiota antigens, in which Tregs maintain homeostasis and provide critical survival factors to IgA+ B cells. In order to amplify the Treg-IgA pathway, we have generated a fusion protein, CBirTox, comprised of a portion of the carboxy terminus of CBir1, a microbiota flagellin, genetically coupled to Cholera Toxin B subunit (CTB via the A2 linker of CT. Both dendritic cells (DCs and B cells pulsed with CBirTox selectively induced functional CD4+Foxp3+ Tregs in vitro, and CBirTox augmented CD4+Foxp3+ cell numbers in vivo. The induced Foxp3 expression was independent of retinoic acid (RA signaling but was inhibited by neutralization of TGF-β. CBirTox treatment of B cells downregulated mammalian target of rapamycin (mTOR signaling. Furthermore, CBirTox-pulsed DCs induced substantial production of IgA from naïve B cells. Collectively these data demonstrate that CBirTox represents a novel approach to bolstering the Treg-IgA pathway at the host-microbiota interface.

  4. Characterization of a series of anabaseine-derived compounds reveals that the 3-(4)-dimethylaminocinnamylidine derivative is a selective agonist at neuronal nicotinic alpha 7/125I-alpha-bungarotoxin receptor subtypes.

    Science.gov (United States)

    de Fiebre, C M; Meyer, E M; Henry, J C; Muraskin, S I; Kem, W R; Papke, R L

    1995-01-01

    Investigation of the naturally occurring, nicotinic agonist anabaseine and novel derivatives has shown that these compounds have cytoprotective and memory-enhancing effects. The hypothesis that these arise at least in part through actions on brain nicotinic receptors was evaluated by examining the ability of these compounds to displace the binding of nicotinic ligands and to affect the function of the alpha 4 beta 2 and alpha 7 receptor subtypes expressed in Xenopus oocytes. The derivative 3-(4)-dimethylaminocinnamylidine anabaseine (DMAC) was found to be a selective alpha 7 receptor agonist; it was more potent than nicotine, acetylcholine, anabaseine, and other derivatives at activating the alpha 7 receptor subtype, while displaying little agonist activity at alpha 4 beta 2 and other receptor subtypes. Compared with anabaseine and the other derivatives, DMAC was the most potent at displacing 125I-alpha-bungarotoxin binding (putative alpha 7) and the least potent at displacing [3H]cytisine binding (putative alpha 4 beta 2) to brain membranes. Independently of agonist activities, all of the novel compounds displayed secondary inhibitory activity at both receptor subtypes. At the alpha 4 beta 2 receptor subtype, inhibition by the 3-(2,4)-dimethoxybenzylidene derivative was enhanced by coapplication of acetylcholine, suggesting a noncompetitive form of inhibition. Anabaseine and nicotine prolonged the time course of activation of alpha 4 beta 2 receptors, compared with acetylcholine, suggesting sequential channel-blocking activity. As selective agonists, anabaseine derivatives such as DMAC may be useful for elucidating the function of alpha 7 nicotinic receptors, including their potential role(s) in the cytoprotective and memory-enhancing effects of nicotinic agents.

  5. Synthesis and pharmacological evaluation of thiopyran analogues of the dopamine D-3 receptor-selective agonist (4aR,10bR)-(+)-trans-3,4,4a,10b-tetrahydro-4-n-propyl-2H,5H-[1]benzopyrano[4,3-b]-1,4-oxazin-9-ol (PD 128907)

    NARCIS (Netherlands)

    van Vliet, LA; Rodenhuis, N; Dijkstra, D; Wikstrom, H; Pugsley, TA; Serpa, KA; Meltzer, LT; Heffner, TG; Wise, LD; Lajiness, ME; Huff, RM; Svensson, K; Sundell, S; Lundmark, M

    2000-01-01

    Benzopyranoxazine (+)-7 (PD 128907) is the most dopamine (DA) D-3 receptor-selective agonist presently known. The only structural feature which distinguishes 7 from the analogous nonselective naphthoxazines is an oxygen atom in the 6-position. To extend this series of tricyclic DA agonists we used a

  6. Cardiohemodynamic and electrophysiological effects of a selective EP4 receptor agonist ONO--AE1--329 in the halothane-anesthetized dogs.

    Science.gov (United States)

    Nomura, Hiroaki; Nakamura, Yuji; Cao, Xin; Honda, Atsushi; Katagi, Jun; Ohara, Hiroshi; Izumi-Nakaseko, Hiroko; Satoh, Yoshioki; Ando, Kentaro; Sugiyama, Atsushi

    2015-08-15

    Cardiovascular effects of a highly selective prostaglandin E2 type 4 (EP4) receptor agonist ONO-AE1-329 were assessed with the halothane-anesthetized dogs (n=6). ONO-AE1-329 was intravenously infused in three escalating doses of 0.3, 1 and 3ng/kg/min for 10min with a pause of 20min between the doses. The low dose of 0.3ng/kg/min significantly increased maximum upstroke velocity of left ventricular pressure by 18% at 20min, indicating increase of ventricular contractility. The middle dose of 1ng/kg/min significantly decreased total peripheral resistance by 24% and left ventricular end-diastolic pressure by 32% at 10min, indicating dilation of arteriolar resistance vessels and venous capacitance ones, respectively; and increased cardiac output by 25% at 10min in addition to the change induced by the low dose. The high dose of 3ng/kg/min increased heart rate by 34% at 10min; decreased mean blood pressure by 14% at 10min and atrioventricular nodal conduction time by 13% at 5min; and shortened left ventricular systolic period by 8% at 10min and electromechanical coupling defined as an interval from completion of repolarization to the start of ventricular diastole by 39% at 10min in addition to the changes induced by the middle dose. No significant change was detected in a ventricular repolarization period. These results indicate that ONO-AE1-329 may possess a similar cardiovascular profile to typical phosphodiesterase 3 inhibitors as an inodilator, and suggest that EP4 receptor stimulation can become an alternative strategy for the treatment of congestive heart failure. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. YH12852, a potent and highly selective 5-HT4 receptor agonist, significantly improves both upper and lower gastrointestinal motility in a guinea pig model of postoperative ileus.

    Science.gov (United States)

    Hussain, Z; Lee, Y J; Yang, H; Jeong, E J; Sim, J Y; Park, H

    2017-10-01

    Postoperative ileus (POI) is a transient gastrointestinal (GI) dysmotility that commonly develops after abdominal surgery. YH12852, a novel, potent and highly selective 5-hydroxytryptamine 4 (5-HT 4 ) receptor agonist, has been shown to improve both upper and lower GI motility in various animal studies and may have applications for the treatment of POI. Here, we investigated the effects and mechanism of action of YH12852 in a guinea pig model of POI to explore its therapeutic potential. The guinea pig model of POI was created by laparotomy, evisceration, and gentle manipulation of the cecum for 60 seconds, followed by closure with sutures under anesthesia. Group 1 received an oral administration of vehicle or YH12852 (1, 3, 10 or 30 mg/kg) only, while POI Group 2 was intraperitoneally pretreated with vehicle or 5-HT 4 receptor antagonist GR113808 (10 mg/kg) prior to oral dosing of vehicle or YH12852 (3 or 10 mg/kg). Upper GI transit was evaluated by assessing the migration of a charcoal mixture in the small intestine, while lower GI transit was assessed via measurement of fecal pellet output (FPO). YH12852 significantly accelerated upper and lower GI transit at the doses of 3, 10, and 30 mg/kg and reached its maximal effect at 10 mg/kg. These effects were significantly blocked by pretreatment of GR113808 10 mg/kg. Oral administration of YH12852 significantly accelerates and restores delayed upper and lower GI transit in a guinea pig model of POI. This drug may serve as a useful candidate for the treatment of postoperative ileus. © 2017 John Wiley & Sons Ltd.

  8. F104S c-Mpl responds to a transmembrane domain-binding thrombopoietin receptor agonist: proof of concept that selected receptor mutations in congenital amegakaryocytic thrombocytopenia can be stimulated with alternative thrombopoietic agents.

    Science.gov (United States)

    Fox, Norma E; Lim, Jihyang; Chen, Rose; Geddis, Amy E

    2010-05-01

    To determine whether specific c-Mpl mutations might respond to thrombopoietin receptor agonists. We created cell line models of type II c-Mpl mutations identified in congenital amegakaryocytic thrombocytopenia. We selected F104S c-Mpl for further study because it exhibited surface expression of the receptor. We measured proliferation of cell lines expressing wild-type or F104S c-Mpl in response to thrombopoietin receptor agonists targeting the extracellular (m-AMP4) or transmembrane (LGD-4665) domains of the receptor by 1-methyltetrazole-5-thiol assay. We measured thrombopoietin binding to the mutant receptor using an in vitro thrombopoietin uptake assay and identified F104 as a potentially critical residue for the interaction between the receptor and its ligand by aligning thrombopoietin and erythropoietin receptors from multiple species. Cells expressing F104S c-Mpl proliferated in response to LGD-4665, but not thrombopoietin or m-AMP4. Compared to thrombopoietin, LGD-4665 stimulates signaling with delayed kinetics in both wild-type and F104S c-Mpl-expressing cells. Although F104S c-Mpl is expressed on the cell surface in our BaF3 cell line model, the mutant receptor does not bind thrombopoietin. Comparison to the erythropoietin receptor suggests that F104 engages in hydrogen-bonding interactions that are critical for binding to thrombopoietin. These findings suggest that a small subset of patients with congenital amegakaryocytic thrombocytopenia might respond to treatment with thrombopoietin receptor agonists, but that responsiveness will depend on the type of mutation and agonist used. We postulate that F104 is critical for thrombopoietin binding. The kinetics of signaling in response to a transmembrane domain-binding agonist are delayed in comparison to thrombopoietin. 2010 ISEH Society for Hematology and Stem Cells. Published by Elsevier Inc. All rights reserved.

  9. Glutamate receptor agonists

    DEFF Research Database (Denmark)

    Vogensen, Stine Byskov; Greenwood, Jeremy R; Bunch, Lennart

    2011-01-01

    The neurotransmitter (S)-glutamate [(S)-Glu] is responsible for most of the excitatory neurotransmission in the central nervous system. The effect of (S)-Glu is mediated by both ionotropic and metabotropic receptors. Glutamate receptor agonists are generally a-amino acids with one or more...... stereogenic centers due to strict requirements in the agonist binding pocket of the activated state of the receptor. By contrast, there are many examples of achiral competitive antagonists. The present review addresses how stereochemistry affects the activity of glutamate receptor ligands. The review focuses...... mainly on agonists and discusses stereochemical and conformational considerations as well as biostructural knowledge of the agonist binding pockets, which is useful in the design of glutamate receptor agonists. Examples are chosen to demonstrate how stereochemistry not only determines how the agonist...

  10. Modification of kindled amygdaloid seizures by opiate agonists and antagonists.

    Science.gov (United States)

    Albertson, T E; Joy, R M; Stark, L G

    1984-03-01

    The effects of 19 opiate agonists and antagonists on kindled amygdaloid seizures in the rat were studied. The mu agonists tended to reduce the length of elicited afterdischarges and behavioral ranks, while markedly increasing postictal electroencephalogram spikes and behavioral arrest time. These effects were reversed by naloxone. The kappa agonists reduced behavioral rank and variably reduced afterdischarge length with a concomitant lengthening of postictal behavioral arrest time and number of electroencephalogram spikes. The putative sigma agonist, SKF 10,047, reduced afterdischarge durations only at the higher doses tested. The decreases found after the sigma agonists in postictal electroencephalogram spiking and time of behavioral arrest were not reversed by naloxone. Only the lower doses of normeperidine were found to decrease seizure thresholds. The mixed agonist/antagonists (MAA) cyclazocine and cyclorphan markedly increased seizure threshold and reduced afterdischarge duration and behavioral rank. Only the MAA pentazocine tended to increase threshold but not suprathreshold afterdischarge durations. The order of ability to modify the ictal events was MAA (selected) greater than kappa agonists greater than mu agonists greater than sigma agonists. The increase in postictal events (behavior arrest and spikes) was caused most effectively by pretreatment with mu agonist greater than kappa agonist greater than selected MAA greater than sigma agonists.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Increase in skeletal muscle protein content by the ß-2 selective adrenergic agonist clenbuterol exacerbates hypoalbuminemia in rats fed a low-protein diet

    Directory of Open Access Journals (Sweden)

    A.L. Sawaya

    1998-06-01

    Full Text Available This investigation examined how the nutritional status of rats fed a low-protein diet was affected when the animals were treated with the ß-2 selective agonist clenbuterol (CL. Males (4 weeks old from an inbred, specific-pathogen-free strain of hooded rats maintained at the Dunn Nutritional Laboratory were used in the experiments (N = 6 rats per group. CL treatment (Ventipulmin, Boehringer-Ingelheim Ltd., 3.2 mg/kg diet for 2 weeks caused an exacerbation of the symptoms associated with protein deficiency in rats. Plasma albumin concentrations, already low in rats fed a low-protein diet (group A, were further reduced in CL rats (A = 25.05 ± 0.31 vs CL = 23.64 ± 0.30 g/l, P<0.05. Total liver protein decreased below the level seen in either pair-fed animals (group P or animals with free access to the low-protein diet (A = 736.56 ± 26 vs CL = 535.41 ± 54 mg, P<0.05, whereas gastrocnemius muscle protein was higher than the values normally described for control (C animals (C = 210.88 ± 3.2 vs CL = 227.14 ± 1.7 mg/g, P<0.05. Clenbuterol-treated rats also showed a reduction in growth when compared to P rats (P = 3.2 ± 1.1 vs CL = -10.2 ± 1.9 g, P<0.05. This was associated with a marked decrease in fat stores (P = 5.35 ± 0.81 vs CL = 2.02 ± 0.16 g, P<0.05. Brown adipose tissue (BAT cytochrome oxidase activity, although slightly lower than in P rats (P = 469.96 ± 16.20 vs CL = 414.48 ± 11.32 U/BAT x kg body weight, P<0.05, was still much higher than in control rats (C = 159.55 ± 11.54 vs CL = 414.48 ± 11.32 U/BAT x kg body weight, P<0.05. The present findings support the hypothesis that an increased muscle protein content due to clenbuterol stimulation worsened amino acid availability to the liver and further reduced albumin synthesis causing exacerbation of hypoalbuminemia in rats fed a low-protein diet.

  12. 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.

  13. Selective agonists at group II metabotropic glutamate receptors: synthesis, stereochemistry, and molecular pharmacology of (S)- and (R)-2-amino-4-(4-hydroxy[1,2,5]thiadiazol-3-yl)butyric acid

    DEFF Research Database (Denmark)

    Clausen, Rasmus P; Bräuner-Osborne, Hans; Greenwood, Jeremy R

    2002-01-01

    Homologation of analogues of the central excitatory neurotransmitter glutamic acid (Glu), in which the distal carboxy group has been bioisosterically replaced by acidic heterocyclic units, has previously provided subtype selective ligands for metabotropic Glu receptors (mGluRs). The (S......)-form of the 1,2,5-thiadiazol-3-ol Glu analogue, 2-amino-3-(4-hydroxy[1,2,5]thiadiazol-3-yl)propionic acid (TDPA, 6), is an 2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid (AMPA) receptor agonist, which in addition stereospecifically activates group I mGluRs. We have now synthesized the (S)- and (R......)-forms of 2-amino-4-(4-hydroxy[1,2,5]thiadiazol-3-yl)butyric acid (homo-TDPA, 7) and shown that whereas neither enantiomer interacts with AMPA receptors, (S)- and (R)-7 appear to be selective and equipotent agonists at group II mGluRs as represented by the mGluR2 subtype. The activities of (S)- and (R)-7...

  14. Kaposi sarcoma-associated herpes virus targets the lymphotactin receptor with both a broad spectrum antagonist vCCL2 and a highly selective and potent agonist vCCL3

    DEFF Research Database (Denmark)

    Lüttichau, Hans R; Johnsen, Anders H; Jurlander, Jesper

    2007-01-01

    virus (KSHV) encodes three chemokine-like proteins named vCCL1, vCCL2, and vCCL3. In this study vCCL3 was probed in parallel with vCCL1 and vCCL2 against a panel of the 18 classified human chemokine receptors. In calcium mobilization assays vCCL1 acted as a selective CCR8 agonist, whereas vCCL2......Large DNA viruses such as herpesvirus and poxvirus encode proteins that target and exploit the chemokine system of their host. These proteins have the potential to block or change the orchestrated recruitment of leukocytes to sites of viral infection. The genome of Kaposi sarcoma-associated herpes...... was found to act as a broad spectrum chemokine antagonist of human chemokine receptors, including the lymphotactin receptor. In contrast vCCL3 was found to be a highly selective agonist for the human lymphotactin receptor XCR1. The potency of vCCL3 was found to be 10-fold higher than the endogenous human...

  15. Balancing selected medication costs with total number of daily injections: a preference analysis of GnRH-agonist and antagonist protocols by IVF patients

    Directory of Open Access Journals (Sweden)

    Sills E

    2012-08-01

    Full Text Available Abstract Background During in vitro fertilization (IVF, fertility patients are expected to self-administer many injections as part of this treatment. While newer medications have been developed to substantially reduce the number of these injections, such agents are typically much more expensive. Considering these differences in both cost and number of injections, this study compared patient preferences between GnRH-agonist and GnRH-antagonist based protocols in IVF. Methods Data were collected by voluntary, anonymous questionnaire at first consultation appointment. Patient opinion concerning total number of s.c. injections as a function of non-reimbursed patient cost associated with GnRH-agonist [A] and GnRH-antagonist [B] protocols in IVF was studied. Results Completed questionnaires (n = 71 revealed a mean +/− SD patient age of 34 +/− 4.1 yrs. Most (83.1% had no prior IVF experience; 2.8% reported another medical condition requiring self-administration of subcutaneous medication(s. When out-of-pocket cost for [A] and [B] were identical, preference for [B] was registered by 50.7% patients. The tendency to favor protocol [B] was weaker among patients with a health occupation. Estimated patient costs for [A] and [B] were $259.82 +/− 11.75 and $654.55 +/− 106.34, respectively (p  Conclusions This investigation found consistently higher non-reimbursed direct medication costs for GnRH-antagonist IVF vs. GnRH-agonist IVF protocols. A conditional preference to minimize downregulation (using GnRH-antagonist was noted among some, but not all, IVF patient sub-groups. Compared to IVF patients with a health occupation, the preference for GnRH-antagonist was weaker than for other patients. While reducing total number of injections by using GnRH-antagonist is a desirable goal, it appears this advantage is not perceived equally by all IVF patients and its utility is likely discounted heavily by patients when nonreimbursed medication costs

  16. Balancing selected medication costs with total number of daily injections: a preference analysis of GnRH-agonist and antagonist protocols by IVF patients.

    Science.gov (United States)

    Sills, E Scott; Collins, Gary S; Salem, Shala A; Jones, Christopher A; Peck, Alison C; Salem, Rifaat D

    2012-08-30

    During in vitro fertilization (IVF), fertility patients are expected to self-administer many injections as part of this treatment. While newer medications have been developed to substantially reduce the number of these injections, such agents are typically much more expensive. Considering these differences in both cost and number of injections, this study compared patient preferences between GnRH-agonist and GnRH-antagonist based protocols in IVF. Data were collected by voluntary, anonymous questionnaire at first consultation appointment. Patient opinion concerning total number of s.c. injections as a function of non-reimbursed patient cost associated with GnRH-agonist [A] and GnRH-antagonist [B] protocols in IVF was studied. Completed questionnaires (n = 71) revealed a mean +/- SD patient age of 34 +/- 4.1 yrs. Most (83.1%) had no prior IVF experience; 2.8% reported another medical condition requiring self-administration of subcutaneous medication(s). When out-of-pocket cost for [A] and [B] were identical, preference for [B] was registered by 50.7% patients. The tendency to favor protocol [B] was weaker among patients with a health occupation. Estimated patient costs for [A] and [B] were $259.82 +/- 11.75 and $654.55 +/- 106.34, respectively (p cost difference increased. This investigation found consistently higher non-reimbursed direct medication costs for GnRH-antagonist IVF vs. GnRH-agonist IVF protocols. A conditional preference to minimize downregulation (using GnRH-antagonist) was noted among some, but not all, IVF patient sub-groups. Compared to IVF patients with a health occupation, the preference for GnRH-antagonist was weaker than for other patients. While reducing total number of injections by using GnRH-antagonist is a desirable goal, it appears this advantage is not perceived equally by all IVF patients and its utility is likely discounted heavily by patients when nonreimbursed medication costs reach a critical level.

  17. Actions of alpha2 adrenoceptor ligands at alpha2A and 5-HT1A receptors: the antagonist, atipamezole, and the agonist, dexmedetomidine, are highly selective for alpha2A adrenoceptors.

    Science.gov (United States)

    Newman-Tancredi, A; Nicolas, J P; Audinot, V; Gavaudan, S; Verrièle, L; Touzard, M; Chaput, C; Richard, N; Millan, M J

    1998-08-01

    This study examined the activity of chemically diverse alpha2 adrenoceptor ligands at recombinant human (h) and native rat (r) alpha2A adrenoceptors compared with 5-HT1A receptors. First, in competition binding experiments at h alpha2A and h5-HT1A receptors expressed in CHO cells, several compounds, including the antagonists 1-(2-pyrimidinyl)piperazine (1-PP), (+/-)-idazoxan, benalfocin (SKF 86466), yohimbine and RX 821,002, displayed preference for h alpha2A versus h5-HT1A receptors of only 1.4-, 3.6-, 4-, 10- and 11-fold, respectively (based on differences in pKi values). Clonidine, brimonidine (UK 14304), the benzopyrrolidine fluparoxan and the guanidines guanfacine and guanabenz exhibited intermediate selectivity (22- to 31-fold) for h alpha2A receptors. Only the antagonist atipamezole and the agonist dexmedetomidine (DMT) displayed high preference for alpha2 adrenoceptors (1290- and 91-fold, respectively). Second, the compounds were tested for their ability to induce h5-HT1A receptor-mediated G-protein activation, as indicated by the stimulation of [35S]GTPgammaS binding. All except atipamezole and RX 821,002 exhibited agonist activity, with potencies which correlated with their affinity for h5-HT1A receptors. Relative efficacies (Emax values) were 25-35% for guanabenz, guanfacine, WB 4101 and benalfocin, 50-65% for 1-PP, (+/-)-idazoxan and clonidine, and over 70% for fluparoxan, oxymetazoline and yohimbine (relative to 5-HT = 100%). Yohimbine-induced [35S]GTPgammaS binding was inhibited by the selective 5-HT1A receptor antagonist WAY 100,635. In contrast, RX 821,002 was the only ligand which exhibited antagonist activity at h5-HT1A receptors, inhibiting 5-HT-stimulated [35S]GTPgammaS binding. Atipamezole, which exhibited negligeable affinity for 5-HT1A receptors, was inactive. Third, the affinities for r alpha2A differed considerably from the affinities for h alpha2A receptors whereas the affinities for r5-HT1A differed much less from the affinities for h5-HT

  18. Dgroup: DG01000 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available pioid receptor agonist ... DG01563 ... mu-Opioid receptor agonist Analgesic ... DG01984 ... Opioid analgesics Other ... DG01718 ... Drugs... for addictive disorder ... DG01717 ... Drugs for opioid dependence Cyp su

  19. Dgroup: DG00999 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available agonist ... DG01563 ... mu-Opioid receptor agonist Analgesic ... DG01984 ... Opioid analgesics Other ... DG01718 ... Drugs fo...r addictive disorder ... DG01717 ... Drugs for opioid dependence Cyp substrate ... DG0163

  20. The selective alpha7 nicotinic acetylcholine receptor agonist PNU-282987 [N-[(3R)-1-Azabicyclo[2.2.2]oct-3-yl]-4-chlorobenzamide hydrochloride] enhances GABAergic synaptic activity in brain slices and restores auditory gating deficits in anesthetized rats.

    Science.gov (United States)

    Hajós, M; Hurst, R S; Hoffmann, W E; Krause, M; Wall, T M; Higdon, N R; Groppi, V E

    2005-03-01

    Schizophrenic patients are thought to have an impaired ability to process sensory information. This deficit leads to disrupted auditory gating measured electrophysiologically as a reduced suppression of the second of paired auditoryevoked responses (P50) and is proposed to be associated with decreased function and/or expression of the homomeric alpha7 nicotinic acetylcholine receptor (nAChR). Here, we provide evidence that N-[(3R)-1-azabicyclo[2.2.2]oct-3-yl]-4-chlorobenzamide hydrochloride (PNU-282987), a novel selective agonist of the alpha7 nAChR, evoked whole-cell currents from cultured rat hippocampal neurons that were sensitive to the selective alpha7 nAChR antagonist methyllycaconitine (MLA) and enhanced GABAergic synaptic activity when applied to hippocampal slices. Amphetamine-induced sensory gating deficit, determined by auditory-evoked potentials in hippocampal CA3 region, was restored by systemic administration of PNU-282987 in chloral hydrate-anesthetized rats. Auditory gating of rat reticular thalamic neurons was also disrupted by amphetamine; however, PNU-282987 normalized gating deficit only in a subset of tested neurons (6 of 11). Furthermore, PNU-282987 improved the inherent hippocampal gating deficit occurring in a subpopulation of anesthetized rats, and enhanced amphetamine-induced hippocampal oscillation. We propose that the alpha7 nAChR agonist PNU-282987, via modulating/enhancing hippocampal GABAergic neurotransmission, improves auditory gating and enhances hippocampal oscillatory activity. These results provide further support for the concept that drugs that selectively activate alpha7 nAChRs may offer a novel, potential pharmacotherapy in treatment of schizophrenia.

  1. Arctigenin functions as a selective agonist of estrogen receptor β to restrict mTORC1 activation and consequent Th17 differentiation.

    Science.gov (United States)

    Wu, Xin; Tong, Bei; Yang, Yan; Luo, Jinque; Yuan, Xusheng; Wei, Zhifeng; Yue, Mengfan; Xia, Yufeng; Dai, Yue

    2016-12-20

    Arctigenin was previously proven to inhibit Th17 cell differentiation and thereby attenuate colitis in mice by down-regulating the activation of mechanistic target of rapamycin complex 1 (mTORC1). The present study was performed to address its underlying mechanism in view of estrogen receptor (ER). The specific antagonist PHTPP or siRNA of ERβ largely diminished the inhibitory effect of arctigenin on the mTORC1 activation in T cell lines and primary CD4+ T cells under Th17-polarization condition, suggesting that arctigenin functioned in an ERβ-dependent manner. Moreover, arctigenin was recognized to be an agonist of ERβ, which could bind to ERβ with a moderate affinity, promote dissociation of ERβ/HSP90 complex and nuclear translocation and phosphorylation of ERβ, and increase the transcription activity. Following activation of ERβ, arctigenin inhibited the activity of mTORC1 by disruption of ERβ-raptor-mTOR complex assembly. Deficiency of ERβ markedly abolished arctigenin-mediated inhibition of Th17 cell differentiation. In colitis mice, the activation of ERβ, inhibition of mTORC1 activation and Th17 response by arctigenin were abolished by PHTPP treatment. In conclusion, ERβ might be the target protein of arctigenin responsible for inhibition of mTORC1 activation and resultant prevention of Th17 cell differentiation and colitis development.

  2. CCR4 agonists CCL22 and CCL17 are elevated in pediatric OMS sera: rapid and selective down-regulation of CCL22 by ACTH or corticosteroids.

    Science.gov (United States)

    Pranzatelli, Michael R; Tate, Elizabeth D; McGee, Nathan R; Colliver, Jerry A; Ransohoff, Richard M

    2013-05-01

    To study the role of Th2-attracting chemokines in opsoclonus-myoclonus syndrome (OMS), a serious neurological paraneoplastic disorder in need of better immunological understanding and therapy. The CCR4 agonists CCL22 and CCL17 were measured in serum by ELISA in children with OMS (238 and 260, respectively), pediatric controls (115 and 143), and other inflammatory neurological disorders (33 and 24). Both CCL22 (+55 %) and CCL17 (+121 %) were significantly elevated in untreated OMS compared to controls and inter-correlated (p OMS also were higher than in OIND (21 %, 41 %). The concentration of CCL22 in ACTH and steroids groups (not IVIg) was 51 % lower than in controls, but only a smaller effect of ACTH on CCL17 was found. Prospective longitudinal studies revealed a precipitous 81 % drop in CCL22 even by the first week of high-dose ACTH therapy, staying below control mean for at least 12 weeks, and a 34 % reduction after 8 months of combined treatment. Response to ACTH was dose-related (r = -0.50, p OMS. Marked and rapid reduction in CCL22, not CCL17, with either ACTH or steroid therapy suggests differential regulation and cellular sources of CCR4 ligands, and CCL22 as a potential candidate biomarker for ACTH or corticosteroid effect.

  3. Ocular Hypotensive Response in Nonhuman Primates of (8R)-1-[(2S)-2-Aminopropyl]-8,9-dihydro-7H-pyrano[2,3-g]indazol-8-ol a Selective 5-HT2 Receptor Agonist.

    Science.gov (United States)

    May, Jesse A; Sharif, Najam A; McLaughlin, Marsha A; Chen, Hwang-Hsing; Severns, Bryon S; Kelly, Curtis R; Holt, William F; Young, Richard; Glennon, Richard A; Hellberg, Mark R; Dean, Thomas R

    2015-11-25

    Recently, it has been reported that 5-HT2 receptor agonists effectively reduce intraocular pressure (IOP) in a nonhuman primate model of glaucoma. Although 1-[(2S)-2-aminopropyl]indazol-6-ol (AL-34662) was shown to have good efficacy in this nonhuman primate model of ocular hypertension as well as a desirable physicochemical and permeability profile, subsequently identified cardiovascular side effects in multiple species precluded further clinical evaluation of this compound. Herein, we report selected structural modifications that resulted in the identification of (8R)-1-[(2S)-2-aminopropyl]-8,9-dihydro-7H-pyrano[2,3-g]indazol-8-ol (13), which displayed an acceptable profile to support advancement for further preclinical evaluation as a candidate for proof-of-concept studies in humans.

  4. Modification on ursodeoxycholic acid (UDCA) scaffold. discovery of bile acid derivatives as selective agonists of cell-surface G-protein coupled bile acid receptor 1 (GP-BAR1).

    Science.gov (United States)

    Sepe, Valentina; Renga, Barbara; Festa, Carmen; D'Amore, Claudio; Masullo, Dario; Cipriani, Sabrina; Di Leva, Francesco Saverio; Monti, Maria Chiara; Novellino, Ettore; Limongelli, Vittorio; Zampella, Angela; Fiorucci, Stefano

    2014-09-25

    Bile acids are signaling molecules interacting with the nuclear receptor FXR and the G-protein coupled receptor 1 (GP-BAR1/TGR5). GP-BAR1 is a promising pharmacological target for the treatment of steatohepatitis, type 2 diabetes, and obesity. Endogenous bile acids and currently available semisynthetic bile acids are poorly selective toward GP-BAR1 and FXR. Thus, in the present study we have investigated around the structure of UDCA, a clinically used bile acid devoid of FXR agonist activity, to develop a large family of side chain modified 3α,7β-dihydroxyl cholanoids that selectively activate GP-BAR1. In vivo and in vitro pharmacological evaluation demonstrated that administration of compound 16 selectively increases the expression of pro-glucagon 1, a GP-BAR1 target, in the small intestine, while it had no effect on FXR target genes in the liver. Further, compound 16 results in a significant reshaping of bile acid pool in a rodent model of cholestasis. These data demonstrate that UDCA is a useful scaffold to generate novel and selective steroidal ligands for GP-BAR1.

  5. Small-molecule AT2 receptor agonists

    DEFF Research Database (Denmark)

    Hallberg, Mathias; Sumners, Colin; Steckelings, U Muscha

    2018-01-01

    The discovery of the first selective, small-molecule ATR receptor (AT2R) agonist compound 21 (C21) (8) that is now extensively studied in a large variety of in vitro and in vivo models is described. The sulfonylcarbamate derivative 8, encompassing a phenylthiofen scaffold is the drug-like agonist...... with the highest affinity for the AT2R reported to date (Ki = 0.4 nM). Structure-activity relationships (SAR), regarding different biaryl scaffolds and functional groups attached to these scaffolds and with a particular focus on the impact of various para substituents displacing the methylene imidazole group of 8......, are discussed. Furthermore, the consequences of migration of the methylene imidazole group and presumed structural requirements for ligands that are aimed as AT2R agonists (e.g. 8) or AT2R antagonists (e.g. 9), respectively, are briefly addressed. A summary of the pharmacological actions of C21 (8) is also...

  6. Discovery of an Oxybenzylglycine Based Peroxisome Proliferator Activated Receptor [alpha] Selective Agonist 2-((3-((2-(4-Chlorophenyl)-5-methyloxazol-4-yl)methoxy)benzyl)(methoxycarbonyl)amino)acetic Acid (BMS-687453)

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jun; Kennedy, Lawrence J.; Shi, Yan; Tao, Shiwei; Ye, Xiang-Yang; Chen, Stephanie Y.; Wang, Ying; Hernndez, Andrs S.; Wang, Wei; Devasthale, Pratik V.; Chen, Sean; Lai, Zhi; Zhang, Hao; Wu, Shung; Smirk, Rebecca A.; Bolton, Scott A.; Ryono, Denis E.; Zhang, Huiping; Lim, Ngiap-Kie; Chen, Bang-Chi; Locke, Kenneth T.; O’Malley, Kevin M.; Zhang, Litao; Srivastava, Rai Ajit; Miao, Bowman; Meyers, Daniel S.; Monshizadegan, Hossain; Search, Debra; Grimm, Denise; Zhang, Rongan; Harrity, Thomas; Kunselman, Lori K.; Cap, Michael; Kadiyala, Pathanjali; Hosagrahara, Vinayak; Zhang, Lisa; Xu, Carrie; Li, Yi-Xin; Muckelbauer, Jodi K.; Chang, Chiehying; An, Yongmi; Krystek, Stanley R.; Blanar, Michael A.; Zahler, Robert; Mukherjee, Ranjan; Cheng, Peter T.W.; Tino, Joseph A. (BMS)

    2010-04-12

    An 1,3-oxybenzylglycine based compound 2 (BMS-687453) was discovered to be a potent and selective peroxisome proliferator activated receptor (PPAR) {alpha} agonist, with an EC{sub 50} of 10 nM for human PPAR{alpha} and 410-fold selectivity vs human PPAR{gamma} in PPAR-GAL4 transactivation assays. Similar potencies and selectivity were also observed in the full length receptor co-transfection assays. Compound 2 has negligible cross-reactivity against a panel of human nuclear hormone receptors including PPAR{delta}. Compound 2 demonstrated an excellent pharmacological and safety profile in preclinical studies and thus was chosen as a development candidate for the treatment of atherosclerosis and dyslipidemia. The X-ray cocrystal structures of the early lead compound 12 and compound 2 in complex with PPAR{alpha} ligand binding domain (LBD) were determined. The role of the crystal structure of compound 12 with PPAR{alpha} in the development of the SAR that ultimately resulted in the discovery of compound 2 is discussed.

  7. In vitro study on the effects of some selected agonists and antagonists of alpha(1)-adrenergic receptors on the contractility of the aneurysmally-changed aortic smooth muscle in humans.

    Science.gov (United States)

    Gnus, J; Czerski, A; Ferenc, S; Zawadzki, W; Witkiewicz, W; Hauzer, W; Rusiecka, A; Bujok, J

    2012-02-01

    The study included 18 sections of the aneurysmally-changed abdominal aortas, obtained from patients of the Provincial Specialist Hospital in Wroclaw and 18 sections of normal abdominal aortas obtained from swine. The collected samples were placed horizontally in the incubation chamber. Changes in their transverse section area were registered. They were stretched to a tension of 5 mN. Krebs-Henseleit buffer was used as the incubatory environment. Incubation of the sections was performed at a temperature of 37°C, in the gaseous mixture of oxygen and carbon dioxide used in the following proportion: 95% of O(2) and 5% of CO(2). Contractions of the aorta were registered with isotonic transducers (Letica Scientific Instruments). In the studies, we examined the influence of α(1)-adrenergic receptors (and their subtypes α(1A), α(1B), α(1D)) on the contractility of the aortic muscle in humans and swine by their stimulation or inhibition with some selected agonists or antagonists. This time, it was shown that the stimulation of α(1)-adrenergic receptors leads to contractions of the human and swine aortic muscle; the observed increase in the muscle tone may follow from the stimulation of all subtypes of alpha-1 receptor (α(1A), α(1B), α(1D)). All three subtypes of 1-adrenergic receptor are engaged in vasoconstriction, especially of α(1A) and α(1D) subtypes; the α(1B) subtype is less significant for aortic contractility. The contractile response of the aneurysmally-changed abdominal aorta in humans to agonists of α-adrenergic receptors was significantly less intense than that of the normal porcine aorta. It can be concluded that aneurysms influence the contractile response of the aorta.

  8. The selective estrogen receptor alpha agonist Org 37663 induces estrogenic effects but lacks antirheumatic activity: a phase IIa trial investigating efficacy and safety of Org 37663 in postmenopausal female rheumatoid arthritis patients receiving stable background methotrexate or sulfasalazine.

    Science.gov (United States)

    van Vollenhoven, Ronald F; Houbiers, Jos G A; Buttgereit, Frank; In 't Hout, Joanna; Boers, Maarten; Leij, Susanne; Kvien, Tore K; Dijkmans, Ben A C; Szczepański, Leszek; Szombati, Istvan; Sierakowski, Stanislaw; Miltenburg, André M M

    2010-02-01

    Multiple lines of evidence suggest that sex hormones may play a role in the pathogenesis or clinical expression of rheumatoid arthritis (RA). Studies on the effects of exogenous estrogens in RA patients have yielded contradictory results. We undertook this study to determine the effects of the selective estrogen receptor alpha (ERalpha) agonist Org 37663 in patients with RA, in terms of both its estrogenic effects and its ability to ameliorate disease activity. A 10-week, multicenter, randomized, double-blind, placebo-controlled, parallel group, dose-finding, proof-of-concept trial was initiated to obtain data on the efficacy and safety of Org 37663 in postmenopausal female patients with RA who were receiving background treatment with either methotrexate or sulfasalazine. Patients were randomized to receive placebo or Org 37663 at doses of 4 mg/day, 15 mg/day, or 50 mg/week. The primary efficacy variable was the Disease Activity Score in 28 joints (DAS28). Org 37663 induced a clear biologic, estrogenic response in several organ systems, including a dose-related increase in levels of sex hormone binding globulin. However, the DAS28 decreased similarly for all treatment groups including placebo, indicating lack of clinical efficacy of Org 37663 in this trial. The observed lack of clinical benefit in RA patients treated with an ERalpha agonist, in association with a clear biologic response to the study drug, provides evidence that a biologically relevant ERalpha-mediated estrogenic effect is not associated with a clinically relevant effect on RA symptoms and signs.

  9. MDAN-21: A Bivalent Opioid Ligand Containing mu-Agonist and Delta-Antagonist Pharmacophores and Its Effects in Rhesus Monkeys

    Directory of Open Access Journals (Sweden)

    Mario D. Aceto

    2012-01-01

    Full Text Available MDAN-21, 7′-{2-[(7-{2-[({(5α,6α-4,5-Epoxy-3,14-dihydroxy-17-methylmorphin-6-yl}-aminocarbonylmetoxy]-acetylamino}-heptylaminocarbonyl-methoxy]-acetylamino}-naltrindole, a bivalent opioid ligand containing a mu-opioid receptor agonist (derived from oxymorphone linked to the delta-opioid receptor antagonist (related to naltrindole by a spacer of 21 atoms, was reported to have potent analgesic properties in mice. Tolerance, physical dependence, and conditioned place preference were not evident in that species. The finding that bivalent ligands in this series, with spacers 19 atoms or greater, were devoid of tolerance and dependence led to the proposal that MDAN-21 targets heteromeric mu-delta-opioid receptors. The present study focused on its effects in nonhuman primates (Macaca mulatta, a species with a physiology and behavioral repertoire not unlike humans. With regard to opioids, this species usually better predicts clinical outcomes. MDAN-21 substituted for morphine in morphine-dependent monkeys in the remarkably low dose range 0.006–0.032 mg/kg, subcutaneously. Although MDAN-21 failed to produce reliable thermal analgesia in the dose range 0.0032–0.032 mg/kg, intramuscularly, it was active in the same dose range and by the same route of administration, in the capsaicin-induced thermal allodynia assay. The results suggest that MDAN-21 may be useful in the treatment of opioid dependence and allodynia. The data provide additional evidence that opioid withdrawal is associated with sensitized pain.

  10. Endothelium-dependent relaxant responses to selective 5-HT(1B/1D) receptor agonists in the isolated middle cerebral artery of the rat

    DEFF Research Database (Denmark)

    Hansen-Schwartz, Jacob; Løvland Hoel, Natalie; Nilsson, Elisabeth

    2003-01-01

    perfused. Luminally added 5- hydroxytryptamine (5-HT), sumatriptan and rizatriptan induced maximal dilatations of 22 +/- 4, 10 +/- 2 and 13 +/- 5%, respectively, compared to the resting diameter. The relaxant effect of sumatriptan was blocked by the 5- HT(1B/1D) receptor selective antagonist GR 55562 (10......The vasomotor effects of triptans in the middle cerebral artery (MCA) of rats were studied using the pressurised arteriography method and in vitro vessel baths. Using the arteriograph, MCAs from Sprague-Dawley rats were mounted on two glass micropipettes, pressurised to 85 mm Hg and luminally...... response to 5-HT and triptans. Using the vessel bath technique, MCA segments were mounted on two metal wires. The relaxant responses to sumatriptan could not be reproduced using this model; instead, weak contractile responses (6 +/- 3% of submaximal contractile capacity) were observed. The difference...

  11. Distribution of seratonin-1A receptors in the monkey and the postmortem human hippocampal region. A quantitative autoradiographic study using the selective agonist (3H)8-PH-DPAT

    International Nuclear Information System (INIS)

    Koehler, Christer; Radesaeter, A.C.; Lang, Walter; Chan-Palay, Victoria

    1986-01-01

    Serotonin-1A receptors were visualized and their anatomical distribution mapped within the monkey and the human hippocampus by using in vitro receptor autoradiography of the selective agonist ( 3 H)8-OH-N, N-dipropyl-2-aminotetralin (( 3 H)8-OH-DPAT). The results show high densities of serotonin-1A receptors hetergeneously distributed in different subfields and layers of the monkey and the human hippocampal region. High densities are found in the molecular layer of area dentata, all layers of regio superior and the subiculum, parasubiculum, and layers 2, and 4 through 6 of the entorhinal area. In the human hippocampus, a distinct band of ( 3 H)8-OH-DPAT binding sites is present in the subgranular zone of the area dentata. The similar anatomical distribution of ( 3 H)8-OH-DPAT binding sites in the monkey and the human hippocampal region suggests that the serotonin-1A receptor is phylogenetically well preserved and indicates that this receptor may mediate action(s) of serotonin in the primate, including the human hippocampal region. (author)

  12. A novel selective VPAC2 agonist peptide-conjugated chitosan modified selenium nanoparticles with enhanced anti-type 2 diabetes synergy effects

    Directory of Open Access Journals (Sweden)

    Zhao SJ

    2017-03-01

    Full Text Available Shao-Jun Zhao,1,2,* De-Hua Wang,1,2 Yan-Wei Li,1,2 Lei Han,1,2 Xing Xiao,1,2 Min Ma,3,* David Chi-Cheong Wan,4 An Hong,1,2 Yi Ma1,2 1Institute of Biomedicine, Department of Cellular Biology, Jinan University, 2National Engineering Research Center of Genetic Medicine, Key Laboratory of Bioengineering Medicine of Guangdong Province, Jinan University, 3College of traditional Chinese Medicine, Institute of Integrated Traditional Chinese and Western Medicine, Jinan University, Guangdong, 4School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, People’s Republic of China *These authors contributed equally to this work Abstract: A novel neuroendocrine peptide, pituitary adenylate cyclase activating peptide (PACAP, was found to have an important role in carbohydrate or lipid metabolism and was susceptible to dipeptidyl peptidase IV degradation. It can not only mediate glucose-dependent insulin secretion and lower blood glucose by activating VPAC2 receptor, but also raise blood glucose by promoting glucagon production by VPAC1 receptor activation. Therefore, its therapeutic application is restricted by the exceedingly short-acting half-life and the stimulatory function for glycogenolysis. Herein, we generated novel peptide-conjugated selenium nanoparticles (SeNPs; named as SCD, comprising a 32-amino acid PACAP-derived peptide DBAYL that selectively binds to VPAC2, and chitosan-modified SeNPs (SeNPs-CTS, SC as slow-release carrier. The circulating half-life of SCD is 14.12 h in mice, which is 168.4- and 7.1-fold longer than wild PACAP (~5 min and DBAYL (~1.98 h, respectively. SCD (10 nmol/L significantly promotes INS-1 cell proliferation, glucose uptake, insulin secretion, insulin receptor expression and also obviously reduces intracellular reactive oxygen species levels in H2O2-injured INS-1 cells. Furthermore, the biological effects of SCD are stronger than Exendin-4 (a clinically approved drug

  13. Dopaminergic agonists for hepatic encephalopathy

    DEFF Research Database (Denmark)

    Als-Nielsen, B; Gluud, L L; Gluud, C

    2004-01-01

    Hepatic encephalopathy may be associated with an impairment of the dopaminergic neurotransmission. Dopaminergic agonists may therefore have a beneficial effect on patients with hepatic encephalopathy.......Hepatic encephalopathy may be associated with an impairment of the dopaminergic neurotransmission. Dopaminergic agonists may therefore have a beneficial effect on patients with hepatic encephalopathy....

  14. Drug: D02102 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available gonist ... DG01563 ... mu-Opioid receptor agonist Analgesic ... DG01984 ... Opioid analgesics Other ... DG01718 ... Drugs for... addictive disorder ... DG01717 ... Drugs for opioid dependence Cyp substrate ... DG01633

  15. Drug: D07810 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available gonist ... DG01563 ... mu-Opioid receptor agonist Analgesic ... DG01984 ... Opioid analgesics Other ... DG01718 ... Drugs for... addictive disorder ... DG01717 ... Drugs for opioid dependence ATC code: N07BC06 Chem

  16. Dgroup: DG01002 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available gonist ... DG01563 ... mu-Opioid receptor agonist Analgesic ... DG01984 ... Opioid analgesics Other ... DG01718 ... Drugs for... addictive disorder ... DG01717 ... Drugs for opioid dependence Cyp substrate ... DG01633

  17. Dgroup: DG01339 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available il citrate (USAN) Neuropsychiatric agent ... DG01564 ... Opioid receptor agonist ... DG01563 ... mu-Opioid receptor ago... DG01339 Chemical ... DGroup Carfentanil ... D07620 ... Carfentanil (INN) D03405 ... Carfentan

  18. Dgroup: DG00823 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available DG00823 Chemical ... DGroup Tilidine ... D08597 ... Tilidine (INN) D06147 ... Tilidine hydrochloride (USAN) Neuropsych...iatric agent ... DG01564 ... Opioid receptor agonist ... DG01563 ... mu-Opioid receptor agonis

  19. Ecdysone Agonist: New Insecticides with Novel Mode of Action

    Directory of Open Access Journals (Sweden)

    Y. Andi Trisyono

    2002-12-01

    Full Text Available Development of insect resistance to insecticide has been the major driving force for the development of new insecticides. Awareness and demand from public for more environmentally friendly insecticides have contributed in shifting the trend from using broad spectrum to selective insecticides. As a result, scientists have looked for new target sites beyond the nervous system. Insect growth regulators (IGRs are more selective insecticides than conventional insecticides, and ecdysone agonists are the newest IGRs being commercialized, e.g. tebufenozide, methoxyfenozide, and halofenozide. Ecdysone agonists bind to the ecdysteroid receptors, and they act similarly to the molting hormone 20-hydroxyecdysone. The binding provides larvae or nymphs with a signal to enter a premature and lethal molting cycle. In addition, the ecdysone agonists cause a reduction in the number of eggs laid by female insects. The ecdysone agonists are being developed as selective biorational insecticides. Tebufenozide and methoxyfenozide are used to control lepidopteran insect pests, whereas halofenozide is being used to control coleopteran insect pests. Their selectivity is due to differences in the binding affinity between these compounds to the receptors in insects from different orders. The selectivity of these compounds makes them candidates to be used in combinations with other control strategies to develop integrated pest management programs in agricultural ecosystems. Key words: new insecticides, selectivity, ecdysone agonists

  20. Characterization of the nociceptin receptor (ORL-1) agonist, Ro64-6198, in tests of anxiety across multiple species.

    Science.gov (United States)

    Varty, G B; Hyde, L A; Hodgson, R A; Lu, S X; McCool, M F; Kazdoba, T M; Del Vecchio, R A; Guthrie, D H; Pond, A J; Grzelak, M E; Xu, X; Korfmacher, W A; Tulshian, D; Parker, E M; Higgins, G A

    2005-10-01

    Previous studies have demonstrated behaviors indicative of anxiolysis in rats pretreated with the nociceptin receptor (opioid receptor like-1, ORL-1) agonist, Ro64-6198. The aim of this study was to examine the effects of Ro64-6198 in anxiety models across three species: rat, guinea pig, and mouse. In addition, the receptor specificity of Ro64-6198 was studied, using the ORL-1 receptor antagonist, J-113397, and ORL-1 receptor knockout (KO) mice. Finally, neurological studies examined potential side effects of Ro64-6198 in the rat and mouse. Ro64-6198 (3-10 mg/kg) increased punished responding in a rat conditioned lick suppression test similarly to chlordiazepoxide (6 mg/kg). This effect of Ro64-6198 was attenuated by J-113397 (10 mg/kg), but not the mu opioid antagonist, naltrexone (3 mg/kg). In addition, Ro64-6198 (1-3 mg/kg) reduced isolation-induced vocalizations in rat and guinea pig pups. Ro64-6198 (3 mg/kg) increased the proportion of punished responding in a mouse Geller-Seifter test in wild-type (WT) but not ORL-1 KO mice, whereas diazepam (1-5.6 mg/kg) was effective in both genotypes. In rats, Ro64-6198 reduced locomotor activity (LMA) and body temperature and impaired rotarod, beam walking, and fixed-ratio (FR) performance at doses of 10-30 mg/kg, i.e., three to ten times higher than an anxiolytic dose. In WT mice, Ro64-6198 (3-10 mg/kg) reduced LMA and rotarod performance, body temperature, and FR responding, but these same measures were unaffected in ORL-1 KO mice. Haloperidol (0.3-3 mg/kg) reduced these measures to a similar extent in both genotypes. These studies confirm the potent, ORL-1 receptor-mediated, anxiolytic-like effects of Ro64-6198, extending the findings across three species. Ro64-6198 has target-based side effects, although the magnitude of these effects varies across species.

  1. The Selective Angiotensin II Type 2 Receptor Agonist, Compound 21, Attenuates the Progression of Lung Fibrosis and Pulmonary Hypertension in an Experimental Model of Bleomycin-Induced Lung Injury.

    Science.gov (United States)

    Rathinasabapathy, Anandharajan; Horowitz, Alana; Horton, Kelsey; Kumar, Ashok; Gladson, Santhi; Unger, Thomas; Martinez, Diana; Bedse, Gaurav; West, James; Raizada, Mohan K; Steckelings, Ulrike M; Sumners, Colin; Katovich, Michael J; Shenoy, Vinayak

    2018-01-01

    Idiopathic Pulmonary Fibrosis (IPF) is a chronic lung disease characterized by scar formation and respiratory insufficiency, which progressively leads to death. Pulmonary hypertension (PH) is a common complication of IPF that negatively impacts clinical outcomes, and has been classified as Group III PH. Despite scientific advances, the dismal prognosis of IPF and associated PH remains unchanged, necessitating the search for novel therapeutic strategies. Accumulating evidence suggests that stimulation of the angiotensin II type 2 (AT 2 ) receptor confers protection against a host of diseases. In this study, we investigated the therapeutic potential of Compound 21 (C21), a selective AT 2 receptor agonist in the bleomycin model of lung injury. A single intra-tracheal administration of bleomycin (2.5 mg/kg) to 8-week old male Sprague Dawley rats resulted in lung fibrosis and PH. Two experimental protocols were followed: C21 was administered (0.03 mg/kg/day, ip) either immediately (prevention protocol, BCP) or after 3 days (treatment protocol, BCT) of bleomycin-instillation. Echocardiography, hemodynamic, and Fulton's index assessments were performed after 2 weeks of bleomycin-instillation. Lung tissue was processed for gene expression, hydroxyproline content (a marker of collagen deposition), and histological analysis. C21 treatment prevented as well as attenuated the progression of lung fibrosis, and accompanying PH. The beneficial effects of C21 were associated with decreased infiltration of macrophages in the lungs, reduced lung inflammation and diminished pulmonary collagen accumulation. Further, C21 treatment also improved pulmonary pressure, reduced muscularization of the pulmonary vessels and normalized cardiac function in both the experimental protocols. However, there were no major differences in any of the outcomes measured from the two experimental protocols. Collectively, our findings indicate that stimulation of the AT 2 receptor by C21 attenuates

  2. The Selective Angiotensin II Type 2 Receptor Agonist, Compound 21, Attenuates the Progression of Lung Fibrosis and Pulmonary Hypertension in an Experimental Model of Bleomycin-Induced Lung Injury

    Directory of Open Access Journals (Sweden)

    Anandharajan Rathinasabapathy

    2018-03-01

    Full Text Available Idiopathic Pulmonary Fibrosis (IPF is a chronic lung disease characterized by scar formation and respiratory insufficiency, which progressively leads to death. Pulmonary hypertension (PH is a common complication of IPF that negatively impacts clinical outcomes, and has been classified as Group III PH. Despite scientific advances, the dismal prognosis of IPF and associated PH remains unchanged, necessitating the search for novel therapeutic strategies. Accumulating evidence suggests that stimulation of the angiotensin II type 2 (AT2 receptor confers protection against a host of diseases. In this study, we investigated the therapeutic potential of Compound 21 (C21, a selective AT2 receptor agonist in the bleomycin model of lung injury. A single intra-tracheal administration of bleomycin (2.5 mg/kg to 8-week old male Sprague Dawley rats resulted in lung fibrosis and PH. Two experimental protocols were followed: C21 was administered (0.03 mg/kg/day, ip either immediately (prevention protocol, BCP or after 3 days (treatment protocol, BCT of bleomycin-instillation. Echocardiography, hemodynamic, and Fulton's index assessments were performed after 2 weeks of bleomycin-instillation. Lung tissue was processed for gene expression, hydroxyproline content (a marker of collagen deposition, and histological analysis. C21 treatment prevented as well as attenuated the progression of lung fibrosis, and accompanying PH. The beneficial effects of C21 were associated with decreased infiltration of macrophages in the lungs, reduced lung inflammation and diminished pulmonary collagen accumulation. Further, C21 treatment also improved pulmonary pressure, reduced muscularization of the pulmonary vessels and normalized cardiac function in both the experimental protocols. However, there were no major differences in any of the outcomes measured from the two experimental protocols. Collectively, our findings indicate that stimulation of the AT2 receptor by C21 attenuates

  3. Overlapping binding site for the endogenous agonist, small-molecule agonists, and ago-allosteric modulators on the ghrelin receptor

    DEFF Research Database (Denmark)

    Holst, Birgitte; Frimurer, Thomas M; Mokrosinski, Jacek

    2008-01-01

    A library of robust ghrelin receptor mutants with single substitutions at 22 positions in the main ligand-binding pocket was employed to map binding sites for six different agonists: two peptides (the 28-amino-acid octanoylated endogenous ligand ghrelin and the hexapeptide growth hormone......, and PheVI:23 on the opposing face of transmembrane domain (TM) VI. Each of the agonists was also affected selectively by specific mutations. The mutational map of the ability of L-692,429 and GHRP-6 to act as allosteric modulators by increasing ghrelin's maximal efficacy overlapped with the common....... It is concluded that although each of the ligands in addition exploits other parts of the receptor, a large, common binding site for both small-molecule agonists--including ago-allosteric modulators--and the endogenous agonist is found on the opposing faces of TM-III and -VI of the ghrelin receptor....

  4. Anhedonia to music and mu-opioids: Evidence from the administration of naltrexone

    Science.gov (United States)

    Mallik, Adiel; Chanda, Mona Lisa; Levitin, Daniel J.

    2017-01-01

    Music’s universality and its ability to deeply affect emotions suggest an evolutionary origin. Previous investigators have found that naltrexone (NTX), a μ-opioid antagonist, may induce reversible anhedonia, attenuating both positive and negative emotions. The neurochemical basis of musical experience is not well-understood, and the NTX-induced anhedonia hypothesis has not been tested with music. Accordingly, we administered NTX or placebo on two different days in a double-blind crossover study, and assessed participants’ responses to music using both psychophysiological (objective) and behavioral (subjective) measures. We found that both positive and negative emotions were attenuated. We conclude that endogenous opioids are critical to experiencing both positive and negative emotions in music, and that music uses the same reward pathways as food, drug and sexual pleasure. Our findings add to the growing body of evidence for the evolutionary biological substrates of music. PMID:28176798

  5. Should We Use PPAR Agonists to Reduce Cardiovascular Risk?

    Directory of Open Access Journals (Sweden)

    Jennifer G. Robinson

    2008-01-01

    Full Text Available Trials of peroxisome proliferator-activated receptor (PPAR agonists have shown mixed results for cardiovascular prevention. Fibrates are PPAR- agonists that act primarily to improve dyslipidemia. Based on low- and high-density lipoprotein cholesterol (LDL and HDL effects, gemfibrozil may be of greater cardiovascular benefit than expected, fenofibrate performed about as expected, and bezafibrate performed worse than expected. Increases in both cardiovascular and noncardiovascular serious adverse events have been observed with some fibrates. Thiazolidinediones (TZDs are PPAR- agonists used to improve impaired glucose metabolism but also influence lipids. Pioglitazone reduces atherosclerotic events in diabetic subjects, but has no net cardiovascular benefit due to increased congestive heart failure risk. Rosiglitazone may increase the risk of atherosclerotic events, and has a net harmful effect on the cardiovascular system when congestive heart failure is included. The primary benefit of TZDs appears to be the prevention of diabetic microvascular complications. Dual PPAR-/ agonists have had unacceptable adverse effects but more selective agents are in development. PPAR- and pan-agonists are also in development. It will be imperative to prove that future PPAR agonists not only prevent atherosclerotic events but also result in a net reduction on total cardiovascular events without significant noncardiovascular adverse effects with long-term use.

  6. Differential effects of a selective dopamine D1-like receptor agonist on motor activity and c-fos expression in the frontal-striatal circuitry of SHR and Wistar-Kyoto rats

    Directory of Open Access Journals (Sweden)

    Diaz Heijtz Rochellys

    2006-05-01

    Full Text Available Abstract Background Molecular genetic studies suggest the dopamine D1 receptor (D1R may be implicated in attention-deficit/hyperactivity disorder (ADHD. As little is known about the potential motor role of D1R in ADHD, animal models may provide important insights into this issue. Methods We investigated the effects of a full and selective D1R agonist, SKF-81297 (0.3, 3 and 10 mg/kg, on motor behaviour and expression of the plasticity-associated gene, c-fos, in habituated young adult male Spontaneously Hypertensive Rats (SHR, the most commonly used animal model of ADHD, and Wistar-Kyoto (WKY; the strain from which SHR were derived. Results SHR rats were more behaviourally active than WKY rats after injection with vehicle. The 0.3 mg/kg dose of SKF-81297 increased motor behaviour (locomotion, sifting, rearing, and sniffing in both SHR and WKY rats. Total grooming was also stimulated, but only in WKY rats. The same dose increased c-fos mRNA expression in the piriform cortex of both strains. The 3 mg/kg dose increased sifting and sniffing in both strains. Locomotion was also stimulated towards the end of the testing period. The intermediate dose decreased total rearing in both strains, and produced a significant increase in c-fos mRNA in the striatum, nucleus accumbens, olfactory tuberculum, and in the cingulate, agranular insular and piriform cortices. The 10 mg/kg dose of SKF-81297 produced a biphasic effect on locomotion, which was characterized by an initial decrease followed by later stimulation. The latter stimulatory effect was more pronounced in SHR than in WKY rats when compared to their respective vehicle-injected groups. The 10 mg/kg dose also stimulated sifting and sniffing in both strains. Both the 3 and 10 mg/kg doses had no effect on total grooming. The 10 mg/kg dose induced significantly higher levels of c-fos mRNA expression in the nucleus accumbens and adjacent cortical regions (but not striatum of SHR when compared to WKY rats

  7. The 5-HT(1F) receptor agonist lasmiditan as a potential treatment of migraine attacks

    DEFF Research Database (Denmark)

    Tfelt-Hansen, Peer C; Olesen, Jes

    2012-01-01

    Lasmiditan is a novel selective 5-HT(1F) receptor agonist. It is both scientifically and clinically relevant to review whether a 5-HT(1F) receptor agonist is effective in the acute treatment of migraine. Two RCTs in the phase II development of lasmiditan was reviewed. In the intravenous placebo...

  8. Pavlovian conditioning of multiple opioid-like responses in mice

    OpenAIRE

    Bryant, Camron D.; Roberts, Kristofer W.; Culbertson, Christopher S.; Le, Alan; Evans, Christopher J.; Fanselow, Michael S.

    2009-01-01

    Conditional responses in rodents such as locomotion have been reported for drugs of abuse and similar to the placebo response in humans, may be associated with the expectation of reward. We examined several conditional opioid-like responses and the influence of drug expectation on conditioned place preference and concomitant conditional locomotion. Male C57BL/6J mice were conditioned with the selective mu opioid receptor agonist fentanyl (0.2 mg/kg, i.p.) in a novel context and subsequently g...

  9. New insights on mu/delta selectivity of opioid peptides: conformational analysis of deltorphin analogues.

    Science.gov (United States)

    Tancredi, T; Temussi, P A; Picone, D; Amodeo, P; Tomatis, R; Salvadori, S; Marastoni, M; Santagada, V; Balboni, G

    1991-05-01

    The message domain of dermorphin (Tyr-D-Ala-Phe), a natural mu-opioid heptapeptide, has long been considered the main cause of the high mu selectivity of this peptide and of its analogues. The recent discovery, in the skin of Phyllomedusa sauvagei (i.e., the same natural source of dermorphin) and of Phyllomedusa bicolor of deltorphins, challenges this belief. Deltorphins, in fact, are three heptapeptides characterized by a message domain typical of mu-selective peptides, but endowed of an extremely high delta selectivity, the highest of all natural opioid peptides. A conformational analysis of dermorphin and deltorphins, based on nmr studies in DMSO and cryoprotective mixtures and internal energy calculations, showed that the enormous differences in receptor selectivity can be interpreted on the basis of receptor models for mu and delta opioids that recognize the same beta-turn in the N-terminal part, but discriminate for the conformation and polarity of the C-terminal part. Here we present the synthesis, biological activity, and conformational analysis in solution of three deltorphin analogues with very similar constitution, but with different net charge, different location of negative residues, or even without negative residues, which confirm these hypotheses and show that His4 can play a specific structural role.

  10. Seladelpar (MBX-8025), a selective PPAR-δ agonist, in patients with primary biliary cholangitis with an inadequate response to ursodeoxycholic acid: a double-blind, randomised, placebo-controlled, phase 2, proof-of-concept study.

    Science.gov (United States)

    Jones, David; Boudes, Pol F; Swain, Mark G; Bowlus, Christopher L; Galambos, Michael R; Bacon, Bruce R; Doerffel, Yvonne; Gitlin, Norman; Gordon, Stuart C; Odin, Joseph A; Sheridan, David; Wörns, Markus-Alexander; Clark, Virginia; Corless, Linsey; Hartmann, Heinz; Jonas, Mark E; Kremer, Andreas E; Mells, George F; Buggisch, Peter; Freilich, Bradley L; Levy, Cynthia; Vierling, John M; Bernstein, David E; Hartleb, Marek; Janczewska, Ewa; Rochling, Fedja; Shah, Hemant; Shiffman, Mitchell L; Smith, John H; Choi, Yun-Jung; Steinberg, Alexandra; Varga, Monika; Chera, Harinder; Martin, Robert; McWherter, Charles A; Hirschfield, Gideon M

    2017-10-01

    Many patients with primary biliary cholangitis have an inadequate response to first-line therapy with ursodeoxycholic acid. Seladelpar is a potent, selective agonist for the peroxisome proliferator-activated receptor-delta (PPAR-δ), which is implicated in bile acid homoeostasis. This first-in-class study evaluated the anti-cholestatic effects and safety of seladelpar in patients with an inadequate response to ursodeoxycholic acid. The study was a 12-week, double-blind, placebo-controlled, phase 2 trial of patients with alkaline phosphatase of at least 1·67 times the upper limit of normal (ULN) despite treatment with ursodeoxycholic acid. Patients, recruited at 29 sites in North America and Europe, were randomly assigned to placebo, seladelpar 50 mg/day, or seladelpar 200 mg/day while ursodeoxycholic acid was continued. Randomisation was done centrally (1:1:1) by a computerised system using an interactive voice-web response system with a block size of three. Randomisation was stratified by region (North America and Europe). The primary outcome was the percentage change from baseline in alkaline phosphatase over 12 weeks, analysed in the modified intention-to-treat (ITT) population (any randomised patient who received at least one dose of medication and had at least one post-baseline alkaline phosphatase evaluation). This study is registered with ClinicalTrials.gov (NCT02609048) and the EU Clinical Trials Registry (EudraCT2015-002698-39). Between Nov 4, 2015, and May 26, 2016, 70 patients were screened at 29 sites in North America and Europe. During recruitment, three patients treated with seladelpar developed fully reversible, asymptomatic grade 3 alanine aminotransferase increases (one on 50 mg, two on 200 mg), ranging from just over five to 20 times the ULN; as a result, the study was terminated after 41 patients were randomly assigned. The modified ITT population consisted of 12 patients in the placebo group, 13 in the seladelpar 50 mg group, and 10 in the

  11. Hormones and β-Agonists

    NARCIS (Netherlands)

    Ginkel, van L.A.; Bovee, T.F.H.; Blokland, M.H.; Sterk, S.S.; Smits, N.G.E.; Pleadin, Jelka; Vulić, Ana

    2016-01-01

    This chapter provides some updated information on contemporary methods for hormone and β-agonist analyses. It deals with the classical approaches for the effective detection and identification of exogenous hormones. The chapter examines specific problems related to control strategies for natural

  12. Atypical Opioid Mechanisms of Control of Injury-Induced Cutaneous Pain by Delta Receptors

    Science.gov (United States)

    2016-07-01

    treat, and current opioids (i.e. mu opioid receptor agonists such as morphine) cause unacceptable side effects including addiction . Injuries suffered...treat, and current opioids that act on mu opioid receptors such as morphine generate significant side effects including addiction . War-related...al., J Neurosci Methods, 1994), starting with 0.1 g and ending with 2.0 g filament as cutoff value. As shown in Figure 2, our preliminary experiments

  13. Analysis of agonist dissociation constants as assessed by functional antagonism in guinea pig left atria

    International Nuclear Information System (INIS)

    Molenaar, P.; Malta, E.

    1986-01-01

    In electrically driven guinea pig left atria, positive inotropic responses to (-)-isoprenaline and the selective beta 1-adrenoceptor agonist RO363 were obtained in the absence and in the presence of the functional antagonists adenosine, carbachol, gallopamil, nifedipine, and Ro 03-7894. Each of the functional antagonists reduced the maximum response to both agonists and produced nonparallel rightward shifts in the cumulative concentration effect curves. For both agonists, dissociation constants (KA) were calculated using the equation described by Furchgott (1966) for irreversible antagonism. For RO363, which is a partial agonist with high agonist activity, the equations outlined for functional interaction by Mackay (1981) were also employed to calculate KA values. The KA values obtained by each method were compared with the dissociation constants (KD) for the two agonists determined from their ability to displace the radioligand (-)-[ 125 I]iodocyanopindolol from beta 1-adrenoceptors in guinea pig left atrial membrane preparations. The estimates of KA varied substantially from KD values. The KD values were taken as more accurate estimates of the true values for the dissociation constants because a high degree of correlation exists between pKD and pD2 values for a number of other beta-adrenoceptor agonists that behave as partial agonists and between pKD and pKB values for a number of beta-adrenoceptor antagonists. Thus, it appears that there are serious limitations in the current theory for using functional antagonism as a means of obtaining agonist dissociation constants

  14. Effect of (R)-2-(2-aminothiazol-4-yl)-4'-{2-[(2-hydroxy-2-phenylethyl)amino]ethyl} acetanilide (YM178), a novel selective beta3-adrenoceptor agonist, on bladder function.

    Science.gov (United States)

    Takasu, Toshiyuki; Ukai, Masashi; Sato, Shuichi; Matsui, Tetsuo; Nagase, Itsuro; Maruyama, Tatsuya; Sasamata, Masao; Miyata, Keiji; Uchida, Hisashi; Yamaguchi, Osamu

    2007-05-01

    We evaluated the pharmacological characteristics of (R)-2-(2-aminothiazol-4-yl)-4'-{2-[(2-hydroxy-2-phenylethyl)amino]-ethyl} acetanilide (YM178). YM178 increased cyclic AMP accumulation in Chinese hamster ovary (CHO) cells expressing human beta3-adrenoceptor (AR). The half-maximal effective concentration (EC50) value was 22.4 nM. EC50 values of YM178 for human beta1- and beta2-ARs were 10,000 nM or more, respectively. The ratio of intrinsic activities of YM178 versus maximal response induced by isoproterenol (nonselective beta-AR agonist) was 0.8 for human beta3-ARs, 0.1 for human beta1-ARs, and 0.1 for human beta2-ARs. The relaxant effects of YM178 were evaluated in rats and humans bladder strips precontracted with carbachol (CCh) and compared with those of isoproterenol and 4-[3-[(1,1-dimethylethyl)amino]-2-hydroxypropoxy]-1,3-dihydro-2H-benzimidazol-2-one hydrochloride (CGP-12177A) (beta3-AR agonist). EC50 values of YM178 and isoproterenol in rat bladder strips precontracted with 10(-6) M CCh were 5.1 and 1.4 microM, respectively, whereas those in human bladder strips precontracted with 10(-7) M CCh were 0.78 and 0.28 microM, respectively. In in vivo study, YM178 at a dose of 3 mg/kg i.v. decreased the frequency of rhythmic bladder contraction induced by intravesical filling with saline without suppressing its amplitude in anesthetized rats. These findings suggest the suitability of YM178 as a therapeutic drug for the treatment of symptoms of overactive bladder such as urinary frequency, urgency, and urge incontinence.

  15. Deltorphins: a family of naturally occurring peptides with high affinity and selectivity for delta opioid binding sites.

    Science.gov (United States)

    Erspamer, V; Melchiorri, P; Falconieri-Erspamer, G; Negri, L; Corsi, R; Severini, C; Barra, D; Simmaco, M; Kreil, G

    1989-07-01

    Deltorphins are endogenous linear heptapeptides, isolated from skin extracts of frogs belonging to the genus Phyllomedusa, that have a higher affinity and selectivity for delta opioid binding sites than any other natural compound known. Two deltorphins with the sequence Tyr-Ala-Phe-Asp(or Glu)-Val-Val-Gly-NH2 have been isolated from skin extracts of Phyllomedusa bicolor. The alanine in position 2 is in the D configuration. These peptides, [D-Ala2]deltorphins I and II, show an even higher affinity for delta receptors than the previously characterized deltorphin, which contains D-methionine as the second amino acid. These peptides show some similarity to another constituent of Phyllomedusa skin, dermorphin, which is highly selective for mu-opioid receptors. These peptides all have the N-terminal sequence Tyr-D-Xaa-Phe, where D-Xaa is either D-alanine or D-methionine. While this structure seems to be capable of activating both mu and delta opioid receptors, differences in the C-terminal regions of these peptides are probably responsible for the observed high receptor selectivity of dermorphin and deltorphin.

  16. Analysis of Drug Design for a Selection of G Protein-Coupled Neuro-Receptors Using Neural Network Techniques

    DEFF Research Database (Denmark)

    Agerskov, Claus; Mortensen, Rasmus M.; Bohr, Henrik G.

    2015-01-01

    A study is presented on how well possible drug-molecules can be predicted with respect to their function and binding to a selection of neuro-receptors by the use of artificial neural networks. The ligands investigated in this study are chosen to be corresponding to the G protein-coupled receptors...... computational tools, able to aid in drug-design in a fast and cheap fashion, compared to conventional pharmacological techniques....... mu-opioid, serotonin 2B (5-HT2B) and metabotropic glutamate D5. They are selected due to the availability of pharmacological drug-molecule binding data for these receptors. Feedback and deep belief artificial neural network architectures (NNs) were chosen to perform the task of aiding drug-design.......925. The performance of 8 category networks (8 output classes for binding strength) obtained a prediction accuracy of above 60 %. After training the networks, tests were done on how well the systems could be used as an aid in designing candidate drug molecules. Specifically, it was shown how a selection of chemical...

  17. Emerging GLP-1 receptor agonists

    DEFF Research Database (Denmark)

    Lund, Asger; Knop, Filip K; Vilsbøll, Tina

    2011-01-01

    and liraglutide, as well as the emerging GLP-1R agonists including the long-acting compounds. Expert opinion: An emerging therapeutic trend toward initial or early combination therapy with metformin- and incretin-based therapy is anticipated for patients with type 2 diabetes. GLP-1-based therapy has so far proven...... development may improve the effects of GLP-1 even further with optimized pharmacokinetic profiles resulting in fewer side effects. Meta-analyses have shown promising effects on cardiovascular disease and data from ongoing multicenter trials with cardiovascular endpoints are expected in 2015....

  18. The epileptogenic spectrum of opiate agonists.

    Science.gov (United States)

    Snead, O C; Bearden, L J

    1982-11-01

    The present authors gave mu, delta, kappa, epsilon and sigma opiate receptor agonists intracerebroventricularly to rats both singly and in combination while monitoring the electroencephalogram from cortical and depth electrodes. Dose-response curves were plotted with naloxone against the changes produced by each agonist, and the effect of a number of anticonvulsant drugs on agonist-induced seizures was ascertained. Each opiate agonist produced a different seizure pattern with a different naloxone dose-response curve and anticonvulsant profile. The order of convulsive potency was epsilon greater than delta greater than mu greater than sigma much greater than kappa. Petit mal-like seizure activity was unique to the delta agonist, leucine-enkephalin, while only the mu agonist, morphine produced generalized convulsive seizures. These experiments raise the possibility that opiate systems in the brain may be involved in the pathogenesis of a wide spectrum of seizure disorders.

  19. AGONISTIC BEHAVIOR OF LABORATORY MICE

    Directory of Open Access Journals (Sweden)

    D. Cinghiţă

    2005-01-01

    Full Text Available In this work we study agonistic behavior of laboratory white mice when they are kept in captivity. For all this experimental work we used direct observation of mice, in small lists, because we need a reduced space to emphasize characteristics of agonistic behavior. Relations between members of the same species that live in organized groups are based in most cases on hierarchical structure. Relations between leader and subservient, decided by fighting, involve a thorough observation between individuals. Each member of a group has its own place on the ierarchical scale depending on resultes of fhights – it can be leader or it can be subsurvient, depending on if it wines or looses the fight. Once hierarchical scale made, every animal will adjust its behavior. After analyzing the obtained data we have enough reasons to believe that after fights the winner, usually, is the massive mouse, but it is also very important the sexual ripeness, so the immature male will be beaten. The leader male had a big exploring area and it checks up all territory.The females can be more aggressive, its fights are more brutal, than male fights are, when they fight for supremacy, but in this case fights are not as frequent as in the case of males. Always the superior female, on hierarchical scale, shows males its own statute, so the strongest genes will be perpetuated.

  20. Pharmacophore-driven identification of PPARγ agonists from natural sources

    DEFF Research Database (Denmark)

    Petersen, R. K.; Christensen, Kathrine Bisgaard; Assimopoulou, A. N.

    2011-01-01

    mastic gum fractions, whereas some other sub-fractions exhibited also biological activity towards PPARγ. The results from the present work are two-fold: on the one hand we demonstrate that the pharmacophore model we developed is able to select novel ligand scaffolds that act as PPARγ agonists; while...... at the same time it manifests that natural products are highly relevant for use in virtual screening-based drug discovery....

  1. Correlating the Metabolic Stability of Psychedelic 5-HT2A Agonists with Anecdotal Reports of Human Oral Bioavailability

    DEFF Research Database (Denmark)

    Leth-Petersen, Sebastian; Bundgaard, Christoffer; Hansen, Martin

    2014-01-01

    2,5-Dimethoxyphenethylamines and their N-benzylated derivatives are potent 5-HT2A agonists with psychedelic effects in humans. The N-benzylated derivatives are among the most selective 5-HT2A agonists currently available and their usage as biochemical and brain imaging tools is increasing, yet ve...

  2. The effects of the dopamine agonist rotigotine on hemispatial neglect following stroke

    OpenAIRE

    Gorgoraptis, Nikos; Mah, Yee-Haur; Machner, Bjoern; Singh-Curry, Victoria; Malhotra, Paresh; Hadji-Michael, Maria; Cohen, David; Simister, Robert; Nair, Ajoy; Kulinskaya, Elena; Ward, Nick; Greenwood, Richard; Husain, Masud

    2012-01-01

    Hemispatial neglect following right-hemisphere stroke is a common and disabling disorder, for which there is currently no effective pharmacological treatment. Dopamine agonists have been shown to play a role in selective attention and working memory, two core cognitive components of neglect. Here, we investigated whether the dopamine agonist rotigotine would have a beneficial effect on hemispatial neglect in stroke patients. A double-blind, randomized, placebo-controlled ABA design was used, ...

  3. Systematic review: cardiovascular safety profile of 5-HT(4) agonists developed for gastrointestinal disorders.

    Science.gov (United States)

    Tack, J; Camilleri, M; Chang, L; Chey, W D; Galligan, J J; Lacy, B E; Müller-Lissner, S; Quigley, E M M; Schuurkes, J; De Maeyer, J H; Stanghellini, V

    2012-04-01

    The nonselective 5-HT(4) receptor agonists, cisapride and tegaserod have been associated with cardiovascular adverse events (AEs). To perform a systematic review of the safety profile, particularly cardiovascular, of 5-HT(4) agonists developed for gastrointestinal disorders, and a nonsystematic summary of their pharmacology and clinical efficacy. Articles reporting data on cisapride, clebopride, prucalopride, mosapride, renzapride, tegaserod, TD-5108 (velusetrag) and ATI-7505 (naronapride) were identified through a systematic search of the Cochrane Library, Medline, Embase and Toxfile. Abstracts from UEGW 2006-2008 and DDW 2008-2010 were searched for these drug names, and pharmaceutical companies approached to provide unpublished data. Retrieved articles on pharmacokinetics, human pharmacodynamics and clinical data with these 5-HT(4) agonists, are reviewed and summarised nonsystematically. Articles relating to cardiac safety and tolerability of these agents, including any relevant case reports, are reported systematically. Two nonselective 5-HT(4) agonists had reports of cardiovascular AEs: cisapride (QT prolongation) and tegaserod (ischaemia). Interactions with, respectively, the hERG cardiac potassium channel and 5-HT(1) receptor subtypes have been suggested to account for these effects. No cardiovascular safety concerns were reported for the newer, selective 5-HT(4) agonists prucalopride, velusetrag, naronapride, or for nonselective 5-HT(4) agonists with no hERG or 5-HT(1) affinity (renzapride, clebopride, mosapride). 5-HT(4) agonists for GI disorders differ in chemical structure and selectivity for 5-HT(4) receptors. Selectivity for 5-HT(4) over non-5-HT(4) receptors may influence the agent's safety and overall risk-benefit profile. Based on available evidence, highly selective 5-HT(4) agonists may offer improved safety to treat patients with impaired GI motility. © 2012 Blackwell Publishing Ltd.

  4. Systematic review: cardiovascular safety profile of 5-HT4 agonists developed for gastrointestinal disorders

    Science.gov (United States)

    Tack, J; Camilleri, M; Chang, L; Chey, W D; Galligan, J J; Lacy, B E; Müller-Lissner, S; Quigley, E M M; Schuurkes, J; Maeyer, J H; Stanghellini, V

    2012-01-01

    Summary Background The nonselective 5-HT4 receptor agonists, cisapride and tegaserod have been associated with cardiovascular adverse events (AEs). Aim To perform a systematic review of the safety profile, particularly cardiovascular, of 5-HT4 agonists developed for gastrointestinal disorders, and a nonsystematic summary of their pharmacology and clinical efficacy. Methods Articles reporting data on cisapride, clebopride, prucalopride, mosapride, renzapride, tegaserod, TD-5108 (velusetrag) and ATI-7505 (naronapride) were identified through a systematic search of the Cochrane Library, Medline, Embase and Toxfile. Abstracts from UEGW 2006–2008 and DDW 2008–2010 were searched for these drug names, and pharmaceutical companies approached to provide unpublished data. Results Retrieved articles on pharmacokinetics, human pharmacodynamics and clinical data with these 5-HT4 agonists, are reviewed and summarised nonsystematically. Articles relating to cardiac safety and tolerability of these agents, including any relevant case reports, are reported systematically. Two nonselective 5-HT4 agonists had reports of cardiovascular AEs: cisapride (QT prolongation) and tegaserod (ischaemia). Interactions with, respectively, the hERG cardiac potassium channel and 5-HT1 receptor subtypes have been suggested to account for these effects. No cardiovascular safety concerns were reported for the newer, selective 5-HT4 agonists prucalopride, velusetrag, naronapride, or for nonselective 5-HT4 agonists with no hERG or 5-HT1 affinity (renzapride, clebopride, mosapride). Conclusions 5-HT4 agonists for GI disorders differ in chemical structure and selectivity for 5-HT4 receptors. Selectivity for 5-HT4 over non-5-HT4 receptors may influence the agent's safety and overall risk–benefit profile. Based on available evidence, highly selective 5-HT4 agonists may offer improved safety to treat patients with impaired GI motility. PMID:22356640

  5. Inhibition by TRPA1 agonists of compound action potentials in the frog sciatic nerve

    Energy Technology Data Exchange (ETDEWEB)

    Matsushita, Akitomo; Ohtsubo, Sena; Fujita, Tsugumi; Kumamoto, Eiichi, E-mail: kumamote@cc.saga-u.ac.jp

    2013-04-26

    Highlights: •TRPA1 agonists inhibited compound action potentials in frog sciatic nerves. •This inhibition was not mediated by TRPA1 channels. •This efficacy was comparable to those of lidocaine and cocaine. •We found for the first time an ability of TRPA1 agonists to inhibit nerve conduction. -- Abstract: Although TRPV1 and TRPM8 agonists (vanilloid capsaicin and menthol, respectively) at high concentrations inhibit action potential conduction, it remains to be unknown whether TRPA1 agonists have a similar action. The present study examined the actions of TRPA1 agonists, cinnamaldehyde (CA) and allyl isothiocyanate (AITC), which differ in chemical structure from each other, on compound action potentials (CAPs) recorded from the frog sciatic nerve by using the air-gap method. CA and AITC concentration-dependently reduced the peak amplitude of the CAP with the IC{sub 50} values of 1.2 and 1.5 mM, respectively; these activities were resistant to a non-selective TRP antagonist ruthenium red or a selective TRPA1 antagonist HC-030031. The CA and AITC actions were distinct in property; the latter but not former action was delayed in onset and partially reversible, and CA but not AITC increased thresholds to elicit CAPs. A CAP inhibition was seen by hydroxy-α-sanshool (by 60% at 0.05 mM), which activates both TRPA1 and TRPV1 channels, a non-vanilloid TRPV1 agonist piperine (by 20% at 0.07 mM) and tetrahydrolavandulol (where the six-membered ring of menthol is opened; IC{sub 50} = 0.38 mM). It is suggested that TRPA1 agonists as well as TRPV1 and TRPM8 agonists have an ability to inhibit nerve conduction without TRP activation, although their agonists are quite different in chemical structure from each other.

  6. Beta-agonists and animal welfare

    Science.gov (United States)

    The use of beta-agonists in animal feed is a high profile topic within the U.S. as consumers and activist groups continue to question its safety. The only beta-agonist currently available for use in swine is ractopamine hydrochloride (RAC). This is available as Paylean™ (Elanco Animal Health – FDA a...

  7. Maintenance on naltrexone+amphetamine decreases cocaine-vs.-food choice in male rhesus monkeys.

    Science.gov (United States)

    Moerke, Megan J; Banks, Matthew L; Cheng, Kejun; Rice, Kenner C; Negus, S Stevens

    2017-12-01

    Cocaine use disorder remains a significant public health issue for which there are no FDA-approved pharmacotherapies. Amphetamine maintenance reduces cocaine use in preclinical and clinical studies, but the mechanism of this effect is unknown. Previous studies indicate a role for endogenous opioid release and subsequent opioid receptor activation in some amphetamine effects; therefore, the current study examined the role of mu-opioid receptor activation in d-amphetamine treatment effects in an assay of cocaine-vs-food choice. Adult male rhesus monkeys with double-lumen intravenous catheters responded for concurrently available food pellets and cocaine injections (0-0.1mg/kg/injection) during daily sessions. Cocaine choice and overall reinforcement rates were evaluated during 7-day treatments with saline or test drugs. During saline treatment, cocaine maintained a dose-dependent increase in cocaine-vs.-food choice. The mu-opioid receptor agonist morphine (0.032-0.32mg/kg/h) dose-dependently increased cocaine choice and decreased rates of reinforcement. A dose of the mu-selective opioid receptor antagonist naltrexone (0.0032mg/kg/h) that completely blocked morphine effects had no effect on cocaine choice when it was administered alone, but it enhanced the effectiveness of a threshold dose of 0.032mg/kg/h amphetamine to decrease cocaine choice without also enhancing nonselective behavioral disruption by this dose of amphetamine. Conversely, the kappa-selective opioid antagonist norbinalorphimine did not enhance amphetamine effects on cocaine choice. These results suggest that amphetamine maintenance produces mu opioid-receptor mediated effects that oppose its anti-cocaine effects. Co-administration of naltrexone may selectively enhance amphetamine potency to decrease cocaine choice without increasing amphetamine potency to produce general behavioral disruption. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Small molecule fluoride toxicity agonists.

    Science.gov (United States)

    Nelson, James W; Plummer, Mark S; Blount, Kenneth F; Ames, Tyler D; Breaker, Ronald R

    2015-04-23

    Fluoride is a ubiquitous anion that inhibits a wide variety of metabolic processes. Here, we report the identification of a series of compounds that enhance fluoride toxicity in Escherichia coli and Streptococcus mutans. These molecules were isolated by using a high-throughput screen (HTS) for compounds that increase intracellular fluoride levels as determined via a fluoride riboswitch reporter fusion construct. A series of derivatives were synthesized to examine structure-activity relationships, leading to the identification of compounds with improved activity. Thus, we demonstrate that small molecule fluoride toxicity agonists can be identified by HTS from existing chemical libraries by exploiting a natural fluoride riboswitch. In addition, our findings suggest that some molecules might be further optimized to function as binary antibacterial agents when combined with fluoride. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Development of specific dopamine D-1 agonists and antagonists

    International Nuclear Information System (INIS)

    Sakolchai, S.

    1987-01-01

    To develop potentially selective dopamine D-1 agonists and to investigate on the structural requirement for D-1 activity, the derivatives of dibenzocycloheptadiene are synthesized and pharmacologically evaluated. The target compounds are 5-aminomethyl-10,11-dihydro-1,2-dihydroxy-5H-dibenzo[a,d]cycloheptene hydrobromide 10 and 9,10-dihydroxy-1,2,3,7,8,12b-hexahydrobenzo[1,2]cyclohepta[3,4,5d,e]isoquinoline hydrobromide 11. In a dopamine-sensitive rat retinal adenylate cyclase assay, a model for D-1 activity, compound 10 is essentially inert for both agonist and antagonist activity. In contrast, compound 11 is approximately equipotent to dopamine in activation of the D-1 receptor. Based on radioligand and binding data, IC 50 of compound 11 for displacement of 3 H-SCH 23390, a D-1 ligand, is about 7 fold less than that for displacement of 3 H-spiperone, a D-2 ligand. These data indicate that compound 11 is a potent selective dopamine D-1 agonist. This study provides a new structural class of dopamine D-1 acting agent: dihydroxy-benzocycloheptadiene analog which can serve as a lead compound for further drug development and as a probe for investigation on the nature of dopamine D-1 receptor

  10. Detailed characterization of the in vitro pharmacological and pharmacokinetic properties of N-(2-hydroxybenzyl)-2,5-dimethoxy-4-cyanophenylethylamine (25CN-NBOH), a highly selective and brain-penetrant 5-HT2A receptor agonist

    DEFF Research Database (Denmark)

    Jensen, Anders A; McCorvy, John D; Petersen, Sebastian Leth

    2017-01-01

    ]ketanserin/[3H]mesulergine, [3H]LSD and [3H]Cimbi-36 binding assays (Ki 2C/Ki 2A ratio range 52-81, Ki 2B/Ki 2A ratio 37). Moreover, in inositol phosphate and intracellular Ca2+ mobilization assays 25CN-NBOH exhibited 30- to 180-fold 5-HT2A/5-HT2C selectivities and 54-fold 5-HT2A/5-HT2B selectivity as measured...

  11. Non-Acidic Free Fatty Acid Receptor 4 Agonists with Antidiabetic Activity

    DEFF Research Database (Denmark)

    Goncalves de Azavedo, Carlos M. B. P.; Watterson, Kenneth R; Wargent, Ed T

    2016-01-01

    The free fatty acid receptor 4 (FFA4 or GPR120) has appeared as an interesting potential target for the treatment of metabolic disorders. At present, most FFA4 ligands are carboxylic acids that are assumed to mimic the endogenous long-chain fatty acid agonists. Here, we report preliminary structure......-activity relationship studies of a previously disclosed non-acidic sulfonamide FFA4 agonist. Mutagenesis studies indicate that the compounds are orthosteric agonists despite the absence of a carboxylate function. The preferred compounds showed full agonist activity on FFA4 and complete selectivity over FFA1, although...... a significant fraction of these non-carboxylic acids also showed partial antagonistic activity on FFA1. Studies in normal and diet-induced obese (DIO) mice with the preferred compound 34 showed improved glucose tolerance after oral dosing in an oral glucose tolerance test. Chronic dosing of 34 in DIO mice...

  12. Serotonin 2A receptor agonist binding in the human brain with [C]Cimbi-36

    DEFF Research Database (Denmark)

    Ettrup, A.; da Cunha-Bang, S.; McMahon, Barry P.

    2014-01-01

    [C]Cimbi-36 was recently developed as a selective serotonin 2A (5-HT) receptor agonist radioligand for positron emission tomography (PET) brain imaging. Such an agonist PET radioligand may provide a novel, and more functional, measure of the serotonergic system and agonist binding is more likely ....... Thus, we here describe [C]Cimbi-36 as the first agonist PET radioligand to successfully image and quantify 5-HT receptors in the human brain.Journal of Cerebral Blood Flow & Metabolism advance online publication, 30 April 2014; doi:10.1038/jcbfm.2014.68....... than antagonist binding to reflect 5-HT levels in vivo. Here, we show data from a first-in-human clinical trial with [C]Cimbi-36. In 29 healthy volunteers, we found high brain uptake and distribution according to 5-HT receptors with [C]Cimbi-36 PET. The two-tissue compartment model using arterial input...

  13. Dopamine Agonists and Pathologic Behaviors

    Directory of Open Access Journals (Sweden)

    Brendan J. Kelley

    2012-01-01

    Full Text Available The dopamine agonists ropinirole and pramipexole exhibit highly specific affinity for the cerebral dopamine D3 receptor. Use of these medications in Parkinson’s disease has been complicated by the emergence of pathologic behavioral patterns such as hypersexuality, pathologic gambling, excessive hobbying, and other circumscribed obsessive-compulsive disorders of impulse control in people having no history of such disorders. These behavioral changes typically remit following discontinuation of the medication, further demonstrating a causal relationship. Expression of the D3 receptor is particularly rich within the limbic system, where it plays an important role in modulating the physiologic and emotional experience of novelty, reward, and risk assessment. Converging neuroanatomical, physiological, and behavioral science data suggest the high D3 affinity of these medications as the basis for these behavioral changes. These observations suggest the D3 receptor as a therapeutic target for obsessive-compulsive disorder and substance abuse, and improved understanding of D3 receptor function may aid drug design of future atypical antipsychotics.

  14. Endogenous Receptor Agonists: Resolving Inflammation

    Directory of Open Access Journals (Sweden)

    Gerhard Bannenberg

    2007-01-01

    Full Text Available Controlled resolution or the physiologic resolution of a well-orchestrated inflammatory response at the tissue level is essential to return to homeostasis. A comprehensive understanding of the cellular and molecular events that control the termination of acute inflammation is needed in molecular terms given the widely held view that aberrant inflammation underlies many common diseases. This review focuses on recent advances in the understanding of the role of arachidonic acid and ω-3 polyunsaturated fatty acids (PUFA–derived lipid mediators in regulating the resolution of inflammation. Using a functional lipidomic approach employing LC-MS-MS–based informatics, recent studies, reviewed herein, uncovered new families of local-acting chemical mediators actively biosynthesized during the resolution phase from the essential fatty acids eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA. These new families of local chemical mediators are generated endogenously in exudates collected during the resolution phase, and were coined resolvins and protectins because specific members of these novel chemical families control both the duration and magnitude of inflammation in animal models of complex diseases. Recent advances on the biosynthesis, receptors, and actions of these novel anti-inflammatory and proresolving lipid mediators are reviewed with the aim to bring to attention the important role of specific lipid mediators as endogenous agonists in inflammation resolution.

  15. Design, synthesis, and pharmacology of a highly subtype-selective GluR1/2 agonist, (RS)-2-amino-3-(4-chloro-3-hydroxy-5-isoxazolyl)propionic acid (Cl-HIBO)

    DEFF Research Database (Denmark)

    Bjerrum, Esben J; Kristensen, Anders S; Pickering, Darryl S

    2003-01-01

    On the basis of structural studies, chloro-homoibotenic acid (Cl-HIBO) was designed and synthesized. Cl-HIBO was characterized in binding and electrophysiology experiments on native and cloned subtypes of GluRs. Electrophysiological selectivities ranged from 275 to 1600 for GluR1/2 over GluR3/4. ...

  16. 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.

  17. Examining the role of mu opioid receptor endocytosis in the beneficial and side-effects of prolonged opioid use: From a symposium on new concepts in mu-opioid pharmacology

    OpenAIRE

    Whistler, Jennifer L.

    2012-01-01

    Opioid drugs remain the gold standard for the treatment of severe pain, both acute/post-surgical and chronic. However, the utility of opioid drugs for the treatment of chronic pain is compromised by the development of analgesic tolerance which, in turn, leads to dose-escalation and increased likelihood of dangerous side effects, including dependence. Consequently, there remains resistance among clinicians and the general population to using opiates for pain management because of risk of “addi...

  18. Dopamine agonist activity of EMD 23,448

    Energy Technology Data Exchange (ETDEWEB)

    Martin, G E; Pettibone, D J [Merck Sharp and Dohme Research Laboratories, West Point, Pennsylvania (USA). Dept. of Pharmacology

    1985-01-01

    EMD 23,448 was examined in tests of dopaminergic function and was found to be an atypical dopamine (DA) agonist. EMD 23,448 was a weak or inactive DA agonist when examined in tests of normal postsynaptic DA receptor function: production of stereotypy in the rat (ED/sub 50/ greater than sign 5.0 mg/kg.i.p.); production of emesis in beagles (minimum effective dose = 81..mu..g/kg i.v.); and, enhanced locomotor activity of the mouse (no excitation in doses <=50 mg/i.p.). Moreover, EMD 23,448 was relatively weak in competing for (/sup 3/H)-apomorphine binding to rat striatal membranes (Ki, 205 nM). On the other hand, this indolyl-3-butylamine did activate supersensitive postsynaptic DA receptors. Specifically, it elicited contralateral turning in rats with a unilateral 6-hydroxydopamine lesion of the substantia nigra (ED/sub 50/ value = 0.9 mg/kg) and did elicit stereotypy in rats given chronic daily haloperidol treatments. EMD 23,448 also exerted pharmacological effects in tests designed to measure activation of dopamine autoreceptors. It inhibited the ..gamma..-butyrolactone-induced increase in striatal dopa levels (ED/sub 50/ = 1 mg/kg i.p.) and produced a dose-related fall in the locomotor activity of the mouse. The results are discussed and contrasted with data derived for apomorphine and the putatively selective autoreceptor agonist (+-)-3-PPP.

  19. Dopamine agonist activity of EMD 23,448

    International Nuclear Information System (INIS)

    Martin, G.E.; Pettibone, D.J.

    1985-01-01

    EMD 23,448 was examined in tests of dopaminergic function and was found to be an atypical dopamine (DA) agonist. EMD 23,448 was a weak or inactive DA agonist when examined in tests of normal postsynaptic DA receptor function: production of stereotypy in the rat (ED 50 greater than sign 5.0 mg/kg.i.p.); production of emesis in beagles (minimum effective dose = 81μg/kg i.v.); and, enhanced locomotor activity of the mouse (no excitation in doses 3 H]-apomorphine binding to rat striatal membranes (Ki, 205 nM). On the other hand, this indolyl-3-butylamine did activate supersensitive postsynaptic DA receptors. Specifically, it elicited contralateral turning in rats with a unilateral 6-hydroxydopamine lesion of the substantia nigra (ED 50 value = 0.9 mg/kg) and did elicit stereotypy in rats given chronic daily haloperidol treatments. EMD 23,448 also exerted pharmacological effects in tests designed to measure activation of dopamine autoreceptors. It inhibited the γ-butyrolactone-induced increase in striatal dopa levels (ED 50 = 1 mg/kg i.p.) and produced a dose-related fall in the locomotor activity of the mouse. The results are discussed and contrasted with data derived for apomorphine and the putatively selective autoreceptor agonist (+-)-3-PPP. (Author)

  20. Dgroup: DG00792 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available hydrochloride (USP) ... Neuropsychiatric agent ... DG02030 ... Anesthetics ... DG02027 ... General anesthetics ... DG02026 ... Opioid anesthetics... ... DG02027 ... General anesthetics ... DG02026 ... Opioid anesthetics ... DG01564 ... Opioid receptor ...agonist ... DG01563 ... mu-Opioid receptor agonist ATC code: N01AH02 General anesthetics OPRM1 [HSA:4988] [KO:K04215] Enzyme: CYP3A [HSA:1576 1577 1551] ...

  1. Dgroup: DG00793 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available anil citrate (USP) ... Neuropsychiatric agent ... DG02030 ... Anesthetics ... DG02027 ... General anesthetics ... DG02026 ... Opioid anesthetics... ... DG02027 ... General anesthetics ... DG02026 ... Opioid anesthetics ... DG01564 ... Opioid receptor a...gonist ... DG01563 ... mu-Opioid receptor agonist Analgesic ... DG01984 ... Opioid analgesics ATC code: N01AH03 General anesthetics OPRM1 [HSA:4988] [KO:K04215] ...

  2. Novel kinin B1 receptor agonists with improved pharmacological profiles.

    Science.gov (United States)

    Côté, Jérôme; Savard, Martin; Bovenzi, Veronica; Bélanger, Simon; Morin, Josée; Neugebauer, Witold; Larouche, Annie; Dubuc, Céléna; Gobeil, Fernand

    2009-04-01

    There is some evidence to suggest that inducible kinin B1 receptors (B1R) may play beneficial and protecting roles in cardiovascular-related pathologies such as hypertension, diabetes, and ischemic organ diseases. Peptide B1R agonists bearing optimized pharmacological features (high potency, selectivity and stability toward proteolysis) hold promise as valuable therapeutic agents in the treatment of these diseases. In the present study, we used solid-phase methodology to synthesize a series of novel peptide analogues based on the sequence of Sar[dPhe(8)]desArg(9)-bradykinin, a relatively stable peptide agonist with moderate affinity for the human B1R. We evaluated the pharmacological properties of these peptides using (1) in vitro competitive binding experiments on recombinant human B1R and B2R (for index of selectivity determination) in transiently transfected human embryonic kidney 293 cells (HEK-293T cells), (2) ex vivo vasomotor assays on isolated human umbilical veins expressing endogenous human B1R, and (3) in vivo blood pressure tests using anesthetized lipopolysaccharide-immunostimulated rabbits. Key chemical modifications at the N-terminus, the positions 3 and 5 on Sar[dPhe(8)]desArg(9)-bradykinin led to potent analogues. For example, peptides 18 (SarLys[Hyp(3),Cha(5), dPhe(8)]desArg(9)-bradykinin) and 20 (SarLys[Hyp(3),Igl(5), dPhe(8)]desArg(9)-bradykinin) outperformed the parental molecule in terms of affinity, functional potency and duration of action in vitro and in vivo. These selective agonists should be valuable in future animal and human studies to investigate the potential benefits of B1R activation.

  3. Targeted Delivery of LXR Agonist Using a Site-Specific Antibody-Drug Conjugate.

    Science.gov (United States)

    Lim, Reyna K V; Yu, Shan; Cheng, Bo; Li, Sijia; Kim, Nam-Jung; Cao, Yu; Chi, Victor; Kim, Ji Young; Chatterjee, Arnab K; Schultz, Peter G; Tremblay, Matthew S; Kazane, Stephanie A

    2015-11-18

    Liver X receptor (LXR) agonists have been explored as potential treatments for atherosclerosis and other diseases based on their ability to induce reverse cholesterol transport and suppress inflammation. However, this therapeutic potential has been hindered by on-target adverse effects in the liver mediated by excessive lipogenesis. Herein, we report a novel site-specific antibody-drug conjugate (ADC) that selectively delivers a LXR agonist to monocytes/macrophages while sparing hepatocytes. The unnatural amino acid para-acetylphenylalanine (pAcF) was site-specifically incorporated into anti-CD11a IgG, which binds the α-chain component of the lymphocyte function-associated antigen 1 (LFA-1) expressed on nearly all monocytes and macrophages. An aminooxy-modified LXR agonist was conjugated to anti-CD11a IgG through a stable, cathepsin B cleavable oxime linkage to afford a chemically defined ADC. The anti-CD11a IgG-LXR agonist ADC induced LXR activation specifically in human THP-1 monocyte/macrophage cells in vitro (EC50-27 nM), but had no significant effect in hepatocytes, indicating that payload delivery is CD11a-mediated. Moreover, the ADC exhibited higher-fold activation compared to a conventional synthetic LXR agonist T0901317 (Tularik) (3-fold). This novel ADC represents a fundamentally different strategy that uses tissue targeting to overcome the limitations of LXR agonists for potential use in treating atherosclerosis.

  4. Reconstitution of high affinity α2 adrenergic agonist binding by fusion with a pertussis toxin substrate

    International Nuclear Information System (INIS)

    Kim, M.H.; Neubig, R.R.

    1986-01-01

    High affinity α 2 adrenergic agonist binding is thought to occur via a coupling of the α 2 receptor with N/sub i/, the inhibitory guanyl nucleotide binding protein. Human platelet membranes pretreated at pH 11.5 exhibit a selective inactivation of agonist binding and N/sub i/. To further study the mechanism of agonist binding, alkali treated membranes (ATM) were mixed with membranes pretreated with 10 μM phenoxybenzamine to block α 2 receptors (POB-M). The combined membrane pellet was incubated in 50% polyethylene glycol (PEG) to promote membrane-membrane fusion and assayed for binding to the α 2 agonist [ 3 H]UK 14,304 (UK) and the antagonist [ 3 H] yohimbine. PEG treatment resulted in a 2-4 fold enhancement of UK binding whereas yohimbine binding was unchanged. No enhancement of UK binding was observed in the absence of PEG treatment. The reconstitution was dependent on the addition of POB-M. They found that a 1:1 ratio of POB-M:ATM was optimal. Reconstituted binding was inhibited by GppNHp. Fusion of rat C6 glioma cell membranes, which do not contain α 2 receptors, also enhanced agonist binding to ATM. Fusion of C6 membranes from cells treated with pertussis toxin did not enhance [ 3 H] UK binding. These data show that a pertussis toxin sensitive membrane component, possibly N/sub i/, can reconstitute high affinity α 2 agonist binding

  5. Selective GABA transporter inhibitors tiagabine and EF1502 exhibit mechanistic differences in their ability to modulate the ataxia and anticonvulsant action of the extrasynaptic GABA(A) receptor agonist gaboxadol

    DEFF Research Database (Denmark)

    Madsen, Karsten Kirkegaard; Ebert, Bjarke; Clausen, Rasmus Prætorius

    2011-01-01

    seizures. Even though less is known about the therapeutic potential of other GABA transport inhibitors, previous investigations have demonstrated that N-[4,4-bis(3-methyl-2-thienyl)-3-butenyl]-3-hydroxy-4-(methylamino)-4,5,6,7-tetrahydrobenzo[d]isoxazol-3-ol (EF1502), which, like tiagabine, is inactive...... of gaboxadol (4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol), which, at the doses used in this study (i.e., 1-5 mg/kg) selectively activates extrasynaptic a4-containing GABA(A) receptors, was determined alone and in combination with either tiagabine or EF1502 using Frings audiogenic seizure-susceptible and CF...

  6. Mechanical stress activates NMDA receptors in the absence of agonists

    OpenAIRE

    Maneshi, Mohammad Mehdi; Maki, Bruce; Gnanasambandam, Radhakrishnan; Belin, Sophie; Popescu, Gabriela K.; Sachs, Frederick; Hua, Susan Z.

    2017-01-01

    While studying the physiological response of primary rat astrocytes to fluid shear stress in a model of traumatic brain injury (TBI), we found that shear stress induced Ca2+ entry. The influx was inhibited by MK-801, a specific pore blocker of N-Methyl-D-aspartic acid receptor (NMDAR) channels, and this occurred in the absence of agonists. Other NMDA open channel blockers ketamine and memantine showed a similar effect. The competitive glutamate antagonists AP5 and GluN2B-selective inhibitor i...

  7. Nicotine receptor partial agonists for smoking cessation

    Directory of Open Access Journals (Sweden)

    Kate Cahill

    Full Text Available BACKGROUND: Nicotine receptor partial agonists may help people to stop smoking by a combination of maintaining moderate levels of dopamine to counteract withdrawal symptoms (acting as an agonist and reducing smoking satisfaction (acting as an antagonist. OBJECTIVES: The primary objective of this review is to assess the efficacy and tolerability of nicotine receptor partial agonists, including cytisine, dianicline and varenicline for smoking cessation. SEARCH METHODS: We searched the Cochrane Tobacco Addiction Group's specialised register for trials, using the terms ('cytisine' or 'Tabex' or 'dianicline' or 'varenicline' or 'nicotine receptor partial agonist' in the title or abstract, or as keywords. The register is compiled from searches of MEDLINE, EMBASE, PsycINFO and Web of Science using MeSH terms and free text to identify controlled trials of interventions for smoking cessation and prevention. We contacted authors of trial reports for additional information where necessary. The latest update of the specialized register was in December 2011. We also searched online clinical trials registers. SELECTION CRITERIA: We included randomized controlled trials which compared the treatment drug with placebo. We also included comparisons with bupropion and nicotine patches where available. We excluded trials which did not report a minimum follow-up period of six months from start of treatment. DATA COLLECTION AND ANALYSIS: We extracted data on the type of participants, the dose and duration of treatment, the outcome measures, the randomization procedure, concealment of allocation, and completeness of follow-up. The main outcome measured was abstinence from smoking at longest follow-up. We used the most rigorous definition of abstinence, and preferred biochemically validated rates where they were reported. Where appropriate we pooled risk ratios (RRs, using the Mantel-Haenszel fixed-effect model. MAIN RESULTS: Two recent cytisine trials (937 people

  8. Interactions of dopaminergic agonists and antagonists with dopaminergic D3 binding sites in rat striatum. Evidence that [3H]dopamine can label a high affinity agonist-binding state of the D1 dopamine receptor

    International Nuclear Information System (INIS)

    Leff, S.E.; Creese, I.

    1985-01-01

    The interactions of dopaminergic agonists and antagonists with 3 H-agonist labeled D3 dopaminergic binding sites of rat striatum have been characterized by radioligand-binding techniques. When the binding of [ 3 H]dopamine and [ 3 H]apomorphine to D2 dopamine receptors is blocked by the inclusion of D2 selective concentrations of unlabeled spiroperidol or domperidone, these ligands appear to label selectively the previously termed D3 binding site. Antagonist/[ 3 H]dopamine competition curves are of uniformly steep slope (nH . 1.0), suggesting the presence of a single D3 binding site. The relative potencies of antagonists to inhibit D3 specific [ 3 H]dopamine binding are significantly correlated with their potencies to block D1 dopamine receptors as measured by the inhibition of both dopamine-stimulated adenylate cyclase and [ 3 H]flupentixol-binding activities. The affinities of agonists to inhibit D3 specific [ 3 H]dopamine binding are also correlated with estimates of these agonists affinities for the high affinity binding component of agonist/[ 3 H]flupentixol competition curves. Both D3 specific [ 3 H] dopamine binding and the high affinity agonist-binding component of dopamine/[ 3 H]flupentixol competition curves show a similar sensitivity to guanine nucleotides. Taken together, these data strongly suggest that the D3 binding site is related to a high affinity agonist-binding state of the D1 dopamine receptor

  9. Structure-Activity Relationships Based on 3D-QSAR CoMFA/CoMSIA and Design of Aryloxypropanol-Amine Agonists with Selectivity for the Human β3-Adrenergic Receptor and Anti-Obesity and Anti-Diabetic Profiles

    Directory of Open Access Journals (Sweden)

    Marcos Lorca

    2018-05-01

    Full Text Available The wide tissue distribution of the adrenergic β3 receptor makes it a potential target for the treatment of multiple pathologies such as diabetes, obesity, depression, overactive bladder (OAB, and cancer. Currently, there is only one drug on the market, mirabegron, approved for the treatment of OAB. In the present study, we have carried out an extensive structure-activity relationship analysis of a series of 41 aryloxypropanolamine compounds based on three-dimensional quantitative structure-activity relationship (3D-QSAR techniques. This is the first combined comparative molecular field analysis (CoMFA and comparative molecular similarity index analysis (CoMSIA study in a series of selective aryloxypropanolamines displaying anti-diabetes and anti-obesity pharmacological profiles. The best CoMFA and CoMSIA models presented values of r2ncv = 0.993 and 0.984 and values of r2test = 0.865 and 0.918, respectively. The results obtained were subjected to extensive external validation (q2, r2, r2m, etc. and a final series of compounds was designed and their biological activity was predicted (best pEC50 = 8.561.

  10. Induction of synaptic long-term potentiation after opioid withdrawal.

    Science.gov (United States)

    Drdla, Ruth; Gassner, Matthias; Gingl, Ewald; Sandkühler, Jürgen

    2009-07-10

    mu-Opioid receptor (MOR) agonists represent the gold standard for the treatment of severe pain but may paradoxically also enhance pain sensitivity, that is, lead to opioid-induced hyperalgesia (OIH). We show that abrupt withdrawal from MOR agonists induces long-term potentiation (LTP) at the first synapse in pain pathways. Induction of opioid withdrawal LTP requires postsynaptic activation of heterotrimeric guanine nucleotide-binding proteins and N-methyl-d-aspartate receptors and a rise of postsynaptic calcium concentrations. In contrast, the acute depression by opioids is induced presynaptically at these synapses. Withdrawal LTP can be prevented by tapered withdrawal and shares pharmacology and signal transduction pathways with OIH. These findings provide a previously unrecognized target to selectively combat pro-nociceptive effects of opioids without compromising opioid analgesia.

  11. The angiotensin type 2 receptor agonist Compound 21 elicits cerebroprotection in endothelin-1 induced ischemic stroke

    DEFF Research Database (Denmark)

    Joseph, Jason P; Mecca, Adam P; Regenhardt, Robert W

    2014-01-01

    Evidence indicates that angiotensin II type 2 receptors (AT2R) exert cerebroprotective actions during stroke. A selective non-peptide AT2R agonist, Compound 21 (C21), has been shown to exert beneficial effects in models of cardiac and renal disease, as well as hemorrhagic stroke. Here, we hypothe...

  12. The GPR120 agonist TUG-891 promotes metabolic health by stimulating mitochondrial respiration in brown fat

    DEFF Research Database (Denmark)

    Schilperoort, Maaike; van Dam, Andrea D; Hoeke, Geerte

    2018-01-01

    the therapeutic potential of GPR120 agonism and addressed GPR120-mediated signaling in BAT We found that activation of GPR120 by the selective agonist TUG-891 acutely increases fat oxidation and reduces body weight and fat mass in C57Bl/6J mice. These effects coincided with decreased brown adipocyte lipid content...

  13. Reciprocity of agonistic support in ravens.

    Science.gov (United States)

    Fraser, Orlaith N; Bugnyar, Thomas

    2012-01-01

    Cooperative behaviour through reciprocation or interchange of valuable services in primates has received considerable attention, especially regarding the timeframe of reciprocation and its ensuing cognitive implications. Much less, however, is known about reciprocity in other animals, particularly birds. We investigated patterns of agonistic support (defined as a third party intervening in an ongoing conflict to attack one of the conflict participants, thus supporting the other) in a group of 13 captive ravens, Corvus corax. We found support for long-term, but not short-term, reciprocation of agonistic support. Ravens were more likely to support individuals who preened them, kin and dominant group members. These results suggest that ravens do not reciprocate on a calculated tit-for-tat basis, but aid individuals from whom reciprocated support would be most useful and those with whom they share a good relationship. Additionally, dyadic levels of agonistic support and consolation (postconflict affiliation from a bystander to the victim) correlated strongly with each other, but we found no evidence to suggest that receiving agonistic support influences the victim's likelihood of receiving support (consolation) after the conflict ends. Our findings are consistent with an emotionally mediated form of reciprocity in ravens and provide additional support for convergent cognitive evolution in birds and mammals.

  14. Ghrelin receptor agonist (TZP-101) accelerates gastric emptying in adults with diabetes and symptomatic gastroparesis

    DEFF Research Database (Denmark)

    Ejskjaer, N; Vestergaard, E T; Hellström, P M

    2009-01-01

    BACKGROUND: TZP-101 is a synthetic, selective ghrelin agonist in development for gastroparesis. AIM: To assess safety and effects of TZP-101 in diabetes patients with symptomatic gastroparesis. METHODS: Adults with type 1 or type 2 diabetes mellitus received placebo and TZP-101 (80, 160, 320 or 600...... between TZP-101 and placebo. CONCLUSIONS: This proof-of-concept study demonstrates that the ghrelin agonist TZP-101 is well-tolerated in diabetes patients with moderate-to-severe chronic gastroparesis and shows statistically significant improvements in gastric emptying....

  15. Tritium labelling of two highly selective agonists for CCK-B receptors : [[sup 3]H]propionyl-Tyr(SO[sub 3]Na)-gNle-mGly-Trp-(N-Me)Nle-Asp-Phe-NHsub (2) ([[sup 3]H]pBC 264) [[sup 3]H]propionyl-[gamma]D. Glu-Tyr(SO[sub 3]H)-Nle-D. Lys-Trp-Nle-Asp-Phe-NH[sub 2] ([[sup 3]H]pBC 254). [Cholecystokini-B receptors

    Energy Technology Data Exchange (ETDEWEB)

    Corringer, P J; Durieux, C; Ruiz-Gayo, M; Roques, B P [UA498 CNRS, U266 INSERM, UFR des Sciences Pharmaceutiques et Biologiques, 75 - Paris (France)

    1992-06-01

    Among the CCK-B receptor agonists reported to date, the two modified peptides BC 264 and BC 254 display a high affinity and selectivity for this binding site and are highly protected from enzymatic degradation. Recently, we reported the biological properties of a tritiated analog of this agonist, [[sup 3]H]pBC 264, which fullfils all the criteria required for in vitro as well as in vivo studies of the CCK-B receptor. On the other hand, BC 254 displays a high affinity for the CCK-B binding sites in the guinea-pig (K[sub i] = 0.56 nM) while its affinity in the rat is more than 60-fold lower, a difference which could be due to the occurrence of CCK-B receptor subtypes. In the present paper, we report the synthesis of [[sup 3]H]pBC 264 and of the new tritiated ligand [[sup 3]H]pBC 254 using [[sup 3]H] NPS (N-succinimidyl[2,3-[sup 3]H]propionate) as labelling agent. These two probes have high specific activity (70-100 Ci/mmol) and will enable extensive studies of the CCK-B receptors to be carried out. (author).

  16. FXR agonist activity of conformationally constrained analogs of GW 4064.

    Science.gov (United States)

    Akwabi-Ameyaw, Adwoa; Bass, Jonathan Y; Caldwell, Richard D; Caravella, Justin A; Chen, Lihong; Creech, Katrina L; Deaton, David N; Madauss, Kevin P; Marr, Harry B; McFadyen, Robert B; Miller, Aaron B; Navas, Frank; Parks, Derek J; Spearing, Paul K; Todd, Dan; Williams, Shawn P; Bruce Wisely, G

    2009-08-15

    Two series of conformationally constrained analogs of the FXR agonist GW 4064 1 were prepared. Replacement of the metabolically labile stilbene with either benzothiophene or naphthalene rings led to the identification of potent full agonists 2a and 2g.

  17. Gonadotropin releasing hormone agonists: Expanding vistas

    Directory of Open Access Journals (Sweden)

    Navneet Magon

    2011-01-01

    Full Text Available Gonadotropin-releasing hormone (GnRH agonists are derived from native GnRH by amino acid substitution which yields the agonist resistant to degradation and increases its half-life. The hypogonadotropic hypogonadal state produced by GnRH agonists has been often dubbed as "pseudomenopause" or "medical oophorectomy," which are both misnomers. GnRH analogues (GnRH-a work by temporarily "switching off" the ovaries. Ovaries can be "switched off" for the therapy and therapeutic trial of many conditions which include but are not limited to subfertility, endometriosis, adenomyosis, uterine leiomyomas, precocious puberty, premenstrual dysphoric disorder, chronic pelvic pain, or the prevention of menstrual bleeding in special clinical situations. Rapidly expanding vistas of usage of GnRH agonists encompass use in sex reassignment of male to female transsexuals, management of final height in cases of congenital adrenal hyperplasia, and preserving ovarian function in women undergoing cytotoxic chemotherapy. Hypogonadic side effects caused by the use of GnRH agonists can be tackled with use of "add-back" therapy. Goserelin, leuprolide, and nafarelin are commonly used in clinical practice. GnRH-a have provided us a powerful therapeutic approach to the treatment of numerous conditions in reproductive medicine. Recent synthesis of GnRH antagonists with a better tolerability profile may open new avenues for both research and clinical applications. All stakeholders who are partners in women′s healthcare need to join hands to spread awareness so that these drugs can be used to realize their full potential.

  18. Reconstitution of high-affinity opioid agonist binding in brain membranes

    Energy Technology Data Exchange (ETDEWEB)

    Remmers, A.E.; Medzihradsky, F. (Univ. of Michigan Medical School, Ann Arbor (United States))

    1991-03-15

    In synaptosomal membranes from rat brain cortex, the {mu} selective agonist ({sup 3}H)dihydromorphine in the absence of sodium, and the nonselective antagonist ({sup 3}H)naltrexone in the presence of sodium, bound to two populations of opioid receptor sites with K{sub d} values of 0.69 and 8.7 nM for dihydromorphine, and 0.34 and 5.5 nM for naltrexone. The addition of 5 {mu}M guanosine 5{prime}-({gamma}-thio)triphosphate (GTP({gamma}S)) strongly reduced high-affinity agonist but not antagonist binding. Exposure of the membranes to high pH reduced the number of GTP({gamma}-{sup 35}S) binding sites by 90% and low K{sub m}, opioid-sensitive GTPase activity by 95%. In these membranes, high-affinity agonist binding was abolished and modulation of residual binding by GTP({gamma}S) was diminished. Alkali treatment of the glioma cell membranes prior to fusion inhibited most of the low K{sub m} GTPase activity and prevented the reconstitution of agonist binding. The results show that high-affinity opioid agonist binding reflects the ligand-occupied receptor - guanine nucleotide binding protein complex.

  19. Identification of adiponectin receptor agonist utilizing a fluorescence polarization based high throughput assay.

    Directory of Open Access Journals (Sweden)

    Yiyi Sun

    Full Text Available Adiponectin, the adipose-derived hormone, plays an important role in the suppression of metabolic disorders that can result in type 2 diabetes, obesity, and atherosclerosis. It has been shown that up-regulation of adiponectin or adiponectin receptor has a number of therapeutic benefits. Given that it is hard to convert the full size adiponectin protein into a viable drug, adiponectin receptor agonists could be designed or identified using high-throughput screening. Here, we report on the development of a two-step screening process to identify adiponectin agonists. First step, we developed a high throughput screening assay based on fluorescence polarization to identify adiponectin ligands. The fluorescence polarization assay reported here could be adapted to screening against larger small molecular compound libraries. A natural product library containing 10,000 compounds was screened and 9 hits were selected for validation. These compounds have been taken for the second-step in vitro tests to confirm their agonistic activity. The most active adiponectin receptor 1 agonists are matairesinol, arctiin, (--arctigenin and gramine. The most active adiponectin receptor 2 agonists are parthenolide, taxifoliol, deoxyschizandrin, and syringin. These compounds may be useful drug candidates for hypoadiponectin related diseases.

  20. Detection of glucocorticoid receptor agonists in effluents from sewage treatment plants in Japan.

    Science.gov (United States)

    Suzuki, Go; Sato, Kentaro; Isobe, Tomohiko; Takigami, Hidetaka; Brouwer, Abraham; Nakayama, Kei

    2015-09-15

    Glucocorticoids (GCs) are widely used as anti-inflammatory drugs. Our previous study demonstrated that several GCs such as cortisol and dexamethasone (Dex) were frequently detected in effluents collected from Japanese sewage treatment plants (STPs) in 2012. In this study, we used the GC-Responsive Chemical-Activated LUciferase gene eXpression (GR-CALUX) assay to elucidate GC receptor (GR) agonistic activities of ten pure synthetic GCs and selected STP effluents in Japan for assessment of the risks associated with the presence of GR agonists. The tested GCs demonstrated dose-dependent agonistic effects in the GR-CALUX assay and their EC50 values were calculated for estimation of relative potencies (REPs) compared to Dex. The GR agonistic potency was in the rank of: clobetasol propionate > clobetasone butyrate > betamethasone 17-valerate > difluprednate > betamethasone 17,21-dipropionate > Dex > betamethasone > 6α-methylprednisolone > prednisolone > cortisol. The GR agonistic activity in STP effluents as measured in Dex-equivalent (Dex-EQ) activities ranged from effluents in Japan. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Sports doping: Emerging designer and therapeutic B2-agonists

    NARCIS (Netherlands)

    Fragkaki, A.G.; Georgakopoulos, C.; Sterk, S.S.; Nielen, M.W.F.

    2013-01-01

    Beta2-adrenergic agonists, or ß2-agonists, are considered essential bronchodilator drugs in the treatment of bronchial asthma, both as symptom-relievers and, in combination with inhaled corticosteroids, as disease-controllers. The use of ß2-agonists is prohibited in sports by the World Anti-Doping

  2. AMP is an adenosine A1 receptor agonist.

    Science.gov (United States)

    Rittiner, Joseph E; Korboukh, Ilia; Hull-Ryde, Emily A; Jin, Jian; Janzen, William P; Frye, Stephen V; Zylka, Mark J

    2012-02-17

    Numerous receptors for ATP, ADP, and adenosine exist; however, it is currently unknown whether a receptor for the related nucleotide adenosine 5'-monophosphate (AMP) exists. Using a novel cell-based assay to visualize adenosine receptor activation in real time, we found that AMP and a non-hydrolyzable AMP analog (deoxyadenosine 5'-monophosphonate, ACP) directly activated the adenosine A(1) receptor (A(1)R). In contrast, AMP only activated the adenosine A(2B) receptor (A(2B)R) after hydrolysis to adenosine by ecto-5'-nucleotidase (NT5E, CD73) or prostatic acid phosphatase (PAP, ACPP). Adenosine and AMP were equipotent human A(1)R agonists in our real-time assay and in a cAMP accumulation assay. ACP also depressed cAMP levels in mouse cortical neurons through activation of endogenous A(1)R. Non-selective purinergic receptor antagonists (pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid and suramin) did not block adenosine- or AMP-evoked activation. Moreover, mutation of His-251 in the human A(1)R ligand binding pocket reduced AMP potency without affecting adenosine potency. In contrast, mutation of a different binding pocket residue (His-278) eliminated responses to AMP and to adenosine. Taken together, our study indicates that the physiologically relevant nucleotide AMP is a full agonist of A(1)R. In addition, our study suggests that some of the physiological effects of AMP may be direct, and not indirect through ectonucleotidases that hydrolyze this nucleotide to adenosine.

  3. Identification of agonists for a group of human odorant receptors

    Directory of Open Access Journals (Sweden)

    Daniela eGonzalez-Kristeller

    2015-03-01

    Full Text Available Olfaction plays a critical role in several aspects of the human life. Odorants are detected by hundreds of odorant receptors (ORs which belong to the superfamily of G protein-coupled receptors. These receptors are expressed in the olfactory sensory neurons of the nose. The information provided by the activation of different combinations of ORs in the nose is transmitted to the brain, leading to odorant perception and emotional and behavioral responses. There are ~400 intact human ORs, and to date only a small percentage of these receptors (~10% have known agonists. The determination of the specificity of the human ORs will contribute to a better understanding of how odorants are discriminated by the olfactory system. In this work, we aimed to identify human specific ORs, that is, ORs that are present in humans but absent from other species, and their corresponding agonists. To do this, we first selected 22 OR gene sequences from the human genome with no counterparts in the mouse, rat or dog genomes. Then we used a heterologous expression system to screen a subset of these human ORs against a panel of odorants of biological relevance, including foodborne aroma volatiles. We found that different types of odorants are able to activate some of these previously uncharacterized human ORs.

  4. Functionally Selective Signaling for Morphine and Fentanyl Antinociception and Tolerance Mediated by the Rat Periaqueductal Gray

    Science.gov (United States)

    Morgan, Michael M.; Reid, Rachel A.; Saville, Kimber A.

    2014-01-01

    Functionally selective signaling appears to contribute to the variability in mechanisms that underlie tolerance to the antinociceptive effects of opioids. The present study tested this hypothesis by examining the contribution of G protein-coupled receptor kinase (GRK)/Protein kinase C (PKC) and C-Jun N-terminal kinase (JNK) activation on both the expression and development of tolerance to morphine and fentanyl microinjected into the ventrolateral periaqueductal gray of the rat. Microinjection of morphine or fentanyl into the periaqueductal gray produced a dose-dependent increase in hot plate latency. Microinjection of the non-specific GRK/PKC inhibitor Ro 32-0432 into the periaqueductal gray to block mu-opioid receptor phosphorylation enhanced the antinociceptive effect of morphine but had no effect on fentanyl antinociception. Microinjection of the JNK inhibitor SP600125 had no effect on morphine or fentanyl antinociception, but blocked the expression of tolerance to repeated morphine microinjections. In contrast, a microinjection of Ro 32-0432 blocked the expression of fentanyl, but not morphine tolerance. Repeated microinjections of Ro 32-0432 blocked the development of morphine tolerance and inhibited fentanyl antinociception whether rats were tolerant or not. Repeated microinjections of SP600125 into the periaqueductal gray blocked the development of tolerance to both morphine and fentanyl microinjections. These data demonstrate that the signaling molecules that contribute to tolerance vary depending on the opioid and methodology used to assess tolerance (expression vs. development of tolerance). This signaling difference is especially clear for the expression of tolerance in which JNK contributes to morphine tolerance and GRK/PKC contributes to fentanyl tolerance. PMID:25503060

  5. Discovery of N-(4-aryl-5-aryloxy-thiazol-2-yl)-amides as potent RORγt inverse agonists.

    Science.gov (United States)

    Wang, Yonghui; Yang, Ting; Liu, Qian; Ma, Yingli; Yang, Liuqing; Zhou, Ling; Xiang, Zhijun; Cheng, Ziqiang; Lu, Sijie; Orband-Miller, Lisa A; Zhang, Wei; Wu, Qianqian; Zhang, Kathleen; Li, Yi; Xiang, Jia-Ning; Elliott, John D; Leung, Stewart; Ren, Feng; Lin, Xichen

    2015-09-01

    A novel series of N-(4-aryl-5-aryloxy-thiazol-2-yl)-amides as RORγt inverse agonists was discovered. Binding mode analysis of a RORγt partial agonist (2c) revealed by co-crystal structure in RORγt LBD suggests that the inverse agonists do not directly interfere with the interaction between H12 and the RORγt LBD. Detailed SAR exploration led to identification of potent RORγt inverse agonists such as 3m with a pIC50 of 8.0. Selected compounds in the series showed reasonable activity in Th17 cell differentiation assay as well as low intrinsic clearance in mouse liver microsomes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. The GABAA receptor agonist THIP is neuroprotective in organotypic hippocampal slice cultures

    DEFF Research Database (Denmark)

    Kristensen, Bjarne Winther; Noraberg, Jens; Zimmer, Jens

    2003-01-01

    The potential neuroprotective effects of the GABA(A) receptor agonists THIP (4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol) and muscimol, and the selective GluR5 kainate receptor agonist ATPA ((RS)-2-amino-3-(3-hydroxy-5-tert-butylisoxazol-4-yl)propanoic acid), which activates GABAergic interneu......The potential neuroprotective effects of the GABA(A) receptor agonists THIP (4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol) and muscimol, and the selective GluR5 kainate receptor agonist ATPA ((RS)-2-amino-3-(3-hydroxy-5-tert-butylisoxazol-4-yl)propanoic acid), which activates GABAergic...... interneurons, were examined in hippocampal slice cultures exposed to N-methyl-D-aspartate (NMDA). The NMDA-induced excitotoxicity was quantified by densitometric measurements of propidium iodide (PI) uptake. THIP (100-1000 microM) was neuroprotective in slice cultures co-exposed to NMDA (10 microM) for 48 h......, while muscimol (100-1000 microM) and ATPA (1-3 microM) were without effect. The results demonstrate that direct GABA(A) agonism can mediate neuroprotection in the hippocampus in vitro as previously suggested in vivo....

  7. N-methyl-D-aspartic acid receptor agonists

    DEFF Research Database (Denmark)

    Madsen, U; Frydenvang, Karla Andrea; Ebert, B

    1996-01-01

    (R,S)-2-Amino-2-(3-hydroxy-5-methyl-4-isoxazolyl)acetic acid [(R,S)-AMAA, 4] is a potent and selective agonist at the N-methyl-D-aspartic acid (NMDA) subtype of excitatory amino acid receptors. Using the Ugi "four-component condensation" method, the two diastereomers (2R)- and (2S)-2-[3-(benzyloxy......) showed peak affinity for [3H]AMPA receptor sites (IC50 = 72 +/- 13 microM) and was shown to be a more potent inhibitor of [3H]CPP binding (IC50 = 3.7 +/- 1.5 microM) than (S)-AMAA (9) (IC50 = 61 +/- 6.4 microM). Neither enantiomer of AMAA affected [3H]kainic acid receptor binding significantly...

  8. Drug: D07122 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available hetics ... DG02027 ... General anesthetics ... DG02026 ... Opioid anesthetics ... DG02027 ... General anesthetic...s ... DG02026 ... Opioid anesthetics ... DG01564 ... Opioid receptor agonist ... DG01563 ... mu-Opioid recepto... D07122 Drug Alfentanil (INN); Rapifen (TN) ... C21H32N6O3 D07122.gif ... Neuropsychiatric agent ... DG02030 ... Anest

  9. Drug: D08473 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available tric agent ... DG02030 ... Anesthetics ... DG02027 ... General anesthetics ... DG02026 ... Opioid anesthetics ... DG02027 ... General anesthetic...s ... DG02026 ... Opioid anesthetics ... DG01564 ... Opioid receptor agonist ... DG01563 ... mu-Opioid recept... D08473 Drug Remifentanil (INN); Ultiva (TN) ... C20H28N2O5 D08473.gif ... Neuropsychia

  10. Drug: D05938 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D05938 Drug Sufentanil (USAN/INN) ... C22H30N2O2S D05938.gif ... Neuropsychiatric agent ... DG02030 ... Anesthetic...s ... DG02027 ... General anesthetics ... DG02026 ... Opioid anesthetics ... DG02027 ... General anesthetic...s ... DG02026 ... Opioid anesthetics ... DG01564 ... Opioid receptor agonist ... DG01563 ... mu-Opioid receptor agonis

  11. Analysis of Remifentanil with Liquid Chromatography-Tandem Mass Spectrometry and an Extensive Stability Investigation in EDTA Whole Blood and Acidified EDTA Plasma

    NARCIS (Netherlands)

    Koster, Remco A.; Vereecke, Hugo E. M.; Greijdanus, Ben; Touw, Daan J.; Struys, Michel M. R. F.; Alffenaar, Jan Willem C.

    BACKGROUND: Remifentanil is a mu-opioid receptor agonist that was developed as a synthetic opioid for use in anesthesia and intensive care medicine. Remifentanil is rapidly metabolized in both blood and tissues, which results in a very short duration of action. Even after blood sampling,

  12. Endogenous Opioid-Masked Latent Pain Sensitization

    DEFF Research Database (Denmark)

    Pereira, Manuel P; Donahue, Renee R; Dahl, Jørgen B

    2015-01-01

    UNLABELLED: Following the resolution of a severe inflammatory injury in rodents, administration of mu-opioid receptor inverse agonists leads to reinstatement of pain hypersensitivity. The mechanisms underlying this form of latent pain sensitization (LS) likely contribute to the development of chr...

  13. Evaluation of partial beta-adrenoceptor agonist activity.

    Science.gov (United States)

    Lipworth, B J; Grove, A

    1997-01-01

    A partial beta-adrenoceptor (beta-AR) agonist will exhibit opposite agonist and antagonist activity depending on the prevailing degree of adrenergic tone or the presence of a beta-AR agonist with higher intrinsic activity. In vivo partial beta-AR agonist activity will be evident at rest with low endogenous adrenergic tone, as for example with chronotropicity (beta 1/beta 2), inotropicity (beta 1) or peripheral vasodilatation and finger tremor (beta 2). beta-AR blocking drugs which have partial agonist activity may exhibit a better therapeutic profile when used for hypertension because of maintained cardiac output without increased systemic vascular resistance, along with an improved lipid profile. In the presence of raised endogenous adrenergic tone such as exercise or an exogenous full agonist, beta-AR subtype antagonist activity will become evident in terms of effects on exercise induced heart rate (beta 1) and potassium (beta 2) responses. Reduction of exercise heart rate will occur to a lesser degree in the case of a beta-adrenoceptor blocker with partial beta 1-AR agonist activity compared with a beta-adrenoceptor blocker devoid of partial agonist activity. This may result in reduced therapeutic efficacy in the treatment of angina on effort when using beta-AR blocking drugs with partial beta 1-AR agonist activity. Effects on exercise hyperkalaemia are determined by the balance between beta 2-AR partial agonist activity and endogenous adrenergic activity. For predominantly beta 2-AR agonist such as salmeterol and salbutamol, potentiation of exercise hyperkalaemia occurs. For predominantly beta 2-AR antagonists such as carteolol, either potentiation or attenuation of exercise hyperkalaemia occurs at low and high doses respectively. beta 2-AR partial agonist activity may also be expressed as antagonism in the presence of an exogenous full agonist, as for example attenuation of fenoterol induced responses by salmeterol. Studies are required to investigate whether

  14. Reports of pathological gambling, hypersexuality, and compulsive shopping associated with dopamine receptor agonist drugs.

    Science.gov (United States)

    Moore, Thomas J; Glenmullen, Joseph; Mattison, Donald R

    2014-12-01

    Severe impulse control disorders involving pathological gambling, hypersexuality, and compulsive shopping have been reported in association with the use of dopamine receptor agonist drugs in case series and retrospective patient surveys. These agents are used to treat Parkinson disease, restless leg syndrome, and hyperprolactinemia. To analyze serious adverse drug event reports about these impulse control disorders received by the US Food and Drug Administration (FDA) and to assess the relationship of these case reports with the 6 FDA-approved dopamine receptor agonist drugs. We conducted a retrospective disproportionality analysis based on the 2.7 million serious domestic and foreign adverse drug event reports from 2003 to 2012 extracted from the FDA Adverse Event Reporting System. Cases were selected if they contained any of 10 preferred terms in the Medical Dictionary for Regulatory Activities (MedDRA) that described the abnormal behaviors. We used the proportional reporting ratio (PRR) to compare the proportion of target events to all serious events for the study drugs with a similar proportion for all other drugs. We identified 1580 events indicating impulse control disorders from the United States and 21 other countries:710 fordopamine receptor agonist drugs and 870 for other drugs. The dopamine receptor agonist drugs had a strong signal associated with these impulse control disorders (n = 710; PRR = 277.6, P < .001). The association was strongest for the dopamine agonists pramipexole (n = 410; PRR = 455.9, P < .001) and ropinirole (n = 188; PRR = 152.5, P < .001), with preferential affinity for the dopamine D3 receptor. A signal was also seen for aripiprazole, an antipsychotic classified as a partial agonist of the D3 receptor (n = 37; PRR = 8.6, P < .001). Our findings confirm and extend the evidence that dopamine receptor agonist drugs are associated with these specific impulse control disorders. At present

  15. Sulfoximines as potent RORγ inverse agonists.

    Science.gov (United States)

    Ouvry, Gilles; Bihl, Franck; Bouix-Peter, Claire; Christin, Olivier; Defoin-Platel, Claire; Deret, Sophie; Feret, Christophe; Froude, David; Hacini-Rachinel, Feriel; Harris, Craig S; Hervouet, Catherine; Lafitte, Guillaume; Luzy, Anne-Pascale; Musicki, Branislav; Orfila, Danielle; Parnet, Veronique; Pascau, Coralie; Pascau, Jonathan; Pierre, Romain; Raffin, Catherine; Rossio, Patricia; Spiesse, Delphine; Taquet, Nathalie; Thoreau, Etienne; Vatinel, Rodolphe; Vial, Emmanuel; Hennequin, Laurent F

    2018-05-01

    Progress in the identification of suitable RORγ inverse agonists as clinical candidates has been hampered by the high lipophilicity that seems required for high potency on this nuclear receptor. In this context, we decided to focus on the replacement of the hydroxymethyl group found on known modulators to determine if more polarity could be tolerated in this position. SAR of the replacement of this moiety is presented in this article leading to the identification of sulfoximine derivatives as potent modulators with pharmacological activity in the in vivo mouse Imiquimod psoriasis model. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. GLP-1 agonists for type 2 diabetes

    DEFF Research Database (Denmark)

    Jespersen, Maria J; Knop, Filip K; Christensen, Mikkel

    2013-01-01

    and legal documents in the form of assessment reports from the European Medicines Agency and the United States Food and Drug Administration. EXPERT OPINION: GLP-1-based therapy combines several unique mechanisms of action and have the potential to gain widespread use in the fight against diabetes......Within recent years, glucagon-like peptide 1 receptor agonists (GLP-1-RA) have emerged as a new treatment option for type 2 diabetes. The GLP-1-RA are administered subcutaneously and differ substantially in pharmacokinetic profiles. AREAS COVERED: This review describes the pharmacokinetics...

  17. Sports doping: emerging designer and therapeutic β2-agonists.

    Science.gov (United States)

    Fragkaki, A G; Georgakopoulos, C; Sterk, S; Nielen, M W F

    2013-10-21

    Beta2-adrenergic agonists, or β2-agonists, are considered essential bronchodilator drugs in the treatment of bronchial asthma, both as symptom-relievers and, in combination with inhaled corticosteroids, as disease-controllers. The use of β2-agonists is prohibited in sports by the World Anti-Doping Agency (WADA) due to claimed anabolic effects, and also, is prohibited as growth promoters in cattle fattening in the European Union. This paper reviews the last seven-year (2006-2012) literature concerning the development of novel β2-agonists molecules either by modifying the molecule of known β2-agonists or by introducing moieties producing indole-, adamantyl- or phenyl urea derivatives. New emerging β2-agonists molecules for future therapeutic use are also presented, intending to emphasize their potential use for doping purposes or as growth promoters in the near future. © 2013.

  18. Preclinical evaluation of SMM-189, a cannabinoid receptor 2-specific inverse agonist.

    Science.gov (United States)

    Presley, Chaela; Abidi, Ammaar; Suryawanshi, Satyendra; Mustafa, Suni; Meibohm, Bernd; Moore, Bob M

    2015-08-01

    Cannabinoid receptor 2 agonists and inverse agonists are emerging as new therapeutic options for a spectrum of autoimmune-related disease. Of particular interest, is the ability of CB2 ligands to regulate microglia function in neurodegenerative diseases and traumatic brain injury. We have previously reported the receptor affinity of 3',5'-dichloro-2,6-dihydroxy-biphenyl-4-yl)-phenyl-methanone (SMM-189) and the characterization of the beneficial effects of SMM-189 in the mouse model of mild traumatic brain injury. Herein, we report the further characterization of SMM-189 as a potent and selective CB2 inverse agonist, which acts as a noncompetitive inhibitor of CP 55,940. The ability of SMM-189 to regulate microglial activation, in terms of chemokine expression and cell morphology, has been determined. Finally, we have determined that SMM-189 possesses acceptable biopharmaceutical properties indicating that the triaryl class of CB2 inverse agonists are viable compounds for continued preclinical development for the treatment of neurodegenerative disorders and traumatic brain injury.

  19. AMP Is an Adenosine A1 Receptor Agonist*

    Science.gov (United States)

    Rittiner, Joseph E.; Korboukh, Ilia; Hull-Ryde, Emily A.; Jin, Jian; Janzen, William P.; Frye, Stephen V.; Zylka, Mark J.

    2012-01-01

    Numerous receptors for ATP, ADP, and adenosine exist; however, it is currently unknown whether a receptor for the related nucleotide adenosine 5′-monophosphate (AMP) exists. Using a novel cell-based assay to visualize adenosine receptor activation in real time, we found that AMP and a non-hydrolyzable AMP analog (deoxyadenosine 5′-monophosphonate, ACP) directly activated the adenosine A1 receptor (A1R). In contrast, AMP only activated the adenosine A2B receptor (A2BR) after hydrolysis to adenosine by ecto-5′-nucleotidase (NT5E, CD73) or prostatic acid phosphatase (PAP, ACPP). Adenosine and AMP were equipotent human A1R agonists in our real-time assay and in a cAMP accumulation assay. ACP also depressed cAMP levels in mouse cortical neurons through activation of endogenous A1R. Non-selective purinergic receptor antagonists (pyridoxalphosphate-6-azophenyl-2′,4′-disulfonic acid and suramin) did not block adenosine- or AMP-evoked activation. Moreover, mutation of His-251 in the human A1R ligand binding pocket reduced AMP potency without affecting adenosine potency. In contrast, mutation of a different binding pocket residue (His-278) eliminated responses to AMP and to adenosine. Taken together, our study indicates that the physiologically relevant nucleotide AMP is a full agonist of A1R. In addition, our study suggests that some of the physiological effects of AMP may be direct, and not indirect through ectonucleotidases that hydrolyze this nucleotide to adenosine. PMID:22215671

  20. Effects of the potential 5-HT7 receptor agonist AS 19 in an autoshaping learning task.

    Science.gov (United States)

    Perez-García, Georgina S; Meneses, A

    2005-08-30

    This work aimed to evaluate further the role of 5-HT7 receptors during memory formation in an autoshaping Pavlovian/instrumental learning task. Post-training administration of the potential 5-HT7 receptor agonist AS 19 or antagonist SB-269970 enhanced memory formation or had no effect, respectively. The AS 19 facilitatory effect was reversed by SB-269970, but not by the selective 5-HT1A antagonist WAY100635. Amnesia induced by scopolamine (cholinergic antagonist) or dizocilpine (NMDA antagonist) was also reversed by AS 19. Certainly, reservations regarding the selectivity of AS 19 for 5-HT7 and other 5-HT receptors in vivo are noteworthy and, therefore, its validity for use in animal models as a pharmacological tool. Having mentioned that, it should be noticed that together these data are providing further support to the notion of the 5-HT7 receptors role in memory formation. Importantly, this 5-HT7 receptor agonist AS 19 appears to represent a step forward respect to the notion that potent and selective 5-HT7 receptor agonists can be useful in the treatment of dysfunctional memory in aged-related decline and Alzheimer's disease.

  1. Gonadotropin Releasing Hormone Agonists or Antagonists for Preimplantation Genetic Diagnosis (PGD)? A Prospective Randomised Trial.

    Science.gov (United States)

    Verpoest, Willem; De Vos, Anick; De Rycke, Martine; Parikh, Shruti; Staessen, Catherine; Tournaye, Herman; De Vos, Michel; Vloeberghs, Veerle; Blockeel, Christophe

    2017-11-10

    The use of GnRH analogue medication is essential in reproductive medicine to avoid premature ovulation by pituitary suppression for the duration of ovarian stimulation by gonadotrophins. The type of pituitary suppression by either GnRH agonist analogues versus GnRH antagonist analogues may result in different embryological hence clinical results. Preimplantation genetic diagnosis is a subtype of IVF in which embryos are created for genetic diagnosis of hereditary disorders in order to avoid genetically affected children. Embryological quality hence ovarian stimulation in preimplantation genetic diagnosis is crucial as genetic selection will reduce the number of available embryos to a fraction of the total. The aim of this study was to assess the efficiency of GnRH antagonist versus GnRH agonist treatment for pituitary suppression in ovarian stimulation for PGD, by proxy of number and quality of embryos at cleavage stage available for biopsy. We conducted a prospective randomised controlled trial comparing pituitary suppression by GnRH antagonist versus GnRH agonist in ovarian stimulation for PGD. The primary outcome measure was the number of embryos of sufficient quality for biopsy at cleavage stage. Secondary outcome parameters were the number of blastocysts available of top quality, and clinical pregnancy rate. There was no difference in number of oocytes retrieved, embryos at cleavage stage available for biopsy or embryo quality. The clinical pregnancy rate was higher in the GnRH agonist group; however the sample size was insufficient to allow conclusions. The use of GnRH agonist versus antagonist treatment does not result in differences in a number of oocytes, embryos or embryo quality in ovarian stimulation for preimplantation genetic diagnosis. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  2. Efficacy and Safety of GLP-1 Receptor Agonists for Type 2 Diabetes Mellitus Treatment: Systematic Review

    Directory of Open Access Journals (Sweden)

    Ana Paula Martins

    2016-04-01

    Full Text Available Introduction: Glucagon-like peptide analogues are a new class of drugs used in the treatment of type 2 diabetes mellitus that mimic the endogenous hormone glucagon-like peptide 1. Glucagon-like peptide 1 regulates glucose levels by stimulating glucose-dependent insulin secretion, suppressing glucagon secretion, delayed gastric emptying and promoting satiety. The individualized treatment of type 2 diabetes mellitus, using various glucagon--like peptide receptor agonists, has recently been described and the interest related to these drugs continues to grow. Objectives: To review the efficacy and safety of glucagon-like peptide 1 agonists in patients with inadequately controlled type 2 diabetes mellitus on metformin alone, highlighting their added value in therapeutic use comparatively to second line oral therapies used in type 2 diabetes mellitus. Methods: Studies were obtained from electronic searches of The Cochrane Library and PubMed. Randomized controlled trials were selected if they were at least 8 weeks in duration; compared a glucagon-like peptide 1 analogue with an oral anti-diabetic agent in patients experiencing inadequate glycemic control with metformin monotherapy; and reported hemoglobin A1c data in non-pregnant adults with type 2 diabetes mellitus. Results: Of 72 potentially relevant articles identified, 23 were retrieved for detailed evaluation and 10 met the inclusion criteria. The majority of glucagon-like peptide 1 agonists showed equivalent or superior efficacy than most active comparators for reducing hemoglobin A1c, with a greater proportion of patients achieving hemoglobin A1c <7%. Glucagon-like peptide 1 agonists also showed extra-glycemic effects such as weight loss and the reduction of important cardiovascular parameters. Side effects included gastrointestinal complications, mainly nausea, vomiting and diarrhea. The incidence of hypoglycemia was less common for this class of agents. Conclusion: Glucagon-like peptide 1

  3. Principles of agonist recognition in Cys-loop receptors

    DEFF Research Database (Denmark)

    Lynagh, Timothy Peter; Pless, Stephan Alexander

    2014-01-01

    , functional studies, and X-ray crystallography experiments identified the extracellular interface of adjacent subunits as the principal site of agonist binding. The question of how subtle differences at and around agonist-binding sites of different Cys-loop receptors can accommodate transmitters as chemically...

  4. Combining GLP-1 receptor agonists with insulin

    DEFF Research Database (Denmark)

    Holst, Jens Juul; Vilsbøll, T

    2013-01-01

    Due to the increasing prevalence of type 2 diabetes mellitus (T2DM), the emergent trend towards diagnosis in younger patients and the progressive nature of this disease, many more patients than before now require insulin to maintain glycaemic control. However, there is a degree of inertia among...... physicians and patients regarding the initiation and intensification of insulin therapy, in part due to concerns about the associated weight gain and increased risk of hypoglycaemia. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) increase insulin release and suppress glucagon secretion in a glucose......, compared with insulin, the antihyperglycaemic efficacy of GLP-1RAs is limited. The combination of a GLP-1RA and insulin might thus be highly effective for optimal glucose control, ameliorating the adverse effects typically associated with insulin. Data from clinical studies support the therapeutic...

  5. PPARγ partial agonist GQ-16 strongly represses a subset of genes in 3T3-L1 adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Milton, Flora Aparecida [Faculdade de Ciências da Saúde, Laboratório de Farmacologia Molecular, Universidade de Brasília (Brazil); Genomic Medicine, Houston Methodist Research Institute, Houston, TX (United States); Cvoro, Aleksandra [Genomic Medicine, Houston Methodist Research Institute, Houston, TX (United States); Amato, Angelica A. [Faculdade de Ciências da Saúde, Laboratório de Farmacologia Molecular, Universidade de Brasília (Brazil); Sieglaff, Douglas H.; Filgueira, Carly S.; Arumanayagam, Anithachristy Sigamani [Genomic Medicine, Houston Methodist Research Institute, Houston, TX (United States); Caro Alves de Lima, Maria do; Rocha Pitta, Ivan [Laboratório de Planejamento e Síntese de Fármacos – LPSF, Universidade Federal de Pernambuco (Brazil); Assis Rocha Neves, Francisco de [Faculdade de Ciências da Saúde, Laboratório de Farmacologia Molecular, Universidade de Brasília (Brazil); Webb, Paul, E-mail: pwebb@HoustonMethodist.org [Genomic Medicine, Houston Methodist Research Institute, Houston, TX (United States)

    2015-08-28

    Thiazolidinediones (TZDs) are peroxisome proliferator-activated receptor gamma (PPARγ) agonists that improve insulin resistance but trigger side effects such as weight gain, edema, congestive heart failure and bone loss. GQ-16 is a PPARγ partial agonist that improves glucose tolerance and insulin sensitivity in mouse models of obesity and diabetes without inducing weight gain or edema. It is not clear whether GQ-16 acts as a partial agonist at all PPARγ target genes, or whether it displays gene-selective actions. To determine how GQ-16 influences PPARγ activity on a gene by gene basis, we compared effects of rosiglitazone (Rosi) and GQ-16 in mature 3T3-L1 adipocytes using microarray and qRT-PCR. Rosi changed expression of 1156 genes in 3T3-L1, but GQ-16 only changed 89 genes. GQ-16 generally showed weak effects upon Rosi induced genes, consistent with partial agonist actions, but a subset of modestly Rosi induced and strongly repressed genes displayed disproportionately strong GQ-16 responses. PPARγ partial agonists MLR24 and SR1664 also exhibit disproportionately strong effects on transcriptional repression. We conclude that GQ-16 displays a continuum of weak partial agonist effects but efficiently represses some negatively regulated PPARγ responsive genes. Strong repressive effects could contribute to physiologic actions of GQ-16. - Highlights: • GQ-16 is an insulin sensitizing PPARγ ligand with reduced harmful side effects. • GQ-16 displays a continuum of weak partial agonist activities at PPARγ-induced genes. • GQ-16 exerts strong repressive effects at a subset of genes. • These inhibitor actions should be evaluated in models of adipose tissue inflammation.

  6. PPARγ partial agonist GQ-16 strongly represses a subset of genes in 3T3-L1 adipocytes

    International Nuclear Information System (INIS)

    Milton, Flora Aparecida; Cvoro, Aleksandra; Amato, Angelica A.; Sieglaff, Douglas H.; Filgueira, Carly S.; Arumanayagam, Anithachristy Sigamani; Caro Alves de Lima, Maria do; Rocha Pitta, Ivan; Assis Rocha Neves, Francisco de; Webb, Paul

    2015-01-01

    Thiazolidinediones (TZDs) are peroxisome proliferator-activated receptor gamma (PPARγ) agonists that improve insulin resistance but trigger side effects such as weight gain, edema, congestive heart failure and bone loss. GQ-16 is a PPARγ partial agonist that improves glucose tolerance and insulin sensitivity in mouse models of obesity and diabetes without inducing weight gain or edema. It is not clear whether GQ-16 acts as a partial agonist at all PPARγ target genes, or whether it displays gene-selective actions. To determine how GQ-16 influences PPARγ activity on a gene by gene basis, we compared effects of rosiglitazone (Rosi) and GQ-16 in mature 3T3-L1 adipocytes using microarray and qRT-PCR. Rosi changed expression of 1156 genes in 3T3-L1, but GQ-16 only changed 89 genes. GQ-16 generally showed weak effects upon Rosi induced genes, consistent with partial agonist actions, but a subset of modestly Rosi induced and strongly repressed genes displayed disproportionately strong GQ-16 responses. PPARγ partial agonists MLR24 and SR1664 also exhibit disproportionately strong effects on transcriptional repression. We conclude that GQ-16 displays a continuum of weak partial agonist effects but efficiently represses some negatively regulated PPARγ responsive genes. Strong repressive effects could contribute to physiologic actions of GQ-16. - Highlights: • GQ-16 is an insulin sensitizing PPARγ ligand with reduced harmful side effects. • GQ-16 displays a continuum of weak partial agonist activities at PPARγ-induced genes. • GQ-16 exerts strong repressive effects at a subset of genes. • These inhibitor actions should be evaluated in models of adipose tissue inflammation

  7. Estradiol agonists inhibit human LoVo colorectal-cancer cell proliferation and migration through p53.

    Science.gov (United States)

    Hsu, Hsi-Hsien; Kuo, Wei-Wen; Ju, Da-Tong; Yeh, Yu-Lan; Tu, Chuan-Chou; Tsai, Ying-Lan; Shen, Chia-Yao; Chang, Sheng-Huang; Chung, Li-Chin; Huang, Chih-Yang

    2014-11-28

    To investigate the effects of 17β-estradiol via estrogen receptors (ER) or direct administration of ER agonists on human colorectal cancer. LoVo cells were established from the Bioresource Collection and Research Center and cultured in phenol red-free DMEM (Sigma, United States). To investigate the effects of E2 and/or ER selective agonists on cellular proliferation, LoVo colorectal cells were treated with E2 or ER-selective agonists for 24 h and 48 h and subjected to the MTT (Sigma) assay to find the concentration. And investigate the effects of E2 and/or ER selective agonists on cell used western immunoblotting to find out the diversification of signaling pathways. In order to observe motility and migration the wound healing assay and a transwell chamber (Neuro Probe) plate were tased. For a quantitative measure, we counted the number of migrating cells to the wound area post-wounding for 24 h. We further examined the cellular migration-regulating factors urokinase-type plasminogen activator (u-PA), tissue-type plasminogen activator (t-PA) and matrix metalloproteinase (MMP)-9 in human LoVo cells so gelatin zymography that we used and gelatinolytic activity was visualized by Coomassie blue staining. And these results are presented as means ± SE, and statistical comparisons were made using Student's t-test. The structure was first compared with E2 and ER agonists. We then treated the LoVo cells with E2 and ER agonists (10(-8) mol/L) for 24 h and 48 h and subsequently measured the cell viability using MTT assay. Our results showed that treatment with 17β-estradiol and/or ER agonists in human LoVo colorectal cancer cells activated p53 and then up-regulated p21 and p27 protein levels, subsequently inhibiting the downstream target gene, cyclin D1, which regulates cell proliferation. Taken together, our findings demonstrate the anti-tumorigenesis effects of 17β-estradiol and/or ER agonists and suggest that these compounds may prove to be a potential alternative

  8. Melanocortin Receptor Agonists Facilitate Oxytocin-Dependent Partner Preference Formation in the Prairie Vole.

    Science.gov (United States)

    Modi, Meera E; Inoue, Kiyoshi; Barrett, Catherine E; Kittelberger, Kara A; Smith, Daniel G; Landgraf, Rainer; Young, Larry J

    2015-07-01

    The central melanocortin (MC) system has been widely studied for its effects on food intake and sexual behavior. However, the MC system, and more specifically the MC4 receptor (MC4R), also interacts with neurochemical systems that regulate socioemotional behaviors, including oxytocin (OT) and dopamine. In monogamous prairie voles, OT and dopamine interact to promote partner preference formation, a laboratory measure of an enduring social bond between mates. Here we investigated the effects of MC receptor activation on partner preference formation in prairie voles, as well as the interaction between the MC and OT systems during this process. Peripheral administration of the brain penetrant MC3/4R receptor peptide agonist, Melanotan II (MTII), and the highly selective, small-molecule MC4R agonist, Pf-446687, enhanced partner preference formation in the prairie vole, but not in the non-monogamous meadow vole. MTII-induced partner preferences were enduring, as they were present 1 week after drug manipulation. The prosocial effects of MCR agonists may be mediated, in part, through modulation of OT, as coadministration of an OT receptor antagonist prevented MTII-induced partner preferences. MTII also selectively activated hypothalamic OT neurons and potentiated central OT release. As OT has been shown to enhance some aspects of social cognition in humans, our data suggest that the MC4R may be a viable therapeutic target for enhancing social function in psychiatric disorders, including autism spectrum disorders and schizophrenia, potentially through activation of the OT system.

  9. Ghrelin receptor inverse agonists: identification of an active peptide core and its interaction epitopes on the receptor

    DEFF Research Database (Denmark)

    Holst, Birgitte; Lang, Manja; Brandt, Erik

    2006-01-01

    [D-Arg1,D-Phe5,D-Trp7,9,Leu11]Substance P functions as a low-potency antagonist but a high-potency full inverse agonist on the ghrelin receptor. Through a systematic deletion and substitution analysis of this peptide, the C-terminal carboxyamidated pentapeptide wFwLX was identified as the core...... structure, which itself displayed relatively low inverse agonist potency. Mutational analysis at 17 selected positions in the main ligand-binding crevice of the ghrelin receptor demonstrated that ghrelin apparently interacts only with residues in the middle part of the pocket [i.e., between transmembrane...... upon both AspII:20 and GluIII:09. The identified pharmacophore can possibly serve as the basis for targeted discovery of also nonpeptide inverse agonists for the ghrelin receptor....

  10. Alpha-2 receptor agonists for the treatment of posttraumatic stress disorder

    Directory of Open Access Journals (Sweden)

    Molly R Belkin

    2017-09-01

    Full Text Available Clonidine and guanfacine are alpha-2 receptor agonists that decrease sympathetic outflow from the central nervous system. Posttraumatic stress disorder (PTSD is an anxiety disorder that is theorized to be related to a hyperactive sympathetic nervous system. Currently, the only US Food and Drug Administration (FDA-approved medications for PTSD are the selective serotonin reuptake inhibitors (SSRIs sertraline and paroxetine. Sometimes use of the SSRIs may not lead to full remission and symptoms of hyperarousal often persist. This article specifically reviews the literature on alpha-2 receptor agonist use for the treatment of PTSD and concludes that while the evidence base is limited, these agents might be considered useful when SSRIs fail to treat symptoms of agitation and hyperarousal in patients with PTSD.

  11. A Novel Non-Peptidic Agonist of the Ghrelin Receptor with Orexigenic Activity In vivo

    Science.gov (United States)

    Pastor-Cavada, Elena; Pardo, Leticia M.; Kandil, Dalia; Torres-Fuentes, Cristina; Clarke, Sarah L.; Shaban, Hamdy; McGlacken, Gerard P.; Schellekens, Harriet

    2016-11-01

    Loss of appetite in the medically ill and ageing populations is a major health problem and a significant symptom in cachexia syndromes, which is the loss of muscle and fat mass. Ghrelin is a gut-derived hormone which can stimulate appetite. Herein we describe a novel, simple, non-peptidic, 2-pyridone which acts as a selective agonist for the ghrelin receptor (GHS-R1a). The small 2-pyridone demonstrated clear agonistic activity in both transfected human cells and mouse hypothalamic cells with endogenous GHS-R1a receptor expression. In vivo tests with the hit compound showed significant increased food intake following peripheral administration, which highlights the potent orexigenic effect of this novel GHS-R1a receptor ligand.

  12. (S)-2-Amino-3-(3-hydroxy-7,8-dihydro-6H-cyclohepta[d]isoxazol-4-yl)propionic acid, a potent and selective agonist at the GluR5 subtype of ionotropic glutamate receptors. Synthesis, modeling, and molecular pharmacology

    DEFF Research Database (Denmark)

    Brehm, Lotte; Greenwood, Jeremy R; Hansen, Kasper B

    2003-01-01

    )propionic acid (AMPA) but inactive at NMDA receptors. However, 4-AHCP was found to be much weaker than AMPA as an inhibitor of [(3)H]AMPA binding and to have limited effect in a [(3)H]kainic acid binding assay using rat cortical membranes. To shed light on the mechanism(s) underlying this quite enigmatic......, activated cloned AMPA receptor subunits GluR1o, GluR3o, and GluR4o with EC(50) values in the range 4.5-15 microM and the coexpressed kainate-preferring subunits GluR6 + KA2 (EC(50) = 6.4 microM). Compound 6, but not 7, proved to be a very potent agonist (EC(50) = 0.13 microM) at the kainate-preferring GluR5...... subunit, equipotent with (S)-2-amino-3-(5-tert-butyl-3-hydroxyisothiazol-4-yl)propionic acid [(S)-Thio-ATPA, 4] and almost 4 times more potent than (S)-2-amino-3-(5-tert-butyl-3-hydroxyisoxazol-4-yl)propionic acid [(S)-ATPA, 3]. Compound 6 thus represents a new structural class of GluR5 agonists...

  13. Differential activation of G-proteins by μ-opioid receptor agonists

    Science.gov (United States)

    Saidak, Zuzana; Blake-Palmer, Katherine; Hay, Debbie L; Northup, John K; Glass, Michelle

    2006-01-01

    We investigated the ability of the activated μ-opioid receptor (MOR) to differentiate between myristoylated Gαi1 and GαoA type Gα proteins, and the maximal activity of a range of synthetic and endogenous agonists to activate each Gα protein. Membranes from HEK293 cells stably expressing transfected MOR were chaotrope extracted to denature endogenous G-proteins and reconstituted with specific purified G-proteins. The Gα subunits were generated in bacteria and were demonstrated to be recognised equivalently to bovine brain purified Gα protein by CB1 cannabinoid receptors. The ability of agonists to catalyse the MOR-dependent GDP/[35S]GTPγS exchange was then compared for Gαi1 and GαoA. Activation of MOR by DAMGO produced a high-affinity saturable interaction for GαoA (Km=20±1 nM) but a low-affinity interaction with Gαi1 (Km=116±12 nM). DAMGO, met-enkephalin and leucine-enkephalin displayed maximal Gα activation among the agonists evaluated. Endomorphins 1 and 2, methadone and β-endorphin activated both Gα to more than 75% of the maximal response, whereas fentanyl partially activated both G-proteins. Buprenorphine and morphine demonstrated a statistically significant difference between the maximal activities between Gαi1 and GαoA. Interestingly, DAMGO, morphine, endomorphins 1 and 2, displayed significant differences in the potencies for the activation of the two Gα. Differences in maximal activity and potency, for Gαi1 versus GαoA, are both indicative of agonist selective activation of G-proteins in response to MOR activation. These findings may provide a starting point for the design of drugs that demonstrate greater selectivity between these two G-proteins and therefore produce a more limited range of effects. PMID:16415903

  14. Dopamine agonist withdrawal syndrome: implications for patient care.

    Science.gov (United States)

    Nirenberg, Melissa J

    2013-08-01

    Dopamine agonists are effective treatments for a variety of indications, including Parkinson's disease and restless legs syndrome, but may have serious side effects, such as orthostatic hypotension, hallucinations, and impulse control disorders (including pathological gambling, compulsive eating, compulsive shopping/buying, and hypersexuality). The most effective way to alleviate these side effects is to taper or discontinue dopamine agonist therapy. A subset of patients who taper a dopamine agonist, however, develop dopamine agonist withdrawal syndrome (DAWS), which has been defined as a severe, stereotyped cluster of physical and psychological symptoms that correlate with dopamine agonist withdrawal in a dose-dependent manner, cause clinically significant distress or social/occupational dysfunction, are refractory to levodopa and other dopaminergic medications, and cannot be accounted for by other clinical factors. The symptoms of DAWS include anxiety, panic attacks, dysphoria, depression, agitation, irritability, suicidal ideation, fatigue, orthostatic hypotension, nausea, vomiting, diaphoresis, generalized pain, and drug cravings. The severity and prognosis of DAWS is highly variable. While some patients have transient symptoms and make a full recovery, others have a protracted withdrawal syndrome lasting for months to years, and therefore may be unwilling or unable to discontinue DA therapy. Impulse control disorders appear to be a major risk factor for DAWS, and are present in virtually all affected patients. Thus, patients who are unable to discontinue dopamine agonist therapy may experience chronic impulse control disorders. At the current time, there are no known effective treatments for DAWS. For this reason, providers are urged to use dopamine agonists judiciously, warn patients about the risks of DAWS prior to the initiation of dopamine agonist therapy, and follow patients closely for withdrawal symptoms during dopamine agonist taper.

  15. Triptans, serotonin agonists, and serotonin syndrome (serotonin toxicity): a review.

    Science.gov (United States)

    Gillman, P Ken

    2010-02-01

    The US Food and Drug Administration (FDA) have suggested that fatal serotonin syndrome (SS) is possible with selective serotonin reuptake inhibitors (SSRIs) and triptans: this warning affects millions of patients as these drugs are frequently given simultaneously. SS is a complex topic about which there is much misinformation. The misconception that 5-HT1A receptors can cause serious SS is still widely perpetuated, despite quality evidence that it is activation of the 5-HT2A receptor that is required for serious SS. This review considers SS involving serotonin agonists: ergotamine, lysergic acid diethylamide, bromocriptine, and buspirone, as well as triptans, and reviews the experimental foundation underpinning the latest understanding of SS. It is concluded that there is neither significant clinical evidence, nor theoretical reason, to entertain speculation about serious SS from triptans and SSRIs. The misunderstandings about SS exhibited by the FDA, and shared by the UK Medicines and Healthcare products Regulatory Agency (in relation to methylene blue), are an important issue with wide ramifications.

  16. Mechanical stress activates NMDA receptors in the absence of agonists.

    Science.gov (United States)

    Maneshi, Mohammad Mehdi; Maki, Bruce; Gnanasambandam, Radhakrishnan; Belin, Sophie; Popescu, Gabriela K; Sachs, Frederick; Hua, Susan Z

    2017-01-03

    While studying the physiological response of primary rat astrocytes to fluid shear stress in a model of traumatic brain injury (TBI), we found that shear stress induced Ca 2+ entry. The influx was inhibited by MK-801, a specific pore blocker of N-Methyl-D-aspartic acid receptor (NMDAR) channels, and this occurred in the absence of agonists. Other NMDA open channel blockers ketamine and memantine showed a similar effect. The competitive glutamate antagonists AP5 and GluN2B-selective inhibitor ifenprodil reduced NMDA-activated currents, but had no effect on the mechanically induced Ca 2+ influx. Extracellular Mg 2+ at 2 mM did not significantly affect the shear induced Ca 2+ influx, but at 10 mM it produced significant inhibition. Patch clamp experiments showed mechanical activation of NMDAR and inhibition by MK-801. The mechanical sensitivity of NMDARs may play a role in the normal physiology of fluid flow in the glymphatic system and it has obvious relevance to TBI.

  17. Nicotine receptor partial agonists for smoking cessation.

    Science.gov (United States)

    Cahill, Kate; Stead, Lindsay F; Lancaster, Tim

    2012-04-18

    Nicotine receptor partial agonists may help people to stop smoking by a combination of maintaining moderate levels of dopamine to counteract withdrawal symptoms (acting as an agonist) and reducing smoking satisfaction (acting as an antagonist). The primary objective of this review is to assess the efficacy and tolerability of nicotine receptor partial agonists, including cytisine, dianicline and varenicline for smoking cessation. We searched the Cochrane Tobacco Addiction Group's specialised register for trials, using the terms ('cytisine' or 'Tabex' or 'dianicline' or 'varenicline' or 'nicotine receptor partial agonist') in the title or abstract, or as keywords. The register is compiled from searches of MEDLINE, EMBASE, PsycINFO and Web of Science using MeSH terms and free text to identify controlled trials of interventions for smoking cessation and prevention. We contacted authors of trial reports for additional information where necessary. The latest update of the specialised register was in December 2011. We also searched online clinical trials registers. We included randomized controlled trials which compared the treatment drug with placebo. We also included comparisons with bupropion and nicotine patches where available. We excluded trials which did not report a minimum follow-up period of six months from start of treatment. We extracted data on the type of participants, the dose and duration of treatment, the outcome measures, the randomization procedure, concealment of allocation, and completeness of follow-up.The main outcome measured was abstinence from smoking at longest follow-up. We used the most rigorous definition of abstinence, and preferred biochemically validated rates where they were reported. Where appropriate we pooled risk ratios (RRs), using the Mantel-Haenszel fixed-effect model. Two recent cytisine trials (937 people) found that more participants taking cytisine stopped smoking compared with placebo at longest follow-up, with a pooled RR of

  18. Effect of the α2 -receptor agonists medetomidine, detomidine, xylazine, and romifidine on the ketamine metabolism in equines assessed with enantioselective capillary electrophoresis.

    Science.gov (United States)

    Sandbaumhüter, Friederike A; Theurillat, Regula; Bettschart-Wolfensberger, Regula; Thormann, Wolfgang

    2017-08-01

    The combination of ketamine and an α 2 -receptor agonist is often used in veterinary medicine. Four different α 2 -receptor agonists, medetomidine, detomidine, xylazine, and romifidine, which differ in their chemical structure and thus in selectivity for the α 2 -receptor and in the sedative and analgesic potency, are typically employed during surgery of equines. Recovery following anesthesia with ketamine and an α 2 -receptor agonist is dependent on the α 2 -receptor agonist. This prompted us to investigate (i) the inhibition characteristics for the N-demethylation of ketamine to norketamine and (ii) the formation of the ketamine metabolites norketamine, 6-hydroxynorketamine (6HNK), and 5,6-dehydronorketamine (DHNK) in presence of the four α 2 -receptor agonists and equine liver microsomes. Samples were analyzed with enantioselective capillary electrophoresis using highly sulfated γ-cyclodextrin as chiral selector. All four α 2 -receptor agonists have an impact on the ketamine metabolism. Medetomidine was found to be the strongest inhibitor, followed by detomidine, whereas xylazine and romifidine showed almost no effect on the ketamine N-demethylation in the inhibition studies with a short-incubation period of the reaction mixture. After prolonged incubation, inhibition with xylazine and romifidine was also observed. The formation of 6HNK and DHNK is affected by all selected α 2 -receptor agonists. With medetomidine, levels of these metabolites are reduced compared to the case without an α 2 -receptor agonist. For detomidine, xylazine, and romifidine, the opposite was found. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Chimeric NDP-MSH and MTII melanocortin peptides with agouti-related protein (AGRP) Arg-Phe-Phe amino acids possess agonist melanocortin receptor activity.

    Science.gov (United States)

    Joseph, Christine G; Wilczynski, Andrzej; Holder, Jerry R; Xiang, Zhimin; Bauzo, Rayna M; Scott, Joseph W; Haskell-Luevano, Carrie

    2003-12-01

    Agouti-related protein (AGRP) is one of only two known endogenous antagonists of G-protein coupled receptors (GPCRs). Specifically, AGRP antagonizes the brain melanocortin-3 and -4 receptors involved in energy homeostasis, regulation of feeding behavior, and obesity. Alpha-melanocyte stimulating hormone (alpha-MSH) is one of the known endogenous agonists for these receptors. It has been hypothesized that the Arg-Phe-Phe (111-113) human AGRP amino acids may be mimicking the melanocortin agonist Phe-Arg-Trp (7-9) residue interactions with the melanocortin receptors that are important for both receptor molecular recognition and stimulation. To test this hypothesis, we generated thirteen chimeric peptide ligands based upon the melanocortin agonist peptides NDP-MSH (Ac-Ser-Tyr-Ser-Nle4-Glu-His-DPhe-Arg-Trp-Gly-Lys-Pro-Val-NH2) and MTII (Ac-Nle-c[Asp-His-DPhe-Arg-Trp-Lys]-NH2). In these chimeric ligands, the agonist DPhe-Arg-Trp amino acids were replaced by the AGRP Arg-Phe-Phe residues, and resulted in agonist activity at the mouse melanocortin receptors (mMC1R and mMC3-5Rs), supporting the hypothesis that the AGRP antagonist ligand Arg-Phe-Phe residues mimic the agonist Phe-Arg-Trp amino acids. Interestingly, the Ac-Ser-Tyr-Ser-Nle4-Glu-His-Arg-DPhe-Phe-Gly-Lys-Pro-Val-NH2 peptide possessed 7 nM mMC1R agonist potency, and is 850-fold selective for the mMC1R versus the mMC3R, 2300-fold selective for the mMC1R versus the mMC4R, and 60-fold selective for the MC1R versus the mMC5R, resulting in the discovery of a new peptide template for the design of melanocortin receptor selective ligands.

  20. Partial agonist therapy in schizophrenia: relevance to diminished criminal responsibility.

    Science.gov (United States)

    Gavaudan, Gilles; Magalon, David; Cohen, Julien; Lançon, Christophe; Léonetti, Georges; Pélissier-Alicot, Anne-Laure

    2010-11-01

    Pathological gambling (PG), classified in the DSM-IV among impulse control disorders, is defined as inappropriate, persistent gaming for money with serious personal, family, and social consequences. Offenses are frequently committed to obtain money for gambling. Pathological gambling, a planned and structured behavioral disorder, has often been described as a complication of dopamine agonist treatment in patients with Parkinson's disease. It has never been described in patients with schizophrenia receiving dopamine agonists. We present two patients with schizophrenia, previously treated with antipsychotic drugs without any suggestion of PG, who a short time after starting aripiprazole, a dopamine partial agonist, developed PG and criminal behavior, which totally resolved when aripiprazole was discontinued. Based on recent advances in research on PG and adverse drug reactions to dopamine agonists in Parkinson's disease, we postulate a link between aripiprazole and PG in both our patients with schizophrenia and raise the question of criminal responsibility. © 2010 American Academy of Forensic Sciences.

  1. MELATONIN DAN MELATONIN RECEPTOR AGONIST SEBAGAI PENANGANAN INSOMNIA PRIMER KRONIS

    Directory of Open Access Journals (Sweden)

    Ni Luh Putu Ayu Maha Iswari

    2013-04-01

    Full Text Available Melatonin is a hormone that has an important role in the mechanism of sleep. Hypnotic effects of melatonin and melatonin receptor agonist are mediated via MT1 and MT2 receptors, especially in circadian rhythm pacemaker, suprachiasmatic nucleus, which is worked on the hypothalamic sleep switch. This mechanism is quite different with the GABAergic drugs such as benzodiazepine. Agonist melatonin triggers the initiation of sleep and normalize circadian rhythms so that makes it easier to maintain sleep. The main disadvantage of melatonin in helping sleep maintenance on primary insomnia is that the half life is very short. The solution to this problem is the use of prolonged-release melatonin and melatonin receptor agonist agents such as ramelteon. Melatoninergic agonist does not cause withdrawal effects, dependence, as well as cognitive and psychomotor disorders as often happens on the use of benzodiazepine.  

  2. Identification of Natural Compound Carnosol as a Novel TRPA1 Receptor Agonist

    Directory of Open Access Journals (Sweden)

    Chenxi Zhai

    2014-11-01

    Full Text Available The transient receptor potential ankyrin 1 (TRPA1 cation channel is one of the well-known targets for pain therapy. Herbal medicine is a rich source for new drugs and potentially useful therapeutic agents. To discover novel natural TRPA1 agonists, compounds isolated from Chinese herbs were screened using a cell-based calcium mobilization assay. Out of the 158 natural compounds derived from traditional Chinese herbal medicines, carnosol was identified as a novel agonist of TRPA1 with an EC50 value of 12.46 µM. And the agonistic effect of carnosol on TRPA1 could be blocked by A-967079, a selective TRPA1 antagonist. Furthermore, the specificity of carnosol was verified as it showed no significant effects on two other typical targets of TRP family member: TRPM8 and TRPV3. Carnosol exhibited anti-inflammatory and anti-nociceptive properties; the activation of TRPA1 might be responsible for the modulation of inflammatory nociceptive transmission. Collectively, our findings indicate that carnosol is a new anti-nociceptive agent targeting TRPA1 that can be used to explore further biological role in pain therapy.

  3. CTDP-32476: A Promising Agonist Therapy for Treatment of Cocaine Addiction

    Science.gov (United States)

    Xi, Zheng-Xiong; Song, Rui; Li, Xia; Lu, Guan-Yi; Peng, Xiao-Qing; He, Yi; Bi, Guo-Hua; Sheng, Siyuan Peter; Yang, Hong-Ju; Zhang, Haiying; Li, Jin; Froimowitz, Mark; Gardner, Eliot L

    2017-01-01

    Agonist-replacement therapies have been successfully used for treatment of opiate and nicotine addiction, but not for cocaine addiction. One of the major obstacles is the cocaine-like addictive potential of the agonists themselves. We report here an atypical dopamine (DA) transporter (DAT) inhibitor, CTDP-32476, that may have translational potential for treating cocaine addiction. In vitro ligand-binding assays suggest that CTDP-32476 is a potent and selective DAT inhibitor and a competitive inhibitor of cocaine binding to the DAT. Systemic administration of CTDP-32476 alone produced a slow-onset, long-lasting increase in extracellular nucleus accumbens DA, locomotion, and brain-stimulation reward. Drug-naive rats did not self-administer CTDP-32476. In a substitution test, cocaine self-administration rats displayed a progressive reduction in CTDP-32476 self-administration with an extinction pattern of drug-taking behavior, suggesting significantly lower addictive potential than cocaine. Pretreatment with CTDP-32476 inhibited cocaine self-administration, cocaine-associated cue-induced relapse to drug seeking, and cocaine-enhanced extracellular DA in the nucleus accumbens. These findings suggest that CTDP-32476 is a unique DAT inhibitor that not only could satisfy ‘drug hunger' through its slow-onset long-lasting DAT inhibitor action, but also render subsequent administration of cocaine ineffectual—thus constituting a novel and unique compound with translational potential as an agonist therapy for treatment of cocaine addiction. PMID:27534265

  4. A Rationally Designed Agonist Defines Subfamily IIIA Abscisic Acid Receptors As Critical Targets for Manipulating Transpiration.

    Science.gov (United States)

    Vaidya, Aditya S; Peterson, Francis C; Yarmolinsky, Dmitry; Merilo, Ebe; Verstraeten, Inge; Park, Sang-Youl; Elzinga, Dezi; Kaundal, Amita; Helander, Jonathan; Lozano-Juste, Jorge; Otani, Masato; Wu, Kevin; Jensen, Davin R; Kollist, Hannes; Volkman, Brian F; Cutler, Sean R

    2017-11-17

    Increasing drought and diminishing freshwater supplies have stimulated interest in developing small molecules that can be used to control transpiration. Receptors for the plant hormone abscisic acid (ABA) have emerged as key targets for this application, because ABA controls the apertures of stomata, which in turn regulate transpiration. Here, we describe the rational design of cyanabactin, an ABA receptor agonist that preferentially activates Pyrabactin Resistance 1 (PYR1) with low nanomolar potency. A 1.63 Å X-ray crystallographic structure of cyanabactin in complex with PYR1 illustrates that cyanabactin's arylnitrile mimics ABA's cyclohexenone oxygen and engages the tryptophan lock, a key component required to stabilize activated receptors. Further, its sulfonamide and 4-methylbenzyl substructures mimic ABA's carboxylate and C6 methyl groups, respectively. Isothermal titration calorimetry measurements show that cyanabactin's compact structure provides ready access to high ligand efficiency on a relatively simple scaffold. Cyanabactin treatments reduce Arabidopsis whole-plant stomatal conductance and activate multiple ABA responses, demonstrating that its in vitro potency translates to ABA-like activity in vivo. Genetic analyses show that the effects of cyanabactin, and the previously identified agonist quinabactin, can be abolished by the genetic removal of PYR1 and PYL1, which form subclade A within the dimeric subfamily III receptors. Thus, cyanabactin is a potent and selective agonist with a wide spectrum of ABA-like activities that defines subfamily IIIA receptors as key target sites for manipulating transpiration.

  5. Hypothermia in mouse is caused by adenosine A1 and A3 receptor agonists and AMP via three distinct mechanisms.

    Science.gov (United States)

    Carlin, Jesse Lea; Jain, Shalini; Gizewski, Elizabeth; Wan, Tina C; Tosh, Dilip K; Xiao, Cuiying; Auchampach, John A; Jacobson, Kenneth A; Gavrilova, Oksana; Reitman, Marc L

    2017-03-01

    Small mammals have the ability to enter torpor, a hypothermic, hypometabolic state, allowing impressive energy conservation. Administration of adenosine or adenosine 5'-monophosphate (AMP) can trigger a hypothermic, torpor-like state. We investigated the mechanisms for hypothermia using telemetric monitoring of body temperature in wild type and receptor knock out (Adora1 -/- , Adora3 -/- ) mice. Confirming prior data, stimulation of the A 3 adenosine receptor (AR) induced hypothermia via peripheral mast cell degranulation, histamine release, and activation of central histamine H 1 receptors. In contrast, A 1 AR agonists and AMP both acted centrally to cause hypothermia. Commonly used, selective A 1 AR agonists, including N 6 -cyclopentyladenosine (CPA), N 6 -cyclohexyladenosine (CHA), and MRS5474, caused hypothermia via both A 1 AR and A 3 AR when given intraperitoneally. Intracerebroventricular dosing, low peripheral doses of Cl-ENBA [(±)-5'-chloro-5'-deoxy-N 6 -endo-norbornyladenosine], or using Adora3 -/- mice allowed selective stimulation of A 1 AR. AMP-stimulated hypothermia can occur independently of A 1 AR, A 3 AR, and mast cells. A 1 AR and A 3 AR agonists and AMP cause regulated hypothermia that was characterized by a drop in total energy expenditure, physical inactivity, and preference for cooler environmental temperatures, indicating a reduced body temperature set point. Neither A 1 AR nor A 3 AR was required for fasting-induced torpor. A 1 AR and A 3 AR agonists and AMP trigger regulated hypothermia via three distinct mechanisms. Published by Elsevier Ltd.

  6. Effects of structural modifications of N-CPM-normorphine derivatives on agonist and antagonist activities in isolated organs.

    Science.gov (United States)

    Riba, P; Tóth, Z; Hosztafi, S; Friedmann, T; Fürst, S

    2003-01-01

    The agonistic and antagonistic properties of N-cyclopropylmethyl (N-CPM) morphine derivatives were observed in mouse vas deferens (MVD), longitudinal muscle of guinea pig ileum (GPI) and rabbit vas deferens (LVD). In MVD the K(e) values of the titled compounds (N-CPM-morphine, N-CPM-isomorphine, N-CPM-dihydromorphine, N-CPM-dihydroisomorpPhine, N-CPM-dihydromorphone and naltrexone) were measured for mu-, kappa- and delta-receptors using normorphine, ethylketocyclazocine (EKC) and D-Pen2-D-Pen5-enkephaline (DPDPE) as selective agonists on the receptors, respectively. For mu-receptors of MVD the tested compounds showed similar affinity. For kappa-receptors the non-iso-6-OH derivatives possessed much less affinity than the iso-derivatives. Similar difference could be observed for delta-receptors. The agonistic activities of these compounds in MVD were observed to be between 0-20% of the inhibition of muscle contractions. In GPI the compounds except naltrexone possessed strong agonistic activities effectively antagonized by nor-binaltorphimine (nor-BNI) (K(e) of nor-BNI was 0.23 nM) suggesting that they were strong kappa-receptor agonists. We investigated these agents in LVD too, which contains kappa-receptors, but they did not produce any agonist potencies. It raises the possibility that the kappa-receptor subtypes of LVD and MVD are different from the kappa-receptor subtype of GPI or the vasa deferentia contain much fewer kappa-receptors than GPI and the intrinsic activities of these compounds are too small to reach the 50% inhibition of the contractions.

  7. Trial Watch: Toll-like receptor agonists for cancer therapy.

    Science.gov (United States)

    Vacchelli, Erika; Eggermont, Alexander; Sautès-Fridman, Catherine; Galon, Jérôme; Zitvogel, Laurence; Kroemer, Guido; Galluzzi, Lorenzo

    2013-08-01

    Toll-like receptors (TLRs) have long been known for their ability to initiate innate immune responses upon exposure to conserved microbial components such as lipopolysaccharide (LPS) and double-stranded RNA. More recently, this family of pattern recognition receptors has been attributed a critical role in the elicitation of anticancer immune responses, raising interest in the development of immunochemotherapeutic regimens based on natural or synthetic TLR agonists. In spite of such an intense wave of preclinical and clinical investigation, only three TLR agonists are currently licensed by FDA for use in cancer patients: bacillus Calmette-Guérin (BCG), an attenuated strain of Mycobacterium bovis that operates as a mixed TLR2/TLR4 agonist; monophosphoryl lipid A (MPL), a derivative of Salmonella minnesota that functions as a potent agonist of TLR4; and imiquimod, a synthetic imidazoquinoline that activates TLR7. One year ago, in the August and September issues of OncoImmunology , we described the main biological features of TLRs and discussed the progress of clinical studies evaluating the safety and therapeutic potential of TLR agonists in cancer patients. Here, we summarize the latest developments in this exciting area of research, focusing on preclinical studies that have been published during the last 13 mo and clinical trials launched in the same period to investigate the antineoplastic activity of TLR agonists.

  8. Exploring the binding energy profiles of full agonists, partial agonists, and antagonists of the α7 nicotinic acetylcholine receptor.

    Science.gov (United States)

    Tabassum, Nargis; Ma, Qianyun; Wu, Guanzhao; Jiang, Tao; Yu, Rilei

    2017-09-01

    Nicotinic acetylcholine receptors (nAChRs) belong to the Cys-loop receptor family and are important drug targets for the treatment of neurological diseases. However, the precise determinants of the binding efficacies of ligands for these receptors are unclear. Therefore, in this study, the binding energy profiles of various ligands (full agonists, partial agonists, and antagonists) were quantified by docking those ligands with structural ensembles of the α7 nAChR exhibiting different degrees of C-loop closure. This approximate treatment of interactions suggested that full agonists, partial agonists, and antagonists of the α7 nAChR possess distinctive binding energy profiles. Results from docking revealed that ligand binding efficacy may be related to the capacity of the ligand to stabilize conformational states with a closed C loop.

  9. The α7 nicotinic ACh receptor agonist compound B and positive allosteric modulator PNU-120596 both alleviate inflammatory hyperalgesia and cytokine release in the rat

    DEFF Research Database (Denmark)

    Munro, G; Hansen, Rikke Rie; Erichsen, Hk

    2012-01-01

    BACKGROUND AND PURPOSE: Agonists selective for the α7 nicotinic acetylcholine (nACh) receptor produce anti-hyperalgesic effects in rodent models of inflammatory pain, via direct actions on spinal pain circuits and possibly via attenuated release of peripheral pro-inflammatory mediators. Increasin......BACKGROUND AND PURPOSE: Agonists selective for the α7 nicotinic acetylcholine (nACh) receptor produce anti-hyperalgesic effects in rodent models of inflammatory pain, via direct actions on spinal pain circuits and possibly via attenuated release of peripheral pro-inflammatory mediators...

  10. Model-Based Discovery of Synthetic Agonists for the Zn2+-Sensing G-Protein-Coupled Receptor 39 (GPR39) Reveals Novel Biological Functions

    DEFF Research Database (Denmark)

    Frimurer, Thomas M.; Mende, Franziska; Graae, Anne-Sofie

    2017-01-01

    binding to other receptors with similar binding pockets to select iterative series of mini-libraries. These libraries were cherry-picked from all com. available synthetic compds. A total of only 520 compds. were tested in vitro, making this method broadly applicable for tool compd. development. The compds....... of the initial library were inactive when tested alone, but lead compds. were identified using Zn2 as an allosteric enhancer. Highly selective, highly potent Zn2-independent GPR39 agonists were found in subsequent mini-libraries. These agonists identified GPR39 as a novel regulator of gastric somatostatin...

  11. The melatonin receptor agonist ramelteon effectively treats insomnia and behavioral symptoms in autistic disorder.

    Science.gov (United States)

    Kawabe, Kentaro; Horiuchi, Fumie; Oka, Yasunori; Ueno, Shu-Ichi

    2014-01-01

    Children with autism spectrum disorders (ASD), including autistic disorder, frequently suffer from comorbid sleep problems. An altered melatonin rhythm is considered to underlie the impairment in sleep onset and maintenance in ASD. We report three cases with autistic disorder in whom nocturnal symptoms improved with ramelteon, a selective melatonin receptor agonist. Insomnia and behavior, assessed using the Clinical Global Impression-Improvement Scale, improved in two cases with 2 mg ramelteon and in the third case with 8 mg ramelteon. Our findings demonstrate that ramelteon is effective not only for insomnia, but for behavioral problems as well, in patients with autistic disorder.

  12. Receptor structure-based discovery of non-metabolite agonists for the succinate receptor GPR91

    DEFF Research Database (Denmark)

    Trauelsen, Mette; Rexen Ulven, Elisabeth; Hjorth, Siv A

    2017-01-01

    therefore binds in a very different mode than generally believed. Importantly, an empty side-pocket is identified next to the succinate binding site. All this information formed the basis for a substructure-based search query, which, combined with molecular docking, was used in virtual screening of the ZINC...... database to pick two serial mini-libraries of a total of only 245 compounds from which sub-micromolar, selective GPR91 agonists of unique structures were identified. The best compounds were backbone-modified succinate analogs in which an amide-linked hydrophobic moiety docked into the side-pocket next...

  13. Agonist discrimination between AMPA receptor subtypes

    DEFF Research Database (Denmark)

    Coquelle, T; Christensen, J K; Banke, T G

    2000-01-01

    The lack of subtype-selective compounds for AMPA receptors (AMPA-R) led us to search for compounds with such selectivity. Homoibotenic acid analogues were investigated at recombinant GluR1o, GluR2o(R), GluR3o and GluR1o + 3o receptors expressed in Sf9 insect cells and affinities determined in [3H...

  14. GABAA receptor partial agonists and antagonists

    DEFF Research Database (Denmark)

    Krall, Jacob; Balle, Thomas; Krogsgaard-Larsen, Niels

    2015-01-01

    to the local temporal pattern of GABA impact, enabling phasic or tonic inhibition. Specific GABAAR antagonists are essential tools for physiological and pharmacological elucidation of the different type of GABAAR inhibition. However, distinct selectivity among the receptor subtypes (populations) has been shown...... antagonists have been essential in defining the tonic current but both remaining issues concerning the GABAARs involved and the therapeutic possibilities of modulating tonic inhibition underline the need for GABAAR antagonists with improved selectivity....

  15. Correlation of stable elevations in striatal mu-opioid receptor availability in detoxified alcoholic patients with alcohol craving: a positron emission tomography study using carbon 11-labeled carfentanil.

    Science.gov (United States)

    Heinz, Andreas; Reimold, Matthias; Wrase, Jana; Hermann, Derik; Croissant, Bernhard; Mundle, Götz; Dohmen, Bernhard M; Braus, Dieter F; Braus, Dieter H; Schumann, Gunter; Machulla, Hans-Jürgen; Bares, Roland; Mann, Karl

    2005-01-01

    The pleasant effects of food and alcohol intake are partially mediated by mu-opiate receptors in the ventral striatum, a central area of the brain reward system. Blockade of mu-opiate receptors with naltrexone reduces the relapse risk among some but not all alcoholic individuals. To test the hypothesis that alcohol craving is pronounced among alcoholic individuals with a high availability of mu-opiate receptors in the brain reward system. Patients and comparison sample. The availability of central mu-opiate receptors was measured in vivo with positron emission tomography (PET) and the radioligand carbon 11-labeled carfentanil in the ventral striatum and compared with the severity of alcohol craving as assessed by the Obsessive Compulsive Drinking Scale (OCDS). Hospitalized care. Volunteer sample of 25 male alcohol-dependent inpatients assessed after detoxification of whom 12 underwent PET again 5 weeks later. Control group of 10 healthy men. After 1 to 3 weeks of abstinence, the availability of mu-opiate receptors in the ventral striatum, including the nucleus accumbens, was significantly elevated in alcoholic patients compared with healthy controls and remained elevated when 12 alcoholic patients had these levels measured 5 weeks later (P<.05 corrected for multiple testing). Higher availability of mu-opiate receptors in this brain area correlated significantly with the intensity of alcohol craving as assessed by the OCDS. Abstinent alcoholic patients displayed an increase in mu-opiate receptors in the ventral striatum, including the nucleus accumbens, which correlated with the severity of alcohol craving. These findings point to a neuronal correlate of alcohol urges.

  16. Studies of the Mu-Opioid Receptor/G-protein Complex Affinity Co-Purified and Membrane Preparations from 7315c Cells

    Science.gov (United States)

    1989-06-09

    drugs. This assay was terminated by glass fiber rapid filtration as described above. Phospholipid Vesicle Formation and Reconstituted Ligand Binding...m 1!:~1!: COCO CD ~~~ ...... I I I a o a .......... 0 a ... 0 ~ ɛ 0 = = = 00 co .. N a a a a . .. . ~ (wnwJiitw %) 9MIONI8

  17. Dual growth of adolescent smoking and drinking: Evidence for an interaction between the mu-opioid receptor (OPRM1) A118G polymorphism and sex

    NARCIS (Netherlands)

    Kleinjan, M.; Poelen, E.A.P.; Engels, R.C.M.E.; Verhagen, M.

    2013-01-01

    Smoking and alcohol use often co-occur during adolescence, but little is known about the codevelopment of these substances. In the search for etiological factors that help to explain the development of adolescent substance use patterns, studies have revealed substantial heritability for both alcohol

  18. (S)-homo-AMPA, a specific agonist at the mGlu6 subtype of metabotropic glutamic acid receptors

    DEFF Research Database (Denmark)

    Ahmadian, H; Nielsen, B; Bräuner-Osborne, Hans

    1997-01-01

    of the spectroscopic configurational assignments. The activities of 6 and 7 at ionotropic EAA (iGlu) receptors and at mGlu1-7 were studied. (S)-Homo-AMPA (6) was shown to be a specific agonist at mGlu6 (EC50 = 58 +/- 11 microM) comparable in potency with the endogenous mGlu agonist (S)-glutamic acid (EC50 = 20 +/- 3......Our previous publication (J. Med. Chem. 1996, 39, 3188-3194) described (RS)-2-amino-4-(3-hydroxy-5-methylisoxazol-4-yl)butyric acid (Homo-AMPA) as a highly selective agonist at the mGlu6 subtype of metabotropic excitatory amino acid (EAA) receptors. Homo-AMPA has already become a standard agonist...... microM). Although Homo-AMPA did not show significant effects at iGlu receptors, (R)-Homo-AMPA (7), which was inactive at mGlu1-7, turned out to be a weak N-methyl-D-aspartic acid (NMDA) receptor antagonist (IC50 = 131 +/- 18 microM)....

  19. A preliminary PET evaluation of the new dopamine D2 receptor agonist [11C]MNPA in cynomolgus monkey

    International Nuclear Information System (INIS)

    Finnema, Sjoerd J.; Seneca, Nicholas; Farde, Lars; Shchukin, Evgeny; Sovago, Judit; Gulyas, Balazs; Wikstroem, Hakan V.; Innis, Robert B.; Neumeyer, John L.; Halldin, Christer

    2005-01-01

    This study describes the preliminary positron emission tomography (PET) evaluation of a dopamine D 2 -like receptor agonist (R)-2- 11 CH 3 O-N-n-propylnorapomorphine ([ 11 C]MNPA), as a potential new radioligand for in vivo imaging of the high-affinity state of the dopamine D 2 receptor (D 2 R). MNPA is a selective D 2 -like receptor agonist with a high affinity (K i =0.17 nM). [ 11 C]MNPA was successfully synthesized by direct O-methylation of (R)-2-hydroxy-NPA using [ 11 C]methyl iodide and was evaluated in cynomolgus monkeys. This study included baseline PET experiments and a pretreatment study using unlabeled raclopride (1 mg/kg). High uptake of radioactivity was seen in regions known to contain high D 2 R, with a maximum striatum-to-cerebellum ratio of 2.23±0.21 at 78 min and a maximum thalamus-to-cerebellum ratio of 1.37±0.06 at 72 min. The pretreatment study demonstrated high specific binding to D 2 R by reducing the striatum-to-cerebellum ratio to 1.26 at 78 min. This preliminary study indicates that the dopamine agonist [ 11 C]MNPA has potential as an agonist radioligand for the D 2 -like receptor and has potential for examination of the high-affinity state of the D 2 R in human subjects and patients with neuropsychiatric disorders

  20. Discovery and cardioprotective effects of the first non-Peptide agonists of the G protein-coupled prokineticin receptor-1.

    Directory of Open Access Journals (Sweden)

    Adeline Gasser

    Full Text Available Prokineticins are angiogenic hormones that activate two G protein-coupled receptors: PKR1 and PKR2. PKR1 has emerged as a critical mediator of cardiovascular homeostasis and cardioprotection. Identification of non-peptide PKR1 agonists that contribute to myocardial repair and collateral vessel growth hold promises for treatment of heart diseases. Through a combination of in silico studies, medicinal chemistry, and pharmacological profiling approaches, we designed, synthesized, and characterized the first PKR1 agonists, demonstrating their cardioprotective activity against myocardial infarction (MI in mice. Based on high throughput docking protocol, 250,000 compounds were computationally screened for putative PKR1 agonistic activity, using a homology model, and 10 virtual hits were pharmacologically evaluated. One hit internalizes PKR1, increases calcium release and activates ERK and Akt kinases. Among the 30 derivatives of the hit compound, the most potent derivative, IS20, was confirmed for its selectivity and specificity through genetic gain- and loss-of-function of PKR1. Importantly, IS20 prevented cardiac lesion formation and improved cardiac function after MI in mice, promoting proliferation of cardiac progenitor cells and neovasculogenesis. The preclinical investigation of the first PKR1 agonists provides a novel approach to promote cardiac neovasculogenesis after MI.

  1. Unique interaction pattern for a functionally biased ghrelin receptor agonist

    DEFF Research Database (Denmark)

    Sivertsen, Bjørn Behrens; Lang, Manja; Frimurer, Thomas M.

    2011-01-01

    Based on the conformationally constrained D-Trp-Phe-D-Trp (wFw) core of the prototype inverse agonist [D-Arg(1),D-Phe(5),D-Trp(7,9),Leu(11)]substance P, a series of novel, small, peptide-mimetic agonists for the ghrelin receptor were generated. By using various simple, ring-constrained spacers...... connecting the D-Trp-Phe-D-Trp motif with the important C-terminal carboxyamide group, 40 nm agonism potency was obtained and also in one case (wFw-Isn-NH(2), where Isn is isonipecotic acid) ~80% efficacy. However, in contrast to all previously reported ghrelin receptor agonists, the piperidine-constrained w......Fw-Isn-NH(2) was found to be a functionally biased agonist. Thus, wFw-Isn-NH(2) mediated potent and efficacious signaling through the Ga(q) and ERK1/2 signaling pathways, but in contrast to all previous ghrelin receptor agonists it did not signal through the serum response element, conceivably the Ga(12...

  2. Modification of opiate agonist binding by pertussis toxin

    Energy Technology Data Exchange (ETDEWEB)

    Abood, M.E.; Lee, N.M.; Loh, H.H.

    1986-03-05

    Opiate agonist binding is decreased by GTP, suggesting the possible involvement of GTP binding proteins in regulation of opiate receptor binding. This possibility was addressed by asking whether pertussis toxin treatment, which results in ADP-ribosylation and modification of G proteins, would alter opiate agonist binding. The striatum was chosen for the initial brain area to be studied, since regulation of opiate action in this area had been shown to be modified by pertussis toxin. Treatment of striatal membranes with pertussis toxin results in up to a 55% decrease in /sup 3/(H)-DADLE binding as compared with membranes treated identically without toxin. This corresponds to a near complete ADP-ribosylation of both G proteins in the striatal membrane. The decrease in agonist binding appears to be due to an altered affinity of the receptor for agonist as opposed to a decrease in the number of sites. This effect of pertussis toxin on opiate agonist binding demonstrates the actual involvement of G proteins in regulation of opiate receptor binding.

  3. Modification of opiate agonist binding by pertussis toxin

    International Nuclear Information System (INIS)

    Abood, M.E.; Lee, N.M.; Loh, H.H.

    1986-01-01

    Opiate agonist binding is decreased by GTP, suggesting the possible involvement of GTP binding proteins in regulation of opiate receptor binding. This possibility was addressed by asking whether pertussis toxin treatment, which results in ADP-ribosylation and modification of G proteins, would alter opiate agonist binding. The striatum was chosen for the initial brain area to be studied, since regulation of opiate action in this area had been shown to be modified by pertussis toxin. Treatment of striatal membranes with pertussis toxin results in up to a 55% decrease in 3 (H)-DADLE binding as compared with membranes treated identically without toxin. This corresponds to a near complete ADP-ribosylation of both G proteins in the striatal membrane. The decrease in agonist binding appears to be due to an altered affinity of the receptor for agonist as opposed to a decrease in the number of sites. This effect of pertussis toxin on opiate agonist binding demonstrates the actual involvement of G proteins in regulation of opiate receptor binding

  4. Preventing or attenuating amphotericin B nephrotoxicity with dopamine receptor agonists: a literature review

    Directory of Open Access Journals (Sweden)

    Iman Karimzadeh

    2016-09-01

    Full Text Available Nephrotoxicity is generally considered as the most clinically significant and dose-limiting adverse reaction of amphotericin B. Currently, only the clinical effectiveness of salt loading and administering lipid formulations of amphotericin B have been clearly demonstrated to prevent its nephrotoxicity. In this review, we collected the published data related to dopamine receptor agonists in preventing amphotericin B nephrotoxicity. A literature search was conducted by the relevant keywords like ‘‘amphotericin B”, “nephrotoxicity’’, and ‘‘dopamine’’in databases such as Scopus, Medline, Embase and ISI Web of Knowledge. Four relevant articles were considered. Results of all the 3 experimental studies demonstrated that co-administration of dopamine (0.5-10 μg/kg/min as continuous intravenous infusion, SK&F R-105058, a prodrug of fenoldopam (10 mg/kg twice daily, orally or fenoldopam, a relatively selective dopamine receptor type 1 agonist, (0.5 or 1 μg/kg/min as continuous intravenous infusion can at least significantly mitigate the decrease in creatinine clearance caused by amphotericin B. Furthermore, fenoldopam and SK&F R-105058 can also protect against or delay amphotericin B-induced tubular damage. In contrast, the only clinical trial published until now found that simultaneous continuous intravenous infusion of low dose dopamine (3 μg/kg/min had no beneficial effect on the incidence, severity and time onset of developing amphotericin B-induced nephrotoxicity in autologous bone marrow transplant and leukemia patients. Considering the lack of beneficial effects in different settings such as acute kidney injury of any cause, negative results of the only clinical trial, and risk of significant adverse reactions, continuous intravenous infusion of low dose dopamine (1-3 μg/kg/min or selective dopamine receptor type 1 agonists (e.g., fenoldopam currently appears to have no promising clinical role in preventing or attenuating

  5. Reduction in lipophilicity improved the solubility, plasma–protein binding, and permeability of tertiary sulfonamide RORc inverse agonists

    Energy Technology Data Exchange (ETDEWEB)

    Fauber, Benjamin P.; René, Olivier; de Leon Boenig, Gladys; Burton, Brenda; Deng, Yuzhong; Eidenschenk, Céline; Everett, Christine; Gobbi, Alberto; Hymowitz, Sarah G.; Johnson, Adam R.; La, Hank; Liimatta, Marya; Lockey, Peter; Norman, Maxine; Ouyang, Wenjun; Wang, Weiru; Wong, Harvey (Genentech); (Argenta)

    2014-08-01

    Using structure-based drug design principles, we identified opportunities to reduce the lipophilicity of our tertiary sulfonamide RORc inverse agonists. The new analogs possessed improved RORc cellular potencies with >77-fold selectivity for RORc over other nuclear receptors in our cell assay suite. The reduction in lipophilicity also led to an increased plasma–protein unbound fraction and improvements in cellular permeability and aqueous solubility.

  6. Reduced suppression of CO2-induced ventilatory stimulation by endomorphins relative to morphine.

    Science.gov (United States)

    Czapla, Marc A; Zadina, James E

    2005-10-19

    Opioids are among the most effective analgesics, but a major limitation for their therapeutic usefulness is their induction of respiratory depression. Endomorphin-1 (EM1), in contrast to several other mu opioids, exhibits a threshold for respiratory depression that is well above its threshold for analgesia. Its effect on sensitivity to CO(2), however, remains unknown. Minute ventilation (V(E)) in 2, 4, and 6% CO(2) was measured before and after systemic administration of EM1, endomorphin-2 (EM2), DAMGO, and morphine in the conscious rat. EM1 and EM2 attenuated the hypercapnic ventilatory response (HCVR) only in high doses, while DAMGO and morphine diminished the HCVR in much lower doses. The ventilatory effects of high doses of all 4 agonists were blocked by the mu-opioid antagonist naloxone (0.4 mg/kg i.v.), but not by the peripherally restricted mu-opioid antagonist, methyl-naloxone (0.4 mg/kg i.v.). It was concluded that the endomorphins attenuated the HCVR only in large doses, well beyond the analgesic threshold, and did so through a centrally mediated mu-opioid mechanism.

  7. Unique in vitro and in vivo thrombopoietic activities of ingenol 3,20 dibenzoate, a Ca(++-independent protein kinase C isoform agonist.

    Directory of Open Access Journals (Sweden)

    Frederick K Racke

    Full Text Available Thrombopoiesis following severe bone marrow injury frequently is delayed, thereby resulting in life-threatening thrombocytopenia for which there are limited treatment options. The reasons for these delays in recovery are not well understood. Protein kinase C (PKC agonists promote megakaryocyte differentiation in leukemia cell lines and primary cells. However, little is known about the megakaryopoietic effects of PKC agonists on primary CD34+ cells grown in culture or in vivo. Here we present evidence that the novel PKC isoform-selective agonist 3,20 ingenol dibenzoate (IDB potently stimulates early megakaryopoiesis of human CD34+ cells. In contrast, broad spectrum PKC agonists failed to do so. In vivo, a single intraperitoneal injection of IDB selectively increased platelets in mice without affecting hemoglobin or white counts. Finally, IDB strongly mitigated radiation-induced thrombocytopenia, even when administered 24 hours after irradiation. Our data demonstrate that novel PKC isoform agonists such as IDB may represent a unique therapeutic strategy for accelerating the recovery of platelet counts following severe marrow injury.

  8. Principles of agonist recognition in Cys-loop receptors

    Directory of Open Access Journals (Sweden)

    Timothy eLynagh

    2014-04-01

    Full Text Available Cys-loop receptors are ligand-gated ion channels that are activated by a structurally diverse array of neurotransmitters, including acetylcholine, serotonin, glycine and GABA. After the term chemoreceptor emerged over 100 years ago, there was some wait until affinity labeling, molecular cloning, functional studies and X-ray crystallography experiments identified the extracellular interface of adjacent subunits as the principal site of agonist binding. The question of how subtle differences at and around agonist-binding sites of different Cys-loop receptors can accommodate transmitters as chemically diverse as glycine and serotonin has been subject to intense research over the last three decades. This review outlines the functional diversity and current structural understanding of agonist-binding sites, including those of invertebrate Cys-loop receptors. Together, this provides a framework to understand the atomic determinants involved in how these valuable therapeutic targets recognize and bind their ligands.

  9. In silico discovery of novel Retinoic Acid Receptor agonist structures

    Directory of Open Access Journals (Sweden)

    Samuels Herbert H

    2001-06-01

    Full Text Available Abstract Background Several Retinoic Acid Receptors (RAR agonists have therapeutic activity against a variety of cancer types; however, unacceptable toxicity profiles have hindered the development of drugs. RAR agonists presenting novel structural and chemical features could therefore open new avenues for the discovery of leads against breast, lung and prostate cancer or leukemia. Results We have analysed the induced fit of the active site residues upon binding of a known ligand. The derived binding site models were used to dock over 150,000 molecules in silico (or virtually to the structure of the receptor with the Internal Coordinates Mechanics (ICM program. Thirty ligand candidates were tested in vitro. Conclusions Two novel agonists resulting from the predicted receptor model were active at 50 nM. One of them displays novel structural features which may translate into the development of new ligands for cancer therapy.

  10. Long-acting β2-agonists in asthma

    DEFF Research Database (Denmark)

    Jacobson, Glenn A; Raidal, Sharanne; Hostrup, Morten

    2018-01-01

    Long-acting β2-agonists (LABAs) such as formoterol and salmeterol are used for prolonged bronchodilatation in asthma, usually in combination with inhaled corticosteroids (ICSs). Unexplained paradoxical asthma exacerbations and deaths have been associated with LABAs, particularly when used without...... and effects on BHR, particularly that (S)-enantiomers of β2-agonists may be deleterious to asthma control. LABAs display enantioselective pharmacokinetics and pharmacodynamics. Biological plausibility of the deleterious effects of β2-agonists (S)-enantiomers is provided by in vitro and in vivo studies from...... mechanism in rapid asthma deaths. More effort should therefore be applied to investigating potential enantiospecific effects of LABAs on safety, specifically bronchoprotection. Safety studies directly assessing the effects of LABA (S)-enantiomers on BHR are long overdue....

  11. [Effects of GLP-1 receptor agonists on carbohydrate metabolism control].

    Science.gov (United States)

    Fernández-García, José Carlos; Colomo, Natalia; Tinahones, Francisco José

    2014-09-01

    Glucagon-like peptide-1 (GLP-1) receptor agonists are a new group of drugs for the treatment of type 2 diabetes mellitus (DM2). In the present article, we review the available evidence on the efficacy of GLP-1 receptor agonists as glucose-lowering agents, their place in therapeutic algorithms, and the clinical factors associated with a favorable treatment response. Finally, we describe the clinical characteristics of patients who may benefit from these drugs. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

  12. Investigation of the mechanism of radioprotective action of adrenoceptor agonists

    International Nuclear Information System (INIS)

    Kulinskij, V.I.; Klimova, A.D.; Yashunskij, V.G.; Alpatova, T.V.; 4205700SU)

    1986-01-01

    α-Adrenoceptor agonists of both main groups, i.e. arylalkylamines and imidazolines, have a pronounced radioprotective effect. Their chemical analogs, which fail to stimulate α-adrenoceptors, do not protect mice. The effect of phenylephrine, adrenaline, and noradrenaline comes into play via α 1 -adrenoceptors and that of clonidine, via α 2 -adrenoceptors and also via α 1 -adrenoceptors. Adrenoceptor agonists can probably manifest their radioprotective action via both subtypes of α-adrenoceptors. Possible intracellular mechanisms of the radioprotective action are discussed

  13. Diindolylmethane Derivatives: Potent Agonists of the Immunostimulatory Orphan G Protein-Coupled Receptor GPR84.

    Science.gov (United States)

    Pillaiyar, Thanigaimalai; Köse, Meryem; Sylvester, Katharina; Weighardt, Heike; Thimm, Dominik; Borges, Gleice; Förster, Irmgard; von Kügelgen, Ivar; Müller, Christa E

    2017-05-11

    The G i protein-coupled receptor GPR84, which is activated by (hydroxy)fatty acids, is highly expressed on immune cells. Recently, 3,3'-diindolylmethane was identified as a heterocyclic, nonlipid-like GPR84 agonist. We synthesized a broad range of diindolylmethane derivatives by condensation of indoles with formaldehyde in water under microwave irradiation. The products were evaluated at the human GPR84 in cAMP and β-arrestin assays. Structure-activity relationships (SARs) were steep. 3,3'-Diindolylmethanes bearing small lipophilic residues at the 5- and/or 7-position of the indole rings displayed the highest activity in cAMP assays, the most potent agonists being di(5-fluoro-1H-indole-3-yl)methane (38, PSB-15160, EC 50 80.0 nM) and di(5,7-difluoro-1H-indole-3-yl)methane (57, PSB-16671, EC 50 41.3 nM). In β-arrestin assays, SARs were different, indicating biased agonism. The new compounds were selective versus related fatty acid receptors and the arylhydrocarbon receptor. Selected compounds were further investigated and found to display an ago-allosteric mechanism of action and increased stability in comparison to the lead structure.

  14. Synthesis and SAR studies of benzyl ether derivatives as potent orally active S1P₁ agonists.

    Science.gov (United States)

    Tsuji, Takashi; Suzuki, Keisuke; Nakamura, Tsuyoshi; Goto, Taiji; Sekiguchi, Yukiko; Ikeda, Takuya; Fukuda, Takeshi; Takemoto, Toshiyasu; Mizuno, Yumiko; Kimura, Takako; Kawase, Yumi; Nara, Futoshi; Kagari, Takashi; Shimozato, Takaichi; Yahara, Chizuko; Inaba, Shinichi; Honda, Tomohiro; Izumi, Takashi; Tamura, Masakazu; Nishi, Takahide

    2014-08-01

    We report herein the synthesis and structure-activity relationships (SAR) of a series of benzyl ether compounds as an S1P₁ receptor modulator. From our SAR studies, the installation of substituents onto the central benzene ring of 2a was revealed to potently influence the S1P₁ and S1P₃ agonistic activities, in particular, an ethyl group on the 2-position afforded satisfactory S1P₁/S1P₃ selectivity. These changes of the S1P₁ and S1P₃ agonistic activities caused by the alteration of substituents on the 2-position were reasonably explained by a docking study using an S1P₁ X-ray crystal structure and S1P₃ homology modeling. We found that compounds 2b and 2e had a potent in vivo immunosuppressive efficacy along with acceptable S1P₁/S1P₃ selectivity, and confirmed that these compounds had less in vivo bradycardia risk through the evaluation of heart rate change after oral administration of the compounds (30 mg/kg, p.o.) in rats. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Palovarotene, a novel retinoic acid receptor gamma agonist for the treatment of emphysema.

    Science.gov (United States)

    Hind, Matthew; Stinchcombe, Sian

    2009-11-01

    Emphysema is characterized by the destruction of alveoli and alveolar ducts within the lungs. Retinoid signaling is believed to play a role in alveologenesis, with the retinoic acid receptor gamma thought to be required for alveolar formation. Based on this hypothesis, Roche Holding AG is developing palovarotene (R-667, RO-3300074), a selective retinoic acid receptor gamma agonist for the treatment of emphysema. In small animal studies, palovarotene was claimed to reverse the structural, functional and inflammatory features of cigarette smoke-induced emphysema. Phase I clinical trials of palovarotene in patients with emphysema demonstrated that the drug is well tolerated, with improvements observed in markers of emphysema progression. Unlike all-trans retinoic acid, the pharmacokinetic profile of palovarotene appears to be dose-proportional. At the time of publication, a phase II, placebo-controlled trial was ongoing, and was expected to report prospective measurements of exercise, gas transfer and lung densitometry endpoints. The development of a selective retinoic acid receptor gamma agonist for the treatment of emphysema represents the first of a new class of small-molecule regenerative therapies that may prove useful for the treatment of destructive or age-related lung disease.

  16. Blockade of alcohol's amnestic activity in humans by an alpha5 subtype benzodiazepine receptor inverse agonist.

    Science.gov (United States)

    Nutt, David J; Besson, Marie; Wilson, Susan J; Dawson, Gerard R; Lingford-Hughes, Anne R

    2007-12-01

    Alcohol produces many subjective and objective effects in man including pleasure, sedation, anxiolysis, plus impaired eye movements and memory. In human volunteers we have used a newly available GABA-A/benzodiazepine receptor inverse agonist that is selective for the alpha5 subtype (a5IA) to evaluate the role of this subtype in mediating these effects of alcohol on the brain. After pre-treatment with a5IA, we found almost complete blockade of the marked impairment caused by alcohol (mean breath concentration 150mg/100ml) of word list learning and partial but non-significant reversal of subjective sedation without effects on other measures such as intoxication, liking, and slowing of eye movements. This action was not due to alterations in alcohol kinetics and so provides the first proof of concept that selectively decreasing GABA-A receptor function at a specific receptor subtype can offset some actions of alcohol in humans. It also supports growing evidence for a key role of the alpha5 subtype in memory. Inverse agonists at other GABA-A receptor subtypes may prove able to reverse other actions of alcohol, and so offer a new approach to understanding the actions of alcohol in the human brain and in the treatment of alcohol related disorders in humans.

  17. TRANSDERMAL ADMINISTRATION OF THE DOPAMINE AGONIST N-0437 AND 7 ESTER PRODRUGS - COMPARISON WITH ORAL-ADMINISTRATION IN THE 6-OHDA TURNING MODEL

    NARCIS (Netherlands)

    DENDAAS, [No Value; TEPPER, PG; ROLLEMA, H; HORN, AS

    1990-01-01

    The potent and selective D2-agonist N-0437 [2-(N-propyl-N-2-thienylethylamino)-5-hydroxytetralin] undergoes considerable first-pass metabolism after oral administration due to glucuronidation of the phenolic group. In an attempt to improve its bioavailability, seven ester prodrugs of N-0437 were

  18. Identification of transcriptional biomarkers by RNA-sequencing for improved detection of β2-agonists abuse in goat skeletal muscle.

    Directory of Open Access Journals (Sweden)

    Luyao Zhao

    Full Text Available In this paper, high-throughput RNA-sequencing (RNA-seq was used to search for transcriptional biomarkers for β2-agonists. In combination with drug mechanisms, a smaller group of genes with higher detection accuracy was screened out. Unknown samples were first predicted by this group of genes, and liquid chromatograph tandem mass spectrometer (LC-MS/MS was applied to positive samples to validate the biomarkers. The results of principal component analysis (PCA, hierarchical cluster analysis (HCA and discriminant analysis (DA indicated that the eight genes screened by high-throughput RNA-seq were able to distinguish samples in the experimental group and control group. Compared with the nine genes selected from an earlier literature, 17 genes including these nine genes were proven to have a more satisfactory effect, which validated the accuracy of gene selection by RNA-seq. Then, six key genes were selected from the 17 genes according to the variable importance in projection (VIP value of greater than 1. The test results using the six genes and 17 genes were similar, revealing that the six genes were critical genes. By using the six genes, three positive samples possibly treated with drugs were screened out from 25 unknown samples through DA and partial least squares discriminant analysis (PLS-DA. Then, the three samples were verified by a standard method, and mapenterol was detected in a sample. Therefore, the six genes can be used as biomarkers to detect β2-agonists. Compared with the previous study, accurate detection of β2-agonists abuse using six key genes is an improvement method, which show great significance in the monitoring of β2-agonists abuse in animal husbandry.

  19. Neonatal co-lesion by DSP-4 and 5,7-DHT produces adulthood behavioral sensitization to dopamine D(2) receptor agonists.

    Science.gov (United States)

    Nowak, Przemysław; Nitka, Dariusz; Kwieciński, Adam; Jośko, Jadwiga; Drab, Jacek; Pojda-Wilczek, Dorota; Kasperski, Jacek; Kostrzewa, Richard M; Brus, Ryszard

    2009-01-01

    To assess the possible modulatory effects of noradrenergic and serotoninergic neurons on dopaminergic neuronal activity, the noradrenergic and serotoninergic neurotoxins DSP-4 N-(2-chlorethyl)-N-ethyl-2-bromobenzylamine (50.0 mg/kg, sc) and 5,7-dihydroxytryptamine (5,7-DHT) (37.5 microg icv, half in each lateral ventricle), respectively, were administered toWistar rats on the first and third days of postnatal ontogeny, and dopamine (DA) agonist-induced behaviors were assessed in adulthood. At eight weeks, using an HPLC/ED technique, DSP-4 treatment was associated with a reduction in NE content of the corpus striatum (> 60%), hippocampus (95%), and frontal cortex (> 85%), while 5,7-DHT was associated with an 80-90% serotonin reduction in the same brain regions. DA content was unaltered in the striatum and the cortex. In the group lesioned with both DSP-4 and 5,7-DHT, quinpirole-induced (DA D(2) agonist) yawning, 7-hydroxy-DPAT-induced (DA D(3) agonist) yawning, and apomorphine-induced (non-selective DA agonist) stereotypies were enhanced. However, SKF 38393-induced (DA D(1) agonist) oral activity was reduced in the DSP-4 + 5,7-DHT group. These findings demonstrate that DA D(2)- and D(3)-agonist-induced behaviors are enhanced while DA D(1)-agonist-induced behaviors are suppressed in adult rats in which brain noradrenergic and serotoninergic innervation of the brain has largely been destroyed. This study indicates that noradrenergic and serotoninergic neurons have a great impact on the development of DA receptor reactivity (sensitivity).

  20. Thrombopoietin-receptor agonists in haematological disorders: The Danish experience

    DEFF Research Database (Denmark)

    Gudbrandsdottir, Sif; Frederiksen, Henrik; Hasselbalch, Hans

    2011-01-01

    The objective of this study was to investigate the use of thrombopoietin-receptor agonists (TPO-ra) in patients with refractory primary immune thrombocytopenia (ITP) as well as off-label use of TPO-ra in Danish haematology departments. Hospital medical records from 32 of the 39 patients having re...

  1. Use of ß-adrenergic agonists in hybrid catfish

    Science.gov (United States)

    Ractopamine hydrochloride (RH) is a potent ß-adrenergic agonist that has been used in some species of fish to improve growth performance and dress out characteristics. While this metabolic modifier has been shown to have positive effects on growth of fish, little research has focused on the mechani...

  2. Free Fatty Acid Receptor 1 (FFA1/GPR40) Agonists

    DEFF Research Database (Denmark)

    Christiansen, Elisabeth; Due-Hansen, Maria E; Urban, Christian

    2012-01-01

    FFA1 (GPR40) is a new target for treatment of type 2 diabetes. We recently identified the potent FFA1 agonist TUG-469 (5). Inspired by the structurally related TAK-875, we explored the effects of a mesylpropoxy appendage on 5. The appendage significantly lowers lipophilicity and improves metaboli...

  3. Inhalation by design: novel ultra-long-acting β(2)-adrenoreceptor agonists for inhaled once-daily treatment of asthma and chronic obstructive pulmonary disease that utilize a sulfonamide agonist headgroup.

    Science.gov (United States)

    Glossop, Paul A; Lane, Charlotte A L; Price, David A; Bunnage, Mark E; Lewthwaite, Russell A; James, Kim; Brown, Alan D; Yeadon, Michael; Perros-Huguet, Christelle; Trevethick, Michael A; Clarke, Nicholas P; Webster, Robert; Jones, Rhys M; Burrows, Jane L; Feeder, Neil; Taylor, Stefan C J; Spence, Fiona J

    2010-09-23

    A novel series of potent and selective sulfonamide derived β(2)-adrenoreceptor agonists are described that exhibit potential as inhaled ultra-long-acting bronchodilators for the treatment of asthma and chronic obstructive pulmonary disease. Analogues from this series mediate very long-lasting smooth muscle relaxation in guinea pig tracheal strips. The sulfonamide agonist headgroup confers high levels of intrinsic crystallinity that could relate to the acidic sulfonamide motif supporting a zwitterionic form in the solid state. Optimization of pharmacokinetic properties was achieved through targeted introduction of a phenolic moiety to support rapid phase II clearance, thereby minimizing systemic exposure following inhalation and reducing systemically mediated adverse events. Compound 38 (PF-610355) is identified as a clinical candidate from this series, with in vivo duration of action studies confirming its potential for once-daily use in humans. Compound 38 is currently in advanced phase II clinical studies.

  4. Dopamine agonists and risk: impulse control disorders in Parkinson's disease.

    Science.gov (United States)

    Voon, Valerie; Gao, Jennifer; Brezing, Christina; Symmonds, Mkael; Ekanayake, Vindhya; Fernandez, Hubert; Dolan, Raymond J; Hallett, Mark

    2011-05-01

    Impulse control disorders are common in Parkinson's disease, occurring in 13.6% of patients. Using a pharmacological manipulation and a novel risk taking task while performing functional magnetic resonance imaging, we investigated the relationship between dopamine agonists and risk taking in patients with Parkinson's disease with and without impulse control disorders. During functional magnetic resonance imaging, subjects chose between two choices of equal expected value: a 'Sure' choice and a 'Gamble' choice of moderate risk. To commence each trial, in the 'Gain' condition, individuals started at $0 and in the 'Loss' condition individuals started at -$50 below the 'Sure' amount. The difference between the maximum and minimum outcomes from each gamble (i.e. range) was used as an index of risk ('Gamble Risk'). Sixteen healthy volunteers were behaviourally tested. Fourteen impulse control disorder (problem gambling or compulsive shopping) and 14 matched Parkinson's disease controls were tested ON and OFF dopamine agonists. Patients with impulse control disorder made more risky choices in the 'Gain' relative to the 'Loss' condition along with decreased orbitofrontal cortex and anterior cingulate activity, with the opposite observed in Parkinson's disease controls. In patients with impulse control disorder, dopamine agonists were associated with enhanced sensitivity to risk along with decreased ventral striatal activity again with the opposite in Parkinson's disease controls. Patients with impulse control disorder appear to have a bias towards risky choices independent of the effect of loss aversion. Dopamine agonists enhance sensitivity to risk in patients with impulse control disorder possibly by impairing risk evaluation in the striatum. Our results provide a potential explanation of why dopamine agonists may lead to an unconscious bias towards risk in susceptible individuals.

  5. Effect of beta-agonists on LAM progression and treatment.

    Science.gov (United States)

    Le, Kang; Steagall, Wendy K; Stylianou, Mario; Pacheco-Rodriguez, Gustavo; Darling, Thomas N; Vaughan, Martha; Moss, Joel

    2018-01-30

    Lymphangioleiomyomatosis (LAM), a rare disease of women, is associated with cystic lung destruction resulting from the proliferation of abnormal smooth muscle-like LAM cells with mutations in the tuberous sclerosis complex (TSC) genes TSC1 and/or TSC2 The mutant genes and encoded proteins are responsible for activation of the mechanistic target of rapamycin (mTOR), which is inhibited by sirolimus (rapamycin), a drug used to treat LAM. Patients who have LAM may also be treated with bronchodilators for asthma-like symptoms due to LAM. We observed stabilization of forced expiratory volume in 1 s over time in patients receiving sirolimus and long-acting beta-agonists with short-acting rescue inhalers compared with patients receiving only sirolimus. Because beta-agonists increase cAMP and PKA activity, we investigated effects of PKA activation on the mTOR pathway. Human skin TSC2 +/- fibroblasts or LAM lung cells incubated short-term with isoproterenol (beta-agonist) showed a sirolimus-independent increase in phosphorylation of S6, a downstream effector of the mTOR pathway, and increased cell growth. Cells incubated long-term with isoproterenol, which may lead to beta-adrenergic receptor desensitization, did not show increased S6 phosphorylation. Inhibition of PKA blocked the isoproterenol effect on S6 phosphorylation. Thus, activation of PKA by beta-agonists increased phospho-S6 independent of mTOR, an effect abrogated by beta-agonist-driven receptor desensitization. In agreement, retrospective clinical data from patients with LAM suggested that a combination of bronchodilators in conjunction with sirolimus may be preferable to sirolimus alone for stabilization of pulmonary function.

  6. Rational screening of peroxisome proliferator-activated receptor-γ agonists from natural products: potential therapeutics for heart failure.

    Science.gov (United States)

    Chen, Rui; Wan, Jing; Song, Jing; Qian, Yan; Liu, Yong; Gu, Shuiming

    2017-12-01

    Peroxisome proliferator-activated receptor-γ (PPARγ) is a member of the nuclear hormone receptor superfamily of ligand-activated transcription factors. Activation of PPARγ pathway has been shown to enhance fatty acid oxidation, improve endothelial cell function, and decrease myocardial fibrosis in heart failure. Thus, the protein has been raised as an attractive target for heart failure therapy. This work attempted to discover new and potent PPARγ agonists from natural products using a synthetic strategy of computer virtual screening and transactivation reporter assay. A large library of structurally diverse, drug-like natural products was compiled, from which those with unsatisfactory pharmacokinetic profile and/or structurally redundant compounds were excluded. The binding mode of remaining candidates to PPARγ ligand-binding domain (LBD) was computationally modelled using molecular docking and their relative binding potency was ranked by an empirical scoring scheme. Consequently, eight commercially available hits with top scores were selected and their biological activity was determined using a cell-based reporter-gene assay. Four natural product compounds, namely ZINC13408172, ZINC4292805, ZINC44179 and ZINC901461, were identified to have high or moderate agonistic potency against human PPARγ with EC 50 values of 0.084, 2.1, 0.35 and 5.6 μM, respectively, which are comparable to or even better than that of the approved PPARγ full agonists pioglitazone (EC 50  =   0.16 μM) and rosiglitazone (EC 50  =   0.034 μM). Hydrophobic interactions and van der Waals contacts are the primary chemical forces to stabilize the complex architecture of PPARγ LBD domain with these agonist ligands, while few hydrogen bonds, salt bridges and/or π-π stacking at the complex interfaces confer selectivity and specificity for the domain-agonist recognition. The integrated in vitro-in silico screening strategy can be successfully applied to rational discovery of

  7. The effects of the dopamine agonist rotigotine on hemispatial neglect following stroke.

    Science.gov (United States)

    Gorgoraptis, Nikos; Mah, Yee-Haur; Machner, Bjoern; Singh-Curry, Victoria; Malhotra, Paresh; Hadji-Michael, Maria; Cohen, David; Simister, Robert; Nair, Ajoy; Kulinskaya, Elena; Ward, Nick; Greenwood, Richard; Husain, Masud

    2012-08-01

    Hemispatial neglect following right-hemisphere stroke is a common and disabling disorder, for which there is currently no effective pharmacological treatment. Dopamine agonists have been shown to play a role in selective attention and working memory, two core cognitive components of neglect. Here, we investigated whether the dopamine agonist rotigotine would have a beneficial effect on hemispatial neglect in stroke patients. A double-blind, randomized, placebo-controlled ABA design was used, in which each patient was assessed for 20 testing sessions, in three phases: pretreatment (Phase A1), on transdermal rotigotine for 7-11 days (Phase B) and post-treatment (Phase A2), with the exact duration of each phase randomized within limits. Outcome measures included performance on cancellation (visual search), line bisection, visual working memory, selective attention and sustained attention tasks, as well as measures of motor control. Sixteen right-hemisphere stroke patients were recruited, all of whom completed the trial. Performance on the Mesulam shape cancellation task improved significantly while on rotigotine, with the number of targets found on the left side increasing by 12.8% (P = 0.012) on treatment and spatial bias reducing by 8.1% (P = 0.016). This improvement in visual search was associated with an enhancement in selective attention but not on our measures of working memory or sustained attention. The positive effect of rotigotine on visual search was not associated with the degree of preservation of prefrontal cortex and occurred even in patients with significant prefrontal involvement. Rotigotine was not associated with any significant improvement in motor performance. This proof-of-concept study suggests a beneficial role of dopaminergic modulation on visual search and selective attention in patients with hemispatial neglect following stroke.

  8. Radiosynthesis and in vivo evaluation of a series of substituted 11C-phenethylamines as 5-HT (2A) agonist PET tracers

    DEFF Research Database (Denmark)

    Ettrup, Anders; Hansen, Martin; Santini, Martin A

    2011-01-01

    Positron emission tomography (PET) imaging of serotonin 2A (5-HT(2A)) receptors with agonist tracers holds promise for the selective labelling of 5-HT(2A) receptors in their high-affinity state. We have previously validated [(11)C]Cimbi-5 and found that it is a 5-HT(2A) receptor agonist PET tracer....... In an attempt to further optimize the target-to-background binding ratio, we modified the chemical structure of the phenethylamine backbone and carbon-11 labelling site of [(11)C]Cimbi-5 in different ways. Here, we present the in vivo validation of nine novel 5-HT(2A) receptor agonist PET tracers in the pig...

  9. Radiosynthesis and in vivo evaluation of a series of substituted 11C-phenethylamines as 5-HT2A agonist PET tracers

    DEFF Research Database (Denmark)

    Ettrup, Anders; Hansen, Martin; Santini, Martin A

    2011-01-01

    Positron emission tomography (PET) imaging of serotonin 2A (5-HT(2A)) receptors with agonist tracers holds promise for the selective labelling of 5-HT(2A) receptors in their high-affinity state. We have previously validated [(11)C]Cimbi-5 and found that it is a 5-HT(2A) receptor agonist PET tracer....... In an attempt to further optimize the target-to-background binding ratio, we modified the chemical structure of the phenethylamine backbone and carbon-11 labelling site of [(11)C]Cimbi-5 in different ways. Here, we present the in vivo validation of nine novel 5-HT(2A) receptor agonist PET tracers in the pig...

  10. Risk of severe ovarian hyperstimulation syndrome in GnRH antagonist versus GnRH agonist protocol

    DEFF Research Database (Denmark)

    Toftager, M.; Bogstad, J; Bryndorf, T

    2016-01-01

    interval (CI): 0.33-0.57) compared with the traditional GnRH agonist protocol. Previous trials comparing the two protocols mainly included selected patient populations, a limited number of patients and the applied OHSS criteria differed, making direct comparisons difficult. In two recent large meta...... IV, dual-centre, open-label, RCT including 1050 women allocated to either short GnRH antagonist or long GnRH agonist protocol in a 1:1 ratio and enrolled over a 5-year period using a web-based concealed randomization code. This is a superiority study designed to detect a difference in severe OHSS...... between the two arms. None of the women had undergone previous ART treatment. PARTICIPANTS/MATERIALS, SETTING, METHODS: All infertile women referred for their first IVF/ICSI at two public fertility clinics, less than 40 years of age and with no uterine malformations were asked to participate. A total...

  11. Agonists and partial agonists of rhodopsin: retinal polyene methylation affects receptor activation.

    Science.gov (United States)

    Vogel, Reiner; Lüdeke, Steffen; Siebert, Friedrich; Sakmar, Thomas P; Hirshfeld, Amiram; Sheves, Mordechai

    2006-02-14

    Using Fourier transform infrared (FTIR) difference spectroscopy, we have studied the impact of sites and extent of methylation of the retinal polyene with respect to position and thermodynamic parameters of the conformational equilibrium between the Meta I and Meta II photoproducts of rhodopsin. Deletion of methyl groups to form 9-demethyl and 13-demethyl analogues, as well as addition of a methyl group at C10 or C12, shifted the Meta I/Meta II equilibrium toward Meta I, such that the retinal analogues behaved like partial agonists. This equilibrium shift resulted from an apparent reduction of the entropy gain of the transition of up to 65%, which was only partially offset by a concomitant reduction of the enthalpy increase. The analogues produced Meta II photoproducts with relatively small alterations, while their Meta I states were significantly altered, which accounted for the aberrant transitions to Meta II. Addition of a methyl group at C14 influenced the thermodynamic parameters but had little impact on the position of the Meta I/Meta II equilibrium. Neutralization of the residue 134 in the E134Q opsin mutant increased the Meta II content of the 13-demethyl analogue, but not of the 9-demethyl analogue, indicating a severe impairment of the allosteric coupling between the conserved cytoplasmic ERY motif involved in proton uptake and the Schiff base/Glu 113 microdomain in the 9-demethyl analogue. The 9-methyl group appears therefore essential for the correct positioning of retinal to link protonation of the cytoplasmic motif with protonation of Glu 113 during receptor activation.

  12. Opioid regulation of mu receptor internalisation: relevance to the development of tolerance and dependence.

    Science.gov (United States)

    Lopez-Gimenez, Juan F; Milligan, Graeme

    2010-11-01

    Internalisation of the mu opioid receptor from the surface of cells is generally achieved by receptor occupancy with agonist ligands of high efficacy. However, in many situations the potent analgesic morphine fails to promote internalisation effectively and whether there is a direct link between this and the propensity for the sustained use of morphine to result in both tolerance and dependence has been studied intensely. Although frequently described as a partial agonist, this characteristic appears insufficient to explain the poor capacity of morphine to promote internalisation of the mu opioid receptor. Experiments performed using both transfected cell systems and ex vivo/in vivo models have provided evidence that when morphine can promote internalisation of the mu receptor there is a decrease in the development of tolerance and dependence. Although aspects of this model are controversial, such observations suggest a number of approaches to further enhance the use of morphine as an analgesic.

  13. A retinoic acid receptor β2 agonist reduces hepatic stellate cell activation in nonalcoholic fatty liver disease.

    Science.gov (United States)

    Trasino, Steven E; Tang, Xiao-Han; Jessurun, Jose; Gudas, Lorraine J

    2016-10-01

    Hepatic stellate cells (HSCs) are an important cellular target for the development of novel pharmacological therapies to prevent and treat nonalcoholic fatty liver diseases (NAFLD). Using a high fat diet (HFD) model of NAFLD, we sought to determine if synthetic selective agonists for retinoic acid receptor β2 (RARβ2) and RARγ can mitigate HSC activation and HSC relevant signaling pathways during early stages of NAFLD, before the onset of liver injury. We demonstrate that the highly selective RARβ2 agonist, AC261066, can reduce the activation of HSCs, marked by decreased HSC expression of α-smooth muscle actin (α-SMA), in mice with HFD-induced NAFLD. Livers of HFD-fed mice treated with AC261066 exhibited reduced steatosis, oxidative stress, and expression of pro-inflammatory mediators, such as tumor necrosis factor-alpha (TNFα), interleukin 1β (IL-1β), and monocyte chemotactic protein-1 (MCP-1). Kupffer cell (macrophage) expression of transforming growth factor-β1 (TGF-β1), which plays a critical role in early HSC activation, was markedly reduced in AC261066-treated, HFD-fed mice. In contrast, HFD-fed mice treated with an RARγ agonist (CD1530) showed no decreases in steatosis, HSC activation, or Kupffer cell TGF-β1 levels. In conclusion, our data demonstrate that RARβ2 is an attractive target for development of NAFLD therapies. • Hepatic stellate cells (HSCs) are an important pharmacological target for the prevention of nonalcoholic fatty liver diseases (NAFLD). • Retinoids and retinoic acid receptors (RARs) possess favorable metabolic modulating properties. • We show that an agonist for retinoic acid receptor-β2 (RARβ2), but not RARγ, mitigates HSC activation and NAFLD.

  14. The FXR agonist PX20606 ameliorates portal hypertension by targeting vascular remodelling and sinusoidal dysfunction.

    Science.gov (United States)

    Schwabl, Philipp; Hambruch, Eva; Seeland, Berit A; Hayden, Hubert; Wagner, Michael; Garnys, Lukas; Strobel, Bastian; Schubert, Tim-Lukas; Riedl, Florian; Mitteregger, Dieter; Burnet, Michael; Starlinger, Patrick; Oberhuber, Georg; Deuschle, Ulrich; Rohr-Udilova, Nataliya; Podesser, Bruno K; Peck-Radosavljevic, Markus; Reiberger, Thomas; Kremoser, Claus; Trauner, Michael

    2017-04-01

    Steroidal farnesoid X receptor (FXR) agonists demonstrated potent anti-fibrotic activities and lowered portal hypertension in experimental models. The impact of the novel non-steroidal and selective FXR agonist PX20606 on portal hypertension and fibrosis was explored in this study. In experimental models of non-cirrhotic (partial portal vein ligation, PPVL, 7days) and cirrhotic (carbon tetrachloride, CCl 4 , 14weeks) portal hypertension, PX20606 (PX,10mg/kg) or the steroidal FXR agonist obeticholic acid (OCA,10mg/kg) were gavaged. We then measured portal pressure, intrahepatic vascular resistance, liver fibrosis and bacterial translocation. PX decreased portal pressure in non-cirrhotic PPVL (12.6±1.7 vs. 10.4±1.1mmHg; p=0.020) and cirrhotic CCl 4 (15.2±0.5 vs. 11.8±0.4mmHg; p=0.001) rats. In PPVL animals, we observed less bacterial translocation (-36%; p=0.041), a decrease in lipopolysaccharide binding protein (-30%; p=0.024) and splanchnic tumour necrosis factor α levels (-39%; p=0.044) after PX treatment. In CCl 4 rats, PX decreased fibrotic Sirius Red area (-43%; p=0.005), hepatic hydroxyproline (-66%; pportal pressure (-14%; p=0.041) by restoring endothelial function, 14week PX therapy additionally inhibited sinusoidal remodelling and decreased portal pressure to a greater extent (-22%; p=0.001). In human liver sinusoidal endothelial cells, PX increased eNOS and DDAH expression. The non-steroidal FXR agonist PX20606 ameliorates portal hypertension by reducing liver fibrosis, vascular remodelling and sinusoidal dysfunction. The novel drug PX20606 activates the bile acid receptor FXR and shows beneficial effects in experimental liver cirrhosis: In the liver, it reduces scarring and inflammation, and also widens blood vessels. Thus, PX20606 leads to an improved blood flow through the liver and decreases hypertension of the portal vein. Additionally, PX20606 improves the altered intestinal barrier and decreases bacterial migration from the gut. Copyright

  15. Structural Probing and Molecular Modeling of the A₃ Adenosine Receptor: A Focus on Agonist Binding.

    Science.gov (United States)

    Ciancetta, Antonella; Jacobson, Kenneth A

    2017-03-11

    Adenosine is an endogenous modulator exerting its functions through the activation of four adenosine receptor (AR) subtypes, termed A₁, A 2A , A 2B and A₃, which belong to the G protein-coupled receptor (GPCR) superfamily. The human A₃AR (hA₃AR) subtype is implicated in several cytoprotective functions. Therefore, hA₃AR modulators, and in particular agonists, are sought for their potential application as anti-inflammatory, anticancer, and cardioprotective agents. Structure-based molecular modeling techniques have been applied over the years to rationalize the structure-activity relationships (SARs) of newly emerged A₃AR ligands, guide the subsequent lead optimization, and interpret site-directed mutagenesis (SDM) data from a molecular perspective. In this review, we showcase selected modeling-based and guided strategies that were applied to elucidate the binding of agonists to the A₃AR and discuss the challenges associated with an accurate prediction of the receptor extracellular vestibule through homology modeling from the available X-ray templates.

  16. Structural Probing and Molecular Modeling of the A3 Adenosine Receptor: A Focus on Agonist Binding

    Science.gov (United States)

    Ciancetta, Antonella; Jacobson, Kenneth A.

    2017-01-01

    Adenosine is an endogenous modulator exerting its functions through the activation of four adenosine receptor (AR) subtypes, termed A1, A2A, A2B and A3, which belong to the G protein-coupled receptor (GPCR) superfamily. The human A3AR (hA3AR) subtype is implicated in several cytoprotective functions. Therefore, hA3AR modulators, and in particular agonists, are sought for their potential application as anti-inflammatory, anticancer, and cardioprotective agents. Structure-based molecular modeling techniques have been applied over the years to rationalize the structure-activity relationships (SARs) of newly emerged A3AR ligands, guide the subsequent lead optimization, and interpret site-directed mutagenesis (SDM) data from a molecular perspective. In this review, we showcase selected modeling-based and guided strategies that were applied to elucidate the binding of agonists to the A3AR and discuss the challenges associated with an accurate prediction of the receptor extracellular vestibule through homology modeling from the available X-ray templates. PMID:28287473

  17. Structural Probing and Molecular Modeling of the A3 Adenosine Receptor: A Focus on Agonist Binding

    Directory of Open Access Journals (Sweden)

    Antonella Ciancetta

    2017-03-01

    Full Text Available Adenosine is an endogenous modulator exerting its functions through the activation of four adenosine receptor (AR subtypes, termed A1, A2A, A2B and A3, which belong to the G protein-coupled receptor (GPCR superfamily. The human A3AR (hA3AR subtype is implicated in several cytoprotective functions. Therefore, hA3AR modulators, and in particular agonists, are sought for their potential application as anti-inflammatory, anticancer, and cardioprotective agents. Structure-based molecular modeling techniques have been applied over the years to rationalize the structure–activity relationships (SARs of newly emerged A3AR ligands, guide the subsequent lead optimization, and interpret site-directed mutagenesis (SDM data from a molecular perspective. In this review, we showcase selected modeling-based and guided strategies that were applied to elucidate the binding of agonists to the A3AR and discuss the challenges associated with an accurate prediction of the receptor extracellular vestibule through homology modeling from the available X-ray templates.

  18. Design of Glucagon-Like Peptide-1 Receptor Agonist for Diabetes Mellitus from Traditional Chinese Medicine

    Directory of Open Access Journals (Sweden)

    Hsin-Chieh Tang

    2014-01-01

    Full Text Available Glucagon-like peptide-1 (GLP-1 is a promising target for diabetes mellitus (DM therapy and reduces the occurrence of diabetes due to obesity. However, GLP-1 will be hydrolyzed soon by the enzyme dipeptidyl peptidase-4 (DPP-4. We tried to design small molecular drugs for GLP-1 receptor agonist from the world's largest traditional Chinese medicine (TCM Database@Taiwan. According to docking results of virtual screening, we selected 2 TCM compounds, wenyujinoside and 28-deglucosylchikusetsusaponin IV, for further molecular dynamics (MD simulation. GLP-1 was assigned as the control compound. Based on the results of root mean square deviation (RMSD, solvent accessible surface (SAS, mean square deviation (MSD, Gyrate, total energy, root mean square fluctuation (RMSF, matrices of smallest distance of residues, database of secondary structure assignment (DSSP, cluster analysis, and distance of H-bond, we concluded that all the 3 compounds could bind and activate GLP-1 receptor by computational simulation. Wenyujinoside and 28-deglucosylchikusetsusaponin IV were the TCM compounds that could be GLP-1 receptor agonists.

  19. Antibodies against the melanocortin-4 receptor act as inverse agonists in vitro and in vivo.

    Science.gov (United States)

    Peter, Jean-Christophe; Nicholson, Janet R; Heydet, Déborah; Lecourt, Anne-Catherine; Hoebeke, Johan; Hofbauer, Karl G

    2007-06-01

    Functionally active antibodies (Abs) against central G-protein-coupled receptors have not yet been reported. We selected the hypothalamic melanocortin-4 receptor (MC4-R) as a target because of its crucial role in the regulation of energy homeostasis. A 15 amino acid sequence of the N-terminal (NT) domain was used as an antigen. This peptide showed functional activity in surface plasmon resonance experiments and in studies on HEK-293 cells overexpressing the human MC4-R (hMC4-R). Rats immunized against the NT peptide produced specific antibodies, which were purified and characterized in vitro. In HEK-293 cells, rat anti-NT Abs showed specific immunofluorescence labeling of hMC4-R. They reduced the production of cAMP under basal conditions and after stimulation with a synthetic MC4-R agonist. Rats immunized against the NT peptide developed a phenotype consistent with MC4-R blockade, that is, increased food intake and body weight, increased liver and fat pad weight, and elevated plasma triglycerides. In a separate experiment in rats, an increase in food intake could be produced after injection of purified Abs into the third ventricle. Similar results were obtained in rats injected with anti-NT Abs raised in rabbits. Our data show for the first time that active immunization of rats against the NT sequence of the MC4-R results in specific Abs, which appear to stimulate food intake by acting as inverse agonists in the hypothalamus.

  20. Agonist of inward rectifier K+ channels enhances the protection of ischemic postconditioning in isolated rat hearts.

    Science.gov (United States)

    Liao, Z; Feng, Z; Long, C

    2014-07-01

    Selective inhibition of inward rectifier K + channels could abolish the protection mediated by ischemic preconditioning, but the roles of these channels in ischemic postconditioning have not been well characterized. Our study aims to evaluate the effect of inward rectifier K + channels on the protection induced by ischemic postconditioning. Langendorff-perfused rat hearts (n=8 per group) were split into four groups: postconditioning hearts (IPO group); ischemic postconditioning with BaCl 2 hearts (PB group); ischemic postconditioning with zacopride hearts (PZ group); and without ischemic postconditioning (CON group). After suffering 30 minutes of global ischemia, groups IPO, PB and PZ went through 10 seconds of ischemic postconditioning with three different perfusates: respectively, Krebs-Henseleit buffer (IPO group); 20 μmol/L BaCl 2 (antagonist of the channel, PB group); 1 μmol/L zacopride (agonist of the channel, PZ group). At the end of reperfusion, the myocardial performance was better preserved in the PZ group than the other three groups. The PB group showed no significant differences from the CON group. Our study has shown that the I K1 channel agonist zacopride is associated with the enhancement of ischemic postconditioning. © The Author(s) 2014.

  1. Therapeutic potential of α7 nicotinic receptor agonists to regulate neuroinflammation in neurodegenerative diseases

    Directory of Open Access Journals (Sweden)

    Laura Foucault-Fruchard

    2017-01-01

    Full Text Available Neurodegenerative diseases, such as Alzheimer's, Parkinson's and Huntington's diseases, are all characterized by a component of innate immunity called neuroinflammation. Neuronal loss and neuroinflammation are two phenomena closely linked. Hence, the neuroinflammation is a relevant target for the management of the neurodegenerative diseases given that, to date, there is no treatment to stop neuronal loss. Several studies have investigated the potential effects of activators of alpha 7 nicotinic acetylcholine receptors in animal models of neurodegenerative diseases. These receptors are widely distributed in the central nervous system. After activation, they seem to mediate the cholinergic anti-inflammatory pathway in the brain. This anti-inflammatory pathway, first described in periphery, regulates activation of microglial cells considered as the resident macrophage population of the central nervous system. In this article, we shortly review the agonists of the alpha 7 nicotinic acetylcholine receptors that have been evaluated in vivo and we focused on the selective positive allosteric modulators of these receptors. These compounds represent a key element to enhance receptor activity only in the presence of the endogenous agonist.

  2. Agonistic reciprocity is associated with reduced male reproductive success within haremic social networks

    Science.gov (United States)

    Solomon-Lane, Tessa K.; Pradhan, Devaleena S.; Willis, Madelyne C.; Grober, Matthew S.

    2015-01-01

    While individual variation in social behaviour is ubiquitous and causes social groups to differ in structure, how these structural differences affect fitness remains largely unknown. We used social network analysis of replicate bluebanded goby (Lythrypnus dalli) harems to identify the reproductive correlates of social network structure. In stable groups, we quantified agonistic behaviour, reproduction and steroid hormones, which can both affect and respond to social/reproductive cues. We identified distinct, optimal social structures associated with different reproductive measures. Male hatching success (HS) was negatively associated with agonistic reciprocity, a network structure that describes whether subordinates ‘reciprocated’ agonism received from dominants. Egg laying was associated with the individual network positions of the male and dominant female. Thus, males face a trade-off between promoting structures that facilitate egg laying versus HS. Whether this reproductive conflict is avoidable remains to be determined. We also identified different social and/or reproductive roles for 11-ketotestosterone, 17β-oestradiol and cortisol, suggesting that specific neuroendocrine mechanisms may underlie connections between network structure and fitness. This is one of the first investigations of the reproductive and neuroendocrine correlates of social behaviour and network structure in replicate, naturalistic social groups and supports network structure as an important target for natural selection. PMID:26156769

  3. 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%

  4. Molecular pharmacology of the AMPA agonist, (S)-2-amino-3-(3-hydroxy-5-phenyl-4-isoxazolyl)propionic acid [(S)-APPA] and the AMPA antagonist, (R)-APPA

    DEFF Research Database (Denmark)

    Ebert, B; Madsen, U; Lund, Trine Meldgaard

    1994-01-01

    )-APPA, whereas (R)-APPA is a non-N-methyl-D-aspartic acid (non-NMDA) receptor antagonist showing preferential AMPA blocking effects. In agreement with classical theories for competitive interaction between agonists and antagonists, the efficacy of depolarizations produced by (S)-APPA in the rat cortical wedge......The heterocyclic analogue of (S)-glutamic acid, (S)-2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid [(S)-AMPA] is a potent and selective AMPA receptor agonist, whereas the enantiomeric compound, (R)-AMPA, is virtually inactive. We have previously characterized (RS)-2-amino-3-(3-hydroxy-5......-phenyl-4-isoxazolyl)propionic acid [(RS)-APPA] as a partial AMPA receptor agonist showing about 60% of the efficacy of (RS)-AMPA. This partial agonism produced by (RS)-APPA is, however, only apparent, since resolution of (RS)-APPA has now been shown to provide the full AMPA receptor agonist, (S...

  5. Dopamine D2 receptor radiotracers [{sup 11}C](+)-PHNO and [{sup 3}H]raclopride are indistinguishably inhibited by D2 agonists and antagonists ex vivo

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, Patrick N. [Institute of Medical Science, University of Toronto, Toronto, Ontario, M5S 1A8 (Canada)], E-mail: patrick.mccormick@camhpet.ca; Kapur, Shitij [Department of Psychiatry, University of Toronto, Toronto, Ontario, M5S 1A8 (Canada); PET Center, Center for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada); Seeman, Philip [Department of Psychiatry, University of Toronto, Toronto, Ontario, M5S 1A8 (Canada); Department of Pharmacology, University of Toronto, Toronto, Ontario, M5S 1A8 (Canada); Wilson, Alan A. [Department of Psychiatry, University of Toronto, Toronto, Ontario, M5S 1A8 (Canada); PET Center, Center for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada)

    2008-01-15

    Introduction: In vitro, the dopamine D2 receptor exists in two states, with high and low affinity for agonists. The high-affinity state is the physiologically active state thought to be involved in dopaminergic illnesses such as schizophrenia. The positron emission tomography radiotracer [{sup 11}C](+)-PHNO ([{sup 11}C](+)-4-propyl-3,4,4a,5,6,10b-hexahydro-2H-naphtho[1,2-b][1,4] oxazin-9-o l), being a D2 agonist, should selectively label the high-affinity state at tracer dose and therefore be more susceptible to competition by agonist as compared to the antagonist [{sup 3}H]raclopride, which binds to both affinity states. Methods: We tested this prediction using ex vivo dual-radiotracer experiments in conscious rats. D2 antagonists (haloperidol or clozapine), a partial agonist (aripiprazole), a full agonist [(-)-NPA] or the dopamine-releasing drug amphetamine (AMPH) were administered to rats prior to an intravenous coinjection of [{sup 11}C](+)-PHNO and [{sup 3}H]raclopride. Rats were sacrificed 60 min after radiotracer injection. Striatum, cerebellum and plasma samples were counted for {sup 11}C and {sup 3}H. The specific binding ratio {l_brace}SBR, i.e., [%ID/g (striatum)-%ID/g (cerebellum)]/(%ID/g (cerebellum){r_brace} was used as the outcome measure. Results: In response to D2 antagonists, partial agonist or full agonist, [{sup 11}C](+)-PHNO and [{sup 3}H]raclopride SBRs responded indistinguishably in terms of both ED{sub 50} and Hill slope (e.g., (-)-NPA ED{sub 50} values are 0.027 and 0.023 mg/kg for [{sup 11}C](+)-PHNO and [{sup 3}H]raclopride, respectively). In response to AMPH challenge, [{sup 11}C](+)-PHNO and [{sup 3}H]raclopride SBRs were inhibited to the same degree. Conclusions: We have shown that the SBRs of [{sup 11}C](+)-PHNO- and [{sup 3}H]raclopride do not differ in their response to agonist challenge. These results do not support predictions of the in vivo binding behavior of a D2 agonist radiotracer and cast some doubt on the in vivo

  6. Dopamine D2 receptor radiotracers [11C](+)-PHNO and [3H]raclopride are indistinguishably inhibited by D2 agonists and antagonists ex vivo

    International Nuclear Information System (INIS)

    McCormick, Patrick N.; Kapur, Shitij; Seeman, Philip; Wilson, Alan A.

    2008-01-01

    Introduction: In vitro, the dopamine D2 receptor exists in two states, with high and low affinity for agonists. The high-affinity state is the physiologically active state thought to be involved in dopaminergic illnesses such as schizophrenia. The positron emission tomography radiotracer [ 11 C](+)-PHNO ([ 11 C](+)-4-propyl-3,4,4a,5,6,10b-hexahydro-2H-naphtho[1,2-b][1,4] oxazin-9-o l), being a D2 agonist, should selectively label the high-affinity state at tracer dose and therefore be more susceptible to competition by agonist as compared to the antagonist [ 3 H]raclopride, which binds to both affinity states. Methods: We tested this prediction using ex vivo dual-radiotracer experiments in conscious rats. D2 antagonists (haloperidol or clozapine), a partial agonist (aripiprazole), a full agonist [(-)-NPA] or the dopamine-releasing drug amphetamine (AMPH) were administered to rats prior to an intravenous coinjection of [ 11 C](+)-PHNO and [ 3 H]raclopride. Rats were sacrificed 60 min after radiotracer injection. Striatum, cerebellum and plasma samples were counted for 11 C and 3 H. The specific binding ratio {SBR, i.e., [%ID/g (striatum)-%ID/g (cerebellum)]/(%ID/g (cerebellum)} was used as the outcome measure. Results: In response to D2 antagonists, partial agonist or full agonist, [ 11 C](+)-PHNO and [ 3 H]raclopride SBRs responded indistinguishably in terms of both ED 50 and Hill slope (e.g., (-)-NPA ED 50 values are 0.027 and 0.023 mg/kg for [ 11 C](+)-PHNO and [ 3 H]raclopride, respectively). In response to AMPH challenge, [ 11 C](+)-PHNO and [ 3 H]raclopride SBRs were inhibited to the same degree. Conclusions: We have shown that the SBRs of [ 11 C](+)-PHNO- and [ 3 H]raclopride do not differ in their response to agonist challenge. These results do not support predictions of the in vivo binding behavior of a D2 agonist radiotracer and cast some doubt on the in vivo applicability of the D2 two-state model, as described by in vitro binding experiments

  7. Atypical Opioid Mechanisms of Control of Injury-Induced Cutaneous Pain by Delta Receptors

    Science.gov (United States)

    2017-07-01

    i.e. mu opioid receptor agonists such as morphine) cause unacceptable side effects including addiction . Injuries suffered most frequently by active...slides. The slides were then processed for fluorescent in situ hybridization with RNAscope technology (ACD Biosystems) to detect Oprd1 mRNA, as...tissue as done in Bardoni et al., Neuron, 2014) and negative controls (no probe). Controls indicated that the technology and reagents work as expected

  8. nor-BNI Antagonism of Kappa Opioid Agonist-Induced Reinstatement of Ethanol-Seeking Behavior

    Directory of Open Access Journals (Sweden)

    Erin Harshberger

    2016-01-01

    Full Text Available Recent work suggests that the dynorphin (DYN/kappa opioid receptor (KOR system may be a key mediator in the behavioral effects of alcohol. The objective of the present study was to examine the ability of the KOR antagonist norbinaltorphimine (nor-BNI to attenuate relapse to ethanol seeking due to priming injections of the KOR agonist U50,488 at time points consistent with KOR selectivity. Male Wistar rats were trained to self-administer a 10% ethanol solution, and then responding was extinguished. Following extinction, rats were injected with U50,488 (0.1–10 mg/kg, i.p. or saline and were tested for the reinstatement of ethanol seeking. Next, the ability of the nonselective opioid receptor antagonist naltrexone (0 or 3.0 mg/kg, s.c. and nor-BNI (0 or 20.0 mg/kg, i.p. to block U50,488-induced reinstatement was examined. Priming injections U50,488 reinstated responding on the previously ethanol-associated lever. Pretreatment with naltrexone reduced the reinstatement of ethanol-seeking behavior. nor-BNI also attenuated KOR agonist-induced reinstatement, but to a lesser extent than naltrexone, when injected 24 hours prior to injections of U50,488, a time point that is consistent with KOR selectivity. While these results suggest that activation of KORs is a key mechanism in the regulation of ethanol-seeking behavior, U50,488-induced reinstatement may not be fully selective for KORs.

  9. Five hTRPA1 Agonists Found in Indigenous Korean Mint, Agastache rugosa.

    Directory of Open Access Journals (Sweden)

    Hana Moon

    Full Text Available Transient receptor potential ankyrin1 (TRPA1 and transient receptor potential vanilloid 1 (TRPV1 are members of the TRP superfamily of structurally related, nonselective cation channels and mediators of several signaling pathways. Previously, we identified methyl syringate as an hTRPA1 agonist with efficacy against gastric emptying. The aim of this study was to find hTRPA1 and/or hTRPV1 activators in Agastache rugosa (Fisch. et Meyer O. Kuntze (A.rugosa, commonly known as Korean mint to improve hTRPA1-related phenomena. An extract of the stem and leaves of A.rugosa (Labiatae selectively activated hTRPA1 and hTRPV1. We next investigated the effects of commercially available compounds found in A.rugosa (acacetin, 4-allylanisole, p-anisaldehyde, apigenin 7-glucoside, L-carveol, β-caryophyllene, trans-p-methoxycinnamaldehyde, methyl eugenol, pachypodol, and rosmarinic acid on cultured hTRPA1- and hTRPV1-expressing cells. Of the ten compounds, L-carveol, trans-p-methoxycinnamaldehyde, methyl eugenol, 4-allylanisole, and p-anisaldehyde selectively activated hTRPA1, with EC50 values of 189.1±26.8, 29.8±14.9, 160.2±21.9, 1535±315.7, and 546.5±73.0 μM, respectively. The activities of these compounds were effectively inhibited by the hTRPA1 antagonists, ruthenium red and HC-030031. Although the five active compounds showed weaker calcium responses than allyl isothiocyanate (EC50=7.2±1.4 μM, our results suggest that these compounds from the stem and leaves of A.rugosa are specific and selective agonists of hTRPA1.

  10. GnRH antagonist versus long agonist protocols in IVF

    DEFF Research Database (Denmark)

    Lambalk, C B; Banga, F R; Huirne, J A

    2017-01-01

    BACKGROUND: Most reviews of IVF ovarian stimulation protocols have insufficiently accounted for various patient populations, such as ovulatory women, women with polycystic ovary syndrome (PCOS) or women with poor ovarian response, and have included studies in which the agonist or antagonist...... was not the only variable between the compared study arms. OBJECTIVE AND RATIONALE: The aim of the current study was to compare GnRH antagonist protocols versus standard long agonist protocols in couples undergoing IVF or ICSI, while accounting for various patient populations and treatment schedules. SEARCH...... in couples undergoing IVF or ICSI. The primary outcome was ongoing pregnancy rate. Secondary outcomes were: live birth rate, clinical pregnancy rate, number of oocytes retrieved and safety with regard to ovarian hyperstimulation syndrome (OHSS). Separate comparisons were performed for the general IVF...

  11. Adenine Nucleotide Analogues Locked in a Northern Methanocarba Conformation: Enhanced Stability and Potency as P2Y1 Receptor Agonists

    Science.gov (United States)

    Ravi, R. Gnana; Kim, Hak Sung; Servos, Jörg; Zimmermann, Herbert; Lee, Kyeong; Maddileti, Savitri; Boyer, José L.; Harden, T. Kendall; Jacobson, Kenneth A.

    2016-01-01

    Preference for the Northern (N) ring conformation of the ribose moiety of nucleotide 5′-triphosphate agonists at P2Y1, P2Y2, P2Y4, and P2Y11 receptors, but not P2Y6 receptors, was established using a ring-constrained methanocarba (a 3.1.0-bicyclohexane) ring as a ribose substitute (Kim et al. J. Med. Chem. 2002, 45, 208–218.). We have now combined the ring-constrained (N)-methanocarba modification of adenine nucleotides with other functionalities known to enhance potency at P2 receptors. The potency of the newly synthesized analogues was determined in the stimulation of phospholipase C through activation of turkey erythrocyte P2Y1 or human P2Y1 and P2Y2 receptors stably expressed in astrocytoma cells. An (N)-methanocarba-2-methylthio-ADP analogue displayed an EC50 at the hP2Y1 receptor of 0.40 nM and was 55-fold more potent than the corresponding triphosphate and 16-fold more potent than the riboside 5′-diphosphate. 2-Cl–(N)-methanocarba-ATP and its N6-Me analogue were also highly selective, full agonists at P2Y1 receptors. The (N)-methanocarba-2-methylthio and 2-chloromonophosphate analogues were full agonists exhibiting micromolar potency at P2Y1 receptors, while the corresponding ribosides were inactive. Although β,γ-methylene-ATP was inactive at P2Y receptors, β,γ-methylene-(N)-methanocarba-ATP was a potent hP2Y1 receptor agonist with an EC50 of 160 nM and was selective versus hP2Y2 and hP2Y4 receptors. The rates of hydrolysis of Northern (N) and Southern (S) methanocarba analogues of AMP by rat 5′-ectonucleotidase were negligible. The rates of hydrolysis of the corresponding triphosphates by recombinant rat NTPDase1 and 2 were studied. Both isomers were hydrolyzed by NTPDase 1 at about half the rate of ATP hydrolysis. The (N) isomer was hardly hydrolyzed by NTPDase 2, while the (S) isomer was hydrolyzed at one-third of the rate of ATP hydrolysis. This suggests that new, more stable and selective nucleotide agonists may be designed on the basis of

  12. [The receptorial responsiveness method (RRM): a new possibility to estimate the concentration of pharmacologic agonists at their receptors].

    Science.gov (United States)

    Pák, Krisztián; Kiss, Zsuzsanna; Erdei, Tamás; Képes, Zita; Gesztelyi, Rudolf

    2014-01-01

    Cardiovascular disease is the biggest challenge in terms of life expectancy in developed countries. Adenosine contributes to the adaptation of the heart to ischemia and hypoxia, because adenosine, in addition to its metabolite role in the nucleic acid metabolism, is the endogenous agonist of the ubiquitous adenosine receptor family. Adenosine receptor activation is beneficial in most cases, it improves the balance between energy supply and consumption, reduces injury caused by stressors and inhibits the unfavorable tissue remodeling. Pharmacological manipulation of cardioprotective effects evoked by adenosine is an important, although to date not sufficiently utilized endeavor that may have therapeutic and preventive implications in cardiovascular diseases. As the ligand binding site of adenosine receptors is accessible from the extracellular space, it is especially important to know the adenosine concentration of the interstitial fluid ([Ado](ISF)). However, in the functioning heart, [Ado](ISF) values range in an extremely wide interval, spanning from nano- to micromolar concentrations, as estimated by the commonly used methods. Our recently developed procedure, the receptorial responsiveness method (RRM), may resolve this problem in certain cases. RRM enables quantification of an acute increase in the concentration of a pharmacological agonist, uniquely in the microenvironment of the receptors of the given agonist. As a limitation, concentration of agonists with short half-life (just like adenosine) at their receptors can only be quantified with the equieffective concentration of a stable agonist exerting the same action. In a previous study using RRM, inhibition of the transmembrane nucleoside transport in the euthyroid guinea pig atrium produced an increase in [Ado](ISF) that was equieffective with 18.8 +/- 3 nM CPA (N6-cyclopentyladenosine, a stable, selective A1 adenosine receptor agonist). This finding is consistent with observations of others, i.e., in the

  13. Dopamine agonists and risk: impulse control disorders in Parkinson's; disease

    OpenAIRE

    Voon, Valerie; Gao, Jennifer; Brezing, Christina; Symmonds, Mkael; Ekanayake, Vindhya; Fernandez, Hubert; Dolan, Raymond J.; Hallett, Mark

    2011-01-01

    Impulse control disorders are common in Parkinson's; disease, occurring in 13.6% of patients. Using a pharmacological manipulation and a novel risk taking task while performing functional magnetic resonance imaging, we investigated the relationship between dopamine agonists and risk taking in patients with Parkinson's; disease with and without impulse control disorders. During functional magnetic resonance imaging, subjects chose between two choices of equal expected value: a ‘Sure’ choice an...

  14. Improving the developability profile of pyrrolidine progesterone receptor partial agonists

    Energy Technology Data Exchange (ETDEWEB)

    Kallander, Lara S.; Washburn, David G.; Hoang, Tram H.; Frazee, James S.; Stoy, Patrick; Johnson, Latisha; Lu, Qing; Hammond, Marlys; Barton, Linda S.; Patterson, Jaclyn R.; Azzarano, Leonard M.; Nagilla, Rakesh; Madauss, Kevin P.; Williams, Shawn P.; Stewart, Eugene L.; Duraiswami, Chaya; Grygielko, Eugene T.; Xu, Xiaoping; Laping, Nicholas J.; Bray, Jeffrey D.; Thompson, Scott K. (GSKPA)

    2010-09-17

    The previously reported pyrrolidine class of progesterone receptor partial agonists demonstrated excellent potency but suffered from serious liabilities including hERG blockade and high volume of distribution in the rat. The basic pyrrolidine amine was intentionally converted to a sulfonamide, carbamate, or amide to address these liabilities. The evaluation of the degree of partial agonism for these non-basic pyrrolidine derivatives and demonstration of their efficacy in an in vivo model of endometriosis is disclosed herein.

  15. TSH and Thyrotropic Agonists: Key Actors in Thyroid Homeostasis

    OpenAIRE

    Dietrich, Johannes W.; Landgrafe, Gabi; Fotiadou, Elisavet H.

    2012-01-01

    This paper provides the reader with an overview of our current knowledge of hypothalamic-pituitary-thyroid feedback from a cybernetic standpoint. Over the past decades we have gained a plethora of information from biochemical, clinical, and epidemiological investigation, especially on the role of TSH and other thyrotropic agonists as critical components of this complex relationship. Integrating these data into a systems perspective delivers new insights into static and dynamic behaviour of th...

  16. A single extracellular amino acid in Free Fatty Acid Receptor 2 defines antagonist species selectivity and G protein selection bias

    DEFF Research Database (Denmark)

    Sergeev, Eugenia; Hansen, Anders Højgaard; Bolognini, Daniele

    2017-01-01

    selectivity and mutational swap studies confirmed this hypothesis. Extending these studies to agonist function indicated that although the lysine - arginine variation between human and mouse orthologs had limited effect on G protein-mediated signal transduction, removal of positive charge from this residue...... produced a signalling-biased variant of Free Fatty Acid Receptor 2 in which Gi-mediated signalling by both short chain fatty acids and synthetic agonists was maintained whilst there was marked loss of agonist potency for signalling via Gq/11 and G12/13 G proteins. A single residue at the extracellular face...

  17. Suppression of atherosclerosis by synthetic REV-ERB agonist

    Energy Technology Data Exchange (ETDEWEB)

    Sitaula, Sadichha [Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458 (United States); Billon, Cyrielle [Department of Pharmacological & Physiological Science, Saint Louis University School of Medicine, St. Louis, MO 63104 (United States); Kamenecka, Theodore M.; Solt, Laura A. [Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458 (United States); Burris, Thomas P., E-mail: burristp@slu.edu [Department of Pharmacological & Physiological Science, Saint Louis University School of Medicine, St. Louis, MO 63104 (United States)

    2015-05-08

    The nuclear receptors for heme, REV-ERBα and REV-ERBβ, play important roles in the regulation of metabolism and inflammation. Recently it was demonstrated that reduced REV-ERBα expression in hematopoetic cells in LDL receptor null mice led to increased atherosclerosis. We sought to determine if synthetic REV-ERB agonists that we have developed might have the ability to suppress atherosclerosis in this model. A previously characterized synthetic REV-ERB agonist, SR9009, was used to determine if activation of REV-ERB activity would affect atherosclerosis in LDL receptor deficient mice. Atherosclerotic plaque size was significantly reduced (p < 0.05) in mice administered SR9009 (100 mg/kg) for seven weeks compared to control mice (n = 10 per group). SR9009 treatment of bone marrow-derived mouse macrophages (BMDM) reduced the polarization of BMDMs to proinflammatory M1 macrophage while increasing the polarization of BMDMs to anti-inflammatory M2 macrophages. Our results suggest that pharmacological targeting of REV-ERBs may be a viable therapeutic option for treatment of atherosclerosis. - Highlights: • Synthetic REV-ERB agonist treatment reduced atherosclerosis in a mouse model. • Pharmacological activation of REV-ERB decreased M1 macrophage polarization. • Pharmacological activation of REV-ERB increased M2 macrophage polarization.

  18. PPAR Agonists and Metabolic Syndrome: An Established Role?

    Directory of Open Access Journals (Sweden)

    Margherita Botta

    2018-04-01

    Full Text Available Therapeutic approaches to metabolic syndrome (MetS are numerous and may target lipoproteins, blood pressure or anthropometric indices. Peroxisome proliferator-activated receptors (PPARs are involved in the metabolic regulation of lipid and lipoprotein levels, i.e., triglycerides (TGs, blood glucose, and abdominal adiposity. PPARs may be classified into the α, β/δ and γ subtypes. The PPAR-α agonists, mainly fibrates (including newer molecules such as pemafibrate and omega-3 fatty acids, are powerful TG-lowering agents. They mainly affect TG catabolism and, particularly with fibrates, raise the levels of high-density lipoprotein cholesterol (HDL-C. PPAR-γ agonists, mainly glitazones, show a smaller activity on TGs but are powerful glucose-lowering agents. Newer PPAR-α/δ agonists, e.g., elafibranor, have been designed to achieve single drugs with TG-lowering and HDL-C-raising effects, in addition to the insulin-sensitizing and antihyperglycemic effects of glitazones. They also hold promise for the treatment of non-alcoholic fatty liver disease (NAFLD which is closely associated with the MetS. The PPAR system thus offers an important hope in the management of atherogenic dyslipidemias, although concerns regarding potential adverse events such as the rise of plasma creatinine, gallstone formation, drug–drug interactions (i.e., gemfibrozil and myopathy should also be acknowledged.

  19. Salvinorin A, a kappa-opioid receptor (KOP-r agonist hallucinogen: Pharmacology and potential template for novel pharmacotherapeutic agents in neuropsychiatric disorders

    Directory of Open Access Journals (Sweden)

    Eduardo eButelman

    2015-09-01

    Full Text Available Salvinorin A is a potent hallucinogen, isolated from the ethnomedical plant Salvia divinorum. Salvinorin A is a selective high efficacy kappa-opioid receptor (KOPr agonist, and thus implicates the KOPr system and its endogenous agonist ligands (the dynorphins in higher functions, including cognition, and perceptual effects. Salvinorin A is the only selective KOPr ligand to be widely available outside research or medical settings, and salvinorin A- containing products have undergone frequent non-medical use. KOPr/dynorphin systems in the brain are known to be powerful counter-modulatory mechanisms to dopaminergic function, which is important in mood and reward engendered by natural and drug reinforcers (including drugs of abuse. KOPr activation (including by salvinorin A can thus cause aversion and anhedonia in preclinical models. Salvinorin A is also a completely new scaffold for medicinal chemistry approaches, since it is a non-nitrogenous neoclerodane, unlike all other known opioid ligands. Ongoing efforts have the goal of discovering novel semi-synthetic salvinorin analogs with potential KOPr-mediated pharmacotherapeutic effects (including partial agonist or biased agonist effects, with a reduced burden of undesirable effects associated with salvinorin A.

  20. A GPBAR1 (TGR5 small molecule agonist shows specific inhibitory effects on myeloid cell activation in vitro and reduces experimental autoimmune encephalitis (EAE in vivo.

    Directory of Open Access Journals (Sweden)

    Nuruddeen D Lewis

    Full Text Available GPBAR1 is a G protein-coupled receptor that is activated by certain bile acids and plays an important role in the regulation of bile acid synthesis, lipid metabolism, and energy homeostasis. Recent evidence suggests that GPBAR1 may also have important effects in reducing the inflammatory response through its expression on monocytes and macrophages. To further understand the role of GPBAR1 in inflammation, we generated a novel, selective, proprietary GPBAR1 agonist and tested its effectiveness at reducing monocyte and macrophage activation in vitro and in vivo. We have used this agonist, together with previously described agonists to study agonism of GPBAR1, and shown that they can all induce cAMP and reduce TLR activation-induced cytokine production in human monocytes and monocyte-derived macrophages in vitro. Additionally, through the usage of RNA sequencing (RNA-Seq, we identified a select set of genes that are regulated by GPBAR1 agonism during LPS activation. To further define the in vivo role of GPBAR1 in inflammation, we assessed GPBAR1 expression and found high levels on circulating mouse monocytes. Agonism of GPBAR1 reduced LPS-induced cytokine production in mouse monocytes ex vivo and serum cytokine levels in vivo. Agonism of GPBAR1 also had profound effects in the experimental autoimmune encephalomyelitis (EAE mouse model of multiple sclerosis, where monocytes play an important role. Mice treated with the GPBAR1 agonist exhibited a significant reduction in the EAE clinical score which correlated with reduced monocyte and microglial activation and reduced trafficking of monocytes and T cells into the CNS. These data confirm the importance of GPBAR1 in controlling monocyte and macrophage activation in vivo and support the rationale for selective agonists of GPBAR1 in the treatment of inflammatory diseases.

  1. Effect of beta2-adrenoceptor agonists and other cAMP-elevating agents on inflammatory gene expression in human ASM cells: a role for protein kinase A.

    Science.gov (United States)

    Kaur, Manminder; Holden, Neil S; Wilson, Sylvia M; Sukkar, Maria B; Chung, Kian Fan; Barnes, Peter J; Newton, Robert; Giembycz, Mark A

    2008-09-01

    In diseases such as asthma, airway smooth muscle (ASM) cells play a synthetic role by secreting inflammatory mediators such as granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-6, or IL-8 and by expressing surface adhesion molecules, including ICAM-1. In the present study, PGE(2), forskolin, and short-acting (salbutamol) and long-acting (salmeterol and formoterol) beta(2)-adrenoceptor agonists reduced the expression of ICAM-1 and the release of GM-CSF evoked by IL-1beta in ASM cells. IL-1beta-induced IL-8 release was also repressed by PGE(2) and forskolin, whereas the beta(2)-adrenoceptor agonists were ineffective. In each case, repression of these inflammatory indexes was prevented by adenoviral overexpression of PKIalpha, a highly selective PKA inhibitor. These data indicate a PKA-dependent mechanism of repression and suggest that agents that elevate intracellular cAMP, and thereby activate PKA, may have a widespread anti-inflammatory effect in ASM cells. Since ICAM-1 and GM-CSF are highly NF-kappaB-dependent genes, we used an adenoviral-delivered NF-kappaB-dependent luciferase reporter to examine the effects of forskolin and the beta(2)-adrenoceptor agonists on NF-kappaB activation. There was no effect on luciferase activity measured in the presence of forskolin or beta(2)-adrenoceptor agonists. This finding is consistent with the observation that IL-1beta-induced expression of IL-6, a known NF-kappaB-dependent gene in ASM, was also unaffected by beta(2)-adrenoceptor agonists, forskolin, PGE(2), 8-bromo-cAMP, or rolipram. Collectively, these results indicate that repression of IL-1beta-induced ICAM-1 expression and GM-CSF release by cAMP-elevating agents, including beta(2)-adrenoceptor agonists, may not occur through a generic effect on NF-kappaB.

  2. Beta 2-adrenergic receptor agonists are novel regulators of macrophage activation in diabetic renal and cardiovascular complications.

    Science.gov (United States)

    Noh, Hyunjin; Yu, Mi Ra; Kim, Hyun Joo; Lee, Ji Hye; Park, Byoung-Won; Wu, I-Hsien; Matsumoto, Motonobu; King, George L

    2017-07-01

    Macrophage activation is increased in diabetes and correlated with the onset and progression of vascular complications. To identify drugs that could inhibit macrophage activation, we developed a cell-based assay and screened a 1,040 compound library for anti-inflammatory effects. Beta2-adrenergic receptor (β2AR) agonists were identified as the most potent inhibitors of phorbol myristate acetate-induced tumor necrosis factor-α production in rat bone marrow macrophages. In peripheral blood mononuclear cells isolated from streptozotocin-induced diabetic rats, β2AR agonists inhibited diabetes-induced tumor necrosis factor-α production, which was prevented by co-treatment with a selective β2AR blocker. To clarify the underlying mechanisms, THP-1 cells and bone marrow macrophages were exposed to high glucose. High glucose reduced β-arrestin2, a negative regulator of NF-κB activation, and its interaction with IκBα. This subsequently enhanced phosphorylation of IκBα and activation of NF-κB. The β2AR agonists enhanced β-arrestin2 and its interaction with IκBα, leading to downregulation of NF-κB. A siRNA specific for β-arrestin2 reversed β2AR agonist-mediated inhibition of NF-κB activation and inflammatory cytokine production. Treatment of Zucker diabetic fatty rats with a β2AR agonist for 12 weeks attenuated monocyte activation as well as pro-inflammatory and pro-fibrotic responses in the kidneys and heart. Thus, β2AR agonists might have protective effects against diabetic renal and cardiovascular complications. Copyright © 2017 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  3. Statins and PPARα agonists induce myotoxicity in differentiated rat skeletal muscle cultures but do not exhibit synergy with co-treatment

    International Nuclear Information System (INIS)

    Johnson, Timothy E.; Zhang, Xiaohua; Shi, Shu; Umbenhauer, Diane R.

    2005-01-01

    Statins and fibrates (weak PPARα agonists) are prescribed for the treatment of lipid disorders. Both drugs cause myopathy, but with a low incidence, 0.1-0.5%. However, combined statin and fibrate therapy can enhance myopathy risk. We tested the myotoxic potential of PPAR subtype selective agonists alone and in combination with statins in a differentiated rat myotube model. A pharmacologically potent experimental PPARα agonist, Compound A, induced myotoxicity as assessed by TUNEL staining at a minimum concentration of 1 nM, while other weaker PPARα compounds, for example, WY-14643, Gemfibrozil and Bezafibrate increased the percentage of TUNEL-positive nuclei at micromolar concentrations. In contrast, the PPARγ agonist Rosiglitazone caused little or no cell death at up to 10 μM and the PPARδ ligand GW-501516 exhibited comparatively less myotoxicity than that seen with Compound A. An experimental statin (Compound B) and Atorvastatin also increased the percentage of TUNEL-positive nuclei and co-treatment with WY-14643, Gemfibrozil or Bezafibrate had less than a full additive effect on statin-induced cell killing. The mechanism of PPARα agonist-induced cell death was different from that of statins. Unlike statins, Compound A and WY-14643 did not activate caspase 3/7. In addition, mevalonate and geranylgeraniol reversed the toxicity caused by statins, but did not prevent the cell killing induced by WY-14643. Furthermore, unlike statins, Compound A did not inhibit the isoprenylation of rab4 or rap1a. Interestingly, Compound A and Compound B had differential effects on ATP levels. Taken together, these observations support the hypothesis that in rat myotube cultures, PPARα agonism mediates in part the toxicity response to PPARα compounds. Furthermore, PPARα agonists and statins cause myotoxicity through distinct and independent pathways

  4. Statins and PPAR{alpha} agonists induce myotoxicity in differentiated rat skeletal muscle cultures but do not exhibit synergy with co-treatment

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Timothy E [Department of Safety Assessment, Merck Research Laboratories, WP45-319, Merck Research Laboratories, West Point, PA 19486 (United States); Zhang, Xiaohua [Department of Biometrics Research, Merck Research Laboratories, West Point, PA 19486 (United States); Shi, Shu [Department of Safety Assessment, Merck Research Laboratories, WP45-319, Merck Research Laboratories, West Point, PA 19486 (United States); Umbenhauer, Diane R [Department of Safety Assessment, Merck Research Laboratories, WP45-319, Merck Research Laboratories, West Point, PA 19486 (United States)

    2005-11-01

    Statins and fibrates (weak PPAR{alpha} agonists) are prescribed for the treatment of lipid disorders. Both drugs cause myopathy, but with a low incidence, 0.1-0.5%. However, combined statin and fibrate therapy can enhance myopathy risk. We tested the myotoxic potential of PPAR subtype selective agonists alone and in combination with statins in a differentiated rat myotube model. A pharmacologically potent experimental PPAR{alpha} agonist, Compound A, induced myotoxicity as assessed by TUNEL staining at a minimum concentration of 1 nM, while other weaker PPAR{alpha} compounds, for example, WY-14643, Gemfibrozil and Bezafibrate increased the percentage of TUNEL-positive nuclei at micromolar concentrations. In contrast, the PPAR{gamma} agonist Rosiglitazone caused little or no cell death at up to 10 {mu}M and the PPAR{delta} ligand GW-501516 exhibited comparatively less myotoxicity than that seen with Compound A. An experimental statin (Compound B) and Atorvastatin also increased the percentage of TUNEL-positive nuclei and co-treatment with WY-14643, Gemfibrozil or Bezafibrate had less than a full additive effect on statin-induced cell killing. The mechanism of PPAR{alpha} agonist-induced cell death was different from that of statins. Unlike statins, Compound A and WY-14643 did not activate caspase 3/7. In addition, mevalonate and geranylgeraniol reversed the toxicity caused by statins, but did not prevent the cell killing induced by WY-14643. Furthermore, unlike statins, Compound A did not inhibit the isoprenylation of rab4 or rap1a. Interestingly, Compound A and Compound B had differential effects on ATP levels. Taken together, these observations support the hypothesis that in rat myotube cultures, PPAR{alpha} agonism mediates in part the toxicity response to PPAR{alpha} compounds. Furthermore, PPAR{alpha} agonists and statins cause myotoxicity through distinct and independent pathways.

  5. Characterization of a Ca2+ response to both UTP and ATP at human P2Y11 receptors: evidence for agonist-specific signaling.

    Science.gov (United States)

    White, Pamela J; Webb, Tania E; Boarder, Michael R

    2003-06-01

    Previous reports on heterologously-expressed human P2Y11 receptors have indicated that ATP, but not UTP, is an agonist stimulating both phosphoinositidase C and adenylyl cyclase. Consistent with these findings, we report that in 1321N1 cells expressing human P2Y11 receptors, UTP stimulation did not lead to accumulation of inositol(poly)phosphates under conditions in which ATP gave a robust, concentration-dependent effect. Unexpectedly, however, both UTP and ATP stimulated increases in cytosolic Ca2+ concentration ([Ca2+]c), with both nucleotides achieving similar EC50 and maximal responses. The responses to maximally effective concentrations of ATP and UTP were not additive. The [Ca2+]c increase in response to UTP was less dependent on extracellular Ca2+ than was the response to ATP. AR-C67085 (2-propylthio-beta,gamma-difluoromethylene-d-ATP, a P2Y11-selective agonist), adenosine 5'-O-(3-thiotriphosphate), and benzoyl ATP were all full agonists with potencies similar to those of ATP and UTP. In desensitization experiments, exposure to ATP resulted in loss of the UTP response; this response was more sensitive to desensitization than that of ATP. Pertussis toxin pretreatment attenuated the response to UTP but left the ATP response unaffected. The presence of 2-aminoethyl diphenylborate differentially affected the responses of ATP and UTP. No mRNA transcripts for P2Y2 or P2Y4 were detectable in the P2Y11-expressing cells. We conclude that UTP is a Ca2+-mobilizing agonist at P2Y11 receptors and that ATP and UTP acting at the same receptor recruit distinct signaling pathways. This example of agonist-specific signaling is discussed in terms of agonist trafficking and differential signal strength.

  6. NOpiates: Novel Dual Action Neuronal Nitric Oxide Synthase Inhibitors with μ-Opioid Agonist Activity.

    Science.gov (United States)

    Renton, Paul; Green, Brenda; Maddaford, Shawn; Rakhit, Suman; Andrews, John S

    2012-03-08

    A novel series of benzimidazole designed multiple ligands (DMLs) with activity at the neuronal nitric oxide synthase (nNOS) enzyme and the μ-opioid receptor was developed. Targeting of the structurally dissimilar heme-containing enzyme and the μ-opioid GPCR was predicated on the modulatory role of nitric oxide on μ-opioid receptor function. Structure-activity relationship studies yielded lead compound 24 with excellent nNOS inhibitory activity (IC50 = 0.44 μM), selectivity over both endothelial nitric oxide synthase (10-fold) and inducible nitric oxide synthase (125-fold), and potent μ-opioid binding affinity, K i = 5.4 nM. The functional activity as measured in the cyclic adenosine monosphospate secondary messenger assay resulted in full agonist activity (EC50 = 0.34 μM). This work represents a novel approach in the development of new analgesics for the treatment of pain.

  7. Angiotensin II Type 2 Receptor Agonist Experts Sustained Neuroprotective Effects In Aged Rats

    DEFF Research Database (Denmark)

    Sumners, Colin; Isenberg, Jacob; Harmel, Allison

    2016-01-01

    OBJECTIVE: The renin angiotensin system is a promising target for stroke neuroprotection and therapy through activation of angiotensin type II receptors (AT2R). The selective non-peptide AT2R agonist, Compound 21 (C21), has been shown to exhibit neuroprotection and improve stroke outcomes...... in preclinical studies, effects that likely involve neurotropic actions. However, these beneficial actions of C21 have not been demonstrated to occur beyond 1 week post stroke. The objective of this study was to determine if systemic administration of C21 would exert sustained neuroprotective effects in aged...... min), 24 h, and 48 h after stroke. Infarct size was assessed by magnetic resonance imaging at 21 days post MCAO. Animals received blinded neurological exams at 4 h, 24 h, 72 h, 7d, 14d, and 21d post-MCAO. RESULTS: Systemic treatment with C21 after stroke significantly improved neurological function...

  8. New benzylureas as a novel series of potent, nonpeptidic vasopressin V2 receptor agonists.

    Science.gov (United States)

    Yea, Christopher M; Allan, Christine E; Ashworth, Doreen M; Barnett, James; Baxter, Andy J; Broadbridge, Janice D; Franklin, Richard J; Hampton, Sally L; Hudson, Peter; Horton, John A; Jenkins, Paul D; Penson, Andy M; Pitt, Gary R W; Rivière, Pierre; Robson, Peter A; Rooker, David P; Semple, Graeme; Sheppard, Andy; Haigh, Robert M; Roe, Michael B

    2008-12-25

    Vasopressin (AVP) is a hormone that stimulates an increase in water permeability through activation of V2 receptors in the kidney. The analogue of AVP, desmopressin, has proven an effective drug for diseases where a reduction of urine output is desired. However, its peptidic nature limits its bioavailability. We report herein the discovery of potent, nonpeptidic, benzylurea derived agonists of the vasopressin V2 receptor. We describe substitutions on the benzyl group to give improvements in potency and subsequent modifications to the urea end group to provide improvements in solubility and increased oral efficacy in a rat model of diuresis. The lead compound 20e (VA106483) is reported for the first time and has been selected for clinical development.

  9. Molecular interaction of a potent nonpeptide agonist with the chemokine receptor CCR8

    DEFF Research Database (Denmark)

    Jensen, Pia C; Nygaard, Rie; Thiele, Stefanie

    2007-01-01

    Most nonpeptide antagonists for CC-chemokine receptors share a common pharmacophore with a centrally located, positively charged amine that interacts with the highly conserved glutamic acid (Glu) located in position 6 of transmembrane helix VII (VII:06). We present a novel CCR8 nonpeptide agonist......, 8-[3-(2-methoxyphenoxy)benzyl]-1-phenethyl-1,3,8-triaza-spiro[4.5]decan-4-one (LMD-009), that also contains a centrally located, positively charged amine. LMD-009 selectively stimulated CCR8 among the 20 identified human chemokine receptors. It mediated chemotaxis, inositol phosphate accumulation......-binding pockets of CCR8 uncovered that the binding of LMD-009 and of four analogs [2-(1-(3-(2-methoxyphenoxy)benzyl)-4-hydroxypiperidin-4-yl)benzoic acid (LMD-584), N-ethyl-2-4-methoxybenzenesulfonamide (LMD-902), N-(1-(3-(2-methoxyphenoxy)benzyl)piperidin-4-yl)-2-phenyl-4-(pyrrolidin-1yl)butanamide (LMD-268...

  10. 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

  11. Results from an Integrated Safety Analysis of Urelumab, an Agonist Anti-CD137 Monoclonal Antibody

    DEFF Research Database (Denmark)

    Segal, Neil H; Logan, Theodore F; Hodi, F Stephen

    2017-01-01

    Purpose: Urelumab is an agonist antibody to CD137 with potential application as an immuno-oncology therapeutic. Data were analyzed to assess safety, tolerability, and pharmacodynamic activity of urelumab, including the dose selected for ongoing development in patients with advanced solid tumors...... and lymphoma.Experimental Design: A total of 346 patients with advanced cancers who had progressed after standard treatment received at least one dose of urelumab in one of three dose-escalation, monotherapy studies. Urelumab was administered at doses ranging from 0.1 to 15 mg/kg. Safety analyses included...... the most common treatment-related AEs, and was associated with immunologic and pharmacodynamic activity demonstrated by the induction of IFN-inducible genes and cytokines.Conclusions: Integrated evaluation of urelumab safety data showed significant transaminitis was strongly associated with doses of ≥1 mg...

  12. Neuroprotective and memory-related actions of novel alpha-7 nicotinic agents with different mixed agonist/antagonist properties.

    Science.gov (United States)

    Meyer, E M; Tay, E T; Zoltewicz, J A; Meyers, C; King, M A; Papke, R L; De Fiebre, C M

    1998-03-01

    The goals of this study were to develop compounds that were selective and highly efficacious agonists at alpha-7 receptors, while varying in antagonist activity; and to test the hypothesis that these compounds had memory-related and neuroprotective actions associated with both agonist and antagonist alpha-7 receptor activities. Three compounds were identified; E,E-3-(cinnamylidene)anabaseine (3-CA), E,E-3-(2-methoxycinnamylidene) anabaseine (2-MeOCA) and E,E-3-(4-methoxycinnamylidene) anabaseine (4-MeOCA) each displaced [125I]alpha-bungarotoxin binding from rat brain membranes and activated rat alpha-7 receptors in a Xenopus oocyte expression system fully efficaciously. The potency series for binding and receptor activation was 2-MeOCA > 4-MeOCA = 3-CA and 2-MeOCA = 3-CA > 4-MeOCA, respectively. No compound significantly activated oocyte-expressed alpha-4beta-2 receptors. Although each cinnamylidene-anabaseine caused a long-term inhibition of alpha-7 receptors, as measured by ACh-application 5 min later, this inhibition ranged considerably, from less than 20% (3-CA) to 90% (2-MeOCA) at an identical concentration (10 microM). These compounds improved passive avoidance behavior in nucleus basalis lesioned rats, with 2-MeOCA most potent in this respect. In contrast, only 3-CA was neuroprotective against neurite loss during nerve growth factor deprivation in differentiated rat pheochromocytoma (PC12) cells. Choline, an efficacious alpha-7 agonist without antagonist activity, was also protective in this model. These results suggest that the neurite-protective action of alpha-7 receptor agonists may be more sensitive to potential long-term antagonist properties than acute behavioral actions are.

  13. alpha2-Adrenergic agonists antagonise the anxiolytic-like effect of antidepressants in the four-plate test in mice.

    Science.gov (United States)

    Massé, Fabienne; Hascoët, Martine; Bourin, Michel

    2005-10-14

    Selective serotonin reuptake inhibitors (SSRIs) and serotonin/noradrenaline reuptake inhibitors (SNRIs) has been reported to be efficient in anxiety disorders. Some animal models have demonstrated an anxiolytic-like effect following acute administration, however, it is not yet known how noradrenergic receptors are implicated in the therapeutic effects of antidepressants (ADs) in anxiety. The effects of two alpha(2)-adrenoceptor agonists (clonidine, guanabenz) on anxiolytic-like effect of two SSRIs (paroxetine and citalopram) and two SNRIs (venlafaxine and milnacipran) were evaluated in the four-plate test (FPT) in mice. Paroxetine (4 mg/kg), citalopram (8 mg/kg), venlafaxine (8 mg/kg), and milnacipran (8 mg/kg) administered intraperitoneally (i.p.) increased the number of punishments accepted by mice in the FPT. Clonidine (0.0039-0.5 mg/kg) and guanabenz (0.03-0.5mg/kg) had no effect on the number of punishments accepted by mice. Clonidine (0.03 and 0.06 mg/kg) and guanabenz (0.125 and 0.5 mg/kg) (i.p. -45 min) reversed the anti-punishment effect of paroxetine, citalopram, venlafaxine and milnacipran (i.p. -30 min). But if the antidepressants are administered 45 min before the test and alpha(2)-adrenoceptor agonists 30 min before the test, alpha(2)-adrenoceptor agonists failed to alter the anti-punishment effect of antidepressants. The results of this present study indicate that alpha(2)-adrenoceptor agonists antagonise the anxiolytic-like effect of antidepressants in mice when they are administered 15 min before the administration of antidepressant suggesting a close inter-regulation between noradrenergic and serotoninergic system in the mechanism of SSRIs and SNRIs in anxiety-like behaviour.

  14. The treatment of Parkinson's disease with dopamine agonists

    Directory of Open Access Journals (Sweden)

    Frank, Wilhelm

    2008-06-01

    Full Text Available Parkinson’s disease is a chronic degenerative organic disease with unknown causes. A disappearance of cells with melanin in the substantia nigra is considered as biological artefact of the disease, which causes a degenerative loss of neurons in the corpus striatum of mesencephalon. This structure produces also the transmitter substance dopamine. Due to this disappearance of cells dopamine is not produced in a sufficient quantity which is needed for movement of the body. The questions of this report are concerned the efficiency and safety of a treatment with dopamine agonists. Furthermore the cost-effectiveness is investigated as well as ethic questions. The goal is to give recommendation for the use of dopamine agonists to the German health system. A systematic literature search was done. The identified studies have different methodological quality and investigate different hypothesis and different outcome criteria. Therefore a qualitative method of information synthesis was chosen. Since the introduction of L-Dopa in the 1960´s it is considered as the most effective substance to reduce all the cardinal symptoms of Parkinson disease. This substance was improved in the course of time. Firstly some additional substances were given (decarbonxylase inhibitors, catechol-o-transferase inhibitors (COMT-inhibitors, monoaminoxydase-inhibitors (MAO-inhibitors and NMDA-antagonists (N-Methyl-d-aspartat-antagonists. In the practical therapy of Parkinson dopamine agonists play an important role, because they directly use the dopamine receptors. The monotherapy of Parkinson disease is basically possible and is used in early stages of the disease. Clinical practise has shown, that an add on therapy with dopamine agonists can led to a reduction of the dose of L-dopa and a reduction of following dyskinesia. The studies for effectiveness include studies for the initial therapy, monotherapy and add-on-therapy. Basically there is a good effectiveness of dopamine

  15. The Protective Role of PAC1-Receptor Agonist Maxadilan in BCCAO-Induced Retinal Degeneration.

    Science.gov (United States)

    Vaczy, A; Reglodi, D; Somoskeoy, T; Kovacs, K; Lokos, E; Szabo, E; Tamas, A; Atlasz, T

    2016-10-01

    A number of studies have proven that pituitary adenylate cyclase activating polypeptide (PACAP) is protective in neurodegenerative diseases. Permanent bilateral common carotid artery occlusion (BCCAO) causes severe degeneration in the rat retina. In our previous studies, protective effects were observed with PACAP1-38, PACAP1-27, and VIP but not with their related peptides, glucagon, or secretin in BCCAO. All three PACAP receptors (PAC1, VPAC1, VPAC2) appear in the retina. Molecular and immunohistochemical analysis demonstrated that the retinoprotective effects are most probably mainly mediated by the PAC1 receptor. The aim of the present study was to investigate the retinoprotective effects of a selective PAC1-receptor agonist maxadilan in BCCAO-induced retinopathy. Wistar rats were used in the experiment. After performing BCCAO, the right eye was treated with intravitreal maxadilan (0.1 or 1 μM), while the left eye was injected with vehicle. Sham-operated rats received the same treatment. Two weeks after the operation, retinas were processed for standard morphometric and molecular analysis. Intravitreal injection of 0.1 or 1 μM maxadilan caused significant protection in the thickness of most retinal layers and the number of cells in the GCL compared to the BCCAO-operated eyes. In addition, 1 μM maxadilan application was more effective than 0.1 μM maxadilan treatment in the ONL, INL, IPL, and the entire retina (OLM-ILM). Maxadilan treatment significantly decreased cytokine expression (CINC-1, IL-1α, and L-selectin) in ischemia. In summary, our histological and molecular analysis showed that maxadilan, a selective PAC1 receptor agonist, has a protective role in BCCAO-induced retinal degeneration, further supporting the role of PAC1 receptor conveying the retinoprotective effects of PACAP.

  16. Attenuated nicotine‐like effects of varenicline but not other nicotinic ACh receptor agonists in monkeys receiving nicotine daily

    Science.gov (United States)

    Cunningham, Colin S; Moerke, Megan J; Javors, Martin A; Carroll, F Ivy

    2016-01-01

    Background and Purpose Chronic treatment can differentially impact the effects of pharmacologically related drugs that differ in receptor selectivity and efficacy. Experimental Approach The impact of daily nicotine treatment on the effects of nicotinic ACh receptor (nAChR) agonists was examined in two groups of rhesus monkeys discriminating nicotine (1.78 mg·kg−1 base weight) from saline. One group received additional nicotine treatment post‐session (1.78 mg·kg−1 administered five times daily, each dose 2 h apart; i.e. Daily group), and the second group did not (Intermittent group). Key Results Daily repeated nicotine treatment produced a time‐related increase in saliva cotinine. There was no significant difference in the ED50 values of the nicotine discriminative stimulus between the Daily and Intermittent group. Mecamylamine antagonized the effects of nicotine, whereas dihydro‐β‐erythroidine did not. Midazolam produced 0% nicotine‐lever responding. The nAChR agonists epibatidine, RTI‐36, cytisine and varenicline produced >96% nicotine‐lever responding in the Intermittent group. The respective maximum effects in the Daily group were 100, 72, 59 and 28%, which shows that the ability of varenicline to produce nicotine‐like responding was selectively decreased in the Daily as compared with the Intermittent group. When combined with nicotine, both varenicline and cytisine increased the potency of nicotine to produce discriminative stimulus effects. Conclusion and Implications Nicotine treatment has a greater impact on the sensitivity to the effects of varenicline as compared with some other nAChR agonists. Collectively, these results strongly suggest that varenicline differs from nicotine in its selectivity for multiple nAChR subtypes. PMID:27667659

  17. Late-stage optimization of a tercyclic class of S1P3-sparing, S1P1 receptor agonists.

    Science.gov (United States)

    Horan, Joshua C; Kuzmich, Daniel; Liu, Pingrong; DiSalvo, Darren; Lord, John; Mao, Can; Hopkins, Tamara D; Yu, Hui; Harcken, Christian; Betageri, Raj; Hill-Drzewi, Melissa; Patenaude, Lori; Patel, Monica; Fletcher, Kimberly; Terenzzio, Donna; Linehan, Brian; Xia, Heather; Patel, Mita; Studwell, Debbie; Miller, Craig; Hickey, Eugene; Levin, Jeremy I; Smith, Dustin; Kemper, Raymond A; Modis, Louise K; Bannen, Lynne C; Chan, Diva S; Mac, Morrison B; Ng, Stephanie; Wang, Yong; Xu, Wei; Lemieux, René M

    2016-01-15

    Poor solubility and cationic amphiphilic drug-likeness were liabilities identified for a lead series of S1P3-sparing, S1P1 agonists originally developed from a high-throughput screening campaign. This work describes the subsequent optimization of these leads by balancing potency, selectivity, solubility and overall molecular charge. Focused SAR studies revealed favorable structural modifications that, when combined, produced compounds with overall balanced profiles. The low brain exposure observed in rat suggests that these compounds would be best suited for the potential treatment of peripheral autoimmune disorders. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. The angiotensin II type 2 receptor agonist Compound 21 is protective in experimental diabetes-associated atherosclerosis

    DEFF Research Database (Denmark)

    Chow, Bryna S M; Koulis, Christine; Krishnaswamy, Pooja

    2016-01-01

    AIMS/HYPOTHESIS: Angiotensin II is well-recognised to be a key mediator in driving the pathological events of diabetes-associated atherosclerosis via signalling through its angiotensin II type 1 receptor (AT1R) subtype. However, its actions via the angiotensin II type 2 receptor (AT2R) subtype...... are still poorly understood. This study is the first to investigate the role of the novel selective AT2R agonist, Compound 21 (C21) in an experimental model of diabetes-associated atherosclerosis (DAA). METHODS: Streptozotocin-induced diabetic Apoe-knockout mice were treated with vehicle (0.1 mol/l citrate...

  19. A pepducin derived from the third intracellular loop of FPR2 is a partial agonist for direct activation of this receptor in neutrophils but a full agonist for cross-talk triggered reactivation of FPR2.

    Directory of Open Access Journals (Sweden)

    Michael Gabl

    Full Text Available We recently described a novel receptor cross-talk mechanism in neutrophils, unique in that the signals generated by the PAF receptor (PAFR and the ATP receptor (P2Y2R transfer formyl peptide receptor 1 (FPR1 from a desensitized (non-signaling state back to an actively signaling state (Forsman H et al., PLoS One, 8:e60169, 2013; Önnheim K, et al., Exp Cell Res, 323∶209, 2014. In addition to the G-protein coupled FPR1, neutrophils also express the closely related receptor FPR2. In this study we used an FPR2 specific pepducin, proposed to work as an allosteric modulator at the cytosolic signaling interface, to determine whether the cross-talk pathway is utilized also by FPR2. The pepducin used contains a fatty acid linked to a peptide sequence derived from the third intracellular loop of FPR2, and it activates as well as desensensitizes this receptor. We now show that neutrophils desensitized with the FPR2-specific pepducin display increased cellular responses to stimulation with PAF or ATP. The secondary PAF/ATP induced response was sensitive to FPR2-specific inhibitors, disclosing a receptor cross-talk mechanism underlying FPR2 reactivation. The pepducin induced an activity in naïve cells similar to that of a conventional FPR2 agonist, but with lower potency (partial efficacy, meaning that the pepducin is a partial agonist. The PAF- or ATP-induced reactivation was, however, much more pronounced when neutrophils had been desensitized to the pepducin as compared to cells desensitized to conventional agonists. The pepducin should thus in this respect be classified as a full agonist. In summary, we demonstrate that desensitized FPR2 can be transferred back to an actively signaling state by receptor cross-talk signals generated through PAFR and P2Y2R, and the difference in agonist potency with respect to pepducin-induced direct receptor activation and cross-talk reactivation of FPR2 puts the concept of functional selectivity in focus.

  20. Cardiovascular safety and benefits of GLP-1 receptor agonists

    DEFF Research Database (Denmark)

    Dalsgaard, Niels B; Brønden, Andreas; Lauritsen, Tina Vilsbøll

    2017-01-01

    INTRODUCTION: Glucagon-like peptide-1 (GLP-1) receptor agonists (GLP-1RAs) constitute a class of drugs for the treatment of type 2 diabetes, and currently, six different GLP-1RAs are approved. Besides improving glycemic control, the GLP-1RAs have other beneficial effects such as weight loss...... and a low risk of hypoglycemia. Treatment with the GLP-1RA lixisenatide has been shown to be safe in patients with type 2 diabetes and recent acute coronary syndrome. Furthermore, liraglutide and semaglutide have been shown to reduce cardiovascular (CV) disease (CVD) risk in type 2 diabetes patients...

  1. Molecular determinants of subtype-selective efficacies of cytisine and the novel compound NS3861 at heteromeric nicotinic acetylcholine receptors

    DEFF Research Database (Denmark)

    Harpsøe, Kasper; Hald, Helle; Timmermann, Daniel B

    2013-01-01

    Deciphering which specific agonist-receptor interactions affect efficacy levels is of high importance, because this will ultimately aid in designing selective drugs. The novel compound NS3861 and cytisine are agonists of nicotinic acetylcholine receptors (nAChRs) and both bind with high affinity...

  2. 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

  3. 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

  4. Pharmacological, neurochemical, and behavioral profile of JB-788, a new 5-HT1A agonist.

    Science.gov (United States)

    Picard, M; Morisset, S; Cloix, J F; Bizot, J C; Guerin, M; Beneteau, V; Guillaumet, G; Hevor, T K

    2010-09-01

    A novel pyridine derivative, 8-{4-[(6-methoxy-2,3-dihydro-[1,4]dioxino[2,3-b]pyridine-3-ylmethyl)-amino]-butyl}-8-aza-spiro[4.5]decane-7,9-dione hydrochloride, termed JB-788, was designed to selectively target 5-HT(1A) receptors. In the present study, the pharmacological profile of JB-788 was characterized in vitro using radioligands binding tests and in vivo using neurochemical and behavioural experiments. JB-788 bound tightly to human 5-HT(1A) receptor expressed in human embryonic kidney 293 (HEK-293) cells with a K(i) value of 0.8 nM. Its binding affinity is in the same range as that observed for the (+/-)8-OH-DPAT, a reference 5HT(1A) agonist compound. Notably, JB-788 only bound weakly to 5-HT(1B) or 5-HT(2A) receptors and moreover the drug displayed only weak or indetectable binding to muscarinic, alpha(2), beta(1) and beta(2) adrenergic receptors, or dopaminergic D(1) receptors. JB-788 was found to display substantial binding affinity for dopaminergic D(2) receptors and, to a lesser extend to alpha(1) adrenoreceptors. JB-788 dose-dependently decreased forskolin-induced cAMP accumulation in HEK cells expressing human 5-HT(1A), thus acting as a potent 5-HT(1A) receptor agonist (E(max.) 75%, EC(50) 3.5 nM). JB-788 did not exhibit any D(2) receptor agonism but progressively inhibited the effects of quinpirole, a D(2) receptor agonist, in the cAMP accumulation test with a K(i) value of 250 nM. JB-788 induced a weak change in cAMP levels in mouse brain but, like some antipsychotics, transiently increased glycogen contents in various brain regions. Behavioral effects were investigated in mice using the elevated plus-maze. JB-788 was found to increase the time duration spent by animals in anxiogenic situations. Locomotor hyperactivity induced by methamphetamine in mouse, a model of antipsychotic activity, was dose-dependently inhibited by JB-788. Altogether, these results suggest that JB-788 displays pharmacological properties, which could be of interest in the area

  5. The Good, the Bad, and the Ugly: Agonistic Behaviour in Juvenile Crocodilians

    OpenAIRE

    Brien, Matthew L.; Lang, Jeffrey W.; Webb, Grahame J.; Stevenson, Colin; Christian, Keith A.

    2013-01-01

    We examined agonistic behaviour in seven species of hatchling and juvenile crocodilians held in small groups (N = 4) under similar laboratory conditions. Agonistic interactions occurred in all seven species, typically involved two individuals, were short in duration (5-15 seconds), and occurred between 1600-2200 h in open water. The nature and extent of agonistic interactions, the behaviours displayed, and the level of conspecific tolerance varied among species. Discrete postures, non-contact...

  6. Innate Immune Responses to TLR2 and TLR4 Agonists Differ between Baboons, Chimpanzees and Humans

    Science.gov (United States)

    Brinkworth, Jessica F.; Pechenkina, Ekaterina A.; Silver, Jack; Goyert, Sanna M.

    2012-01-01

    Background African catarrhine primates differ in bacterial disease susceptibility. Methods Human, chimpanzee, and baboon blood was stimulated with TLR-detected bacterial agonists and cytokine/chemokine induction assessed by real-time pcr. Results Humans and chimpanzees shared similar cytokine/chemokine responses, while baboon cytokine/chemokine induction differed. Generally, responses were agonist-independent. Conclusions These primates tend to generate species rather than agonist–specific responses to bacterial agonists. PMID:22978822

  7. Contamination with retinoic acid receptor agonists in two rivers in the Kinki region of Japan.

    Science.gov (United States)

    Inoue, Daisuke; Nakama, Koki; Sawada, Kazuko; Watanabe, Taro; Takagi, Mai; Sei, Kazunari; Yang, Min; Hirotsuji, Junji; Hu, Jianying; Nishikawa, Jun-ichi; Nakanishi, Tsuyoshi; Ike, Michihiko

    2010-04-01

    This study was conducted to investigate the agonistic activity against human retinoic acid receptor (RAR) alpha in the Lake Biwa-Yodo River and the Ina River in the Kinki region of Japan. To accomplish this, a yeast two-hybrid assay was used to elucidate the spatial and temporal variations and potential sources of RARalpha agonist contamination in the river basins. RARalpha agonistic activity was commonly detected in the surface water samples collected along two rivers at different periods, with maximum all-trans retinoic acid (atRA) equivalents of 47.6 ng-atRA/L and 23.5 ng-atRA/L being observed in Lake Biwa-Yodo River and Ina River, respectively. The results indicated that RARalpha agonists are always present and widespread in the rivers. Comparative investigation of RARalpha and estrogen receptor alpha agonistic activities at 20 stations along each river revealed that the spatial variation pattern of RARalpha agonist contamination was entirely different from that of the estrogenic compound contamination. This suggests that the effluent from municipal wastewater treatment plants, a primary source of estrogenic compounds, seemed not to be the cause of RARalpha agonist contamination in the rivers. Fractionation using high performance liquid chromatography (HPLC) directed by the bioassay found two bioactive fractions from river water samples, suggesting the presence of at least two RARalpha agonists in the rivers. Although a trial conducted to identify RARalpha agonists in the major bioactive fraction was not completed as part of this study, comparison of retention times in HPLC analysis and quantification with liquid chromatography-mass spectrometry analysis revealed that the major causative contaminants responsible for the RARalpha agonistic activity were not RAs (natural RAR ligands) and 4-oxo-RAs, while 4-oxo-RAs were identified as the major RAR agonists in sewage in Beijing, China. These findings suggest that there are unknown RARalpha agonists with high

  8. Metabolically stable bradykinin B2 receptor agonists enhance transvascular drug delivery into malignant brain tumors by increasing drug half-life

    Directory of Open Access Journals (Sweden)

    Glen Daniel

    2009-05-01

    Full Text Available Abstract Background The intravenous co-infusion of labradimil, a metabolically stable bradykinin B2 receptor agonist, has been shown to temporarily enhance the transvascular delivery of small chemotherapy drugs, such as carboplatin, across the blood-brain tumor barrier. It has been thought that the primary mechanism by which labradimil does so is by acting selectively on tumor microvasculature to increase the local transvascular flow rate across the blood-brain tumor barrier. This mechanism of action does not explain why, in the clinical setting, carboplatin dosing based on patient renal function over-estimates the carboplatin dose required for target carboplatin exposure. In this study we investigated the systemic actions of labradimil, as well as other bradykinin B2 receptor agonists with a range of metabolic stabilities, in context of the local actions of the respective B2 receptor agonists on the blood-brain tumor barrier of rodent malignant gliomas. Methods Using dynamic contrast-enhanced MRI, the pharmacokinetics of gadolinium-diethyltriaminepentaacetic acid (Gd-DTPA, a small MRI contrast agent, were imaged in rodents bearing orthotopic RG-2 malignant gliomas. Baseline blood and brain tumor tissue pharmacokinetics were imaged with the 1st bolus of Gd-DTPA over the first hour, and then re-imaged with a 2nd bolus of Gd-DTPA over the second hour, during which normal saline or a bradykinin B2 receptor agonist was infused intravenously for 15 minutes. Changes in mean arterial blood pressure were recorded. Imaging data was analyzed using both qualitative and quantitative methods. Results The decrease in systemic blood pressure correlated with the known metabolic stability of the bradykinin B2 receptor agonist infused. Metabolically stable bradykinin B2 agonists, methionine-lysine-bradykinin and labradimil, had differential effects on the transvascular flow rate of Gd-DTPA across the blood-brain tumor barrier. Both methionine

  9. Effects of Trace Amine-associated Receptor 1 Agonists on the Expression, Reconsolidation, and Extinction of Cocaine Reward Memory.

    Science.gov (United States)

    Liu, Jian-Feng; Thorn, David A; Zhang, Yanan; Li, Jun-Xu

    2016-07-01

    As a modulator of dopaminergic system, trace amine-associated receptor 1 has been shown to play a critical role in regulating the rewarding properties of additive drugs. It has been demonstrated that activation of trace amine-associated receptor 1 decreased the abuse-related behaviors of cocaine in rats. However, the role of trace amine-associated receptor 1 in specific stages of cocaine reward memory is still unclear. Here, using a cocaine-induced conditioned place preference model, we tested the effects of a selective trace amine-associated receptor 1 agonist RO5166017 on the expression, reconsolidation, and extinction of cocaine reward memory. We found that RO5166017 inhibited the expression but not retention of cocaine-induced conditioned place preference. RO5166017 had no effect on the reconsolidation of cocaine reward memory. Pretreatment with RO5166017 before extinction hindered the formation of extinction long-term memory. RO5166017 did not affect the movement during the conditioned place preference test, indicating the inhibitory effect of RO5166017 on the expression of cocaine-induced conditioned place preference was not caused by locomotion inhibition. Using a cocaine i.v. self-administration model, we found that the combined trace amine-associated receptor 1 partial agonist RO5263397 with extinction had no effect on the following cue- and drug-induced reinstatement of cocaine-seeking behavior. Repeated administration of the trace amine-associated receptor 1 agonist during extinction showed a continually inhibitory effect on the expression of cocaine reward memory both in cocaine-induced conditioned place preference and cocaine self-administration models. Taken together, these results indicate that activation of trace amine-associated receptor 1 specifically inhibited the expression of cocaine reward memory. The inhibitory effect of trace amine-associated receptor 1 agonists on cocaine reward memory suggests that trace amine-associated receptor 1

  10. Synthesis and Pharmacology of α/β(3)-Peptides Based on the Melanocortin Agonist Ac-His-dPhe-Arg-Trp-NH2 Sequence.

    Science.gov (United States)

    Singh, Anamika; Tala, Srinivasa R; Flores, Viktor; Freeman, Katie; Haskell-Luevano, Carrie

    2015-05-14

    The melanocortin-3 and -4 receptors are expressed in the brain and play key roles in regulating feeding behavior, metabolism, and energy homeostasis. In the present study, incorporation of β(3)-amino acids into a melanocortin tetrapeptide template was investigated. Four linear α/β(3)-hybrid tetrapeptides were designed with the modifications at the Phe, Arg, and Trp residues in the agonist sequence Ac-His-dPhe-Arg-Trp-NH2. The most potent mouse melanocortin-4 receptor (mMC4R) agonist, Ac-His-dPhe-Arg-β(3)hTrp-NH2 (8) showed 35-fold selectivity versus the mMC3R. The study presented here has identified a new template with heterogeneous backbone for designing potent and selective melanocortin receptor ligands.

  11. Synthesis and Pharmacology of α/β3-Peptides Based on the Melanocortin Agonist Ac-His-dPhe-Arg-Trp-NH2 Sequence

    Science.gov (United States)

    2015-01-01

    The melanocortin-3 and -4 receptors are expressed in the brain and play key roles in regulating feeding behavior, metabolism, and energy homeostasis. In the present study, incorporation of β3-amino acids into a melanocortin tetrapeptide template was investigated. Four linear α/β3-hybrid tetrapeptides were designed with the modifications at the Phe, Arg, and Trp residues in the agonist sequence Ac-His-dPhe-Arg-Trp-NH2. The most potent mouse melanocortin-4 receptor (mMC4R) agonist, Ac-His-dPhe-Arg-β3hTrp-NH2 (8) showed 35-fold selectivity versus the mMC3R. The study presented here has identified a new template with heterogeneous backbone for designing potent and selective melanocortin receptor ligands. PMID:26005535

  12. Long-acting beta(2)-agonists in management of childhood asthma

    DEFF Research Database (Denmark)

    Bisgaard, H

    2000-01-01

    This review assesses the evidence regarding the use of long-acting beta(2)-agonists in the management of pediatric asthma. Thirty double-blind, randomized, controlled trials on the effects of formoterol and salmeterol on lung function in asthmatic children were identified. Single doses of inhaled......, long-acting beta(2)-agonists provide effective bronchodilatation and bronchoprotection when used as intermittent, single-dose treatment of asthma in children, but not when used as regular treatment. Future studies should examine the positioning of long-acting beta(2)-agonists as an "as needed" rescue...... medication instead of short-acting beta(2)-agonists for pediatric asthma management....

  13. Hypertrophic effect of inhaled beta -agonist with and without concurrent exercise training

    DEFF Research Database (Denmark)

    Jessen, Søren; Onslev, Johan; Lemminger, Anders

    2018-01-01

    INTRODUCTION: Due to a high prevalence of asthma and exercise-induced bronchoconstriction in elite athletes, there is a high use of beta2 -adrenoceptor agonists (beta2 -agonists) in the athletic population. While anabolic in rodents, no study has been able to detect hypertrophy in humans after...... chronic beta2 -agonist inhalation. METHODS: We investigated if inhaled beta2 -agonist, terbutaline, alters body composition and metabolic rate with and without concurrent exercise training in healthy young men. Sixty-seven participants completed a four-week intervention of daily terbutaline (8×0.5 mg...

  14. Agonist-induced affinity alterations of a central nervous system. cap alpha. -bungarotoxin receptor

    Energy Technology Data Exchange (ETDEWEB)

    Lukas, R.J.; Bennett, E.L.

    1979-01-01

    The ability of cholinergic agonists to block the specific interaction of ..cap alpha..-bungarotoxin (..cap alpha..-Bgt) with membrane-bound sites derived from rat brain is enhanced when membranes are preincubated with agonist. Thus, pretreatment of ..cap alpha..-Bgt receptors with agonist (but not antagonist) causes transformation of sites to a high-affinity form toward agonist. This change in receptor state occurs with a half-time on the order of minutes, and is fully reversible on dilution of agonist. The results are consistent with the identity of ..cap alpha..-Bgt binding sites as true central nicotinic acetylcholine receptors. Furthermore, this agonist-induced alteration in receptor state may represent an in vitro correlate of physiological desensitization. As determined from the effects of agonist on toxin binding isotherms, and on the rate of toxin binding to specific sites, agonist inhibition of toxin binding to the high-affinity state is non-competitive. This result suggests that there may exist discrete toxin-binding and agonist-binding sites on central toxin receptors.

  15. BIASED AGONISM OF THREE DIFFERENT CANNABINOID RECEPTOR AGONISTS IN MOUSE BRAIN CORTEX

    Directory of Open Access Journals (Sweden)

    Rebeca Diez-Alarcia

    2016-11-01

    Full Text Available Cannabinoid receptors are able to couple to different families of G-proteins when activated by an agonist drug. It has been suggested that different intracellular responses may be activated depending on the ligand. The goal of the present study was to characterize the pattern of G protein subunit stimulation triggered by three different cannabinoid ligands, THC, WIN55212-2 and ACEA in mouse brain cortex.Stimulation of the [35S]GTPS binding coupled to specific immunoprecipitation with antibodies against different subtypes of G proteins (Gαi1, Gαi2, Gαi3, Gαo, Gαz, Gαs, Gαq/11, and Gα12/13, in the presence of Δ9-THC, WIN55212-2 and ACEA (submaximal concentration 10 µM was determined by Scintillation Proximity Assay (SPA technique in mouse cortex of wild type, CB1 knock-out, CB2 knock-out and CB1/CB2 double knock-out mice. Results show that, in mouse brain cortex, cannabinoid agonists are able to significantly stimulate not only the classical inhibitory Gαi/o subunits but also other G subunits like Gαz, Gαq/11, and Gα12/13. Moreover, the specific pattern of G protein subunit activation is different depending on the ligand. In conclusion, our results demonstrate that, in mice brain native tissue, different exogenous cannabinoid ligands are able to selectively activate different inhibitory and non-inhibitory Gα protein subtypes, through the activation of CB1 and/or CB2 receptors. Results of the present study may help to understand the specific molecular pathways involved in the pharmacological effects of cannabinoid-derived drugs.

  16. NKT-cell glycolipid agonist as adjuvant in synthetic vaccine.

    Science.gov (United States)

    Liu, Zheng; Guo, Jun

    2017-11-27

    NKT cells are CD1d-restricted, glycolipid antigen-reactive, immunoregulatory T lymphocytes that can serve as a bridge between the innate and adaptive immunities. NKT cells have a wide range of therapeutic application in autoimmunity, transplant biology, infectious disease, cancer, and vaccinology. Rather than triggering "danger signal" and eliciting an innate immune response, αGalCer-based NKT-cell agonist act via a unique mechanism, recruiting NKT cells which play a T helper-like role even without peptide as Th epitope. Importantly, the non-polymorphism of CD1d render glycolipid a universal helper epitope, offering the potential to simplify the vaccine construct capable of eliciting consistent immune response in different individuals. This review details recent advances in the design of synthetic vaccines using NKT-cell agonist as adjuvant, highlighting the role of organic synthesis and conjugation technique to enhance the immunological actives and to simplify the vaccine constructs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Mood Disorders, Circadian Rhythms, Melatonin and Melatonin Agonists

    Directory of Open Access Journals (Sweden)

    M.A. Quera Salva

    2012-04-01

    Full Text Available Recent advances in the understanding of circadian rhythms have led to an interest in the treatment of major depressive disorder with chronobiotic agents. Many tissues have autonomous circadian rhythms, which are orchestrated by the master clock, situated in the suprachiasmatic nucleus (SNC. Melatonin (N-acetyl-5-hydroxytryptamine is secreted from the pineal gland during darkness. Melatonin acts mainly on MT1 and MT2 receptors, which are present in the SNC, regulating physiological and neuroendocrine functions, including circadian entrainment, referred to as the chronobiotic effet. Circadian rhythms has been shown to be either misaligned or phase shifted or decreased in amplitude in both acute episodes and relapse of major depressive disorder (MDD and bipolar disorder. Manipulation of circadian rhythms either using physical treatments (such as high intensity light or behavioral therapy has shown promise in improving symptoms. Pharmacotherapy using melatonin and pure melatonin receptor agonists, while improving sleep, has not been shown to improve symptoms of depression. A novel antidepressant, agomelatine, combines 5HT2c antagonist and melatonin agonist action, and has shown promise in both acute treatment of MDD and in preventing relapse.

  18. Cold suppresses agonist-induced activation of TRPV1.

    Science.gov (United States)

    Chung, M-K; Wang, S

    2011-09-01

    Cold therapy is frequently used to reduce pain and edema following acute injury or surgery such as tooth extraction. However, the neurobiological mechanisms of cold therapy are not completely understood. Transient receptor potential vanilloid 1 (TRPV1) is a capsaicin- and heat-gated nociceptive ion channel implicated in thermosensation and pathological pain under conditions of inflammation or injury. Although capsaicin-induced nociception, neuropeptide release, and ionic currents are suppressed by cold, it is not known if cold suppresses agonist-induced activation of recombinant TRPV1. We demonstrate that cold strongly suppressed the activation of recombinant TRPV1 by multiple agonists and capsaicin-evoked currents in trigeminal ganglia neurons under normal and phosphorylated conditions. Cold-induced suppression was partially impaired in a TRPV1 mutant that lacked heat-mediated activation and potentiation. These results suggest that cold-induced suppression of TRPV1 may share a common molecular basis with heat-induced potentiation, and that allosteric inhibition may contribute, in part, to the cold-induced suppression. We also show that combination of cold and a specific antagonist of TRPV1 can produce an additive suppression. Our results provide a mechanistic basis for cold therapy and may enhance anti-nociceptive approaches that target TRPV1 for managing pain under inflammation and tissue injury, including that from tooth extraction.

  19. Trial Watch: Toll-like receptor agonists in oncological indications.

    Science.gov (United States)

    Aranda, Fernando; Vacchelli, Erika; Obrist, Florine; Eggermont, Alexander; Galon, Jérôme; Sautès-Fridman, Catherine; Cremer, Isabelle; Henrik Ter Meulen, Jan; Zitvogel, Laurence; Kroemer, Guido; Galluzzi, Lorenzo

    2014-01-01

    Toll-like receptors (TLRs) are an evolutionarily conserved group of enzymatically inactive, single membrane-spanning proteins that recognize a wide panel of exogenous and endogenous danger signals. Besides constituting a crucial component of the innate immune response to bacterial and viral pathogens, TLRs appear to play a major role in anticancer immunosurveillance. In line with this notion, several natural and synthetic TLR ligands have been intensively investigated for their ability to boost tumor-targeting immune responses elicited by a variety of immunotherapeutic and chemotherapeutic interventions. Three of these agents are currently approved by the US Food and Drug Administration (FDA) or equivalent regulatory agencies for use in cancer patients: the so-called bacillus Calmette-Guérin, monophosphoryl lipid A, and imiquimod. However, the number of clinical trials testing the therapeutic potential of both FDA-approved and experimental TLR agonists in cancer patients is stably decreasing, suggesting that drug developers and oncologists are refocusing their interest on alternative immunostimulatory agents. Here, we summarize recent findings on the use of TLR agonists in cancer patients and discuss how the clinical evaluation of FDA-approved and experimental TLR ligands has evolved since the publication of our first Trial Watch dealing with this topic.

  20. How does agonistic behaviour differ in albino and pigmented fish?

    Directory of Open Access Journals (Sweden)

    Ondřej Slavík

    2016-04-01

    Full Text Available In addition to hypopigmentation of the skin and red iris colouration, albino animals also display distinct physiological and behavioural alterations. However, information on the social interactions of albino animals is rare and has mostly been limited to specially bred strains of albino rodents and animals from unique environments in caves. Differentiating between the effects of albinism and domestication on behaviour in rodents can be difficult, and social behaviour in cave fish changes according to species-specific adaptations to conditions of permanent darkness. The agonistic behaviours of albino offspring of pigmented parents have yet to be described. In this study, we observed agonistic behaviour in albino and pigmented juvenile Silurus glanis catfish. We found that the total number of aggressive interactions was lower in albinos than in pigmented catfish. The distance between conspecifics was also analysed, and albinos showed a tendency towards greater separation from their same-coloured conspecifics compared with pigmented catfish. These results demonstrate that albinism can be associated with lower aggressiveness and with reduced shoaling behaviour preference, as demonstrated by a tendency towards greater separation of albinos from conspecifics.

  1. Pharmacology and toxicology of Cannabis derivatives and endocannabinoid agonists.

    Science.gov (United States)

    Gerra, Gilberto; Zaimovic, Amir; Gerra, Maria L; Ciccocioppo, Roberto; Cippitelli, Andrea; Serpelloni, Giovanni; Somaini, Lorenzo

    2010-01-01

    For centuries Cannabis sativa and cannabis extracts have been used in natural medicine. Delta(9)-tetrahydrocannabinol (THC) is the main active ingredient of Cannabis. THC seems to be responsible for most of the pharmacological and therapeutic actions of cannabis. In a few countries THC extracts (i.e. Sativex) or THC derivatives such as nabilone, and dronabinol are used in the clinic for the treatment of several pathological conditions like chemotherapy-induced nausea and vomiting, multiple sclerosis and glaucoma. On the other hand the severe side effects and the high abuse liability of these agents represent a serious limitation in their medical use. In addition, diversion in the use of these active ingredients for recreational purpose is a concern. Over recent years, alternative approaches using synthetic cannabinoid receptor agonists or agents acting as activators of the endocannabinoid systems are under scrutiny with the hope to develop more effective and safer clinical applications. Likely, in the near future few of these new molecules will be available for clinical use. The present article review recent study and patents with focus on the cannabinoid system as a target for the treatment of central nervous system disorders with emphasis on agonists.

  2. Androgen receptor agonists increase lean mass, improve cardiopulmonary functions and extend survival in preclinical models of Duchenne muscular dystrophy.

    Science.gov (United States)

    Ponnusamy, Suriyan; Sullivan, Ryan D; You, Dahui; Zafar, Nadeem; He Yang, Chuan; Thiyagarajan, Thirumagal; Johnson, Daniel L; Barrett, Maron L; Koehler, Nikki J; Star, Mayra; Stephenson, Erin J; Bridges, Dave; Cormier, Stephania A; Pfeffer, Lawrence M; Narayanan, Ramesh

    2017-07-01

    Duchenne muscular dystrophy (DMD) is a neuromuscular disease that predominantly affects boys as a result of mutation(s) in the dystrophin gene. DMD is characterized by musculoskeletal and cardiopulmonary complications, resulting in shorter life-span. Boys afflicted by DMD typically exhibit symptoms within 3-5 years of age and declining physical functions before attaining puberty. We hypothesized that rapidly deteriorating health of pre-pubertal boys with DMD could be due to diminished anabolic actions of androgens in muscle, and that intervention with an androgen receptor (AR) agonist will reverse musculoskeletal complications and extend survival. While castration of dystrophin and utrophin double mutant (mdx-dm) mice to mimic pre-pubertal nadir androgen condition resulted in premature death, maintenance of androgen levels extended the survival. Non-steroidal selective-AR modulator, GTx-026, which selectively builds muscle and bone was tested in X-linked muscular dystrophy mice (mdx). GTx-026 significantly increased body weight, lean mass and grip strength by 60-80% over vehicle-treated mdx mice. While vehicle-treated castrated mdx mice exhibited cardiopulmonary impairment and fibrosis of heart and lungs, GTx-026 returned cardiopulmonary function and intensity of fibrosis to healthy control levels. GTx-026 elicits its musculoskeletal effects through pathways that are distinct from dystrophin-regulated pathways, making AR agonists ideal candidates for combination approaches. While castration of mdx-dm mice resulted in weaker muscle and shorter survival, GTx-026 treatment increased the muscle mass, function and survival, indicating that androgens are important for extended survival. These preclinical results support the importance of androgens and the need for intervention with AR agonists to treat DMD-affected boys. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Promotion of Wound Healing by an Agonist of Adenosine A2A Receptor Is Dependent on Tissue Plasminogen Activator.

    Science.gov (United States)

    Montesinos, M Carmen; Desai-Merchant, Avani; Cronstein, Bruce N

    2015-12-01

    Impaired wound healing, as it occurs in diabetes mellitus or long-term corticoid treatment, is commonly associated with disability, diminished quality of life, and high economic costs. Selective agonists of the A2A receptor subtype of adenosine, an endogenous regulator of inflammation, promote tissue repair in animal models, both healthy and with impaired healing. Plasmin-mediated proteolysis of fibrin and other matrix proteins is essential for cell migration at sites of injury. Since adenosine A2A receptor activation increases plasminogen activator release from macrophages and mast cells, we studied the effect of a selective agonist, CGS-21680, on full-thickness excisional wound closure in wild-type, urokinase plasminogen activator (uPA)-deficient, and tissue plasminogen activator (tPA)-deficient mice. Wound closure was impaired in tPA- and uPA-deficient mice as compared with wild-type mice, and topical application of CGS-21680 significantly increased the rate at which wounds closed in wild-type mice and uPA-deficient mice, but not in tPA-deficient mice. Immunostaining of tissue sections showed that tPA was present in endothelial cells and histiocytes by day 3 post-wound and also by day 6. In contrast, uPA was more prominent in these cell types only by day 6 post-wound. Our results confirm that plasminogen activation contributes to wound repair and are consistent with the hypothesis that adenosine A2A receptor activation promotes wound closure by a mechanism that depends upon tPA, but not uPA. Moreover, our results suggest that topical adenosine A2A receptor agonists may be useful in promotion of wound closure in patients with impaired wound healing.

  4. A novel M1 PAM VU0486846 exerts efficacy in cognition models without displaying agonist activity or cholinergic toxicity.

    Science.gov (United States)

    Rook, Jerri M; Bertron, Jeanette L; Cho, Hyekyung P; Garcia-Barrantes, Pedro M; Moran, Sean P; Maksymetz, James T; Nance, Kellie D; Dickerson, Jonathan W; Remke, Daniel H; Chang, Sichen; Harp, Joel; Blobaum, Anna L; Niswender, Colleen M; Jones, Carrie K; Stauffer, Shaun R; Conn, P Jeffrey; Lindsley, Craig W

    2018-04-27

    Selective activation of the M1 subtype of muscarinic acetylcholine receptor, via positive allosteric modulation (PAM), is an exciting strategy to improve cognition in schizophrenia and Alzheimer's disease patients. However, highly potent M1 ago-PAMs, such as MK-7622, PF-06764427, and PF-06827443, can engender excessive activation of M1, leading to agonist actions in the prefrontal cortex (PFC) that impairs cognitive function, induces behavioral convulsions, and results in other classic cholinergic adverse events (AEs). Here, we report a fundamentally new and highly selective M1 PAM, VU0486846. VU0486846 possesses only weak agonist activity in M1-expressing cell lines with high receptor reserve and is devoid of agonist actions in the PFC, unlike previously reported ago-PAMs MK-7622, PF-06764427 and PF-06827443. Moreover, VU0486846 shows no interaction with antagonist binding at the orthosteric acetylcholine (ACh) site (e.g., neither bitopic nor displaying negative cooperativity with [3H]-NMS binding at theorthosteric site), no seizure liability at high brain exposures, and no cholinergic AEs. However, as opposed to ago-PAMs, VU0486846 produces robust efficacy in the novel object recognition model of cognitive function. Importantly, we show for the first time that an M1 PAM can reverse the cognitive deficits induced by atypical antipsychotics, such as risperidone. These findings further strengthen the argument that compounds with modest in vitro M1 PAM activity (EC50s > 100 nM) and pure-PAM activity in native tissues display robust pro-cognitive efficacy without AEs mediated by excessive activation of M1. Overall, the combination of compound assessment with recombinant in vitro assays (mindful of receptor reserve), native tissue systems (PFC), and phenotypic screens (behavioral convulsions) is essential to fully understand and evaluate lead compounds and enhance success in clinical development.

  5. Protective effect of an alpha 7 nicotinic acetylcholine receptor agonist against enterovirus 71 infection in neuronal cells.

    Science.gov (United States)

    Song, Feng Xia; Zhao, Lin Qing; Zhu, Ru Nan; Song, Qin Wei; Deng, Jie; Tian, Run; Wang, Fang; Qian, Yuan

    2018-01-01

    Enterovirus 71, as one of the dominant pathogens associated with severe hand, foot, and mouth disease, has been well reported to trigger severe neurological symptoms among young children over the last decade, particularly among children in the Asia-Pacific region. To date, no effective antiviral agent has been developed for the treatment of severe enterovirus 71 infection. PNU-282987, a selective alpha 7 nicotinic acetylcholine receptor (α7nAChR) agonist, has been reported to have a neuroprotective effect by participating in inflammatory regulation in previous studies. Therefore, in the present study, we aimed to assess the cell-protective effect of PNU-282987 against enterovirus 71 infection in neuronal cells, and to discuss potential mechanisms underlying this cell-protective effect in order to elucidate the potential impact of such agonists in the treatment of neurotropic viral infection. We observed that treatment with PNU-282987 improved cell viability and inhibited viral replication in enterovirus 71-infected SH-SY5Y cells. Further investigation revealed that inhibition of enterovirus 71 production by PNU-282987 is likely associated with events of RNA replication, and that increased levels of INF mRNA and its downstream antiviral proteins stimulated by the JAK-STAT2 pathway may contribute to the antiviral effect of PNU-282987. Moreover, our findings suggest that both the antiviral and anti-inflammatory effects of PNU-282987 may contribute to the neural protective effect of the drug in enterovirus 71-infected cells. Taken together, the results suggest that selective α7nAChR agonists may represent viable candidates for future therapeutic treatment of severe enterovirus 71 infection, and for other cases of neurotropic viral infection. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Gamma-aminobutyric acid agonists for antipsychotic-induced tardive dyskinesia.

    Science.gov (United States)

    Alabed, Samer; Latifeh, Youssef; Mohammad, Husam Aldeen; Bergman, Hanna

    2018-04-17

    Chronic antipsychotic drug treatment may cause tardive dyskinesia (TD), a long-term movement disorder. Gamma-aminobutyric acid (GABA) agonist drugs, which have intense sedative properties and may exacerbate psychotic symptoms, have been used to treat TD. 1. Primary objectiveThe primary objective was to determine whether using non-benzodiazepine GABA agonist drugs for at least six weeks was clinically effective for the treatment of antipsychotic-induced TD in people with schizophrenia, schizoaffective disorder or other chronic mental illnesses.2. Secondary objectivesThe secondary objectives were as follows.To examine whether any improvement occurred with short periods of intervention (less than six weeks) and, if this did occur, whether this effect was maintained at longer periods of follow-up.To examine whether there was a differential effect between the various compounds.To test the hypothesis that GABA agonist drugs are most effective for a younger age group (less than 40 years old). We searched the Cochrane Schizophrenia Group Trials Register (last searched April 2017), inspected references of all identified studies for further trials, and, when necessary, contacted authors of trials for additional information. We included randomised controlled trials of non-benzodiazepine GABA agonist drugs in people with antipsychotic-induced TD and schizophrenia or other chronic mental illness. Two review authors independently selected and critically appraised studies, extracted and analysed data on an intention-to-treat basis. Where possible and appropriate we calculated risk ratios (RRs) and their 95% confidence intervals (CIs). For continuous data we calculated mean differences (MD). We assumed that people who left early had no improvement. We contacted investigators to obtain missing information. We assessed risk of bias for included studies and created a 'Summary of findings' table using GRADE. We included 11 studies that randomised 343 people. Overall, the risk of bias

  7. Receptor binding properties and antinociceptive effects of chimeric peptides consisting of a micro-opioid receptor agonist and an ORL1 receptor antagonist.

    Science.gov (United States)

    Kawano, Susumu; Ito, Risa; Nishiyama, Miharu; Kubo, Mai; Matsushima, Tomoko; Minamisawa, Motoko; Ambo, Akihiro; Sasaki, Yusuke

    2007-07-01

    Receptor binding properties and antinociceptive activities of chimeric peptides linked by spacers were investigated. The peptides consisted of the micro-opioid receptor ligand dermorphin (Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH(2)) or its analog YRFB (Tyr-D-Arg-Phe-betaAla-NH(2)) linked to the ORL1 receptor ligand Ac-Arg-Tyr-Tyr-Arg-Ile-Lys-NH(2) (Ac-RYYRIK-NH(2)). All chimeric peptides were found to possess high receptor binding affinities for both micro-opioid and ORL1 receptors in mouse brain membranes although their binding affinities for both receptors in spinal membranes were significantly lower. Among them, chimeric peptide 2, which consists of dermorphin and Ac-RYYRIK-NH(2) connected by a long spacer, had the highest binding affinity towards both receptors. In the tail-flick test following intrathecal (i.t.) administration to mice, all chimeric peptides showed potent and dose-dependent antinociceptive activities with an ED(50) of 1.34-4.51 (pmol/mouse), nearly comparable to dermorphin alone (ED(50); 1.08 pmol/mouse). In contrast to their micro-opioid receptor binding profiles, intracerebroventricular (i.c.v.) administration of the chimeric peptides resulted in much less potent antinociceptive activity (ED(50) 5.55-100peptides, and the regulation of mu-opioid receptor-mediated antinociception in brain. The present chimeric peptides may be useful as pharmacological tools for studies on micro-opioid receptor/ORL1 receptor heterodimers.

  8. Group III mGlu receptor agonists potentiate the anticonvulsant effect of AMPA and NMDA receptor block.

    Science.gov (United States)

    De Sarro, Giovambattista; Chimirri, Alba; Meldrum, Brian S

    2002-09-06

    We report the anticonvulsant action in DBA/2 mice of two mGlu Group III receptor agonists: (R,S)-4-phosphonophenylglycine, (R,S)-PPG, a compound with moderate mGlu8 selectivity, and of (1S,3R,4S)-1-aminocyclopentane-1,2,4-tricarboxylic acid, ACPT-1, a selective agonist for mGlu4alpha receptors. Both compounds, given intracerebroventricularly at doses which did not show marked anticonvulsant activity, produced a consistent shift to the left of the dose-response curves (i.e. enhanced the anticonvulsant properties) of 1-(4'-aminophenyl)-3,5-dihydro-7,8-dimethoxy-4H-2,3-benzodiazepin-4-one hydrochloride, CFM-2, a noncompetitive AMPA receptor antagonist, and 3-((+/-)-2-carboxypiperazin-4-yl)-1-phosphonic acid, CPPene, a competitive NMDA receptor antagonist, in DBA/2 mice. In addition, (R,S)-PPG and ACPT-1 administered intracerebroventricularly prolonged the time course of the anticonvulsant properties of CFM-2 (33 micromol/kg, i.p.) and CPPene (3.3 micromol/kg, i.p.) administered intraperitoneally. We conclude that modest reduction of synaptic glutamate release by activation of Group III metabotropic receptors potentiates the anticonvulsant effect of AMPA and NMDA receptor blockade. Copyright 2002 Elsevier Science B.V.

  9. PPAR-alpha agonists as novel antiepileptic drugs: preclinical findings.

    Directory of Open Access Journals (Sweden)

    Monica Puligheddu

    Full Text Available Nicotinic acetylcholine receptors (nAChRs are involved in seizure mechanisms. Hence, nocturnal frontal lobe epilepsy was the first idiopathic epilepsy linked with specific mutations in α4 or β2 nAChR subunit genes. These mutations confer gain of function to nAChRs by increasing sensitivity toward acetylcholine. Consistently, nicotine elicits seizures through nAChRs and mimics the excessive nAChR activation observed in animal models of the disease. Treatments aimed at reducing nicotinic inputs are sought as therapies for epilepsies where these receptors contribute to neuronal excitation and synchronization. Previous studies demonstrated that peroxisome proliferator-activated receptors-α (PPARα, nuclear receptor transcription factors, suppress nicotine-induced behavioral and electrophysiological effects by modulating nAChRs containing β2 subunits. On these bases, we tested whether PPARα agonists were protective against nicotine-induced seizures. To this aim we utilized behavioral and electroencephalographic (EEG experiments in C57BL/J6 mice and in vitro patch clamp recordings from mice and rats. Convulsive doses of nicotine evoked severe seizures and bursts of spike-waves discharges in ∼100% of mice. A single dose of the synthetic PPARα agonist WY14643 (WY, 80 mg/kg, i.p. or chronic administration of fenofibrate, clinically available for lipid metabolism disorders, in the diet (0.2% for 14 days significantly reduced or abolished behavioral and EEG expressions of nicotine-induced seizures. Acute WY effects were reverted by the PPARα antagonist MK886 (3 mg/kg, i.p.. Since neocortical networks are crucial in the generation of ictal activity and synchrony, we performed patch clamp recordings of spontaneous inhibitory postsynaptic currents (sIPSCs from frontal cortex layer II/III pyramidal neurons. We found that both acute and chronic treatment with PPARα agonists abolished nicotine-induced sIPSC increases. PPARα within the CNS are key

  10. Agonist-dependent modulation of G-protein coupling and transduction of 5-HT1A receptors in rat dorsal raphe nucleus.

    Science.gov (United States)

    Valdizán, Elsa Maria; Castro, Elena; Pazos, Angel

    2010-08-01

    5-HT1A receptors couple to different Go/Gi proteins in order to mediate a wide range of physiological actions. While activation of post-synaptic 5-HT1A receptors is mainly related to inhibition of adenylyl cyclase activity, functionality of autoreceptors located in raphe nuclei has been classically ascribed to modifications of the activity of potassium and calcium channels. In order to evaluate the possible existence of agonist-directed trafficking for 5-HT1A autoreceptors in the rat dorsal raphe nucleus, we studied their activation by two agonists with a different profile of efficacy [(+)8-OH-DPAT and buspirone], addressing simultaneously the identification of the specific Galpha subtypes ([35S]GTPgammaS labelling and immunoprecipitation) involved and the subsequent changes in cAMP formation. A significant increase (32%, plabelling of immunoprecipitates was obtained with anti-Galphai3 antibodies but not with anti-Galphao, anti-Galphai1, anti-Galphai2, anti-Galphaz or anti-Galphas antibodies. In contrast, in the presence of buspirone, significant [35S]GTPgammaS labelling of immunoprecipitates was obtained with anti-Galphai3 (50%, plabelling with anti-Galphai1, anti-Galphaz or anti-Galphas. The selective 5-HT1A antagonist WAY 100635 blocked the labelling induced by both agonists. Furthermore, (+)8-OH-DPAT failed to modify forskolin-stimulated cAMP accumulation, while buspirone induced a dose-dependent, WAY 100635-sensitive, inhibition of this response (Imax 30.8+/-4.9, pIC50 5.95+/-0.46). These results demonstrate the existence of an agonist-dependency pattern of G-protein coupling and transduction for 5-HT1A autoreceptors in native brain tissue. These data also open new perspectives for the understanding of the differential profiles of agonist efficacy in pre- vs. post-synaptic 5-HT1A receptor-associated responses.

  11. Maternal aggression in Wistar rats: effect of 5-HT2A/2C receptor agonist and antagonist microinjected into the dorsal periaqueductal gray matter and medial septum

    Directory of Open Access Journals (Sweden)

    Almeida R.M.M. de

    2005-01-01

    Full Text Available The objective of the present study was to assess the role of the 5-HT2A/2C receptor at two specific brain sites, i.e., the dorsal periaqueductal gray matter (DPAG and the medial septal (MS area, in maternal aggressive behavior after the microinjection of either a 5-HT2A/2C receptor agonist or antagonist. Female Wistar rats were microinjected on the 7th postpartum day with the selective agonist alpha-methyl-5-hydroxytryptamine maleate (5-HT2A/2C or the antagonist 5-HT2A/2C, ketanserin. The agonist was injected into the DPAG at 0.2 (N = 9, 0.5 (N = 10, and 1.0 µg/0.2 µl (N = 9, and the antagonist was injected at 1.0 µg/0.2 µl (N = 9. The agonist was injected into the medial septal area (MS at 0.2 (N = 9, 0.5 (N = 7, and 1.0 µg/0.2 µl (N = 6 and the antagonist was injected at 1.0 µg/0.2 µl (N = 5. For the control, saline was injected into the DPAG (N = 7 and the MS (N = 12. Both areas are related to aggressive behavior and contain a high density of 5-HT receptors. Non-aggressive behaviors such as horizontal locomotion (walking and social investigation and aggressive behaviors such as lateral threat (aggressive posture, attacks (frontal and lateral, and biting the intruder were analyzed when a male intruder was placed into the female resident's cage. For each brain area studied, the frequency of the behaviors was compared among the various treatments by analysis of variance. The results showed a decrease in maternal aggressive behavior (number of bites directed at the intruder after microinjection of the agonist at 0.2 and 1.0 µg/0.2 µl (1.6 ± 0.7 and 0.9 ± 0.3 into the DPAG compared to the saline group (5.5 ± 1.1. There was no dose-response relationship with the agonist. The present findings suggest that the 5-HT2A/2C receptor agonist has an inhibitory effect on maternal aggressive behavior when microinjected into the DPAG and no effect when microinjected into the MS. Ketanserin (1.0 µg/0.2 µl decreased locomotion when microinjected

  12. Agonist-induced alterations in lymphocyte β-adrenergic receptor photoaffintiy labelling: effects of phenylarsine oxide

    International Nuclear Information System (INIS)

    Feldman, R.D.; McArdle, W.; Lai, C.

    1986-01-01

    In several models, desensitization of the β-adrenergic receptor (βAR) is associated with a decrease in binding of hydrophilic but not hydrophobic βAR ligands. This suggests a sequestration of cell surface βAR. Desensitization of the lymphobyte βAR is also associated with a selective reduction in the photoaffinity labelling of a 55K βAR protein as compared to a 68K βAR protein. In order to examine the relationship between sequestration and reduction in labelling of the 55K peptide, the authors have studied the effect of phenylarsine oxide (PAO; an inhibitor of sequestration) on lymphocyte βAR desensitization. Incubation of cells with PAO prior to desensitization did not block the consequent reduction in isoproterenol-stimulated adenylate cyclase activity. However, the agonist-induced reduction in binding of the hydrophilic βAR ligand CGP-12177 was blocked by PAO (without PAO:57 +/- 4% of control, with PAO: 97 +/- 2% of control). Photolabelling studies with [ 125 I] iodocyanopindolol diazirine revealed that PAO pretreatment also blocked the selective loss in labelling of the 55K βAR protein seen with desensitization. These data suggest that loss of labelling of the 55K protein of the βAR is closely coupled to βAR sequestration

  13. Conformationally constrained farnesoid X receptor (FXR) agonists: Naphthoic acid-based analogs of GW 4064.

    Science.gov (United States)

    Akwabi-Ameyaw, Adwoa; Bass, Jonathan Y; Caldwell, Richard D; Caravella, Justin A; Chen, Lihong; Creech, Katrina L; Deaton, David N; Jones, Stacey A; Kaldor, Istvan; Liu, Yaping; Madauss, Kevin P; Marr, Harry B; McFadyen, Robert B; Miller, Aaron B; Navas, Frank; Parks, Derek J; Spearing, Paul K; Todd, Dan; Williams, Shawn P; Wisely, G Bruce

    2008-08-01

    Starting from the known FXR agonist GW 4064 1a, a series of stilbene replacements were prepared. The 6-substituted 1-naphthoic acid 1b was an equipotent FXR agonist with improved developability parameters relative to 1a. Analog 1b also reduced the severity of cholestasis in the ANIT acute cholestatic rat model.

  14. Low-dose add-back therapy during postoperative GnRH agonist treatment

    Directory of Open Access Journals (Sweden)

    Hsiao-Wen Tsai

    2016-02-01

    Conclusion: Low dose add-back therapy could effectively ameliorate hypoestrogenic side effects and simultaneously maintain the therapeutic response of GnRH agonist treatment. The treatment dropout was lower compared with a regular dose. Therefore, low dose add-back therapy can be considered a treatment choice during postoperative GnRH agonist treatment.

  15. Small-molecule agonists for the glucagon-like peptide 1 receptor

    DEFF Research Database (Denmark)

    Knudsen, Lotte Bjerre; Kiel, Dan; Teng, Min

    2007-01-01

    and independent agonists. Potency of GLP-1 was not changed by the allosteric agonists, but affinity of GLP-1 for the receptor was increased. The most potent compound identified stimulates glucose-dependent insulin release from normal mouse islets but, importantly, not from GLP-1 receptor knockout mice. Also...

  16. Agonist-induced desensitization of human β3-adrenoceptors expressed in human embryonic kidney cells

    NARCIS (Netherlands)

    Michel-Reher, Martina B.; Michel, Martin C.

    2013-01-01

    β3-Adrenoceptors are resistant to agonist-induced desensitization in some cell types but susceptible in others including transfected human embryonic kidney (HEK) cells. Therefore, we have studied cellular and molecular changes involved in agonist-induced β3-adrenoceptor desensitization in HEK cells.

  17. Long-acting beta 2-agonists in chronic obstructive pulmonary disease.

    Science.gov (United States)

    Llewellyn-Jones, Carol

    2002-01-01

    Until recently, the use of long-acting beta 2-agonists in chronic obstructive pulmonary disease has been understated. There is now evidence that they may offer benefits beyond bronchodilation. This article reviews the management of chronic obstructive pulmonary disease and looks at the place of long-acting beta 2-agonists as a first-line treatment option.

  18. Long-term outcome of patients with macroprolactinomas initially treated with dopamine agonists

    NARCIS (Netherlands)

    Kars, Marleen; Pereira, Alberto M.; Smit, Johannes W.; Romijn, Johannes A.

    2009-01-01

    Dopamine agonists are the first line therapy for the treatment of prolactinomas. The aim of this study was to assess the outcome of macroprolactinomas during long-term follow-up after initial treatment with dopamine agonists. Retrospective follow-up study. We included 72 consecutive patients (age

  19. Impact of estradiol, estrogen receptor subtype-selective agonists and genistein on energy homeostasis

    OpenAIRE

    Weigt, Carmen

    2013-01-01

    The prevalence of obesity is dramatically increasing and thus constitutes a major risk factor for developing chronic diseases such as type 2 diabetes, dyslipidemia, cardiovascular diseases, and certain forms of cancer. High-caloric nutrition and a lack of physical activity are the main contributing factors for this global epidemic. Estrogen receptors (ERs) are recognized to be involved in many processes related to the control of energy homeostasis. In my studies, I investigated the impac...

  20. Synthesis of tritium-labelled (-)-U50,488, a selective kappa opioid agonist

    International Nuclear Information System (INIS)

    Thurkauf, A.; Costa, B. de; Rice, K.C.

    1989-01-01

    The preparation of 3 H labelled (-)-trans-3,4-dichloro-N-methyl-N[2-(1-pyrrolidinyl) cyclohexyl]benzeneacetamide (U50,488) in four steps from N-methylcyclohexylaziridine is described. The synthesis of the pharmacologically active (-) isomer of U50, 488 was accomplished through the resolution of the intermediate 2-[1-(3-pyrrolinyl)]-N-methylcyclohexylamine using (+)-mandelic acid. (Author)

  1. Radiosynthesis and characterisation of a potent and selective GPR139 agonist radioligand

    Czech Academy of Sciences Publication Activity Database

    Kuhne, S.; Nohr, A. C.; Marek, Aleš; Elbert, Tomáš; Klein, A. B.; Bräuner-Osborne, H.; Wellendorph, P.; Pedersen, D. S.

    2016-01-01

    Roč. 6, č. 2 (2016), s. 947-952 ISSN 2046-2069 Grant - others:COST(XE) CM1207 Institutional support: RVO:61388963 Keywords : protein-coupled receptors * amino acids Subject RIV: CC - Organic Chemistry Impact factor: 3.108, year: 2016 http://pubs.rsc.org/en/content/articlehtml/2016/ra/c5ra21326f

  2. Helminthosporic acid functions as an agonist for gibberellin receptor.

    Science.gov (United States)

    Miyazaki, Sho; Jiang, Kai; Kobayashi, Masatomo; Asami, Tadao; Nakajima, Masatoshi

    2017-11-01

    Helminthosporol was isolated from a fungus, Helminthosporium sativum, as a natural plant growth regulator in 1963. It showed gibberellin-like bioactivity that stimulated the growth of the second leaf sheath of rice. After studying the structure-activity relationship between the compound and some synthesized analogs, it was found that helminthosporic acid (H-acid) has higher gibberellin-like activity and chemical stability than helminthosporol. In this study, we showed that (1) H-acid displays gibberellin-like activities not only in rice but also in Arabidopsis, (2) it regulates the expression of gibberellin-related genes, (3) it induces DELLA degradation through binding with a gibberellin receptor (GID1), and (4) it forms the GID1-(H-acid)-DELLA complex to transduce the gibberellin signal in the same manner as gibberellin. This work shows that the H-acid mode of action acts as an agonist for gibberellin receptor.

  3. PPAR Agonists: Potential as Therapeutics for Neovascular Retinopathies

    Directory of Open Access Journals (Sweden)

    Harrihar A. Pershadsingh

    2008-01-01

    Full Text Available The angiogenic, neovascular proliferative retinopathies, proliferative diabetic retinopathy (PDR, and age-dependent macular degeneration (AMD complicated by choroidal neovascularization (CNV, also termed exudative or “wet” AMD, are common causes of blindness. The antidiabetic thiazolidinediones (TZDs, rosiglitazone, and troglitazone are PPAR agonists with demonstrable antiproliferative, and anti-inflammatory effects, in vivo, were shown to ameliorate PDR and CNV in rodent models, implying the potential efficacy of TZDs for treating proliferative retinopathies in humans. Activation of the angiotensin II type 1 receptor (AT1-R propagates proinflammatory and proliferative pathogenic determinants underlying PDR and CNV. The antihypertensive dual AT1-R blocker (ARB, telmisartan, recently was shown to activate PPAR and improve glucose and lipid metabolism and to clinically improve PDR and CNV in rodent models. Therefore, the TZDs and telmisartan, clinically approved antidiabetic and antihypertensive drugs, respectively, may be efficacious for treating and attenuating PDR and CNV humans. Clinical trials are needed to test these possibilities.

  4. Climate Change Journalism: From Agony to Agonistic Debate

    Directory of Open Access Journals (Sweden)

    Yves Pepermans

    2017-04-01

    Full Text Available Starting from a politicized outlook on climate change, this essay criticizes mainstream journalistic norms for failing to enable an agonistic, democratic debate about how to move forward. Based on a targeted search for examples from the reporting (and reflection thereof of two Dutch-speaking alternative news sites (DeWereldMorgen and De Correspondent, we seek to illustrate how their respective (climate journalists look for truth, generate democratic debate and hold power accountable by combining practices from constructive journalism, slow journalism and advocacy journalism. We find these journalists to focus on patterns, root causes and underlying values, rather than on novelty or exceptional events. Furthermore, an impartial and detached style of reporting is explicitly denounced in favor of an open and reflexive choice of news-making based on advocacy.

  5. TSH and Thyrotropic Agonists: Key Actors in Thyroid Homeostasis

    Science.gov (United States)

    Dietrich, Johannes W.; Landgrafe, Gabi; Fotiadou, Elisavet H.

    2012-01-01

    This paper provides the reader with an overview of our current knowledge of hypothalamic-pituitary-thyroid feedback from a cybernetic standpoint. Over the past decades we have gained a plethora of information from biochemical, clinical, and epidemiological investigation, especially on the role of TSH and other thyrotropic agonists as critical components of this complex relationship. Integrating these data into a systems perspective delivers new insights into static and dynamic behaviour of thyroid homeostasis. Explicit usage of this information with mathematical methods promises to deliver a better understanding of thyrotropic feedback control and new options for personalised diagnosis of thyroid dysfunction and targeted therapy, also by permitting a new perspective on the conundrum of the TSH reference range. PMID:23365787

  6. TSH and Thyrotropic Agonists: Key Actors in Thyroid Homeostasis

    Directory of Open Access Journals (Sweden)

    Johannes W. Dietrich

    2012-01-01

    Full Text Available This paper provides the reader with an overview of our current knowledge of hypothalamic-pituitary-thyroid feedback from a cybernetic standpoint. Over the past decades we have gained a plethora of information from biochemical, clinical, and epidemiological investigation, especially on the role of TSH and other thyrotropic agonists as critical components of this complex relationship. Integrating these data into a systems perspective delivers new insights into static and dynamic behaviour of thyroid homeostasis. Explicit usage of this information with mathematical methods promises to deliver a better understanding of thyrotropic feedback control and new options for personalised diagnosis of thyroid dysfunction and targeted therapy, also by permitting a new perspective on the conundrum of the TSH reference range.

  7. INSIGHT AGONISTES: A READING OF SOPHOCLES'S OEDIPUS THE KING.

    Science.gov (United States)

    Mahon, Eugene J

    2015-07-01

    In this reading of Sophocles's Oedipus the King, the author suggests that insight can be thought of as the main protagonist of the tragedy. He personifies this depiction of insight, calling it Insight Agonistes, as if it were the sole conflicted character on the stage, albeit masquerading at times as several other characters, including gods, sphinxes, and oracles. This psychoanalytic reading of the text lends itself to an analogy between psychoanalytic process and Sophocles's tragic hero. The author views insight as always transgressing against, always at war with a conservative, societal, or intrapsychic chorus of structured elements. A clinical vignette is presented to illustrate this view of insight. © 2015 The Psychoanalytic Quarterly, Inc.

  8. [Safety and tolerability of GLP-1 receptor agonists].

    Science.gov (United States)

    Soldevila, Berta; Puig-Domingo, Manel

    2014-09-01

    Glucagon-like peptide-1 receptor agonists (GLP-1ra) are a new group of drugs with a glucose-lowering action due to their incretin effect. The GLP-1 receptor is expressed in various human tissues, which could be related to the pleiotropic effects of human GLP-1, as well as to the adverse effects described in patients treated with GLP-1ra. The risk of hypoglycaemia is low, which is one of the main considerations in the safety of this family of compounds and is also important to patients with diabetes. The most frequent adverse effect is nausea, which usually occurs at the start of treatment and is transient in 20-60% of affected patients. This article also reviews the information available on antibody formation, the potential effect on the thyroid gland, and the controversial association between this group of drugs with pancreatitis and cancer. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

  9. Could Dopamine Agonists Aid in Drug Development for Anorexia Nervosa?

    Science.gov (United States)

    Frank, Guido K. W.

    2014-01-01

    Anorexia nervosa is a severe psychiatric disorder most commonly starting during the teenage-years and associated with food refusal and low body weight. Typically there is a loss of menses, intense fear of gaining weight, and an often delusional quality of altered body perception. Anorexia nervosa is also associated with a pattern of high cognitive rigidity, which may contribute to treatment resistance and relapse. The complex interplay of state and trait biological, psychological, and social factors has complicated identifying neurobiological mechanisms that contribute to the illness. The dopamine D1 and D2 neurotransmitter receptors are involved in motivational aspects of food approach, fear extinction, and cognitive flexibility. They could therefore be important targets to improve core and associated behaviors in anorexia nervosa. Treatment with dopamine antagonists has shown little benefit, and it is possible that antagonists over time increase an already hypersensitive dopamine pathway activity in anorexia nervosa. On the contrary, application of dopamine receptor agonists could reduce circuit responsiveness, facilitate fear extinction, and improve cognitive flexibility in anorexia nervosa, as they may be particularly effective during underweight and low gonadal hormone states. This article provides evidence that the dopamine receptor system could be a key factor in the pathophysiology of anorexia nervosa and dopamine agonists could be helpful in reducing core symptoms of the disorder. This review is a theoretical approach that primarily focuses on dopamine receptor function as this system has been mechanistically better described than other neurotransmitters that are altered in anorexia nervosa. However, those proposed dopamine mechanisms in anorexia nervosa also warrant further study with respect to their interaction with other neurotransmitter systems, such as serotonin pathways. PMID:25988121

  10. Could dopamine agonists aid in drug development for anorexia nervosa?

    Science.gov (United States)

    Frank, Guido K W

    2014-01-01

    Anorexia nervosa is a severe psychiatric disorder most commonly starting during the teenage-years and associated with food refusal and low body weight. Typically there is a loss of menses, intense fear of gaining weight, and an often delusional quality of altered body perception. Anorexia nervosa is also associated with a pattern of high cognitive rigidity, which may contribute to treatment resistance and relapse. The complex interplay of state and trait biological, psychological, and social factors has complicated identifying neurobiological mechanisms that contribute to the illness. The dopamine D1 and D2 neurotransmitter receptors are involved in motivational aspects of food approach, fear extinction, and cognitive flexibility. They could therefore be important targets to improve core and associated behaviors in anorexia nervosa. Treatment with dopamine antagonists has shown little benefit, and it is possible that antagonists over time increase an already hypersensitive dopamine pathway activity in anorexia nervosa. On the contrary, application of dopamine receptor agonists could reduce circuit responsiveness, facilitate fear extinction, and improve cognitive flexibility in anorexia nervosa, as they may be particularly effective during underweight and low gonadal hormone states. This article provides evidence that the dopamine receptor system could be a key factor in the pathophysiology of anorexia nervosa and dopamine agonists could be helpful in reducing core symptoms of the disorder. This review is a theoretical approach that primarily focuses on dopamine receptor function as this system has been mechanistically better described than other neurotransmitters that are altered in anorexia nervosa. However, those proposed dopamine mechanisms in anorexia nervosa also warrant further study with respect to their interaction with other neurotransmitter systems, such as serotonin pathways.

  11. Could Dopamine Agonists Aid in Drug Development for Anorexia Nervosa?

    Directory of Open Access Journals (Sweden)

    Guido eFrank

    2014-11-01

    Full Text Available Anorexia nervosa is a severe psychiatric disorder most commonly starting during the teenage years and associated with food refusal and low body weight. Typically there is a loss of menses, intense fear of gaining weight and an often delusional quality of altered body perception. Anorexia nervosa is also associated with a pattern of high cognitive rigidity, which may contribute to treatment resistance and relapse. The complex interplay of state and trait biological, psychological and social factors has complicated identifying neurobiological mechanisms that contribute to the illness. The dopamine D1 and D2 neurotransmitter receptors are involved in motivational aspects of food approach, fear extinction and cognitive flexibility. They could therefore be important targets to improve core and associated behaviors in anorexia nervosa. Treatment with dopamine antagonists has shown little benefit, and it is possible that antagonists over time increase an already hypersensitive dopamine pathway activity in anorexia nervosa. On the contrary, application of dopamine receptor agonists could reduce circuit responsiveness, facilitate fear extinction and improve cognitive flexibility in anorexia nervosa, as they may be particularly effective during underweight and low gonadal hormone states. This article provides evidence that the dopamine receptor system could be a key factor in the pathophysiology of anorexia nervosa and dopamine agonists could be helpful in reducing core symptoms of the disorder. This review is a theoretical approach that primarily focuses on dopamine receptor function as this system has been mechanistically better described than other neurotransmitters that are altered in anorexia nervosa. However, those proposed dopamine mechanisms in anorexia nervosa also warrant further study with respect to their interaction with other neurotransmitter systems, such as serotonin pathways.

  12. Metabolic effects of beta2-agonists in relation to exercise performance

    DEFF Research Database (Denmark)

    Kalsen, Anders

    2015-01-01

    athletes. The present PhD thesis is based on four manuscripts in which the acute effects of beta2-agonists on exercise performance were investigated. The aims were 1) to investigate whether supratherapeutic inhalation of beta2-agonists enhances muscle strength, anaerobic performance and aerobic performance......, 2) to uncover the mechanisms behind potential beta2-adrenergic improvements in anaerobic performance, 3) to investigate whether inhalation of beta2-agonists is ergogenic in elite athletes with or without airway hyperresponsiveness (AHR). Results from the studies of the thesis show...... administration of a certain dose, but a further increase in dose does not seem to elicit a greater performance-enhancing effect. Moreover, the effects of beta2-agonists on performance are unaffected by training status and AHR, but athletes with AHR who regularly use beta2-agonists get a reduced ergogenic...

  13. Melanocortin Tetrapeptide Ac-His-DPhe-Arg-Trp-NH2 Modified at the Para Position of the Benzyl Side Chain (DPhe): Importance for Mouse Melanocortin-3 Receptor Agonist versus Antagonist Activity

    OpenAIRE

    Proneth, Bettina; Pogozheva, Irina D.; Portillo, Federico P.; Mosberg, Henry I.; Haskell-Luevano, Carrie

    2008-01-01

    The melanocortin-3 and -4 receptors (MC3R, MC4R) have been implicated in energy homeostasis and obesity. Whereas the physiological role of the MC4R is extensively studied, little is known about the MC3R. One caveat is the limited availability of ligands that are selective for the MC3R. Previous studies identified Ac-His-DPhe(p-I)-Arg-Trp-NH2, which possessed partial agonist/antagonist pharmacology at the mMC3R while retaining full nanomolar agonist pharmacology at the mMC4R. These data allowe...

  14. β3-adrenoceptor agonist prevents alterations of muscle diacylglycerol and adipose tissue phospholipids induced by a cafeteria diet

    Directory of Open Access Journals (Sweden)

    Darimont Christian

    2004-08-01

    Full Text Available Abstract Background Insulin resistance induced by a high fat diet has been associated with alterations in lipid content and composition in skeletal muscle and adipose tissue. Administration of β3-adrenoceptor (β3-AR agonists was recently reported to prevent insulin resistance induced by a high fat diet, such as the cafeteria diet. The objective of the present study was to determine whether a selective β3-AR agonist (ZD7114 could prevent alterations of the lipid profile of skeletal muscle and adipose tissue lipids induced by a cafeteria diet. Methods Male Sprague-Dawley rats fed a cafeteria diet were treated orally with either the β3-AR agonist ZD7114 (1 mg/kg per day or the vehicle for 60 days. Rats fed a chow diet were used as a reference group. In addition to the determination of body weight and insulin plasma level, lipid content and fatty acid composition in gastronemius and in epididymal adipose tissue were measured by gas-liquid chromatography, at the end of the study. Results In addition to higher body weights and plasma insulin concentrations, rats fed a cafeteria diet had greater triacylglycerol (TAG and diacylglycerol (DAG accumulation in skeletal muscle, contrary to animals fed a chow diet. As expected, ZD7114 treatment prevented the excessive weight gain and hyperinsulinemia induced by the cafeteria diet. Furthermore, in ZD7114 treated rats, intramyocellular DAG levels were lower and the proportion of polyunsaturated fatty acids, particularly arachidonic acid, in adipose tissue phospholipids was higher than in animals fed a cafeteria diet. Conclusions These results show that activation of the β3-AR was able to prevent lipid alterations in muscle and adipose tissue associated with insulin resistance induced by the cafeteria diet. These changes in intramyocellular DAG levels and adipose tissue PL composition may contribute to the improved insulin sensitivity associated with β3-AR activation.

  15. Progress in the development of histamine H3 receptor antagonists/inverse agonists: a patent review (2013-2017).

    Science.gov (United States)

    Łażewska, Dorota; Kieć-Kononowicz, Katarzyna

    2018-03-01

    Since years, ligands blocking histamine H 3 receptor (H 3 R) activity (antagonists/inverse agonists) are interesting targets in the search for new cures for CNS disorders. Intensive works done by academic and pharmaceutical company researchers have led to many potent and selective H 3 R antagonists/inverse agonists. Some of them have reached to clinical trials. Areas covered: Patent applications from January 2013 to September 2017 and the most important topics connected with H 3 R field are analysed. Espacenet, Patentscope, Pubmed, GoogleScholar or Cochrane Library online databases were principially used to collect all the materials. Expert opinion: The research interest in histamine H 3 R field is still high although the number of patent applications has decreased during the past 4 years (around 20 publications). Complexity of histamine H 3 R biology e.g. many isoforms, constitutive activity, heteromerization with other receptors (dopamine D 2 , D 1 , adenosine A 2A ) and pharmacology make not easy realization and evaluation of therapeutic potential of anti-H 3 R ligands. First results from clinical trials have verified potential utility of histamine H 3 R antagonist/inverse agonists in some diseases. However, more studies are necessary for better understanding of an involvement of the histaminergic system in CNS-related disorders and helping more ligands approach to clinical trials and the market. Lists of abbreviations: hAChEI - human acetylcholinesterase inhibitor; hBuChEI - human butyrylcholinesterase inhibitor; hMAO - human monoamine oxidase; MAO - monoamine oxidase.

  16. Anti-analgesic effect of the mu/delta opioid receptor heteromer revealed by ligand-biased antagonism.

    Directory of Open Access Journals (Sweden)

    Laura Milan-Lobo

    Full Text Available Delta (DOR and mu opioid receptors (MOR can complex as heteromers, conferring functional properties in agonist binding, signaling and trafficking that can differ markedly from their homomeric counterparts. Because of these differences, DOR/MOR heteromers may be a novel therapeutic target in the treatment of pain. However, there are currently no ligands selective for DOR/MOR heteromers, and, consequently, their role in nociception remains unknown. In this study, we used a pharmacological opioid cocktail that selectively activates and stabilizes the DOR/MOR heteromer at the cell surface by blocking its endocytosis to assess its role in antinociception. We found that mice treated chronically with this drug cocktail showed a significant right shift in the ED50 for opioid-mediated analgesia, while mice treated with a drug that promotes degradation of the heteromer did not. Furthermore, promoting degradation of the DOR/MOR heteromer after the right shift in the ED50 had occurred, or blocking signal transduction from the stabilized DOR/MOR heteromer, shifted the ED50 for analgesia back to the left. Taken together, these data suggest an anti-analgesic role for the DOR/MOR heteromer in pain. In conclusion, antagonists selective for DOR/MOR heteromer could provide an avenue for alleviating reduced analgesic response during chronic pain treatment.

  17. Melanocortin tetrapeptide Ac-His-DPhe-Arg-Trp-NH2 modified at the para position of the benzyl side chain (DPhe): importance for mouse melanocortin-3 receptor agonist versus antagonist activity.

    Science.gov (United States)

    Proneth, Bettina; Pogozheva, Irina D; Portillo, Federico P; Mosberg, Henry I; Haskell-Luevano, Carrie

    2008-09-25

    The melanocortin-3 and -4 receptors (MC3R, MC4R) have been implicated in energy homeostasis and obesity. Whereas the physiological role of the MC4R is extensively studied, little is known about the MC3R. One caveat is the limited availability of ligands that are selective for the MC3R. Previous studies identified Ac-His-DPhe(p-I)-Arg-Trp-NH 2, which possessed partial agonist/antagonist pharmacology at the mMC3R while retaining full nanomolar agonist pharmacology at the mMC4R. These data allowed for the hypothesis that the DPhe position in melanocortin tetrapeptides can be used to examine ligand side-chain determinants important for differentiation of mMC3R agonist versus antagonist activity. A series of 15 DPhe (7) modified Ac-His-DPhe (7)-Arg-Trp-NH 2 tetrapeptides has been synthesized and pharmacologically characterized. Most notable results include the identification of modifications that resulted in potent antagonists/partial agonists at the mMC3R and full, potent agonists at the mMC4R. These SAR studies provide experimental evidence that the molecular mechanism of antagonism at the mMC3R differentiates this subtype from the mMC4R.

  18. Preparation of human Melanocortin-4 receptor agonist libraries: linear peptides X-Y-DPhe7-Arg8-Trp(or 2-Nal)9-Z-NH2.

    Science.gov (United States)

    Cheung, Adrian Wai-Hing; Qi, Lida; Gore, Vijay; Chu, Xin-Jie; Bartkovitz, David; Kurylko, Grazyna; Swistok, Joseph; Danho, Waleed; Chen, Li; Yagaloff, Keith

    2005-12-15

    Two libraries of hMC4R agonists, X-Y-DPhe(7)-Arg(8)-2-Nal(9)-Z-NH(2) and X-Y-DPhe(7)-Arg(8)-Trp(9)-Z-NH(2), totaling 185 peptides were prepared using Irori radiofrequency tagging technology and Argonaut Quest 210 Synthesizer, where X stands for N-caps, Y for His(6) surrogates and Z for Gly(10) surrogates. As a result of this study, His-modified pentapeptides with Trp were found to be more hMC4R potent than the corresponding 2-Nal analogs, novel N-caps and Gly surrogates were identified and 19 new peptides which are potent hMC4R agonists (EC(50) 1-15nM) and selective against hMC1R were discovered.

  19. Antidepressant-like effects of nicotinic acetylcholine receptor antagonists, but not agonists, in the mouse forced swim and mouse tail suspension tests

    DEFF Research Database (Denmark)

    Andreasen T., Jesper; Olsen, G M; Wiborg, O

    2009-01-01

    Current literature suggests involvement of nicotinic acetylcholine receptors (nAChRs) in major depression. However, it is controversial whether the antidepressant-like effect of nAChR modulation is induced by activation, desensitization or inhibition of central nAChRs. In addition, the specific n......AChR subtype/s involved remains unknown. In this study, we systematically compared the effects of non-selective and selective nicotinic agonists and antagonists in two different tests for antidepressant effects in mice: the tail suspension test and the forced swim test. Compounds: nicotine, RJR-2403 (alpha4...

  20. Synthesis and evaluation of 18F-labeled 5-HT2A receptor agonists as PET ligands

    International Nuclear Information System (INIS)

    Herth, Matthias M.; Petersen, Ida Nymann; Hansen, Hanne Demant; Hansen, Martin; Ettrup, Anders; Jensen, Anders A.; Lehel, Szabolcs; Dyssegaard, Agnete; Gillings, Nic; Knudsen, Gitte M.

    2016-01-01

    Introduction: The serotonin 2A receptor (5-HT 2A R) is the most abundant excitatory 5-HT receptor in the human brain and implicated in various brain disorders such as schizophrenia, depression, and Alzheimer's disease. Positron emission tomography (PET) can be used to image specific proteins and processes in the human brain and several 5-HT 2A R PET antagonist radioligands are available. In contrast to an antagonist radioligand, an agonist radioligand should be able to image the population of functional receptors, i.e., those capable of inducing neuroreceptor signaling. Recently, we successfully developed and validated the first 5-HT 2A R agonist PET tracer, [ 11 C]Cimbi-36, for neuroimaging in humans and herein disclose some of our efforts to develop an 18 F-labeled 5-HT 2A R agonist PET-ligand. Methods and results: Three fluorine containing derivatives of Cimbi-36 were synthesized and found to be potent 5-HT 2A agonists. 18 F-labeling of the appropriate precursors was performed using [ 18 F]FETos, typically yielding 0.2–2.0 GBq and specific activities of 40–120 GBq/μmol. PET studies in Danish landrace pigs revealed that [ 18 F]1 displayed brain uptake in 5-HT 2A R rich regions. However, high uptake in bone was also observed. No blocking effect was detected during a competition experiment with a 5-HT 2A R selective antagonist. [ 18 F]2 and [ 18 F]3 showed very low brain uptake. Conclusion: None of the investigated 18 F-labeled Cimbi-36 derivatives [ 18 F]1, [ 18 F]2 and [ 18 F]3 show suitable tracer characteristics for in vivo PET neuroimaging of the 5-HT 2A R. Although for [ 18 F]1 there was reasonable brain uptake, we suggest that a large proportion radioactivity in the brain was due to radiometabolites, which would explain why it could not be displaced by a 5-HT 2A R antagonist.

  1. Aryl hydrocarbon receptor (AhR agonists suppress interleukin-6 expression by bone marrow stromal cells: an immunotoxicology study

    Directory of Open Access Journals (Sweden)

    Schlezinger Jennifer J

    2003-12-01

    Full Text Available Abstract Background Bone marrow stromal cells produce cytokines required for the normal growth and development of all eight hematopoietic cell lineages. Aberrant cytokine production by stromal cells contributes to blood cell dyscrasias. Consequently, factors that alter stromal cell cytokine production may significantly compromise the development of normal blood cells. We have shown that environmental chemicals, such as aromatic hydrocarbon receptor (AhR agonists, suppress B lymphopoiesis by modulating bone marrow stromal cell function. Here, we extend these studies to evaluate the potential for two prototypic AhR agonists, 7,12-dimethylbenz [a]anthracene (DMBA and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, to alter stromal cell cytokine responses. Methods Bone marrow stromal cells were treated with AhR agonists and bacterial lipopolysaccharide (LPS to mimic innate inflammatory cytokine responses and to study the effects of AhR ligands on those responses. Steady state cytokine RNA levels were screened by RNAse protection assays (RPA and quantified by real-time PCR. Cytokine (IL-6 protein production was measured by ELISA. NF-κB EMSAs were used to study IL-6 transcriptional regulation. Results RPAs indicated that AhR+ bone marrow stromal cells consistently up-regulated genes encoding IL-6 and LIF in response to LPS, presumably through activation of Toll-like receptor 4. Pre-treatment with low doses of DMBA or TCDD selectively abrogated IL-6 gene induction but had no effect on LIF mRNA. Real-time-PCR indicated a significant inhibition of IL-6 mRNA by AhR ligands within 1 hour of LPS challenge which was reflected in a profound down-regulation of IL-6 protein induction, with DMBA and TCDD suppressing IL-6 levels as much as 65% and 88%, respectively. This potent inhibitory effect persisted for at least 72 hours. EMSAs measuring NF-κB binding to IL-6 promoter sequences, an event known to induce IL-6 transcription, indicated a significant decrease in

  2. The Novel, Nicotinic Alpha7 Receptor Partial Agonist, BMS-933043, Improves Cognition and Sensory Processing in Preclinical Models of Schizophrenia.

    Directory of Open Access Journals (Sweden)

    Linda J Bristow

    Full Text Available The development of alpha7 nicotinic acetylcholine receptor agonists is considered a promising approach for the treatment of cognitive symptoms in schizophrenia patients. In the present studies we characterized the novel agent, (2R-N-(6-(1H-imidazol-1-yl-4-pyrimidinyl-4'H-spiro[4-azabicyclo[2.2.2]octane-2,5'-[1,3]oxazol]-2'-amine (BMS-933043, in vitro and in rodent models of schizophrenia-like deficits in cognition and sensory processing. BMS-933043 showed potent binding affinity to native rat (Ki = 3.3 nM and recombinant human alpha7 nicotinic acetylcholine receptors (Ki = 8.1 nM and agonist activity in a calcium fluorescence assay (EC50 = 23.4 nM and whole cell voltage clamp electrophysiology (EC50 = 0.14 micromolar (rat and 0.29 micromolar (human. BMS-933043 exhibited a partial agonist profile relative to acetylcholine; the relative efficacy for net charge crossing the cell membrane was 67% and 78% at rat and human alpha7 nicotinic acetylcholine receptors respectively. BMS-933043 showed no agonist or antagonist activity at other nicotinic acetylcholine receptor subtypes and was at least 300 fold weaker at binding to and antagonizing human 5-HT3A receptors (Ki = 2,451 nM; IC50 = 8,066 nM. BMS-933043 treatment i improved 24 hour novel object recognition memory in mice (0.1-10 mg/kg, sc, ii reversed MK-801-induced deficits in Y maze performance in mice (1-10 mg/kg, sc and set shift performance in rats (1-10 mg/kg, po and iii reduced the number of trials required to complete the extradimensional shift discrimination in neonatal PCP treated rats performing the intra-dimensional/extradimensional set shifting task (0.1-3 mg/kg, po. BMS-933043 also improved auditory gating (0.56-3 mg/kg, sc and mismatch negativity (0.03-3 mg/kg, sc in rats treated with S(+ketamine or neonatal phencyclidine respectively. Given this favorable preclinical profile BMS-933043 was selected for further development to support clinical evaluation in humans.

  3. The emergence of devastating impulse control disorders during dopamine agonist therapy of the restless legs syndrome.

    Science.gov (United States)

    Dang, Dien; Cunnington, David; Swieca, John

    2011-01-01

    The Restless Legs Syndrome is a common sensorimotor disorder, typically amenable to treatment with dopamine agonist therapy. Dopamine agonists have been associated with emergent impulse control disorders (ICDs) when used in patients with Parkinson disease, and ICDs have now been reported in individuals with RLS on dopamine agonist therapy. Our aim was to characterize cases of emergent ICDs in Australian patients with focus on the dopamine agonists implicated and the social significance of ICDs. A series of RLS patients on dopamine agonist therapy were identified with ICDs over a 2-year period. Additional cases of ICDs were found using a mailout questionnaire designed to capture those with high impulsivity. These patients were assessed using the Barratt Impulsiveness Scale, Version 11, and a modified Minnesota Impulse Disorders Interview. Case records and medication schedules were evaluated. Twelve cases of patients with de novo ICDs were found with a range of impulsive behaviors including pathological gambling, kleptomania, compulsive shopping, and hypersexuality. Criminality, suicidality, and marital discord also were featured. These occurred over a wide range of latencies and l-dopa exposures. This group of Australian RLS patients with ICDs display high levels of impulsivity and is the first to use the BIS-11 questionnaire in this setting. Impulse control disorders can occur over a wide range of dopamine agonist therapy types and dose exposures. Impulse control disorder tendencies may persist, despite withdrawal of dopamine agonists. The emergence of ICDs needs careful consideration in light of their potentially devastating financial, social, and marital consequences.

  4. Ascorbic acid enables reversible dopamine receptor 3H-agonist binding

    International Nuclear Information System (INIS)

    Leff, S.; Sibley, D.R.; Hamblin, M.; Creese, I.

    1981-01-01

    The effects of ascorbic acid on dopaminergic 3 H-agonist receptor binding were studied in membrane homogenates of bovine anterior pituitary and caudate, and rat striatum. In all tissues virtually no stereospecific binding (defined using 1uM (+)butaclamol) of the 3 H-agonists N-propylnorapomorphine (NPA), apomorphine, or dopamine could be demonstrated in the absence of ascorbic acid. Although levels of total 3 H-agonist binding were three to five times greater in the absence than in the presence of 0.1% ascorbic acid, the increased binding was entirely non-stereospecific. Greater amounts of dopamine-inhibitable 3 H-NPA binding could be demonstrated in the absence of 0.1% ascorbic acid, but this measure of ''specific binding'' was demonstrated not to represent dopamine receptor binding since several other catecholamines and catechol were equipotent with dopamine and more potent than the dopamine agonist (+/-)amino-6,7-dihydroxy-1,2,3,4-tetrahydronapthalene (ADTN) in inhibiting this binding. High levels of dopamine-displaceable 3 H-agonist binding were detected in fresh and boiled homogenates of cerebellum, an area of brain which receives no dopaminergic innervation, further demonstrating the non-specific nature of 3 H-agonist binding in the absence of ascorbic acid. These studies emphasize that under typical assay conditions ascorbic acid is required in order to demonstrate reversible and specific 3 H-agonist binding to dopamine receptors

  5. Drug-induced mild therapeutic hypothermia obtained by administration of a transient receptor potential vanilloid type 1 agonist

    DEFF Research Database (Denmark)

    Fosgerau, Keld; Weber, Uno J; Gotfredsen, Jacob W

    2010-01-01

    Background  The use of mechanical/physical devices for applying mild therapeutic hypothermia is the only proven neuroprotective treatment for survivors of out of hospital cardiac arrest. However, this type of therapy is cumbersome and associated with several side-effects. We investigated the feas......Background  The use of mechanical/physical devices for applying mild therapeutic hypothermia is the only proven neuroprotective treatment for survivors of out of hospital cardiac arrest. However, this type of therapy is cumbersome and associated with several side-effects. We investigated...... the feasibility of using a transient receptor potential vanilloid type 1 (TRPV1) agonist for obtaining drug-induced sustainable mild hypothermia. Methods First, we screened a heterogeneous group of TRPV1 agonists and secondly we tested the hypothermic properties of a selected candidate by dose-response studies...... was stopped. Finally, in calves the intravenous infusion of DHC was able to maintain mild hypothermia with ΔT > -3°C for more than 12 hours. Conclusions Our data support the hypothesis that infusion of dihydrocapsaicin is a candidate for testing as a primary or adjunct method of inducing and maintaining...

  6. Binding Mode of Insulin Receptor and Agonist Peptide

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Insulin is a protein hormone secreted by pancreatic β cells. One of its main functions is to keep the balance of glucose inside the body by regulating the absorption and metabolism of glucose in the periphery tissue, as well as the production and storage of hepatic glycogen. The insulin receptor is a transmembrane glycoprotein in which two α subunits with a molecular weight of 135 kD and twoβ subunits with a molecular weight of 95 kD are joined by a disulfide bond to form a β-α-α-β structure. The extracellular α subunit, especially, its three domains near the N-terminal are partially responsible for signal transduction or ligand-binding, as indicated by the experiments. The extracellular α subunits are involved in binding the ligands. The experimental results indicate that the three domains of the N-terminal of the α subunits are the main determinative parts of the insulin receptor to bind the insulin or mimetic peptide.We employed the extracellular domain (PDBID: 1IGR) of the insulin-like growth factor-1 receptor (IGF-1 R ) as the template to simulate and optimize the spatial structures of the three domains in the extracellular domain of the insulin receptor, which includes 468 residues. The work was accomplished by making use of the homology program in the Insight Ⅱ package on an Origin3800 server. The docking calculations of the insulin receptor obtained by homology with hexapeptides were carried out by means of the program Affinity. The analysis indicated that there were hydrogen bonding, and electrostatic and hydrophobic effects in the docking complex of the insulin receptor with hexapeptides.Moreover, we described the spatial orientation of a mimetic peptide with agonist activity in the docking complex. We obtained a rough model of binding of DLAPSQ or STIVYS with the insulin receptor, which provides the powerful theoretical support for designing the minimal insulin mimetic peptide with agonist activity, making it possible to develop oral small

  7. Opioid receptor mediated anticonvulsant effect of pentazocine.

    Science.gov (United States)

    Khanna, N; Khosla, R; Kohli, J

    1998-01-01

    Intraperitoneal (i.p.) administration of (+/-) pentazocine (10, 30 & 50 mg/kg), a Sigma opioid agonist, resulted in a dose dependent anticonvulsant action against maximal electroshock seizures in mice. This anticonvulsant effect of pentazocine was not antagonized by both the doses of naloxone (1 and 10 mg/kg) suggesting thereby that its anticonvulsant action is probably mediated by Sigma opiate binding sites. Its anticonvulsant effect was potentiated by both the anticonvulsant drugs viz. diazepam and diphenylhydantoin. Morphine, mu opioid agonist, on the other hand, failed to protect the animals against maximal electroshock seizures when it was given in doses of 10-40 mg/kg body wt.

  8. Autonomic failure mimicing dopamine agonist induced vertigo in a patient with macroprolactinoma.

    Science.gov (United States)

    Seiler, L; Braune, S; Borm, K; Magerkurth, C; Talazko, J; Peters, T; Reincke, M

    2002-10-01

    A 68-year-old man presented with general fatigue, increasing adynamia, weakness, vertigo and recurrent syncope. Six weeks earlier the diagnosis of a macroprolactinoma had been established based on a greatly elevated prolactin concentration (161 170 micro U/l) and MR-evidence of a 3.5 cm measuring pituitary mass. The patient had been started on cabergoline (1.5 mg weekly). Orthostatic hypotension due to the dopamine agonist was considered very likely and carbergoline therapy was stopped. However, there was no relief of the symptoms and further syncopes followed. Testing of blood pressure and heart rate regulation, selective testing of postganglionic cardiac neurons with [ 123 J] metaiodobenzylguanidine scintigraphy provided evidence of grossly impaired neurogenic cardiovascular regulation due to failure of postganglionic efferent sympathetic activity. This is characteristic for pure autonomic failure. The patient was treated symptomatically with high fluid intake, compression stockings, fludrohydrocortisone (0.1 mg o.d.s.), piroxicam (20 mg o.d.s.) and etilephrin (10 mg q.d.s.), which enabled him to cope with daily activities without syncope. This case shows that vertigo in a patient with macroprolactinoma is not always related to drug therapy but may be related to other causes.

  9. Promotion of adipogenesis by an EP2 receptor agonist via stimulation of angiogenesis in pulmonary emphysema.

    Science.gov (United States)

    Tsuji, Takao; Yamaguchi, Kazuhiro; Kikuchi, Ryota; Itoh, Masayuki; Nakamura, Hiroyuki; Nagai, Atsushi; Aoshiba, Kazutetsu

    2014-08-01

    Body weight loss is a common manifestation in patients with chronic obstructive pulmonary disease (COPD), particularly those with severe emphysema. Adipose angiogenesis is a key mediator of adipogenesis and use of pro-angiogenic agents may serve as a therapeutic option for lean COPD patients. Since angiogenesis is stimulated by PGE2, we examined whether ONO-AE1-259, a selective E-prostanoid (EP) 2 receptor agonist, might promote adipose angiogenesis and adipogenesis in a murine model of elastase-induced pulmonary emphysema (EIE mice). Mice were intratracheally instilled with elastase or saline, followed after 4 weeks by intraperitoneal administration of ONO-AE1-259 for 4 weeks. The subcutaneous adipose tissue (SAT) weight decreased in the EIE mice, whereas in the EIE mice treated with ONO-AE1-259, the SAT weight was largely restored, which was associated with significant increases in SAT adipogenesis, angiogenesis, and VEGF protein production. In contrast, ONO-AE1-259 administration induced no alteration in the weight of the visceral adipose tissue. These results suggest that in EIE mice, ONO-AE1-259 stimulated adipose angiogenesis possibly via VEGF production, and thence, adipogenesis. Our data pave the way for the development of therapeutic interventions for weight loss in emphysema patients, e.g., use of pro-angiogenic agents targeting the adipose tissue vascular component. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Glucose-induced metabolic memory in Schwann cells: prevention by PPAR agonists.

    Science.gov (United States)

    Kim, Esther S; Isoda, Fumiko; Kurland, Irwin; Mobbs, Charles V

    2013-09-01

    A major barrier in reversing diabetic complications is that molecular and pathologic effects of elevated glucose persist despite normalization of glucose, a phenomenon referred to as metabolic memory. In the present studies we have investigated the effects of elevated glucose on Schwann cells, which are implicated in diabetic neuropathy. Using quantitative PCR arrays for glucose and fatty acid metabolism, we have found that chronic (>8 wk) 25 mM high glucose induces a persistent increase in genes that promote glycolysis, while inhibiting those that oppose glycolysis and alternate metabolic pathways such as fatty acid metabolism, the pentose phosphate pathway, and trichloroacetic acid cycle. These sustained effects were associated with decreased peroxisome proliferator-activated receptor (PPAR)γ binding and persistently increased reactive oxygen species, cellular NADH, and altered DNA methylation. Agonists of PPARγ and PPARα prevented select effects of glucose-induced gene expression. These observations suggest that Schwann cells exhibit features of metabolic memory that may be regulated at the transcriptional level. Furthermore, targeting PPAR may prevent metabolic memory and the development of diabetic complications.

  11. Identification of novel peroxisome proliferator-activated receptor-gamma (PPARγ) agonists using molecular modeling method

    Science.gov (United States)

    Gee, Veronica M. W.; Wong, Fiona S. L.; Ramachandran, Lalitha; Sethi, Gautam; Kumar, Alan Prem; Yap, Chun Wei

    2014-11-01

    Peroxisome proliferator-activated receptor-gamma (PPARγ) plays a critical role in lipid and glucose homeostasis. It is the target of many drug discovery studies, because of its role in various disease states including diabetes and cancer. Thiazolidinediones, a synthetic class of agents that work by activation of PPARγ, have been used extensively as insulin-sensitizers for the management of type 2 diabetes. In this study, a combination of QSAR and docking methods were utilised to perform virtual screening of more than 25 million compounds in the ZINC library. The QSAR model was developed using 1,517 compounds and it identified 42,378 potential PPARγ agonists from the ZINC library, and 10,000 of these were selected for docking with PPARγ based on their diversity. Several steps were used to refine the docking results, and finally 30 potentially highly active ligands were identified. Four compounds were subsequently tested for their in vitro activity, and one compound was found to have a K i values of <5 μM.

  12. In Vivo Protection against Strychnine Toxicity in Mice by the Glycine Receptor Agonist Ivermectin

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    Ahmed Maher

    2014-01-01

    Full Text Available The inhibitory glycine receptor, a ligand-gated ion channel that mediates fast synaptic inhibition in mammalian spinal cord and brainstem, is potently and selectively inhibited by the alkaloid strychnine. The anthelminthic and anticonvulsant ivermectin is a strychnine-independent agonist of spinal glycine receptors. Here we show that ivermectin is an effective antidote of strychnine toxicity in vivo and determine time course and extent of ivermectin protection. Mice received doses of 1 mg/kg and 5 mg/kg ivermectin orally or intraperitoneally, followed by an intraperitoneal strychnine challenge (2 mg/kg. Ivermectin, through both routes of application, protected mice against strychnine toxicity. Maximum protection was observed 14 hours after ivermectin administration. Combining intraperitoneal and oral dosage of ivermectin further improved protection, resulting in survival rates of up to 80% of animals and a significant delay of strychnine effects in up to 100% of tested animals. Strychnine action developed within minutes, much faster than ivermectin, which acted on a time scale of hours. The data agree with a two-compartment distribution of ivermectin, with fat deposits acting as storage compartment. The data demonstrate that toxic effects of strychnine in mice can be prevented if a basal level of glycinergic signalling is maintained through receptor activation by ivermectin.

  13. CL316,243, a β3-adrenergic receptor agonist, induces muscle hypertrophy and increased strength.

    Science.gov (United States)

    Puzzo, Daniela; Raiteri, Roberto; Castaldo, Clotilde; Capasso, Raffaele; Pagano, Ester; Tedesco, Mariateresa; Gulisano, Walter; Drozd, Lisaveta; Lippiello, Pellegrino; Palmeri, Agostino; Scotto, Pietro; Miniaci, Maria Concetta

    2016-11-22

    Studies in vitro have demonstrated that β3-adrenergic receptors (β3-ARs) regulate protein metabolism in skeletal muscle by promoting protein synthesis and inhibiting protein degradation. In this study, we evaluated whether activation of β3-ARs by the selective agonist CL316,243 modifies the functional and structural properties of skeletal muscles of healthy mice. Daily injections of CL316,243 for 15 days resulted in a significant improvement in muscle force production, assessed by grip strength and weight tests, and an increased myofiber cross-sectional area, indicative of muscle hypertrophy. In addition, atomic force microscopy revealed a significant effect of CL316,243 on the transversal stiffness of isolated muscle fibers. Interestingly, the expression level of mammalian target of rapamycin (mTOR) downstream targets and neuronal nitric oxide synthase (NOS) was also found to be enhanced in tibialis anterior and soleus muscles of CL316,243 treated mice, in accordance with previous data linking β3-ARs to mTOR and NOS signaling pathways. In conclusion, our data suggest that CL316,243 systemic administration might be a novel therapeutic strategy worthy of further investigations in conditions of muscle wasting and weakness associated with aging and muscular diseases.

  14. Dose-dependent effects of celecoxib on CB-1 agonist-induced antinociception in the mice

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    Mohammad Reza Zarrindast

    2009-04-01

    Full Text Available "nObjective: Endocannabinoid produce analgesia that is comparable which of opioids. The mechanism of antinociceptive effects of (∆ - 9 tetrahydrocannabinol (THC is suggested to be through cyclooxygenase (COX pathway. In the present work, the effect of two extreme dose ranges of celecoxib (mg/kg and ng/kg, a cyclooxygenase-2 (COX-2 antagonist, on arachidonylcyclopropylamide (ACPA, a selective CB1 agonist induced antinociception in mice was examined. "nMethods: We have investigated the interaction between celecoxib, at the doses of mg/kg (50, 100, 200 and 400 i.p.  and ultra low dose (ULD (25 and 50 ng/kg, i.p., on the antinociceptive effect of intracerebroventricular (i.c.v. administration of ACPA (0.004, 0.0625 and 1 μg/mice, using formalin test in mice. "nResults: I.C.V. administration of ACPA induced antinociception. Intraperitoneal administration of celecoxib (mg/kg and its ULD (ng/kg attenuated and potentiated, ACPA antinociceptive effects, respectively. "nConclusion: It is concluded that the mg/kg doses of COX-2 antagonist showed opposite effects compare to the ultra-low dose of the drug.

  15. Discovery of olodaterol, a novel inhaled beta2-adrenoceptor agonist with a 24 h bronchodilatory efficacy.

    Science.gov (United States)

    Bouyssou, Thierry; Hoenke, Christoph; Rudolf, Klaus; Lustenberger, Philipp; Pestel, Sabine; Sieger, Peter; Lotz, Ralf; Heine, Claudia; Büttner, Frank H; Schnapp, Andreas; Konetzki, Ingo

    2010-02-15

    Compound 4p was identified from a series of 6-hydroxy-4H-benzo[1,4]oxazin-3-ones as potent agonist of the human beta2-adrenoceptor with a high beta1/beta2-selectivity. A complete reversal of acetylcholine-induced bronchoconstriction which lasted over the whole study period of 5h was demonstrated for 4p in a guinea pig in vivo model without any signs of cardiovascular effects up to 10-fold above the first dose reaching 100% bronchoprotection. The enantiomerically pure (R)-form of 4p exerted a bronchodilatory efficacy over 24 h in dogs and guinea pigs in the absence of systemic pharmacodynamic effects. Formoterol which was tested as comparator in the same in vivo models of acetylcholine-induced bronchoconstriction did not retain efficacy after 24 h. In summary, the preclinical profile of compound (R)-4p (olodaterol, also known as BI 1744 CL) suggests a potential for once-daily dosing in man accompanied with an improved safety profile. Copyright 2010 Elsevier Ltd. All rights reserved.

  16. Modulation of Autophagy by a Small Molecule Inverse Agonist of ERRα Is Neuroprotective

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    S. N. Suresh

    2018-04-01

    Full Text Available Mechanistic insights into aggrephagy, a selective basal autophagy process to clear misfolded protein aggregates, are lacking. Here, we report and describe the role of Estrogen Related Receptor α (ERRα, HUGO Gene Nomenclature ESRRA, new molecular player of aggrephagy, in keeping autophagy flux in check by inhibiting autophagosome formation. A screen for small molecule modulators for aggrephagy identified ERRα inverse agonist XCT 790, that cleared α-synuclein aggregates in an autophagy dependent, but mammalian target of rapamycin (MTOR independent manner. XCT 790 modulates autophagosome formation in an ERRα dependent manner as validated by siRNA mediated knockdown and over expression approaches. We show that, in a basal state, ERRα is localized on to the autophagosomes and upon autophagy induction by XCT 790, this localization is lost and is accompanied with an increase in autophagosome biogenesis. In a preclinical mouse model of Parkinson’s disease (PD, XCT 790 exerted neuroprotective effects in the dopaminergic neurons of nigra by inducing autophagy to clear toxic protein aggregates and, in addition, ameliorated motor co-ordination deficits. Using a chemical biology approach, we unrevealed the role of ERRα in regulating autophagy and can be therapeutic target for neurodegeneration.

  17. Sigma-1 receptor agonist fluvoxamine for postoperative delirium in older adults: report of three cases

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    Hashimoto Kenji

    2010-06-01

    Full Text Available Abstract Background Postoperative delirium is a topic of great importance in the geriatric surgical specialty. Although antipsychotic drugs are the medications most frequently used to treat this syndrome, these drugs are associated with a variety of adverse events, including sedation, extrapyramidal side effects, and cardiac arrhythmias. Drug treatment for postoperative delirium requires careful consideration of the balance between the effective management of symptoms and potential adverse effects. Methods We report on a Japanese woman (an 86-year-old (open reduction and internal fixation of the right femoral neck fracture, and two Japanese men (an 86-year-old (abdominal aortic aneurysm stent grafting, and a 77-year-old (right upper lobectomy due to lung tumour in which the selective serotonin reuptake inhibitor and sigma-1 receptor agonist fluvoxamine was effective in ameliorating the postoperative delirium of these patients. Results Delirium Rating Scale scores in these patients dramatically decreased after treatment with fluvoxamine. Conclusions Doctors should consider fluvoxamine as an alternative approach to treating postoperative delirium in older patients in order to avoid the risk of side effects and increased mortality by antipsychotic drugs.

  18. Sigma-1 receptor agonist fluvoxamine for delirium in intensive care units: report of five cases

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    Hashimoto Kenji

    2010-04-01

    Full Text Available Abstract Background Delirium is a highly prevalent disorder among older patients in intensive care units (ICUs. Although antipsychotic drugs are the medications most frequently used to treat this syndrome, these drugs are associated with a variety of adverse events, including sedation, extrapyramidal side effects, and cardiac arrhythmias. Drug treatment for delirium requires careful consideration of the balance between the effective management of symptoms and potential adverse effects. Methods We report on five Japanese men (an 84 year old (acute aortic dissociation: Stanford type A, a 55 year old (traumatic subarachnoid hemorrhage and brain contusion, a 76 year old (sepsis by pyelonephritis, an 85 year old (cerebral infarction, and an 86 year old (pulmonary emphysema and severe pneumonia in which the selective serotonin reuptake inhibitor and sigma-1 receptor agonist fluvoxamine was effective in ameliorating the delirium of the patients. Results Delirium Rating Scale (DRS scores in these five patients dramatically decreased after treatment with fluvoxamine. Conclusion Doctors should consider fluvoxamine as an alternative approach to treating delirium in ICU patients in order to avoid the risk of side effects and increased mortality from antipsychotic drugs.

  19. Effects of alpha-2 agonists on renal function in hypertensive humans.

    Science.gov (United States)

    Goldberg, M; Gehr, M

    1985-01-01

    Centrally acting adrenergic agonists, by decreasing peripheral adrenergic activity, are effective antihypertensive agents. The older agents, however, especially methyldopa, have been associated with weight gain, clinical edema, and antihypertensive tolerance when used as monotherapy. While acute studies in humans have demonstrated weight gain and sodium retention with clonidine and guanabenz, chronic administration results in a decrease in weight and plasma volume. The absence of chronic weight gain and of sodium retention could be the result of a counterbalance between hypotension-related antinatriuresis, secondary to a decrease in glomerular filtration rate and renal blood flow, and natriuretic activity, as a result of a decrease in renal sympathetic tone. Whereas natriuresis and water diuresis have been demonstrated in animals with acute clonidine or guanabenz administration, this has not been demonstrated in humans. Recent studies in which saline administration was used to precondition humans to a subsequent natriuretic stimulus (i.e., guanabenz-induced decreased renal adrenergic activity) resulted in stabilization of renal blood flow and natriuresis. Selective reduction renal sympathetic activity affecting salt and water transport may explain why guanabenz and probably also clonidine seem to be devoid of the sodium/fluid-retaining properties that are common with other antihypertensive agents. Because agents of this class have effects other than pure central alpha-2 agonism (such as alpha-1 activity), they might have confounding and counterbalancing side effects leading to sodium and water retention.

  20. Controlled release of sphingosine-1-phosphate agonist with gelatin hydrogels for macrophage recruitment.

    Science.gov (United States)

    Murakami, Masahiro; Saito, Takashi; Tabata, Yasuhiko

    2014-11-01

    The objective of this study is to design a drug delivery system (DDS) for the in vivo promotion of macrophage recruitment. As the drug, a water-insoluble agonist of sphingosine-1-phosphate type 1 receptor (SEW2871) was selected. SEW2871 (SEW) was water-solubilized by micelle formation with gelatin grafted by L-lactic acid oligomer. SEW micelles were mixed with gelatin, followed by dehydrothermal crosslinking of gelatin to obtain gelatin hydrogels incorporating SEW micelles. SEW was released from the hydrogels incorporating SEW micelles in vitro and in vivo. The water-solubilized SEW showed in vitro macrophage migration activity. When implanted into the back subcutis or the skin wound defect of mice, the hydrogel incorporating SEW micelles promoted macrophage migration toward the tissue around the implanted site to a significantly great extent compared with SEW-free hydrogel and that mixed with SEW micelles. The hydrogel is a promising DDS to enhance macrophage recruitment in vivo. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  1. MF-101, an estrogen receptor beta agonist for the treatment of vasomotor symptoms in peri- and postmenopausal women.

    Science.gov (United States)

    Stovall, Dale W; Pinkerton, Joann V

    2009-04-01

    During peri- and postmenopausal stages, the majority of women experience moderate-to-severe vasomotor symptoms, such as hot flashes and night sweats, that interfere with sleep and reduce quality of life. Estrogen alone or in combination with a progestagen has been the standard therapy for such vasomotor symptoms; however, this therapeutic regimen is associated with severe side effects, such as breast cancer or cardiovascular events. To provide a better treatment option for menopausal women, Bionovo Inc is developing the estrogen receptor (ER)beta-selective agonist MF-101. Selective ER agonists can stimulate either ERalpha or ERbeta and induce tissue-specific estrogen-like effects, thus providing a safer alternative to conventional hormone therapy. MF-101 is derived from 22 herbs that are traditionally used in Chinese medicine for the treatment of menopausal symptoms. MF-101 did not promote the growth of breast cancer cells or stimulate uterine growth in preclinical studies and, in a phase II trial, was demonstrated to be safe and more effective in reducing the frequency and severity of hot flashes in postmenopausal women compared with placebo. To confirm the safety and efficacy of MF-101, larger phase III trials were planned for 2009. Although MF-101 appears to be a promising therapeutic, the herbal composition of the drug may be a disadvantage, because of the increased risk of causing allergic reactions in the general population. Studies with the MF-101-isolated active compounds liquiritigen and chalcone demonstrated selectivity for ERbeta, with no induction of proliferative events. If these isolates were demonstrated to be as effective and safe in clinical trials as preliminary data suggest regarding MF-101, these compounds could change the way clinicians treat menopause-associated symptoms.

  2. Pharmacological profile of DA-6886, a novel 5-HT4 receptor agonist to accelerate colonic motor activity in mice.

    Science.gov (United States)

    Lee, Min Jung; Cho, Kang Hun; Park, Hyun Min; Sung, Hyun Jung; Choi, Sunghak; Im, Weonbin

    2014-07-15

    DA-6886, the gastrointestinal prokinetic benzamide derivative is a novel 5-HT4 receptor agonist being developed for the treatment of constipation-predominant irritable bowel syndrome (IBS-C). The purpose of this study was to characterize in vitro and in vivo pharmacological profile of DA-6886. We used various receptor binding assay, cAMP accumulation assay, organ bath experiment and colonic transit assay in normal and chemically constipated mice. DA-6886 exhibited high affinity and selectivity to human 5-HT4 receptor splice variants, with mean pKi of 7.1, 7.5, 7.9 for the human 5-HT4a, 5-HT4b and 5-HT4d, respectively. By contrast, DA-6886 did not show significant affinity for several receptors including dopamine D2 receptor, other 5-HT receptors except for 5-HT2B receptor (pKi value of 6.2). The affinity for 5-HT4 receptor was translated into functional agonist activity in Cos-7 cells expressing 5-HT4 receptor splice variants. Furthermore, DA-6886 induced relaxation of the rat oesophagus preparation (pEC50 value of 7.4) in a 5-HT4 receptor antagonist-sensitive manner. The evaluation of DA-6886 in CHO cells expressing hERG channels revealed that it inhibited hERG channel current with an pIC50 value of 4.3, indicating that the compound was 1000-fold more selective for the 5-HT4 receptor over hERG channels. In the normal ICR mice, oral administration of DA-6886 (0.4 and 2mg/kg) resulted in marked stimulation of colonic transit. Furthermore, in the loperamide-induced constipation mouse model, 2mg/kg of DA-6886 significantly improved the delay of colonic transit, similar to 10mg/kg of tegaserod. Taken together, DA-6886 is a highly potent and selective 5-HT4 receptor agonist to accelerate colonic transit in mice, which might be therapeutic agent having a favorable safety profile in the treatment of gastrointestinal motor disorders such as IBS-C and chronic constipation. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Interleukin-24 as a target cytokine of environmental aryl hydrocarbon receptor agonist exposure in the lung

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    Luo, Yueh-Hsia; Kuo, Yu-Chun; Tsai, Ming-Hsien; Ho, Chia-Chi; Tsai, Hui-Ti; Hsu, Chin-Yu; Chen, Yu-Cheng; Lin, Pinpin, E-mail: pplin@nhri.org.tw

    2017-06-01

    Exposure to environmental aryl hydrocarbon receptor (AhR) agonists, such as halogenated aromatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs), has great impacts on the development of various lung diseases. As emerging molecular targets for AhR agonists, cytokines may contribute to the inflammatory or immunotoxic effects of environmental AhR agonists. However, general cytokine expression may not specifically indicate environmental AhR agonist exposure. By comparing cytokine and chemokine expression profiles in human lung adenocarcinoma cell line CL5 treated with AhR agonists and the non-AhR agonist polychlorinated biphenyl (PCB) 39, we identified a target cytokine of environmental AhR agonist exposure of in the lungs. Thirteen cytokine and chemokine genes were altered in the AhR agonists-treated cells, but none were altered in the PCB39-treated cells. Interleukin (IL)-24 was the most highly induced gene among AhR-modulated cytokines. Cotreatment with AhR antagonist completely prevented IL-24 induction by AhR agonists in the CL5 cells. Knockdown AhR expression with short-hairpin RNA (shRNA) significantly reduced benzo[a]pyrene (BaP)-induced IL-24 mRNA levels. We further confirmed that gene transcription, but not mRNA stability, was involved in IL-24 upregulation by BaP. Particulate matter (PM) in the ambient air contains some PAHs and is reported to activate AhR. Oropharyngeal aspiration of PM significantly increased IL-24 levels in lung epithelia and in bronchoalveolar lavage fluid of mice 4 weeks after treatment. Thus, our data suggests that IL-24 is a pulmonary exposure target cytokine of environmental AhR agonists. - Graphical abstract: (A) Cytokine and chemokine gene expressions were examined in CL5 cells treated with AhR and non-AhR agonists. Thirteen cytokines and chemokines genes were altered in the AhR agonist-treated cells, but not in the non-AhR agonist-treated cells. IL-24 was the most highly induced gene among the AhR-modulated cytokines. (B

  4. Neurotensin Agonist Attenuates Nicotine Potentiation to Cocaine Sensitization

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    Paul Fredrickson

    2014-01-01

    Full Text Available Tobacco usage typically precedes illicit drug use in adolescent and young adult populations. Several animal studies suggest nicotine increases the risk for subsequent cocaine abuse, and may be a negative prognostic factor for treatment of cocaine addiction; i.e., a “gateway drug”. Neurotensin (NT is a 13-amino acid neuropeptide that modulates dopamine, acetylcholine, glutamate, and GABA neurotransmission in brain reward pathways. NT69L, a NT(8-13 analog, blocks behavioral sensitization (an animal model for psychostimulant addiction to nicotine, and nicotine self-administration in rats. The present study tested the effect of NT69L on the potentiating effects of nicotine on cocaine-induced locomotor sensitization. Male Wistar rats were injected daily for seven days with nicotine or saline (control followed by four daily injections of cocaine. NT69L was administered 30 min prior to the last cocaine injection. Behavior was recorded with the use of activity chambers. Subchronic administration of nicotine enhanced cocaine-induced behavioral sensitization in Wistar rats, consistent with an hypothesized gateway effect. These behavioral effects of cocaine were attenuated by pretreatment with NT69L. The effect of the neurotensin agonist on cocaine sensitization in the nicotine treated group indicated a possible therapeutic effect for cocaine addiction, even in the presence of enhanced behavioral sensitization induced by nicotine.

  5. Agonist Binding to Chemosensory Receptors: A Systematic Bioinformatics Analysis

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    Fabrizio Fierro

    2017-09-01

    Full Text Available Human G-protein coupled receptors (hGPCRs constitute a large and highly pharmaceutically relevant membrane receptor superfamily. About half of the hGPCRs' family members are chemosensory receptors, involved in bitter taste and olfaction, along with a variety of other physiological processes. Hence these receptors constitute promising targets for pharmaceutical intervention. Molecular modeling has been so far the most important tool to get insights on agonist binding and receptor activation. Here we investigate both aspects by bioinformatics-based predictions across all bitter taste and odorant receptors for which site-directed mutagenesis data are available. First, we observe that state-of-the-art homology modeling combined with previously used docking procedures turned out to reproduce only a limited fraction of ligand/receptor interactions inferred by experiments. This is most probably caused by the low sequence identity with available structural templates, which limits the accuracy of the protein model and in particular of the side-chains' orientations. Methods which transcend the limited sampling of the conformational space of docking may improve the predictions. As an example corroborating this, we review here multi-scale simulations from our lab and show that, for the three complexes studied so far, they significantly enhance the predictive power of the computational approach. Second, our bioinformatics analysis provides support to previous claims that several residues, including those at positions 1.50, 2.50, and 7.52, are involved in receptor activation.

  6. PPAR Agonists for the Prevention and Treatment of Lung Cancer

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    Sowmya P. Lakshmi

    2017-01-01

    Full Text Available Lung cancer is the most common and most fatal of all malignancies worldwide. Furthermore, with more than half of all lung cancer patients presenting with distant metastases at the time of initial diagnosis, the overall prognosis for the disease is poor. There is thus a desperate need for new prevention and treatment strategies. Recently, a family of nuclear hormone receptors, the peroxisome proliferator-activated receptors (PPARs, has attracted significant attention for its role in various malignancies including lung cancer. Three PPARs, PPARα, PPARβ/δ, and PPARγ, display distinct biological activities and varied influences on lung cancer biology. PPARα activation generally inhibits tumorigenesis through its antiangiogenic and anti-inflammatory effects. Activated PPARγ is also antitumorigenic and antimetastatic, regulating several functions of cancer cells and controlling the tumor microenvironment. Unlike PPARα and PPARγ, whether PPARβ/δ activation is anti- or protumorigenic or even inconsequential currently remains an open question that requires additional investigation. This review of current literature emphasizes the multifaceted effects of PPAR agonists in lung cancer and discusses how they may be applied as novel therapeutic strategies for the disease.

  7. Urolinin: The First Linear Peptidic Urotensin-II Receptor Agonist.

    Science.gov (United States)

    Bandholtz, Sebastian; Erdmann, Sarah; von Hacht, Jan Lennart; Exner, Samantha; Krause, Gerd; Kleinau, Gunnar; Grötzinger, Carsten

    2016-11-23

    This study investigated the role of individual U-II amino acid positions and side chain characteristics important for U-IIR activation. A complete permutation library of 209 U-II variants was studied in an activity screen that contained single substitution variants of each position with one of the other 19 proteinogenic amino acids. Receptor activation was measured using a cell-based high-throughput fluorescence calcium mobilization assay. We generated the first complete U-II substitution map for U-II receptor activation, resulting in a detailed view into the structural features required for receptor activation, accompanied by complementary information from receptor modeling and ligand docking studies. On the basis of the systematic SAR study of U-II, we created 33 further short and linear U-II variants from eight to three amino acids in length, including d- and other non-natural amino acids. We identified the first high-potency linear U-II analogues. Urolinin, a linear U-II agonist (nWWK-Tyr(3-NO 2 )-Abu), shows low nanomolar potency as well as improved metabolic stability.

  8. Characterization of AhR agonists reveals antagonistic activity in European herring gull (Larus argentatus) eggs.

    Science.gov (United States)

    Muusse, Martine; Christensen, Guttorm; Gomes, Tânia; Kočan, Anton; Langford, Katherine; Tollefsen, Knut Erik; Vaňková, Lenka; Thomas, Kevin V

    2015-05-01

    European herring gull (Larus argentatus) eggs from two Norwegian islands, Musvær in the south east and Reiaren in Northern Norway, were screened for dioxins, furans, and dioxin-like and selected non-dioxin-like polychlorinated biphenyls (PCBs), and subjected to non-target analysis to try to identify the aryl hydrocarbon receptor (AhR) agonists, responsible for elevated levels measured using the dioxin responsive chemically activated luciferase expression (DR-CALUX) assay. Eggs from Musvær contained chemically calculated toxic equivalent (WHO TEQ) levels of between 109 and 483 pg TEQ/g lw, and between 82 and 337 pg TEQ/g lw was determined in eggs from Reiaren. In particular PCB126 contributed highly to the total TEQ (69-82%). In 19 of the 23 samples the calculated WHO TEQ was higher than the TEQCALUX. Using CALUX specific relative effect potencies (REPs), the levels were lower at between 77 and 292 pg/g lw in eggs from Musvær and between 55 and 223 pg/g lw in eggs from Reiaren, which was higher than the TEQCALUX in 16 of the 23 samples. However, the means of the REP values and the TEQCALUX were not significantly different. This suggests the presence of compounds that can elicit antagonist effects, with a low binding affinity to the AhR. Non-target analysis identified the presence of hexachlorobenzene (HCB) (quantified at 9.6-185 pg/g lw) but neither this compound nor high concentrations of PCB126 and non-dioxin-like PCBs could explain the differences between the calculated TEQ or REP values and the TEQCALUX. Even though, for most AhR agonists, the sensitivity of herring gulls is not known, the reported levels can be considered to represent a risk for biological effects in the developing embryo, compared to LC50 values in chicken embryos. For human consumers of herring gull eggs, these eggs contain TEQ levels up to four times higher than the maximum tolerable weekly intake. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Infusion of adrenergic receptor agonists and antagonists into the locus coeruleus and ventricular system of the brain. Effects on swim-motivated and spontaneous motor activity.

    Science.gov (United States)

    Weiss, J M; Simson, P G; Hoffman, L J; Ambrose, M J; Cooper, S; Webster, A

    1986-04-01

    These studies examined how pharmacological stimulation and blockade of alpha receptors would affect active motor behavior in rats. In experiment I, alpha-2 receptor antagonists (piperoxane, yohimbine) and agonists [clonidine, norepinephrine (NE)] were infused into various locations in the ventricular system of the brain, including the locus coeruleus region, and motor activity was measured. Activity was measured principally in a swim test but spontaneous (ambulatory) activity was also recorded while drugs were being infused. When infused into the locus coeruleus region, small doses of the antagonists piperoxane and yohimbine depressed activity in the swim test while infusion of the agonists clonidine and NE had the opposite effect of stimulating activity. These effects were highly specific to the region of the locus coeruleus, since infusions of these drugs into other nearby locations in the ventricular system or use of larger doses had different, often opposite effects. This was especially true of clonidine and NE which profoundly depressed activity when infused posterior to the locus coeruleus, particularly over the dorsal vagal complex. Infusion of small doses of these drugs into the lateral ventricle had effects similar to infusion into the locus coeruleus region, though less pronounced. Changes in spontaneous motor activity were also observed, but this measure differentiated the groups less well than did the swim test. In experiment II, the predominantly postsynaptic receptor agonists isoproterenol (beta agonist) and phenylephrine (alpha-1 agonist) were infused into the ventricular system. Since infusions of piperoxane and yohimbine into the locus coeruleus that decreased activity in experiment I increase the release of NE by blocking alpha-2 inhibitory receptors on cell bodies and dendrites of the locus coeruleus, experiment II tested whether ventricular infusion of predominantly postsynaptic receptor agonists would also decrease activity in the swim test

  10. Allosteric enhancers, allosteric agonists and ago-allosteric modulators: where do they bind and how do they act?

    DEFF Research Database (Denmark)

    Schwartz, Thue W; Holst, Birgitte

    2007-01-01

    Many small-molecule agonists also display allosteric properties. Such ago-allosteric modulators act as co-agonists, providing additive efficacy--instead of partial antagonism--and they can affect--and often improve--the potency of the endogenous agonist. Surprisingly, the apparent binding sites...... different binding modes. In another, dimeric, receptor scenario, the endogenous agonist binds to one protomer while the ago-allosteric modulator binds to the other, 'allosteric' protomer. It is suggested that testing for ago-allosteric properties should be an integral part of the agonist drug discovery...... process because a compound that acts with--rather than against--the endogenous agonist could be an optimal agonist drug....

  11. Structure and biological activity of endogenous and synthetic agonists of GPR119

    Science.gov (United States)

    Tyurenkov, I. N.; Ozerov, A. A.; Kurkin, D. V.; Logvinova, E. O.; Bakulin, D. A.; Volotova, E. V.; Borodin, D. D.

    2018-02-01

    A G-protein-coupled receptor, GPR119, is a promising pharmacological target for a new class of hypoglycaemic drugs with an original mechanism of action, namely, increase in the glucose-dependent incretin and insulin secretion. In 2005, the first ligands were found and in the subsequent years, a large number of GPR119 agonists were synthesized in laboratories in various countries; the safest and most promising agonists have entered phase I and II clinical trials as agents for the treatment of type 2 diabetes mellitus and obesity. The review describes the major endogenous GPR119 agonists and the main trends in the design and modification of synthetic structures for increasing the hypoglycaemic activity. The data on synthetic agonists are arranged according to the type of the central core of the molecules. The bibliography includes 104 references.

  12. PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR (PPAR) AGONISTS AS PROMISING NEW MEDICATIONS FOR DRUG ADDICTION: PRECLINICAL EVIDENCE

    Science.gov (United States)

    Foll, Bernard Le; Ciano, Patricia Di; Panlilio, Leigh V.; Goldberg, Steven R.; Ciccocioppo, Roberto

    2013-01-01

    This review examines the growing literature on the role of peroxisome proliferator-activated receptors (PPARs) in addiction. There are two subtypes of PPAR receptors that have been studied in addiction: PPAR-α and PPAR-γ. The role of each PPAR subtype in common models of addictive behavior, mainly pre-clinical models, is summarized. In particular, studies are reviewed that investigated the effects of PPAR-α agonists on relapse, sensitization, conditioned place preference, withdrawal and drug intake, and effects of PPAR-γ agonists on relapse, withdrawal and drug intake. Finally, studies that investigated the effects of PPAR agonists on neural pathways of addiction are reviewed. Taken together this preclinical data indicates that PPAR agonists are promising new medications for drug addiction treatment. PMID:23614675

  13. Regional brain [(11)C]carfentanil binding following tobacco smoking.

    Science.gov (United States)

    Domino, Edward F; Hirasawa-Fujita, Mika; Ni, Lisong; Guthrie, Sally K; Zubieta, Jon Kar

    2015-06-03

    To determine if overnight tobacco abstinent carriers of the AG or GG (*G) vs. the AA variant of the human mu opioid receptor (OPRM1) A118G polymorphism (rs1799971) differ in [(11)C]carfentanil binding after tobacco smoking. Twenty healthy American male smokers who abstained from tobacco overnight were genotyped and completed positron emission tomography (PET) scans with the mu opioid receptor agonist, [(11)C]carfentanil. They smoked deniconized (denic) and average nicotine (avnic) cigarettes during the PET scans. Smoking avnic cigarette decreased the binding potential (BPND) of [(11)C]carfentanil in the right medial prefrontal cortex (mPfc; 6, 56, 18), left anterior medial prefrontal cortex (amPfc; -2, 46, 44), right ventral striatum (vStr; 16, 3, -10), left insula (Ins; -42, 10, -12), right hippocampus (Hippo; 18, -6, -14) and left cerebellum (Cbl; -10, -88, -34), and increased the BPND in left amygdala (Amy; -20, 0, -22), left putamen (Put; -22, 10, -6) and left nucleus accumbens (NAcc; -10, 12, -8). In the AA allele carriers, avnic cigarette smoking significantly changed the BPND compared to after denic smoking in most brain areas listed above. However in the *G carriers the significant BPND changes were confirmed in only amPfc and vStr. Free mu opioid receptor availability was significantly less in the *G than the AA carriers in the Amy and NAcc. The present study demonstrates that BPND changes induced by avnic smoking in OPRM1 *G carriers were blunted compared to the AA carriers. Also *G smokers had less free mu opioid receptor availability in Amy and NAcc. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Reducing inflammation and rescuing FTD-related behavioral deficits in progranulin-deficient mice with α7 nicotinic acetylcholine receptor agonists.

    Science.gov (United States)

    Minami, S Sakura; Shen, Vivian; Le, David; Krabbe, Grietje; Asgarov, Rustam; Perez-Celajes, Liberty; Lee, Chih-Hung; Li, Jinhe; Donnelly-Roberts, Diana; Gan, Li

    2015-10-15

    Mutations in the progranulin gene cause frontotemporal dementia (FTD), a debilitating neurodegenerative disease that involves atrophy of the frontal and temporal lobes and affects personality, behavior, and language. Progranulin-deficient mouse models of FTD exhibit deficits in compulsive and social behaviors reminiscent of patients with FTD, and develop excessive microgliosis and increased release of inflammatory cytokines. Activation of nicotinic acetylcholine receptors (nAChRs) by nicotine or specific α7 nAChR agonists reduces neuroinflammation. Here, we investigated whether activation of nAChRs by nicotine or α7 agonists improved the excessive inflammatory and behavioral phenotypes of a progranulin-deficient FTD mouse model. We found that treatment with selective α7 agonists, PHA-568487 or ABT-107, strongly suppressed the activation of NF-κB in progranulin-deficient cells. Treatment with ABT-107 also reduced microgliosis, decreased TNFα levels, and reduced compulsive behavior in progranulin-deficient mice. Collectively, these data suggest that targeting activation of the α7 nAChR pathway may be beneficial in decreasing neuroinflammation and reversing some of the behavioral deficits observed in progranulin-deficient FTD. Copyright © 2015. Published by Elsevier Inc.

  15. Development and validation of an UHPLC-MS/MS method for β2-agonists quantification in human urine and application to clinical samples.

    Science.gov (United States)

    Bozzolino, Cristina; Leporati, Marta; Gani, Federica; Ferrero, Cinzia; Vincenti, Marco

    2018-02-20

    A fast analytical method for the simultaneous detection of 24 β 2 -agonists in human urine was developed and validated. The method covers the therapeutic drugs most commonly administered, but also potentially abused β 2 -agonists. The procedure is based on enzymatic deconjugation with β-glucuronidase followed by SPE clean up using mixed-phase cartridges with both ion-exchange and lipophilic properties. Instrumental analysis conducted by UHPLC-MS/MS allowed high peak resolution and rapid chromatographic separation, with reduced time and costs. The method was fully validated according ISO 17025:2005 principles. The following parameters were determined for each analyte: specificity, selectivity, linearity, limit of detection, limit of quantification, precision, accuracy, matrix effect, recovery and carry-over. The method was tested on real samples obtained from patients subjected to clinical treatment under chronic or acute therapy with either formoterol, indacaterol, salbutamol, or salmeterol. The drugs were administered using pressurized metered dose inhalers. All β 2 -agonists administered to the patients were detected in the real samples. The method proved adequate to accurately measure the concentration of these analytes in the real samples. The observed analytical data are discussed with reference to the administered dose and the duration of the therapy. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Enhanced down regulation of cortical ±-propranolol sensitive [3H]-DHA binding sites by co-administration of DMI and 5-HT1A partial agonist gepirone

    International Nuclear Information System (INIS)

    Geissler, M.A.; Yocca, F.D.

    1990-01-01

    The putative interrelationship between the noradrenergic and serotonergic systems has been supported by numerous studies. Recently, Dudley et al. (1989) demonstrated significant down regulation of cortical β-adrenergic receptors by co-administration of desipramine (DMI), a norepinephrine uptake inhibitor, and the full 5-HT 1A agonist 8-OH-DPAT. To this end, the effects of acute and chronic (4 and 14 day) administration of DMI, gepirone, a selective 5-HT 1A post-synaptic partial agonist, as well as a combination of the two, on cortical (±)-propranolol sensitive [ 3 H]-DHA binding sites were examined in rats. Down regulation was apparent after 4 and 14 day treatment with DMI. However, this was not the case with gepirone. Of particular importance is the demonstration of a greater magnitude of down regulation with co-administration of a greater magnitude of down regulation with co-administration of DMI and gepirone. These results suggests that alteration in rat cortical (±)-propranolol sensitive [ 3