1
|
Brooke AK, Murrow DP, Caldwell KCN, Witt CE, Ross AE. Measuring neuron-regulated immune cell physiology via the alpha-2 adrenergic receptor in an ex vivo murine spleen model. Cell Mol Life Sci 2023; 80:354. [PMID: 37945921 PMCID: PMC11071927 DOI: 10.1007/s00018-023-05012-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 09/27/2023] [Accepted: 10/23/2023] [Indexed: 11/12/2023]
Abstract
The communication between the nervous and immune systems plays a crucial role in regulating immune cell function and inflammatory responses. Sympathetic neurons, which innervate the spleen, have been implicated in modulating immune cell activity. The neurotransmitter norepinephrine (NE), released by sympathetic neurons, influences immune cell responses by binding to adrenergic receptors on their surface. The alpha-2 adrenergic receptor (α2AR), expressed predominantly on sympathetic neurons, has received attention due to its autoreceptor function and ability to modulate NE release. In this study, we used fast-scan cyclic voltammetry (FSCV) to provide the first subsecond measurements of NE released in the white pulp region of the spleen and validated it with yohimbine, a known antagonist of α2AR. For further application of FSCV in neuroimmunology, we investigated the extent to which subsecond NE from sympathetic neurons is important for immune cell physiology and cytokine production, focusing on tumor necrosis factor-alpha (TNF-α), interleukin-10 (IL-10), and interleukin-6 (IL-6). Our findings provide insights into the regulatory mechanisms underlying sympathetic-immune interactions and show the significance of using FSCV, a traditional neurochemistry technique, to study these neuroimmune mechanisms.
Collapse
Affiliation(s)
- Alexandra K Brooke
- Department of Chemistry, University of Cincinnati, 312 College Dr. 404 Crosley Tower, Cincinnati, OH, 45221-0172, USA
| | - Daniel P Murrow
- Department of Chemistry, University of Cincinnati, 312 College Dr. 404 Crosley Tower, Cincinnati, OH, 45221-0172, USA
| | - Kaejaren C N Caldwell
- Department of Chemistry, University of Cincinnati, 312 College Dr. 404 Crosley Tower, Cincinnati, OH, 45221-0172, USA
| | - Colby E Witt
- Department of Chemistry, University of Cincinnati, 312 College Dr. 404 Crosley Tower, Cincinnati, OH, 45221-0172, USA
| | - Ashley E Ross
- Department of Chemistry, University of Cincinnati, 312 College Dr. 404 Crosley Tower, Cincinnati, OH, 45221-0172, USA.
| |
Collapse
|
2
|
Ishibashi T, Sueto D, Yoshikawa Y, Koga K, Yamaura K, Tsuda M. Identification of Spinal Inhibitory Interneurons Required for Attenuating Effect of Duloxetine on Neuropathic Allodynia-like Signs in Rats. Cells 2022; 11:cells11244051. [PMID: 36552814 PMCID: PMC9777279 DOI: 10.3390/cells11244051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 12/09/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
Neuropathic pain is a chronic pain condition that occurs after nerve damage; allodynia, which refers to pain caused by generally innocuous stimuli, is a hallmark symptom. Although allodynia is often resistant to analgesics, the antidepressant duloxetine has been used as an effective therapeutic option. Duloxetine increases spinal noradrenaline (NA) levels by inhibiting its transporter at NAergic terminals in the spinal dorsal horn (SDH), which has been proposed to contribute to its pain-relieving effect. However, the mechanism through which duloxetine suppresses neuropathic allodynia remains unclear. Here, we identified an SDH inhibitory interneuron subset (captured by adeno-associated viral (AAV) vectors incorporating a rat neuropeptide Y promoter; AAV-NpyP+ neurons) that is mostly depolarized by NA. Furthermore, this excitatory effect was suppressed by pharmacological blockade or genetic knockdown of α1B-adrenoceptors (ARs) in AAV-NpyP+ SDH neurons. We found that duloxetine suppressed Aβ fiber-mediated allodynia-like behavioral responses after nerve injury and that this effect was not observed in AAV-NpyP+ SDH neuron-selective α1B-AR-knockdown. These results indicate that α1B-AR and AAV-NpyP+ neurons are critical targets for spinal NA and are necessary for the therapeutic effect of duloxetine on neuropathic pain, which can support the development of novel analgesics.
Collapse
Affiliation(s)
- Tadayuki Ishibashi
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
- Department of Anesthesiology and Critical Care Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Daichi Sueto
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Yu Yoshikawa
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Keisuke Koga
- Department of Neurophysiology, Hyogo College of Medicine, Nishinomiya 663-8501, Japan
| | - Ken Yamaura
- Department of Anesthesiology and Critical Care Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Makoto Tsuda
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
- Kyushu University Institute for Advanced Study, Fukuoka 819-0395, Japan
- Correspondence:
| |
Collapse
|
3
|
Miller ER, Scheidt KA. Enantioselective Syntheses of Yohimbine Alkaloids: Proving Grounds for New Catalytic Transformations. SYNTHESIS-STUTTGART 2022; 54:1217-1230. [PMID: 36187077 PMCID: PMC9524398 DOI: 10.1055/a-1684-2942] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The total synthesis of bioactive alkaloids is an enduring challenge and an indication of the state of the art of chemical synthesis. With the explosion of catalytic asymmetric methods over the past three decades, these compelling targets have been fertile proving grounds for enantioselective bond forming transformations. These activities are summarized herein both to highlight the power and versatility of these methods and to instill future inspiration for new syntheses of these privileged natural products.
Collapse
|
4
|
Britto-Júnior J, Fernandes Jacintho F, Campos R, Pinheiro DHA, Figueiredo Murari GM, de Souza VB, Schenka AA, Mónica FZ, Moreno RA, Antunes E, De Nucci G. The basal release of endothelium-derived catecholamines regulates the contractions of Chelonoidis carbonaria aorta caused by electrical-field stimulation. Biol Open 2021; 10:bio.057042. [PMID: 33277238 PMCID: PMC7847266 DOI: 10.1242/bio.057042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The contractions of Chelonoidis carbonaria aortic rings induced by electrical field stimulation (EFS) are not inhibited by blockade of the voltage-gated sodium channels by tetrodotoxin but almost abolished by the α1/α2-adrenoceptor antagonist phentolamine. The objective of this study was to identify the mediator(s) responsible for the EFS-induced contractions of Chelonoidis carbonaria aortic rings. Each ring was suspended between two wire hooks and mounted in isolated 10 ml organ chambers filled with oxygenated and heated Krebs-Henseleit's solution. Dopamine, noradrenaline and adrenaline concentrations were analysed by liquid chromatography coupled to tandem mass spectrometry. The contractions caused by dopamine and EFS were done in absence and presence of the nitric oxide (NO) synthesis inhibitor L-NAME, the NO-sensitive guanylyl cyclase inhibitor ODQ, the D1-like receptor antagonist SCH-23390, the D2-like receptor antagonists risperidone, quetiapine, haloperidol, and the tyrosine hydroxylase inhibitors salsolinol and 3-iodo-L-tyrosine. Basal concentrations of dopamine, noradrenaline and adrenaline were detected in Krebs-Henseleit solution containing the aortic rings. The catecholamine concentrations were significantly reduced in endothelium-denuded aortic rings. L-NAME and ODQ significantly potentiated the dopamine-induced contractions. The D2-like receptor antagonists inhibited the EFS-induced contractions of the aortic rings treated with L-NAME, whereas SCH 23390 had no effect. Similar results were observed in the contractions induced by dopamine in L-NAME treated aortic rings. These results indicate that catecholamines released by endothelium regulate the EFS-induced contractions. This may constitute a suitable mechanism by which reptilia modulate specific organ blood flow distribution. This paper has an associated First Person interview with the first author of the article. Summary:Chelonoidis carbonaria aortic rings release endothelium-derived catecholamines that modulate vascular smooth muscle reactivity.
Collapse
Affiliation(s)
- José Britto-Júnior
- Faculty of Medical Sciences, Department of Pharmacology, University of Campinas (UNICAMP), Campinas 13083-894, Brazil
| | - Felipe Fernandes Jacintho
- Faculty of Medical Sciences, Department of Pharmacology, University of Campinas (UNICAMP), Campinas 13083-894, Brazil
| | - Rafael Campos
- Department of Physiology, Superior Institute of Biomedical Sciences, Ceará State University (UECE), Fortaleza 60714-903, Brazil
| | - David Halen Araújo Pinheiro
- Faculty of Medical Sciences, Department of Pharmacology, University of Campinas (UNICAMP), Campinas 13083-894, Brazil
| | - Guilherme M Figueiredo Murari
- Faculty of Medical Sciences, Department of Pharmacology, University of Campinas (UNICAMP), Campinas 13083-894, Brazil
| | - Valéria B de Souza
- Faculty of Medical Sciences, Department of Pharmacology, University of Campinas (UNICAMP), Campinas 13083-894, Brazil
| | - André A Schenka
- Faculty of Medical Sciences, Department of Pharmacology, University of Campinas (UNICAMP), Campinas 13083-894, Brazil
| | - Fabíola Z Mónica
- Faculty of Medical Sciences, Department of Pharmacology, University of Campinas (UNICAMP), Campinas 13083-894, Brazil
| | - Ronilson Agnaldo Moreno
- Faculty of Medical Sciences, Department of Pharmacology, University of Campinas (UNICAMP), Campinas 13083-894, Brazil
| | - Edson Antunes
- Faculty of Medical Sciences, Department of Pharmacology, University of Campinas (UNICAMP), Campinas 13083-894, Brazil
| | - Gilberto De Nucci
- Faculty of Medical Sciences, Department of Pharmacology, University of Campinas (UNICAMP), Campinas 13083-894, Brazil.,Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-060, Brazil
| |
Collapse
|
5
|
Britto‐Júnior J, Pinheiro DHA, Justo AFO, Figueiredo Murari GM, Campos R, Mariano FV, de Souza VB, Schenka AA, Mónica FZ, Antunes E, De Nucci G. Endothelium-derived dopamine modulates EFS-induced contractions of human umbilical vessels. Pharmacol Res Perspect 2020; 8:e00612. [PMID: 32567793 PMCID: PMC7307250 DOI: 10.1002/prp2.612] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 05/02/2020] [Accepted: 05/06/2020] [Indexed: 02/03/2023] Open
Abstract
Electrical field stimulation (EFS) induces contractions of both snake aorta and human umbilical cord vessels (HUCV) which were dependent on the presence of the endothelium. This study aimed to establish the nature of the mediator(s) responsible for EFS-induced contractions in HUCV. Rings with or without endothelium from human umbilical artery (HUA) or vein (HUV) were mounted in organ bath chambers containing oxygenated, heated Krebs-Henseleit's solution. Basal release of dopamine (DA), noradrenaline, and adrenaline was measured by LC-MS-MS. Cumulative concentration-response curves were performed with dopamine in the absence and in the presence of L-NAME or of dopamine antagonists. EFS studies were performed in the presence and absence of L-NAME, the α-adrenergic blockers prazosin and idazoxan, and the dopamine antagonists SCH-23390 and haloperidol. Tyrosine hydroxylase (TH) and dopa-decarboxylase (DDC) were studied by immunohistochemistry and fluorescence in situ hybridizations. Basal release of dopamine requires an intact endothelium in both HUA and HUV. TH and DDC are present only in the endothelium of both HUA and HUV as determined by immunohistochemistry. Dopamine induced contractions in HUA only in the presence of L-NAME. Dopamine-induced contractions in HUV were strongly potentiated by L-NAME. The EFS-induced contractions in both HUA and HUV were potentiated by L-NAME and inhibited by the D2-like receptor antagonist haloperidol. The α-adrenergic antagonists prazosin and idazoxan and the D1-like receptor antagonist SCH-23390 had no effect on the EFS-induced contractions of HUA and HUV. Endothelium-derived dopamine is a major modulator of HUCV reactivity in vitro.
Collapse
Affiliation(s)
- José Britto‐Júnior
- Department of PharmacologyFaculty of Medical SciencesState University of Campinas (UNICAMP)CampinasBrazil
| | - David H. A. Pinheiro
- Department of PharmacologyFaculty of Medical SciencesState University of Campinas (UNICAMP)CampinasBrazil
| | - Alberto F. O. Justo
- Department of PharmacologyFaculty of Medical SciencesState University of Campinas (UNICAMP)CampinasBrazil
| | | | - Rafael Campos
- Superior Institute of Biomedical SciencesCeará State University (UECE)FortalezaBrazil
| | - Fernanda V. Mariano
- Department of PathologyFaculty of Medical ScienceState University of Campinas (UNICAMP)CampinasBrazil
| | - Valéria B. de Souza
- Department of PharmacologyFaculty of Medical SciencesState University of Campinas (UNICAMP)CampinasBrazil
| | - André A. Schenka
- Department of PharmacologyFaculty of Medical SciencesState University of Campinas (UNICAMP)CampinasBrazil
| | - Fabiola Z. Mónica
- Department of PharmacologyFaculty of Medical SciencesState University of Campinas (UNICAMP)CampinasBrazil
| | - Edson Antunes
- Department of PharmacologyFaculty of Medical SciencesState University of Campinas (UNICAMP)CampinasBrazil
| | - Gilberto De Nucci
- Department of PharmacologyFaculty of Medical SciencesState University of Campinas (UNICAMP)CampinasBrazil
- Department of PharmacologyInstitute of Biomedical SciencesUniversity of São Paulo (USP)São PauloBrazil
- Brazil UniversityFernadopolisBrazil
| |
Collapse
|
6
|
Campos R, Jacintho FF, Britto-Júnior J, Mónica FZ, Justo AFO, Pupo AS, Moreno RA, de Souza VB, Schenka AA, Antunes E, De Nucci G. Endothelium modulates electrical field stimulation-induced contractions of Chelonoidis carbonaria aortic rings. Comp Biochem Physiol C Toxicol Pharmacol 2020; 233:108763. [PMID: 32289528 DOI: 10.1016/j.cbpc.2020.108763] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 03/08/2020] [Accepted: 04/04/2020] [Indexed: 12/26/2022]
Abstract
The role of endothelium in the electrical-field stimulation (EFS)-induced contractions of Chelonoidis carbonaria aorta was investigated. Contractions were evaluated in the presence and absence of L-NAME (100 μM), tetrodotoxin (1 μM), phentolamine (10 and 100 μM), phenoxybenzamine (1 and 10 μM), prazosin (100 μM), idazoxan (100 μM), atropine (10 μM), D-tubocurarine (10 μM) or indomethacin (10 μM). EFS-induced contraction was also carried out in endothelium-denuded rings. EFS-induced contraction was investigated by the sandwich assay. Concentration curves to endothelin-1 (0.1-100 nM) and U46619 (0.001-100 μM) were also constructed to calculate both Emax and EC50. EFS at 16 Hz contracted Chelonoidis aorta, which was almost abolished by the endothelium removal. The addition of L-NAME increased the EFS response (2.0 ± 0.4 and 8.3 ± 1.9 mN). In L-NAME treated aortic rings, tetrodotoxin did not change the EFS-response (5.1 ± 1.8 and 4.9 ± 1.7 mN). Indomethacin, atropine and d-tubucurarine also did not affect the EFS-response. Phentolamine at 10 μM did not change the EFS-induced contraction; however, at 100 μM, reduced it (3.9 ± 1 and 1.9 ± 0.3 mN). Prazosin and idazoxan did not change EFS-induced contractions. Phenoxybenzamine at 1 μM reduced by 76% (9.6 ± 3.4 and 2.3 ± 0.8 mN) and at 10 μM by 90% the EFS response. Immunohistochemistry identified tyrosine hydroxylase in the endothelium and brain, whereas S100 protein was found only in brain. In conclusion, endothelium modulates EFS-induced contractions in Chelonoidis aortic rings and this modulation may be due to endothelium-derived catecholamines, possibly dopamine.
Collapse
Affiliation(s)
- Rafael Campos
- Superior Institute of Biomedical Sciences, Ceará State University (UECE), Fortaleza, Brazil; Faculty of Medical Sciences, Department of Pharmacology, University of Campinas (UNICAMP), Campinas, Brazil.
| | - Felipe Fernandes Jacintho
- Faculty of Medical Sciences, Department of Pharmacology, University of Campinas (UNICAMP), Campinas, Brazil
| | - José Britto-Júnior
- Faculty of Medical Sciences, Department of Pharmacology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Fabíola Z Mónica
- Faculty of Medical Sciences, Department of Pharmacology, University of Campinas (UNICAMP), Campinas, Brazil
| | | | - André Sampaio Pupo
- Department of Pharmacology, Institute of Biosciences of Botucatu, UNESP - São Paulo State University, Botucatu, Brazil
| | - Ronilson Agnaldo Moreno
- Faculty of Medical Sciences, Department of Pharmacology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Valéria Barbosa de Souza
- Faculty of Medical Sciences, Department of Pharmacology, University of Campinas (UNICAMP), Campinas, Brazil
| | - André Almeida Schenka
- Faculty of Medical Sciences, Department of Pharmacology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Edson Antunes
- Faculty of Medical Sciences, Department of Pharmacology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Gilberto De Nucci
- Faculty of Medical Sciences, Department of Pharmacology, University of Campinas (UNICAMP), Campinas, Brazil; Department of Pharmacology, Institute of Biomedical Sciences, USP - University of São Paulo, São Paulo, Brazil
| |
Collapse
|
7
|
Normetadrenaline and metadrenaline induce rat thoracic aorta/prostate contraction via α1D/1A-adrenoceptor stimulation. Eur J Pharmacol 2020; 877:173079. [DOI: 10.1016/j.ejphar.2020.173079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 01/31/2020] [Accepted: 03/24/2020] [Indexed: 11/23/2022]
|
8
|
Djikic T, Vucicevic J, Laurila J, Radi M, Veljkovic N, Xhaard H, Nikolic K. Deciphering Imidazoline Off‐targets by Fishing in the Class A of GPCR field. Mol Inform 2020; 39:e1900165. [DOI: 10.1002/minf.201900165] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 02/20/2020] [Indexed: 12/13/2022]
Affiliation(s)
- Teodora Djikic
- Department of Pharmaceutical ChemistryFaculty of PharmacyUniversity of Belgrade Vojvode Stepe 450 11000 Belgrade Serbia
| | - Jelica Vucicevic
- Department of Pharmaceutical ChemistryFaculty of PharmacyUniversity of Belgrade Vojvode Stepe 450 11000 Belgrade Serbia
| | - Jonne Laurila
- Research Center for Integrative Physiology and Pharmacology, Institute of BiomedicineUniversity of Turku FI-20014 Turun yliopisto, Turku Finland
| | - Marco Radi
- Dipartimento di Scienze degli Alimenti e del FarmacoUniversità degli Studi di Parma Viale delle Scienze, 27/A 43124 Parma Italy
| | - Nevena Veljkovic
- Laboratory for bioinformatics and computational chemistry, Institute of Nuclear Sciences VincaUniversity of Belgrade Mihaila Petrovica Alasa 14 11001 Belgrade Serbia
| | - Henri Xhaard
- Division of Pharmaceutical Chemistry, Drug Research Program, Division of Pharmaceutical Chemistry and Technology, Faculty of PharmacyUniversity of Helsinki P.O. Box 56 FI-00014 Helsinki Finland
| | - Katarina Nikolic
- Department of Pharmaceutical ChemistryFaculty of PharmacyUniversity of Belgrade Vojvode Stepe 450 11000 Belgrade Serbia
| |
Collapse
|
9
|
Woodcock EA, Greenwald MK, Khatib D, Diwadkar VA, Stanley JA. Pharmacological stress impairs working memory performance and attenuates dorsolateral prefrontal cortex glutamate modulation. Neuroimage 2019; 186:437-445. [PMID: 30458306 PMCID: PMC6491044 DOI: 10.1016/j.neuroimage.2018.11.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 11/10/2018] [Accepted: 11/12/2018] [Indexed: 02/04/2023] Open
Abstract
Working memory processes are associated with the dorsolateral prefrontal cortex (dlPFC). Prior research using proton functional magnetic resonance spectroscopy (1H fMRS) observed significant dlPFC glutamate modulation during letter 2-back performance, indicative of working memory-driven increase in excitatory neural activity. Acute stress has been shown to impair working memory performance. Herein, we quantified dlPFC glutamate modulation during working memory under placebo (oral lactose) and acute stress conditions (oral yohimbine 54 mg + hydrocortisone 10 mg). Using a double-blind, randomized crossover design, participants (N = 19) completed a letter 2-back task during left dlPFC 1H fMRS acquisition (Brodmann areas 45/46; 4.5 cm3). An automated fitting procedure integrated with LCModel was used to quantify glutamate levels. Working memory-induced glutamate modulation was calculated as percentage change in glutamate levels from passive visual fixation to 2-back levels. Results indicated acute stress significantly attenuated working memory-induced glutamate modulation and impaired 2-back response accuracy, relative to placebo levels. Follow-up analyses indicated 2-back performance significantly modulated glutamate levels relative to passive visual fixation during placebo but not acute stress. Biomarkers, including blood pressure and saliva cortisol, confirmed that yohimbine + hydrocortisone dosing elicited a significant physiological stress response. These findings support a priori hypotheses and demonstrate that acute stress impairs dlPFC function and excitatory activity. This study highlights a neurobiological mechanism through which acute stress may contribute to psychiatric dysfunction and derail treatment progress. Future research is needed to isolate noradrenaline vs. cortisol effects and evaluate anti-stress medications and/or behavioral interventions.
Collapse
Affiliation(s)
- Eric A. Woodcock
- Brain Imaging Research Division, Department of Psychiatry
and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit,
MI,Substance Abuse Research Division, Department of Psychiatry
and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit,
MI,Corresponding author at: 2 Church Street South,
Suite #314, New Haven, CT, USA;
(EAW)
| | - Mark K. Greenwald
- Substance Abuse Research Division, Department of Psychiatry
and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit,
MI
| | - Dalal Khatib
- Brain Imaging Research Division, Department of Psychiatry
and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit,
MI
| | - Vaibhav A. Diwadkar
- Brain Imaging Research Division, Department of Psychiatry
and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit,
MI
| | - Jeffrey A. Stanley
- Brain Imaging Research Division, Department of Psychiatry
and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit,
MI
| |
Collapse
|
10
|
Greenwald MK. Anti-stress neuropharmacological mechanisms and targets for addiction treatment: A translational framework. Neurobiol Stress 2018; 9:84-104. [PMID: 30238023 PMCID: PMC6138948 DOI: 10.1016/j.ynstr.2018.08.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 07/30/2018] [Accepted: 08/10/2018] [Indexed: 12/18/2022] Open
Abstract
Stress-related substance use is a major challenge for treating substance use disorders. This selective review focuses on emerging pharmacotherapies with potential for reducing stress-potentiated seeking and consumption of nicotine, alcohol, marijuana, cocaine, and opioids (i.e., key phenotypes for the most commonly abused substances). I evaluate neuropharmacological mechanisms in experimental models of drug-maintenance and relapse, which translate more readily to individuals presenting for treatment (who have initiated and progressed). An affective/motivational systems model (three dimensions: valence, arousal, control) is mapped onto a systems biology of addiction approach for addressing this problem. Based on quality of evidence to date, promising first-tier neurochemical receptor targets include: noradrenergic (α1 and β antagonist, α2 agonist), kappa-opioid antagonist, nociceptin antagonist, orexin-1 antagonist, and endocannabinoid modulation (e.g., cannabidiol, FAAH inhibition); second-tier candidates may include corticotropin releasing factor-1 antagonists, serotonergic agents (e.g., 5-HT reuptake inhibitors, 5-HT3 antagonists), glutamatergic agents (e.g., mGluR2/3 agonist/positive allosteric modulator, mGluR5 antagonist/negative allosteric modulator), GABA-promoters (e.g., pregabalin, tiagabine), vasopressin 1b antagonist, NK-1 antagonist, and PPAR-γ agonist (e.g., pioglitazone). To address affective/motivational mechanisms of stress-related substance use, it may be advisable to combine agents with actions at complementary targets for greater efficacy but systematic studies are lacking except for interactions with the noradrenergic system. I note clinically-relevant factors that could mediate/moderate the efficacy of anti-stress therapeutics and identify research gaps that should be pursued. Finally, progress in developing anti-stress medications will depend on use of reliable CNS biomarkers to validate exposure-response relationships.
Collapse
Affiliation(s)
- Mark K. Greenwald
- Department of Psychiatry and Behavioral Neurosciences, School of Medicine, Department of Pharmacy Practice, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, 48201, USA
| |
Collapse
|
11
|
Haass-Koffler CL, Swift RM, Leggio L. Noradrenergic targets for the treatment of alcohol use disorder. Psychopharmacology (Berl) 2018; 235:1625-1634. [PMID: 29460163 PMCID: PMC5995154 DOI: 10.1007/s00213-018-4843-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 01/28/2018] [Indexed: 12/17/2022]
Abstract
The role of norepinephrine (NE) in the development of alcohol use disorder (AUD) has been studied over the past several decades. However, the NE system has been largely ignored for many years as a potential target for medication development for AUD. More recently, preclinical and clinical studies have demonstrated the potential value of targeting NE signaling for developing new pharmacological treatments for AUD. This review contributes to a special issue of Psychopharmacology focused on promising targets for alcohol addiction. Specifically, this review coalesces preclinical and clinical neuroscience that re-evaluate the noradrenergic system, and in particular the alpha-1 receptor, as a potential target for AUD.
Collapse
Affiliation(s)
- Carolina L Haass-Koffler
- Center for Alcohol and Addiction Studies, Department of Psychiatry and Human Behavior, Brown University, Providence, RI, 02912, USA.
- Center for Alcohol and Addiction Studies, Department of Behavioral and Social Sciences, Brown University, Providence, RI, USA.
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD, USA.
| | - Robert M Swift
- Center for Alcohol and Addiction Studies, Department of Psychiatry and Human Behavior, Brown University, Providence, RI, 02912, USA
- Providence VA Medical Center, Providence, RI, 02912, USA
| | - Lorenzo Leggio
- Center for Alcohol and Addiction Studies, Department of Behavioral and Social Sciences, Brown University, Providence, RI, USA
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD, USA
| |
Collapse
|
12
|
Rizvić E, Janković G, Kostić-Rajačić S, Savić MM. Atypical sympathomimetic drug lerimazoline mediates contractile effects in rat aorta predominantly by 5-HT2A receptors. Bosn J Basic Med Sci 2017; 17:194-202. [PMID: 28628756 PMCID: PMC5581967 DOI: 10.17305/bjbms.2017.2071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Revised: 05/11/2017] [Accepted: 05/12/2017] [Indexed: 12/20/2022] Open
Abstract
Lerimazoline is a sympathomimetic drug that belongs to the imidazoline class of compounds, and is used as a nasal decongestant. Studies on lerimazoline are rare, and its pharmacological profile is not completely understood. Here, we analyzed the affinity of lerimazoline for dopamine receptor D2, serotonin 5-HT1A and 5-HT2A receptors and α1-adrenoceptor, and investigated lerimazoline contractile effects in isolated rat thoracic aorta. We also determined the effect of several antagonists on the contractile response to lerimazoline, including prazosin (α1-adrenoceptor antagonist), RX 821002 and rauwolscine (α2-adrenoceptor antagonists), JP 1302 (α2C-adrenoceptor antagonist), methiothepin (non-selective 5-HT receptor antagonist), SB 224289 (5-HT1B receptor antagonist), BRL 15572 (5-HT1D receptor antagonist), and ketanserin (5-HT2A receptor antagonist). Lerimazoline displayed high affinity for the 5-HT1A receptor (Ki = 162.5 nM), similar to the previously reported affinity for the 5-HT1D receptor. Binding affinity estimates (Ki) for α1, 5-HT2A, and D2 receptors were 6656, 4202 and 3437.5 nM, respectively (the literature reported Ki for 5-HT1B receptor is 3480 nM). Lerimazoline caused concentration-dependent contractions in 70% of preparations, varying in the range between 40% and 55% of the maximal contraction elicited by phenylephrine. While prazosin reduced the maximum contractile response to lerimazoline, rauwolscine showed a non-significant trend in reduction of the response. Both ketanserin (10 nM and 1 µM) and methiothepin strongly suppressed the maximum response to lerimazoline. Overall, our results suggest that 5-HT2A and, less distinctly, α1-adrenergic receptors are involved in the lerimazoline-induced contractions, which makes lerimazoline an "atypical" decongestant.
Collapse
MESH Headings
- Animals
- Aorta, Thoracic/drug effects
- Dose-Response Relationship, Drug
- In Vitro Techniques
- Male
- Muscle Contraction/drug effects
- Muscle, Smooth, Vascular/drug effects
- Niacinamide/analogs & derivatives
- Niacinamide/antagonists & inhibitors
- Niacinamide/metabolism
- Niacinamide/pharmacology
- Phenylephrine/pharmacology
- Rats
- Rats, Wistar
- Receptor, Serotonin, 5-HT1D/drug effects
- Receptor, Serotonin, 5-HT1D/metabolism
- Receptor, Serotonin, 5-HT2A/drug effects
- Receptor, Serotonin, 5-HT2A/metabolism
- Receptors, Adrenergic, alpha-1/drug effects
- Receptors, Adrenergic, alpha-1/metabolism
- Serotonin Antagonists/pharmacology
- Sympathomimetics/metabolism
- Sympathomimetics/pharmacology
- Vasoconstrictor Agents/pharmacology
Collapse
Affiliation(s)
- Eldina Rizvić
- Department of Pharmacology, Faculty of Pharmacy, University of Belgrade, Belgrade, Serbia.
| | | | | | | |
Collapse
|
13
|
|
14
|
Liu JR, Yuki K, Baek C, Han XH, Soriano SG. Dexmedetomidine-Induced Neuroapoptosis Is Dependent on Its Cumulative Dose. Anesth Analg 2016; 123:1008-17. [PMID: 27529322 DOI: 10.1213/ane.0000000000001527] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
15
|
Gueye AB, Pryslawsky Y, Trigo JM, Poulia N, Delis F, Antoniou K, Loureiro M, Laviolette SR, Vemuri K, Makriyannis A, Le Foll B. The CB1 Neutral Antagonist AM4113 Retains the Therapeutic Efficacy of the Inverse Agonist Rimonabant for Nicotine Dependence and Weight Loss with Better Psychiatric Tolerability. Int J Neuropsychopharmacol 2016; 19:pyw068. [PMID: 27493155 PMCID: PMC5203757 DOI: 10.1093/ijnp/pyw068] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 07/31/2016] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Multiple studies suggest a pivotal role of the endocannabinoid system in regulating the reinforcing effects of various substances of abuse. Rimonabant, a CB1 inverse agonist found to be effective for smoking cessation, was associated with an increased risk of anxiety and depression. Here we evaluated the effects of the CB1 neutral antagonist AM4113 on the abuse-related effects of nicotine and its effects on anxiety and depressive-like behavior in rats. METHODS Rats were trained to self-administer nicotine under a fixed-ratio 5 or progressive-ratio schedules of reinforcement. A control group was trained to self-administer food. The acute/chronic effects of AM4113 pretreatment were evaluated on nicotine taking, motivation for nicotine, and cue-, nicotine priming- and yohimbine-induced reinstatement of nicotine-seeking. The effects of AM4113 in the basal firing and bursting activity of midbrain dopamine neurons were evaluated in a separate group of animals treated with nicotine. Anxiety/depression-like effects of AM4113 and rimonabant were evaluated 24h after chronic (21 days) pretreatment (0, 1, 3, and 10mg/kg, 1/d). RESULTS AM4113 significantly attenuated nicotine taking, motivation for nicotine, as well as cue-, priming- and stress-induced reinstatement of nicotine-seeking behavior. These effects were accompanied by a decrease of the firing and burst rates in the ventral tegmental area dopamine neurons in response to nicotine. On the other hand, AM4113 pretreatment did not have effects on operant responding for food. Importantly, AM4113 did not have effects on anxiety and showed antidepressant-like effects. CONCLUSION Our results indicate that AM4113 could be a promising therapeutic option for the prevention of relapse to nicotine-seeking while lacking anxiety/depression-like side effects.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Bernard Le Foll
- Translational Addiction Research Laboratory (Dr Gueye, Mr Pryslawsky, Dr Trigo, and Dr Le Foll), Alcohol Research and Treatment Clinic, Addiction Medicine Services, Ambulatory Care and Structured Treatments (Dr Le Foll), and Campbell Family Mental Health Research Institute (Dr Le Foll), Centre for Addiction and Mental Health, Toronto, ON, Canada; Department of Family and Community Medicine, Department of Pharmacology, and Department of Psychiatry, Division of Brain and Therapeutics, University of Toronto, Toronto, ON, Canada (Dr Le Foll); Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada (Dr Le Foll); Department of Pharmacology, Faculty of Medicine, School of Health Sciences, University of Ioannina, Greece (Ms Poulia and Drs Delis and Antoniou); Department of Anatomy and Cell Biology, The Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada (Drs Loureiro and Laviolette); Center for Drug Discovery, Department of Pharmaceutical Sciences and Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA (Drs Vemuri and Makriyannis).
| |
Collapse
|
16
|
Rippberger H, van Gaalen MM, Schwarting RKW, Wohr M. Environmental and Pharmacological Modulation of Amphetamine- Induced 50-kHz Ultrasonic Vocalizations in Rats. Curr Neuropharmacol 2016; 13:220-32. [PMID: 26411764 PMCID: PMC4598433 DOI: 10.2174/1570159x1302150525124408] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Rats emit high-frequency 50-kHz ultrasonic vocalizations (USV) in appetitive situations like social interactions. Drugs of abuse are probably the most potent non-social elicitors of 50-kHz USV, possibly reflecting their euphorigenic properties. Psychostimulants induce the strongest elevation in 50-kHz USV emission, particularly amphetamine (AMPH), either when applied systemically or locally into the nucleus accumbens (Nacc). Emission of AMPH-induced 50-kHz USV depends on test context, such as the presence of conspecifics, and can be manipulated pharmacologically by targeting major neurotransmitter systems, including dopamine (DA), noradrenaline (NA), and serotonin (5-HT), but also protein kinase C (PKC) signaling. Several D1 and D2 receptor antagonists, as well as typical and atypical antipsychotics block the AMPH-induced elevation in 50-kHz USV. Inhibiting D1 and D2 receptors in the Nacc abolishes AMPH-induced 50-kHz USV, indicating a key role for this brain area. NA neurotransmission also regulates AMPH-induced 50-kHz USV emission given that α1 receptor antagonists and α2 receptor agonists exert attenuating effects. Supporting the involvement of the 5-HT system, AMPH-induced 50-kHz USV are attenuated by 5-HT2C receptor activation, whereas 5-HT2C receptor antagonism leads to the opposite effect. Finally, treatment with lithium, tamoxifen, and myricitrin was all found to result in a complete abolishment of the AMPH-induced increase in 50-kHz USV, suggesting the involvement of PKC signaling. Neurotransmitter systems involved in AMPH-induced 50-kHz USV emission only partially overlap with other AMPH-induced behaviors like hyperlocomotion. The validity of AMPH-induced 50-kHz USV as a preclinical model for neuropsychiatric disorders is discussed, particularly with relevance to altered drive and mood seen in bipolar disorder.
Collapse
Affiliation(s)
| | | | | | - Markus Wohr
- Behavioral Neuroscience, Experimental and Biological Psychology, Philipps-University of Marburg, Gutenbergstr. 18, 35032 Marburg, Germany.
| |
Collapse
|
17
|
Haass-Koffler CL, Leggio L, Davidson D, Swift RM. Effects of idazoxan on alcohol pharmacokinetics and intoxication: a preliminary human laboratory study. Alcohol Clin Exp Res 2016; 39:594-602. [PMID: 25833022 DOI: 10.1111/acer.12658] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 12/18/2014] [Indexed: 11/30/2022]
Abstract
BACKGROUND Preliminary basic and human studies suggest that the α2 -adrenergic antagonist idazoxan may represent a novel medication for alcohol dependence. The goal of this study was to evaluate the safety and tolerability of the co-administration of idazoxan with alcohol and explore whether pharmacokinetics (PK) and biobehavioral mechanisms of idazoxan may alter alcohol's effects. METHODS This was a preliminary double-blind, single-dose, placebo-controlled, crossover, randomized human laboratory study. Ten social drinkers were dosed, in 2 different alcohol challenge studies (ACS), with a single oral dose of idazoxan (40 mg) or placebo, followed by a fixed alcohol dose 60 minutes later. Participants returned after a 1-week washout, and they were crossed over to the opposite medication condition. RESULTS There were no significant differences in adverse events between idazoxan and placebo. Moreover, during the ACS paradigm, 40 mg idazoxan was well tolerated with no significant autonomic effects compared to placebo; idazoxan reduced the peak blood alcohol level (p < 0.01) and time to peak (p < 0.05) compared to placebo. A PK/pharmacodynamic model aligned the biobehavioral effects, demonstrating that the co-administration of 40 mg idazoxan with alcohol decreased alcohol-related stimulation (p < 0.05) and increased alcohol-related sedation (p < 0.05). CONCLUSIONS This study supports the safety and tolerability of 40 mg idazoxan when co-administered with alcohol. Additionally, this study suggests that idazoxan may alter the biphasic effects of alcohol by decreasing stimulation and increasing sedation. These findings have implications for further investigation of using idazoxan as a probe to develop potential novel medications to treat alcoholic patients.
Collapse
Affiliation(s)
- Carolina L Haass-Koffler
- Center for Alcohol and Addiction Studies, Department of Behavioral and Social Sciences, Brown University, Providence, Rhode Island
| | | | | | | |
Collapse
|
18
|
Li C, Kirby LG. Effects of cocaine history on postsynaptic GABA receptors on dorsal raphe serotonin neurons in a stress-induced relapse model in rats. Eur Neuropsychopharmacol 2016; 26:45-54. [PMID: 26640169 PMCID: PMC4738081 DOI: 10.1016/j.euroneuro.2015.11.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Revised: 10/07/2015] [Accepted: 11/13/2015] [Indexed: 11/30/2022]
Abstract
The serotonin (5-hydroxytryptamine, 5-HT) system plays an important role in stress-related psychiatric disorders and substance abuse. Stressors and stress hormones can inhibit the dorsal raphe nucleus (DRN)-5-HT system, which composes the majority of forebrain-projecting 5-HT. This inhibition is mediated via stimulation of GABA synaptic activity at DRN-5-HT neurons. Using swim stress-induced reinstatement of morphine conditioned place-preference, recent data from our laboratory indicate that morphine history sensitizes DRN-5-HT neurons to GABAergic inhibitory effects of stress. Moreover, GABAA receptor-mediated inhibition of the serotonergic DRN is required for this reinstatement. In our current experiment, we tested the hypothesis that GABAergic sensitization of DRN-5-HT neurons is a neuroadaptation elicited by multiple classes of abused drugs across multiple models of stress-induced relapse by applying a chemical stressor (yohimbine) to induce reinstatement of previously extinguished cocaine self-administration in Sprague-Dawley rats. Whole-cell patch-clamp recordings of GABA synaptic activity in DRN-5-HT neurons were conducted after the reinstatement. Behavioral data indicate that yohimbine triggered reinstatement of cocaine self-administration. Electrophysiology data indicate that 5-HT neurons in the cocaine group exposed to yohimbine had increased amplitude of inhibitory postsynaptic currents compared to yoked-saline controls exposed to yohimbine or unstressed animals in both drug groups. These data, together with previous findings, indicate that interaction between psychostimulant or opioid history and chemical or physical stressors may increase postsynaptic GABA receptor density and/or sensitivity in DRN-5-HT neurons. Such mechanisms may result in serotonergic hypofunction and consequent dysphoric mood states which confer vulnerability to stress-induced drug reinstatement.
Collapse
Affiliation(s)
- Chen Li
- Center for Substance Abuse Research, Department of Anatomy and Cell Biology, Louis Katz School of Medicine at Temple University, 3500 N. Broad Street, Philadelphia, PA 19140, USA
| | - Lynn G Kirby
- Center for Substance Abuse Research, Department of Anatomy and Cell Biology, Louis Katz School of Medicine at Temple University, 3500 N. Broad Street, Philadelphia, PA 19140, USA.
| |
Collapse
|
19
|
Zaretsky DV, Zaretskaia MV, DiMicco JA, Rusyniak DE. Yohimbine is a 5-HT1A agonist in rats in doses exceeding 1 mg/kg. Neurosci Lett 2015; 606:215-9. [PMID: 26366943 DOI: 10.1016/j.neulet.2015.09.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 08/30/2015] [Accepted: 09/08/2015] [Indexed: 02/07/2023]
Abstract
Yohimbine is a prototypical alpha2-adrenergic receptor antagonist. Due to its relatively high selectivity, yohimbine is often used in experiments whose purpose is to examine the role of these receptors. For example, yohimbine has been employed at doses of 1-5 mg/kg to reinstate drug-seeking behavior after extinction or to antagonize general anesthesia, an effects presumably being a consequence of blocking alpha2-adrenergic receptors. In this report we characterized dose-dependent autonomic and behavioral effects of yohimbine and its interaction with an antagonist of 5-HT1A receptors, WAY 100,635. In low doses (0.5-2 mg/kg i.p.) yohimbine induced locomotor activation which was accompanied by a tachycardia and mild hypertension. Increasing the dose to 3-4.5 mg/kg reversed the hypertension and locomotor activation and induced profound hypothermia. The hypothermia as well as the suppression of the locomotion and the hypertension could be reversed by the blockade of 5-HT1A receptors with WAY 100635. Our data confirm that yohimbine possesses 5-HT1A properties, and demonstrated that in doses above 1mg/kg significantly activate these receptors.
Collapse
Affiliation(s)
- Dmitry V Zaretsky
- Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis, IN 46202 USA.
| | - Maria V Zaretskaia
- Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis, IN 46202 USA
| | - Joseph A DiMicco
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Daniel E Rusyniak
- Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis, IN 46202 USA; Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| |
Collapse
|
20
|
da Silva ED, de Souza BP, Vilela VV, Rodrigues JQD, Nichi M, de Agostini Losano JD, Dalmazzo A, Barnabe VH, Jurkiewicz A, Jurkiewicz NH. Epididymal contraction and sperm parameters are affected by clonidine. Andrology 2014; 2:955-66. [DOI: 10.1111/andr.283] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 08/14/2014] [Accepted: 09/02/2014] [Indexed: 11/28/2022]
Affiliation(s)
- E. D. da Silva
- Department of Pharmacology; Mechanism of Drug Action Laboratory; Federal University of São Paulo (UNIFESP); São Paulo Brazil
| | - B. P. de Souza
- Department of Pharmacology; Mechanism of Drug Action Laboratory; Federal University of São Paulo (UNIFESP); São Paulo Brazil
| | - V. V. Vilela
- Department of Morphology and Genetics; Developmental Biology Laboratory; Federal University of São Paulo (UNIFESP); São Paulo Brazil
| | - J. Q. D. Rodrigues
- Department of Pharmacology; Mechanism of Drug Action Laboratory; Federal University of São Paulo (UNIFESP); São Paulo Brazil
| | - M. Nichi
- Department of Animal Reproduction; Faculty of Veterinary Medicine and Animal Science (FMVZ); University of São Paulo (USP); São Paulo Brazil
| | - J. D. de Agostini Losano
- Department of Animal Reproduction; Faculty of Veterinary Medicine and Animal Science (FMVZ); University of São Paulo (USP); São Paulo Brazil
| | - A. Dalmazzo
- Department of Animal Reproduction; Faculty of Veterinary Medicine and Animal Science (FMVZ); University of São Paulo (USP); São Paulo Brazil
| | - V. H. Barnabe
- Department of Animal Reproduction; Faculty of Veterinary Medicine and Animal Science (FMVZ); University of São Paulo (USP); São Paulo Brazil
| | - A. Jurkiewicz
- Department of Pharmacology; Mechanism of Drug Action Laboratory; Federal University of São Paulo (UNIFESP); São Paulo Brazil
| | - N. H. Jurkiewicz
- Department of Pharmacology; Mechanism of Drug Action Laboratory; Federal University of São Paulo (UNIFESP); São Paulo Brazil
| |
Collapse
|
21
|
Dantas da Silva Júnior E, Palmieri de Souza B, Quintella Dantas Rodrigues J, Caricati-Neto A, Jurkiewicz A, Jurkiewicz NH. Effects of clonidine in the isolated rat testicular capsule. Eur J Pharmacol 2014; 726:16-26. [DOI: 10.1016/j.ejphar.2014.01.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 12/18/2013] [Accepted: 01/12/2014] [Indexed: 11/30/2022]
|
22
|
Grella SL, Funk D, Coen K, Li Z, Lê AD. Role of the kappa-opioid receptor system in stress-induced reinstatement of nicotine seeking in rats. Behav Brain Res 2014; 265:188-97. [PMID: 24583188 DOI: 10.1016/j.bbr.2014.02.029] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 02/14/2014] [Accepted: 02/19/2014] [Indexed: 12/14/2022]
Abstract
RATIONALE The correlation between stress and smoking is well established. The mechanisms that underlie this relationship are, however, unclear. Recent data suggest that the kappa-opioid system is involved in the mediation of negative affective states associated with stress thereby promoting drug addiction and relapse. Pharmacological treatments targeting the kappa-opioid system and this mechanism may prove to be useful therapeutics for nicotine addiction in the future. OBJECTIVES We sought to determine whether there was a stress-specific role of the kappa-opioid system in nicotine seeking behavior. METHOD Groups of male Long Evans rats were trained to self-administer nicotine intravenously; their operant responding for nicotine was extinguished prior to tests of reinstatement. Pretreatment with systemic injections of the kappa-opioid receptor (KOR) antagonist nor-binaltorphimine (nor-BNI) was given prior to tests of stress (systemic injections of yohimbine (YOH)) or cue-induced reinstatement of nicotine seeking. Systemic injections of the KOR agonist U50,488 were also given in a test for reinstatement of nicotine seeking. RESULTS Nor-BNI pretreatment at 1h and 24h prior to testing was able to block YOH-induced, but not cue-induced reinstatement of nicotine seeking. U50,488 reinstated nicotine seeking behavior in a dose-dependent manner. CONCLUSIONS These findings support the hypothesis that the kappa-opioid system is involved in relapse to nicotine seeking induced by stress, but not by conditioned cues. KOR antagonists such as nor-BNI may therefore be useful novel therapeutic agents for decreasing the risk of stress-induced drug relapse.
Collapse
Affiliation(s)
- Stephanie L Grella
- Neurobiology of Alcohol Laboratory, Centre for Addiction and Mental Health, 33 Russell St., Toronto, Ontario M5S 2S1, Canada; Department of Pharmacology & Toxicology, University of Toronto, Medical Sciences Building, Rm 4207, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
| | - Douglas Funk
- Neurobiology of Alcohol Laboratory, Centre for Addiction and Mental Health, 33 Russell St., Toronto, Ontario M5S 2S1, Canada.
| | - Kathy Coen
- Neurobiology of Alcohol Laboratory, Centre for Addiction and Mental Health, 33 Russell St., Toronto, Ontario M5S 2S1, Canada
| | - Zhaoxia Li
- Neurobiology of Alcohol Laboratory, Centre for Addiction and Mental Health, 33 Russell St., Toronto, Ontario M5S 2S1, Canada
| | - A D Lê
- Neurobiology of Alcohol Laboratory, Centre for Addiction and Mental Health, 33 Russell St., Toronto, Ontario M5S 2S1, Canada; Department of Pharmacology & Toxicology, University of Toronto, Medical Sciences Building, Rm 4207, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada; Department of Psychiatry, University of Toronto, 250 College Street, 8th Floor, Toronto, Ontario M5T 1R8, Canada
| |
Collapse
|
23
|
Calu DJ, Chen YW, Kawa AB, Nair SG, Shaham Y. The use of the reinstatement model to study relapse to palatable food seeking during dieting. Neuropharmacology 2014; 76 Pt B:395-406. [PMID: 23660229 PMCID: PMC3785569 DOI: 10.1016/j.neuropharm.2013.04.030] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 03/29/2013] [Accepted: 04/16/2013] [Indexed: 12/14/2022]
Abstract
Excessive consumption of unhealthy foods is a major public health problem. While many people attempt to control their food intake through dieting, many relapse to unhealthy eating habits within a few months. We have begun to study this clinical condition in rats by adapting the reinstatement model, which has been used extensively to study relapse to drug seeking. In our adaptation of the relapse model, reinstatement of palatable food seeking by exposure to food-pellet priming, food-associated cues, or stress is assessed in food-restricted (to mimic dieting) rats after operant food-pellet self-administration training and subsequent extinction of the food-reinforced responding. In this review, we first outline the clinical problem and discuss a recent study in which we assessed the predictive validity of the reinstatement model for studying relapse to food seeking during dieting by using the anorexigenic drug fenfluramine. Next, we summarize results from our initial studies on the role of several stress- and feeding-related peptides (corticotropin-releasing factor, hypocretin, melanin-concentrating hormone, peptide YY3-36) in reinstatement of palatable food seeking. We then present results from our studies on the role of dopamine and medial prefrontal cortex in stress-induced reinstatement of food seeking. We conclude by discussing potential clinical implications. We offer two main conclusions: (1) the food reinstatement model is a simple, reliable, and valid model to study mechanisms of relapse to palatable food seeking during dieting, and to identify medications to prevent this relapse; (2) mechanisms of relapse to food seeking are often dissociable from mechanisms of ongoing food intake. This article is part of a Special Issue entitled 'NIDA 40th Anniversary Issue'.
Collapse
Affiliation(s)
- Donna J Calu
- Behavioral Neuroscience Branch, Intramural Research Program, NIDA/NIH, Baltimore, MD, USA.
| | | | | | | | | |
Collapse
|
24
|
Masterson CG, Durham PL. DHE repression of ATP-mediated sensitization of trigeminal ganglion neurons. Headache 2013; 50:1424-39. [PMID: 20561068 DOI: 10.1111/j.1526-4610.2010.01714.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
OBJECTIVE To investigate the mechanism by which adenosine triphosphate (ATP) causes sensitization of trigeminal neurons and how dihydroergotamine (DHE) represses this modulatory effect. BACKGROUND Dihydroergotamine is an effective treatment of migraine. The cellular mechanisms of action of DHE in treating migraine attacks remain unclear. METHODS In this study, neonatal rat trigeminal ganglia cultures were used to investigate effects of ATP, alpha, beta-methyl ATP (α,β-meATP), and DHE on intracellular calcium levels and calcitonin gene-related peptide (CGRP) secretion. RESULTS Pretreatment with ATP or α,β-meATP caused sensitization of neurons, via P2X(3) receptors, such that a subthreshold amount of potassium chloride (KCl) significantly increased intracellular calcium levels and CGRP secretion. Pretreatment with DHE repressed increases in calcium and CGRP secretion in response to ATP-KCl or α,β-meATP-KCl treatment. Importantly, these inhibitory effects of DHE were blocked with an α(2) -adrenoceptor antagonist and unaffected by a 5HT(1B/D) receptor antagonist. DHE also decreased neuronal membrane expression of the P2X(3) receptor. CONCLUSIONS Our findings provide evidence for a novel mechanism of action for DHE that involves blocking ATP-mediated sensitization of trigeminal neurons, repressing stimulated CGRP release, and decreasing P2X(3) membrane expression via activation of α(2) -adrenoceptors.
Collapse
Affiliation(s)
- Caleb G Masterson
- Center for Biomedical and Life Sciences, Missouri State University, Springfield, MO 65806, USA
| | | |
Collapse
|
25
|
Greenwald MK, Lundahl LH, Steinmiller CL. Yohimbine increases opioid-seeking behavior in heroin-dependent, buprenorphine-maintained individuals. Psychopharmacology (Berl) 2013; 225:811-24. [PMID: 23161001 PMCID: PMC3558534 DOI: 10.1007/s00213-012-2868-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Accepted: 08/29/2012] [Indexed: 01/04/2023]
Abstract
RATIONALE In laboratory animals, the biological stressor yohimbine (α(2)-noradrenergic autoreceptor antagonist) promotes drug seeking. Human laboratory studies have demonstrated that psychological stressors can increase drug craving but not that stressors alter drug seeking. OBJECTIVES This clinical study tested whether yohimbine increases opioid-seeking behavior. METHODS Ten heroin-dependent, buprenorphine-stabilized (8 mg/day) volunteers sampled two doses of hydromorphone [12 and 24 mg IM in counterbalanced order, labeled drug A (session 1) and drug B (session 2)]. During each of six later sessions (within-subject, double-blind, randomized crossover design), volunteers could respond on a 12-trial choice progressive ratio task to earn units (1 or 2 mg) of the sampled hydromorphone dose (drug A or B) vs money ($2) following different oral yohimbine pretreatment doses (0, 16.2, and 32.4 mg). RESULTS Behavioral economic demand intensity and peak responding (O (max)) were significantly higher for hydromorphone 2 than 1 mg. Relative to placebo, yohimbine significantly increased hydromorphone demand inelasticity, more so for hydromorphone 1-mg units (P (max) = 909, 3,647, and 3,225 for placebo, 16.2, and 32.4 mg yohimbine doses, respectively) than hydromorphone 2-mg units (P (max) = 2,656, 3,193, and 3,615, respectively). Yohimbine produced significant but clinically modest dose-dependent increases in blood pressure (systolic ≈ 15 and diastolic ≈ 10 mmHg) and opioid withdrawal symptoms, and decreased opioid agonist symptoms and elated mood. CONCLUSIONS These findings concur with preclinical data by demonstrating that yohimbine increases drug seeking; in this study, these effects occurred without clinically significant subjective distress or elevated craving, and partly depended on opioid unit dose.
Collapse
Affiliation(s)
- Mark K. Greenwald
- Substance Abuse Research Division, Dept. of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, MI
| | - Leslie H. Lundahl
- Substance Abuse Research Division, Dept. of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, MI
| | - Caren L. Steinmiller
- Substance Abuse Research Division, Dept. of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, MI,Dept. of Pharmacology, University of Toledo, Toledo, OH
| |
Collapse
|
26
|
|
27
|
|
28
|
COMMUNICATION. Br J Pharmacol 2012. [DOI: 10.1111/j.1476-5381.1984.tb16957.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
|
29
|
Landau AM, Doudet DJ, Jakobsen S. Amphetamine challenge decreases yohimbine binding to α2 adrenoceptors in Landrace pig brain. Psychopharmacology (Berl) 2012; 222:155-63. [PMID: 22227612 DOI: 10.1007/s00213-011-2632-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Accepted: 12/21/2011] [Indexed: 11/29/2022]
Abstract
RATIONALE The noradrenaline (NA) system is implicated in neurodegenerative and psychiatric disorders; however, our understanding is impaired by the lack of well-validated radioligands to assess NA function and release. Yohimbine, an α2 adrenoceptor antagonist, has recently been developed as a carbon-11 [11C]-labeled radioligand for positron emission tomography (PET) imaging studies. OBJECTIVES Here we explore the hypothesis that yohimbine can be used as an in vivo tracer of NA receptor binding and release during amphetamine challenges in Landrace pigs. METHODS Pigs underwent baseline PET scans with [11C]yohimbine and were then challenged with 10 mg/kg d-amphetamine 20 min prior to a second [11C]yohimbine scan. Using the Logan analysis model, volumes of distribution were calculated from fits of the kinetic data 25-90 min post-yohimbine injection. RESULTS Amphetamine decreased [11C]yohimbine volume of distribution in the brain regions under investigation, including the thalamus, caudate nucleus, and cortical regions. CONCLUSION These data suggest that the binding of [11C]yohimbine to α2 adrenoceptors may be displaceable by increases in synaptic concentrations of the endogenous ligand, NA, and possibly dopamine, suggesting the possibility that [11C]yohimbine may be used as a surrogate marker of NA release in vivo.
Collapse
Affiliation(s)
- Anne M Landau
- Department of Nuclear Medicine and PET Center, Aarhus University Hospital, Norrebrogade 44, Building 10G, Aarhus C 8000, Denmark
| | | | | |
Collapse
|
30
|
Microscopic and UPLC–UV–MS analyses of authentic and commercial yohimbe (Pausinystalia johimbe) bark samples. J Nat Med 2012; 67:42-50. [DOI: 10.1007/s11418-012-0642-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Accepted: 02/05/2012] [Indexed: 10/28/2022]
|
31
|
α- and β-Adrenergic receptors differentially modulate the emission of spontaneous and amphetamine-induced 50-kHz ultrasonic vocalizations in adult rats. Neuropsychopharmacology 2012; 37:808-21. [PMID: 22030713 PMCID: PMC3260979 DOI: 10.1038/npp.2011.258] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Amphetamine (AMPH) increases adult rat 50-kHz ultrasonic vocalizations, preferentially promoting frequency-modulated (FM) calls that have been proposed to reflect positive affect. The main objective of this study was to investigate a possible noradrenergic contribution to AMPH-induced calling. Adult male Long-Evans rats were tested with AMPH (1 mg/kg intraperitoneal) or saline combined with various systemic pretreatments: clonidine (α2 adrenergic agonist), prazosin (α1 antagonist), atipamezole (α2 antagonist), propranolol, betaxolol, and/or ICI 118,551 (β1/β2, β1, and β2 antagonists, respectively), nadolol (β1/β2 antagonist, peripheral only), or NAD-299 (5HT(1A) antagonist). In addition, effects of cirazoline (α1 adrenergic agonist) and cocaine (0.25-1.5 mg/kg intravenous) were studied alone. AMPH-induced calling was suppressed by low-dose clonidine and prazosin. Cirazoline and atipamezole did not significantly affect calling rate. Propranolol, without affecting the call rate, dose dependently promoted 'flat' calls under AMPH while suppressing 'trills,' thus reversing the effects of AMPH on the 'call subtype profile.' This effect of propranolol seemed to be mediated by simultaneous inhibition of CNS β1 and β2 rather than by 5HT(1A) receptors. Finally, cocaine elicited fewer calls than did AMPH, but produced the same shift in the call subtype profile. Taken together, these results reveal differential drug effects on flat vs trill vs other FM 50-kHz calls. These findings highlight the value of detailed call subtype analyses, and show that 50-kHz calls are associated with adrenergic α1- and β-receptor mechanisms. These preclinical findings suggest that noradrenergic contributions to psychostimulant subjective effects may warrant further investigation.
Collapse
|
32
|
Lê AD, Funk D, Juzytsch W, Coen K, Navarre BM, Cifani C, Shaham Y. Effect of prazosin and guanfacine on stress-induced reinstatement of alcohol and food seeking in rats. Psychopharmacology (Berl) 2011; 218:89-99. [PMID: 21318567 PMCID: PMC3168954 DOI: 10.1007/s00213-011-2178-7] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Accepted: 01/07/2011] [Indexed: 11/26/2022]
Abstract
RATIONALE AND OBJECTIVES Relapse to alcohol use during abstinence or maladaptive eating habits during dieting is often provoked by stress. The anxiogenic drug yohimbine, which causes stress-like responses in humans and non-humans, reliably reinstates alcohol and food seeking in a rat relapse model. Yohimibine is a prototypical alpha-2 adrenoceptor antagonist, but results from studies on noradrenaline's role in yohimbine-induced reinstatement of drug and food seeking are inconclusive. Here, we further addressed this issue by studying the effect of the alpha-1 adrenoceptor antagonist prazosin and the alpha-2 adrenoceptor agonist guanfacine on yohimbine-induced reinstatement. METHODS In exp. 1, we trained rats to self-administer alcohol (12% w/v, 1 h/day), and after extinction of alcohol-reinforced lever pressing, we tested prazosin's (0.5, 1.0, and 2.0 mg/kg, i.p.) or guanfacine's (0.125, 0.25, and 0.5 mg/kg, i.p.) effect on yohimbine (1.25 mg/kg, i.p.)-induced reinstatement; we also examined prazosin's effect on intermittent-footshock-stress-induced reinstatement. In exp. 2, we trained food-restricted rats to self-administer 45 mg food pellets and first examined prazosin's or guanfacine's effects on food-reinforced responding, and then, after extinction of lever presses, on yohimbine-induced reinstatement. RESULTS Prazosin (0.5-2.0 mg/kg) blocked yohimbine-induced reinstatement of food and alcohol seeking, as well as footshock-induced reinstatement of alcohol seeking. Guanfacine attenuated yohimbine-induced reinstatement of alcohol seeking at the highest dose (0.5 mg/kg), but its effect on yohimbine-induced reinstatement of food seeking was not significant. Neither prazosin nor guanfacine affected high-rate food-reinforced responding. CONCLUSIONS Results demonstrate an important role of postsynaptic alpha-1 adrenoceptors in stress-induced reinstatement of alcohol and food seeking.
Collapse
Affiliation(s)
- A D Lê
- Neurobiology of Alcohol Laboratory, Centre for Addiction and Mental Health, 33 Russell Street, Toronto, ON M5S 2S1, Canada.
| | | | | | | | | | | | | |
Collapse
|
33
|
Evaluation of the effects of α2 adrenoceptor antagonism with the D2 receptor antagonist raclopride on conditioned avoidance responding in rats. Behav Pharmacol 2010; 21:654-9. [PMID: 20729715 DOI: 10.1097/fbp.0b013e32833e7efd] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The α2 adrenoceptor antagonist idazoxan, when combined with a subeffective dose of the D2 receptor antagonist raclopride or other D2 receptor antagonists, produces inhibition of conditioned avoidance responding (CAR) in rats, an effect predictive of antipsychotic effects. In other models, this treatment combination indicates putative atypical antipsychotic effects as well, and has led to a α2/D2 receptor hypothesis for atypicality. However, this hypothesis would be better supported if other α2 adrenoceptor antagonists were investigated and the role of the alternative mechanisms, particularly 5-HT1A receptor agonism, for the behavioral effects of idazoxan were evaluated. This study sought to further test the α2/D2 receptor hypothesis by assessing the effects of α2, D2 and 5-HT1A receptor ligands on CAR in rats. Raclopride significantly reduced CAR. Administration of idazoxan or the α2 adrenoceptor antagonist yohimbine with a subeffective dose of raclopride also significantly reduced CAR. Pretreatment with the 5-HT1A receptor antagonist WAY100635 failed to significantly reverse the inhibition of CAR produced by the idazoxan and raclopride treatment combination. To the extent that 5-HT1A receptor antagonism failed to block the effects of idazoxan in combination with raclopride on CAR, α2 adrenoceptor antagonism alone appears to potentiate the putative antipsychotic effects produced through D2 receptor antagonism.
Collapse
|
34
|
Oppedal D, Goldsmith MI. A chemical screen to identify novel inhibitors of fin regeneration in zebrafish. Zebrafish 2010; 7:53-60. [PMID: 20384483 DOI: 10.1089/zeb.2009.0633] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We performed a chemical screen to look for novel inhibitors of zebrafish caudal fin regeneration. In a pilot screen, 520 compounds were tested. Two compounds, budesonide and AGN192403, abrogated fin regeneration. One compound in particular, AGN192403, targets the imidazoline receptor, a pathway not previously linked to fin regeneration. In addition to inhibiting regeneration of the adult fin, AGN192403 also blocked regeneration of the larval fin fold. Finally, the inhibitory effect of AGN192403 on fin regeneration persisted after removal of the drug. These studies demonstrate that chemical screening is feasible in adult zebrafish and that it is a reasonable strategy to use for exploring the biology of regeneration.
Collapse
Affiliation(s)
- Douglas Oppedal
- Department of Pediatrics, Washington University, St. Louis, Missouri 63110, USA
| | | |
Collapse
|
35
|
Prus AJ, Zornio PA, Schuck CJ, Heerts T, Jacobson SM, Winiarski DA. Discriminative stimulus properties of idazoxan: mediation by both α2 adrenoceptor antagonism and 5-HT1A receptor agonism. Drug Dev Res 2010. [DOI: 10.1002/ddr.20370] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
36
|
Nair SG, Adams-Deutsch T, Epstein DH, Shaham Y. The neuropharmacology of relapse to food seeking: methodology, main findings, and comparison with relapse to drug seeking. Prog Neurobiol 2009; 89:18-45. [PMID: 19497349 PMCID: PMC2745723 DOI: 10.1016/j.pneurobio.2009.05.003] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2009] [Revised: 04/09/2009] [Accepted: 05/26/2009] [Indexed: 12/15/2022]
Abstract
Relapse to old, unhealthy eating habits is a major problem in human dietary treatments. The mechanisms underlying this relapse are unknown. Surprisingly, until recently this clinical problem has not been systematically studied in animal models. Here, we review results from recent studies in which a reinstatement model (commonly used to study relapse to abused drugs) was employed to characterize the effect of pharmacological agents on relapse to food seeking induced by either food priming (non-contingent exposure to small amounts of food), cues previously associated with food, or injections of the pharmacological stressor yohimbine. We also address methodological issues related to the use of the reinstatement model to study relapse to food seeking, similarities and differences in mechanisms underlying reinstatement of food seeking versus drug seeking, and the degree to which the reinstatement procedure provides a suitable model for studying relapse in humans. We conclude by discussing implications for medication development and future research. We offer three tentative conclusions: (1)The neuronal mechanisms of food-priming- and cue-induced reinstatement are likely different from those of reinstatement induced by the pharmacological stressor yohimbine. (2)The neuronal mechanisms of reinstatement of food seeking are possibly different from those of ongoing food-reinforced operant responding. (3)The neuronal mechanisms underlying reinstatement of food seeking overlap to some degree with those of reinstatement of drug seeking.
Collapse
Affiliation(s)
- Sunila G. Nair
- Behavioral Neuroscience Branch, NIDA/IRP, 251 Bayview Boulevard, Baltimore, MD, 21224
| | - Tristan Adams-Deutsch
- Behavioral Neuroscience Branch, NIDA/IRP, 251 Bayview Boulevard, Baltimore, MD, 21224
| | - David H. Epstein
- Clinical Pharmacology and Therapeutics Research Branch, NIDA/IRP, 251 Bayview Boulevard, Baltimore, MD, 21224
| | - Yavin Shaham
- Behavioral Neuroscience Branch, NIDA/IRP, 251 Bayview Boulevard, Baltimore, MD, 21224
| |
Collapse
|
37
|
Dean JM, Gunn AJ, Wassink G, George S, Bennet L. Endogenous alpha2-adrenergic receptor-mediated neuroprotection after severe hypoxia in preterm fetal sheep. Neuroscience 2006; 142:615-28. [PMID: 16952424 DOI: 10.1016/j.neuroscience.2006.06.066] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2006] [Revised: 06/20/2006] [Accepted: 06/21/2006] [Indexed: 11/28/2022]
Abstract
Central alpha-adrenergic receptor activity is important for fetal adaptation to hypoxia before birth. It is unclear whether it is also important during recovery. We therefore tested the hypothesis that an infusion of the specific alpha(2)-adrenergic receptor antagonist idazoxan (1 mg/kg/h i.v.) from 15 min to 4 h after profound hypoxia induced by 25 min umbilical cord occlusion in fetal sheep at 70% of gestation (equivalent to the 28-32 weeks in humans) would increase neural injury. After 3 days' recovery, idazoxan infusion was associated with a significant increase in neuronal loss in the hippocampus (P<0.05), expression of cleaved caspase-3 (P<0.05), and numbers of activated microglia (P<0.05). There was no significant effect on other neuronal regions or on loss of O4-positive premyelinating oligodendrocytes in the subcortical white matter. Idazoxan was associated with an increase in evolving epileptiform electroencephalographic (EEG) transient activity after occlusion (difference at peak 2.5+/-1.0 vs. 11.7+/-4.7 counts/min, P<0.05) and significantly reduced average spectral edge frequency, but not EEG intensity, from 54 until 72 h after occlusion (P<0.05). Hippocampal neuronal loss was correlated with total numbers of epileptiform transients during idazoxan infusion (P<0.01; r(2)=0.7). In conclusion, endogenous inhibitory alpha(2)-adrenergic receptor activation after severe hypoxia appears to significantly limit evolving hippocampal damage in the immature brain.
Collapse
Affiliation(s)
- J M Dean
- Department of Physiology, Faculty of Medicine and Health Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
| | | | | | | | | |
Collapse
|
38
|
Jurkiewicz NH, Caricati-Neto A, Verde LF, Avellar MCW, Reuter HR, Jurkiewicz A. Sympathetic neurotransmission in the rat testicular capsule: functional characterization and identification of mRNA encoding alpha1-adrenoceptor subtypes. Eur J Pharmacol 2006; 543:141-50. [PMID: 16822496 DOI: 10.1016/j.ejphar.2006.05.045] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2006] [Revised: 05/11/2006] [Accepted: 05/19/2006] [Indexed: 12/01/2022]
Abstract
The rat testicular capsule is a thin tissue surrounding the testis, whose precise function is still unknown. We have studied the contractile effects of electrical field stimulation, noradrenaline, and the blockade by antagonists of adrenergic receptors, in order to characterize sympathetic neurotransmission, and adrenoceptor subtypes. In addition, reverse transcription polymerase chain reaction (RT-PCR) assays were made to check for the expression of the three known subtypes of alpha(1)-adrenoceptors. The effects of electrical field stimulation (2 to 20 Hz, 1 ms, 60 V) were almost totally abolished by depletion of neuronal noradrenaline storage with reserpine (10 mg/Kg), but not by the purinergic receptor antagonist suramin (10(-5) M), indicating that noradrenaline, but not ATP, was involved in contractions. The selective alpha(1)-adrenoceptor antagonist prazosin (10(-7) M) was more effective than the selective alpha(2)-adrenoceptor antagonist idazoxan (10(-7) M) to inhibit contractions induced by electrical field stimulation, pointing out a major involvement of alpha(1)-adrenoceptor. When noradrenaline was used instead of electrical field stimulation, it showed a high potency (pD(2)=7.9). Noradrenaline-induced contractions were competitively blocked by the selective alpha(1A)-adrenoceptor antagonists WB 4101 (pA(2)=8.88), phentolamine (pA(2)=8.39) and by the alpha(1B)-adrenoceptor antagonist spiperone (pA(2)=8.57), indicating the presence of functional alpha(1A)- and alpha(1B)-adrenoceptors. In addition, contractions were not blocked by the selective alpha(1D)-adrenoceptor antagonist BMY 7378 (up to 10(-6) M), while selective alpha(2)-adrenoceptor antagonists showed low pA(2) values (yohimbine, 7.25 and idazoxan, 7.49), suggesting a minor role, if any, for alpha(1D)- and alpha(2)-adrenoceptors. To check the proportionate role of alpha(1A)- and alpha(1B)-adrenoceptors, we blocked alpha(1B)-adrenoceptors with chloroethylclonidine (CEC, 30 microM, 45 min), that reduced the maximal effect of noradrenaline by about 60%. The remnant CEC-insensitive noradrenaline contraction was assumed to be unrelated to alpha(1B)-adrenoceptor, and was inhibited by 5-methyl-urapidil (pA(2)=8.94) and by the Ca(2+) channel blocker nifedipine (3 microM), confirming the involvement of alpha(1A)-adrenoceptors. The presence of mRNA encoding alpha(1A)- and alpha(1B)-adrenoceptor was also shown on RT-PCR assays. Unexpectedly, alpha(1D)-transcripts were also detected in these assays. Taken together, our results show that ATP co-transmission could not be detected, and that neurotransmission involves the interaction of noradrenaline with both alpha(1A)- and alpha(1B)-, but not with alpha(1D)- or alpha(2)-adrenoceptor. The fact that the functional alpha(1D)-adrenoceptor could not be detected in spite of the presence of the corresponding mRNA, remains to be investigated.
Collapse
MESH Headings
- Acetyl-CoA C-Acyltransferase/metabolism
- Adenosine Triphosphate/metabolism
- Adrenergic Uptake Inhibitors/pharmacology
- Adrenergic alpha-Antagonists/pharmacology
- Animals
- Calcium Channel Blockers/pharmacology
- Clonidine/analogs & derivatives
- Clonidine/pharmacology
- Dioxanes/pharmacology
- Dose-Response Relationship, Drug
- Electric Stimulation
- Male
- Muscle Contraction/drug effects
- Nifedipine/pharmacology
- Norepinephrine/metabolism
- Norepinephrine/pharmacology
- Prazosin/pharmacology
- Purinergic P2 Receptor Antagonists
- RNA, Messenger/analysis
- Rats
- Rats, Wistar
- Receptors, Adrenergic, alpha-1/drug effects
- Receptors, Adrenergic, alpha-1/genetics
- Receptors, Adrenergic, alpha-1/metabolism
- Receptors, Purinergic P2/metabolism
- Reserpine/pharmacology
- Reverse Transcriptase Polymerase Chain Reaction
- Spiperone/pharmacology
- Suramin/pharmacology
- Sympathetic Nervous System/drug effects
- Sympathetic Nervous System/metabolism
- Synaptic Transmission/drug effects
- Synaptic Transmission/physiology
- Testis/drug effects
- Testis/innervation
- Testis/metabolism
Collapse
|
39
|
|
40
|
Chen Q, Li DP, Pan HL. Presynaptic α1 Adrenergic Receptors Differentially Regulate Synaptic Glutamate and GABA Release to Hypothalamic Presympathetic Neurons. J Pharmacol Exp Ther 2005; 316:733-42. [PMID: 16249372 DOI: 10.1124/jpet.105.094797] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The hypothalamic paraventricular nucleus (PVN) neurons that project to the spinal intermediolateral cell column and brainstem are important for the control of sympathetic outflow. Stimulation of alpha(1) adrenergic receptors in the PVN increases sympathetic outflow, but the cellular mechanisms remain unclear. In this study, we determined the role of alpha(1) adrenergic receptors in the regulation of glutamatergic and GABAergic synaptic inputs to spinally projecting PVN neurons. Whole-cell and cell-attached patch-clamp recordings were performed on retrogradely labeled PVN-spinal neurons in rat brain slices. Bath application of 10 to 100 microM phenylephrine, an alpha(1) adrenergic receptor agonist, significantly increased the frequency of spontaneous excitatory postsynaptic currents in a concentration-dependent manner. This effect was blocked by the alpha (1)adrenergic receptor antagonists prazosin or corynanthine. Phenylephrine also significantly increased the frequency of miniature excitatory postsynaptic currents (mEPSCs) but not the amplitude and decay constant of mEPSCs. Furthermore, activation of alpha(1) adrenergic receptors with phenylephrine or cirazoline significantly decreased the frequency of spontaneous inhibitory postsynaptic currents and miniature inhibitory postsynaptic currents, and this effect also was blocked by corynanthine. In addition, 50 microM phenylephrine significantly increased the firing rate of 13 labeled PVN neurons from 3.16 +/- 0.42 to 5.83 +/- 0.65 Hz. However, phenylephrine failed to increase the firing of most labeled PVN neurons in the presence of GABA(A) and ionotropic glutamate receptor antagonists. Thus, these data suggest that activation of alpha (1)adrenergic receptors increases the excitability of PVN presympathetic neurons primarily through augmentation of glutamatergic tone and attenuation of GABAergic inputs.
Collapse
Affiliation(s)
- Qian Chen
- Department of Anesthesiology, Pennsylvania State University College of Medicine, Hershey, 17033, USA
| | | | | |
Collapse
|
41
|
Jurgens CWD, Boese SJ, King JD, Pyle SJ, Porter JE, Doze VA. Adrenergic receptor modulation of hippocampal CA3 network activity. Epilepsy Res 2005; 66:117-28. [PMID: 16140503 DOI: 10.1016/j.eplepsyres.2005.07.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2005] [Revised: 07/14/2005] [Accepted: 07/27/2005] [Indexed: 10/25/2022]
Abstract
Norepinephrine (NE) has demonstrated proconvulsant and antiepileptic properties; however, the specific pharmacology of these actions has not been clearly established. To address this, we studied the effect of NE on hippocampal CA3 epileptiform activity. Frequency changes of burst discharges in response to NE were biphasic; low concentrations increased the number of bursts, while higher concentrations reduced their frequency, suggesting the involvement of multiple adrenergic receptor (AR) types. This hypothesis was confirmed when, in the presence of betaAR blockade, increasing concentrations of NE caused a monophasic decrease in epileptiform activity. Antagonists selective for alpha1 or alpha2ARs were then used to determine which alphaAR type was involved. While discriminating concentrations of the alpha1AR antagonists prazosin and terazosin had no effect, selective amounts of the alpha2AR antagonists RS79948 and RX821002 significantly reduced the potency of NE in decreasing epileptiform activity. Furthermore, this antiepileptic action of NE persisted when all GABA-mediated inhibition was blocked. This data suggests that, under conditions of impaired GABAergic inhibition, the excitatory and inhibitory effects of NE on hippocampal CA3 epileptiform activity are mediated primarily via beta and alpha2ARs, respectively. Moreover, our results imply that the antiepileptic effect of alpha2AR activation in CA3 is not dependent on the GABAergic system.
Collapse
Affiliation(s)
- Chris W D Jurgens
- Department of Pharmacology, Physiology and Therapeutics, University of North Dakota School of Medicine and Health Sciences, 501 N. Columbia Road, Grand Forks, ND 58203, USA
| | | | | | | | | | | |
Collapse
|
42
|
Lê AD, Harding S, Juzytsch W, Funk D, Shaham Y. Role of alpha-2 adrenoceptors in stress-induced reinstatement of alcohol seeking and alcohol self-administration in rats. Psychopharmacology (Berl) 2005; 179:366-73. [PMID: 15551068 DOI: 10.1007/s00213-004-2036-y] [Citation(s) in RCA: 197] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2004] [Accepted: 09/08/2004] [Indexed: 10/26/2022]
Abstract
RATIONALE AND OBJECTIVES Alpha-2 adrenoceptors are known to be involved in stress-induced reinstatement of heroin and cocaine seeking in laboratory animals. Here, we studied the involvement of these receptors in stress-induced reinstatement of alcohol seeking by using an agonist (lofexidine) and an antagonist (yohimbine) of these receptors, which inhibit and activate, respectively, noradrenaline transmission. We also tested the effect of lofexidine and yohimbine on alcohol self-administration. Lofexidine is used clinically for treating opiate withdrawal symptoms and yohimbine induces stress-like responses in humans and non-humans. METHODS Rats were trained to self-administer alcohol (12% w/v, 1 h/day) and after extinction of the alcohol-reinforced behavior, they were tested for the effect of lofexidine (0, 0.05 and 0.1 mg/kg, IP) on reinstatement of alcohol seeking induced by intermittent footshock stress (10 min, 0.8 mA) or for the effect of yohimbine (0, 1.25 and 2.5 mg/kg, IP) on reinstatement of alcohol seeking. Other rats were trained to self-administer alcohol, and after stable responding, the effects of lofexidine and yohimbine on alcohol self-administration were determined. RESULTS Pretreatment with lofexidine (0.05 mg/kg and 0.1 mg/kg) attenuated stress-induced reinstatement of alcohol seeking and also decreased alcohol self-administration. In contrast, yohimbine pretreatment potently reinstated alcohol seeking after extinction and also induced a profound increase in alcohol self-administration. CONCLUSIONS Results indicate that activation of alpha-2 adrencoceptors is involved in both stress-induced reinstatement of alcohol seeking and alcohol self-administration. To the degree that the present results are relevant to human alcoholism, alpha-2 adrencoceptor agonists should be considered in the treatment of alcohol dependence.
Collapse
Affiliation(s)
- A D Lê
- Department of Neuroscience, Center for Addiction and Mental Health, 33 Russell Street, Toronto, ON, Canada, M5S 2S1.
| | | | | | | | | |
Collapse
|
43
|
Shepard JD, Bossert JM, Liu SY, Shaham Y. The anxiogenic drug yohimbine reinstates methamphetamine seeking in a rat model of drug relapse. Biol Psychiatry 2004; 55:1082-9. [PMID: 15158427 DOI: 10.1016/j.biopsych.2004.02.032] [Citation(s) in RCA: 239] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2003] [Revised: 02/25/2004] [Accepted: 02/29/2004] [Indexed: 10/26/2022]
Abstract
BACKGROUND Brain noradrenaline is involved in footshock stress-induced reinstatement of drug seeking in a rat relapse model. We studied whether yohimbine, an alpha-2 adrenoceptor antagonist that increases noradrenaline release and induces anxiety-like responses in human and nonhuman subjects, would reinstate methamphetamine seeking in rats. METHODS In experiment 1, the effect of yohimbine (1.25-2.5 mg/kg) on reinstatement was compared with that of intermittent footshock (5 min;.2-.6 mA) in rats that were trained to lever press for intravenous methamphetamine (9-11 days) and subsequently underwent 7 days of extinction training. In experiment 2, the effect of yohimbine on reinstatement of drug seeking was determined during early (1 day) and late (21 or 51 days) withdrawal periods. On the test days, rats were first given 3-hour extinction sessions and were then tested for reinstatement induced by yohimbine. RESULTS In experiment 1, both yohimbine and footshock stress reinstated methamphetamine seeking after extinction. In experiment 2, extinction responding was higher after 21 or 51 withdrawal days than after 1 withdrawal day. In contrast, no significant time-dependent changes in yohimbine-induced reinstatement were observed. CONCLUSIONS Results indicate that yohimbine is a potent stimulus for reinstatement of methamphetamine seeking in a rat relapse model.
Collapse
Affiliation(s)
- Jack D Shepard
- Cellular Neurobiology Branch, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health/Department of Health and Human Services, Baltimore, Maryland 21224, USA
| | | | | | | |
Collapse
|
44
|
Lee B, Tiefenbacher S, Platt DM, Spealman RD. Pharmacological blockade of alpha2-adrenoceptors induces reinstatement of cocaine-seeking behavior in squirrel monkeys. Neuropsychopharmacology 2004; 29:686-93. [PMID: 14872205 DOI: 10.1038/sj.npp.1300391] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Converging evidence suggests a role for noradrenergic mechanisms in stress-induced reinstatement of cocaine seeking in animals. Yohimbine, an alpha(2)-adrenoceptor antagonist, is known to be anxiogenic and induce stress-related responses in humans and animals. Here, we tested the ability of yohimbine to reinstate cocaine-seeking behavior and induce behavioral and physiological signs characteristic of stress in squirrel monkeys. Monkeys were trained to self-administer cocaine under a second-order schedule of i.v. drug injection. Drug seeking subsequently was extinguished by substituting saline for cocaine injections and omitting the cocaine-paired stimulus. The ability of yohimbine and the structurally distinct alpha(2)-adrenoceptor antagonist RS-79948 to reinstate cocaine-seeking behavior was assessed by administering priming injections immediately before test sessions in which the cocaine-paired stimulus was either present or absent. Priming injections of yohimbine (0.1-0.56 mg/kg, i.m.) or RS-79948 (0.01-0.1 mg/kg, i.m.) induced dose-related reinstatement of cocaine-seeking behavior. The magnitude of yohimbine-induced reinstatement was similar regardless of the presence or absence of the cocaine-paired stimulus. Yohimbine also significantly increased salivary cortisol levels, a physiological marker of stress, as well as scratching and self-grooming, behavioral markers of stress in nonhuman primates. In drug interaction experiments, pretreatment with the alpha(2)-adrenoceptor agonist clonidine (0.1-0.3 mg/kg, i.m.) dose-dependently inhibited yohimbine-induced reinstatement of cocaine seeking. In contrast, pretreatment with the dopamine receptor antagonist flupenthixol failed to inhibit yohimbine-induced reinstatement of cocaine seeking. The results show that pharmacological blockade of alpha(2)-adrenoceptors can induce reinstatement of cocaine-seeking behavior and characteristic stress responses in squirrel monkeys, providing a potentially useful model of stress-induced relapse to drug seeking.
Collapse
Affiliation(s)
- Buyean Lee
- Harvard Medical School, New England Primate Research Center, Southborough, MA 01772-9102, USA.
| | | | | | | |
Collapse
|
45
|
Clarke RW, Harris J. RX 821002 as a tool for physiological investigation of alpha(2)-adrenoceptors. CNS DRUG REVIEWS 2002; 8:177-92. [PMID: 12177687 PMCID: PMC6741674 DOI: 10.1111/j.1527-3458.2002.tb00222.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
RX 821002 is the 2-methoxy congener of idazoxan. In binding and tissue studies it behaves as a selective antagonist of alpha(2)-adrenoceptors, with at least 5 times greater affinity for these receptors than any other binding site. It does not select between the different types of alpha(2)-receptor. Although this drug probably has no future as a therapeutic agent, it remains a good probe for physiological activity at alpha(2)-adrenoceptors in animal experiments. A particularly useful feature of this compound is its lack of binding at I(1) and I(2) imidazoline receptors. However, it has relatively high affinity for 5-HT(1A) receptors (at which it acts as an antagonist) and a tendency to behave as an inverse agonist at alpha(2A)-adrenoceptors in some cell culture systems. These potential drawbacks may be overcome by careful design of experiments, and the greater selectivity of RX 821002 renders it much superior to yohimbine or idazoxan as a tool for probing physiological actions at alpha(2)-receptors. It can be compared favorably with other selective antagonists such as atipamezole. In physiological studies, RX 821002 augments norepinephrine release in the frontal cortex and increases drinking behavior in rat. In rabbit, intrathecal administration of this drug enhances somatic and autonomic motor outflows, showing that tonic adrenergic descending inhibition of withdrawal reflexes and sympathetic pre-ganglionic neurons is strong in this species. The potentiation of reflexes may be considered a pro-nociceptive action. In the same model, RX 821002 antagonizes the inhibitory effects of the mu opioid fentanyl, indicating that exogenous opioids synergize with endogenously released norepinephrine in the spinal cord. Thus, the careful use of RX 821002 has revealed several aspects of the physiological activity of alpha(2)-adrenoceptors in rabbit spinal cord and rat brain. We recommend that RX 821002 and/or compounds with similar selectivity for alpha(2)-adrenoceptors (atipamezole, MK-912, RS-79948) should be used in preference to yohimbine or idazoxan in all future studies of this type.
Collapse
Affiliation(s)
- R W Clarke
- Division of Animal Physiology, School of Biosciences, Sutton Bonington Campus, University of Nottingham, Loughborough LE12 5RD, UK.
| | | |
Collapse
|
46
|
CNS site of action and brainstem circuitry responsible for the intravenous effects of nicotine on gastric tone. J Neurosci 2002. [PMID: 11923442 DOI: 10.1523/jneurosci.22-07-02764.2002] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The purposes of our study were to determine (1) the effects of intravenous (i.v.) nicotine on gastric mechanical function of anesthetized rats, (2) the CNS site of action of nicotine to produce these effects, (3) the CNS nicotinic acetylcholine receptor (nAChR) subtype(s) responsible for mediating the i.v. effects of nicotine, and (4) the brainstem neurocircuitry engaged by i.v. nicotine for eliciting its gastric effects. This was accomplished by monitoring intragastric pressure (gastric tone) and contractility of the fundus and antrum while administering five doses of i.v. nicotine and microinjecting nicotine into specific brainstem nuclei. Additionally, c-Fos expression in the brainstem after i.v. nicotine and pharmacological agents were used as tools to identify the CNS site and circuitry and reveal the nAChR subtype(s) mediating the gastric effects of nicotine. Using these experimental approaches, we found the following. (1) When given intravenously in doses of 56.5, 113, 226, 452, and 904 nmol/kg, nicotine elicited only inhibitory effects on gastric mechanical function. The most sensitive area of the stomach to nicotine was the fundus, and this effect was mediated by the vagus nerve at doses of 56.5, 113, and 226 nmol/kg. (2) The CNS site of action and nAChR subtype responsible were glutamatergic vagal afferent nerve terminals in the medial subnucleus of the tractus solitarious (mNTS) and alpha4beta2, respectively. (3) The brainstem neurocircuitry that was involved appeared to consist of a mNTS noradrenergic pathway projecting to the dorsal motor nucleus of the vagus (DMV). This pathway seems to be activated via nitriergic interneurons engaged by vagally released glutamate in the mNTS and results in alpha2 adrenergic receptor-mediated inhibition of DMV neurons projecting to the fundus and controlling gastric tone.
Collapse
|
47
|
Holzer P, Painsipp E. Differential effects of clonidine, dopamine, dobutamine, and dopexamine on basal and acid-stimulated mucosal blood flow in the rat stomach. Crit Care Med 2001; 29:335-43. [PMID: 11246314 DOI: 10.1097/00003246-200102000-00021] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To analyze the effects of clonidine, dopamine, dobutamine, and dopexamine on gastric mucosal blood flow (GMBF) at baseline and after stimulation by acid back diffusion through a disrupted gastric mucosal barrier. DESIGN Prospective, randomized, unblinded study. SETTING University research laboratory. SUBJECTS Adult Sprague-Dawley rats. INTERVENTIONS Mean arterial blood pressure (MAP) and heart rate (HR) were recorded from a carotid artery of the phenobarbital-anesthetized animals. A jugular vein was cannulated for continuous infusion of saline and intravenous drug administration. The stomach was prepared for luminal perfusion and for recording GMBF with the hydrogen gas clearance technique. Gastric mucosal vascular conductance (GMVC) was calculated as GMBF divided by MAP. MEASUREMENTS AND MAIN RESULTS Clonidine (37.5 and 112.5 nmol x kg(-1)) lowered MAP and HR and caused gastric vasodilation as shown by a rise of GMVC. The 2.5-fold increase in GMVC elicited by gastric perfusion with HCl (0.15 M) plus ethanol (25%) was depressed by clonidine. All cardiovascular effects of clonidine were prevented by the alpha2-adrenoceptor antagonist idazoxan (2 micromol x kg(-1)). Infusion of dopamine (15 and 45 micromol x kg(-1) x hr(-1)), dobutamine, or dopexamine (each at 5 and 15 micromol x kg(-1) x hr(-1)) caused tachycardia. GMVC at baseline was attenuated by the higher dose of dopamine and dopexamine, but not dobutamine. In contrast, the acid-induced vasodilation in the gastric mucosa was depressed by dobutamine and dopexamine, but not dopamine. CONCLUSIONS Clonidine, dobutamine, and dopexamine at high dosage suppress the gastric mucosal vasodilator response to acid back diffusion, which is an important defense mechanism. Although the dose equivalence between rats and humans is not known, the antivasodilator effects highlight an adverse action whereby large doses of dobutamine, dopexamine, and clonidine may compromise gastric mucosal homeostasis and facilitate stress ulcer formation. Dopamine lacks this detrimental activity.
Collapse
Affiliation(s)
- P Holzer
- Department of Experimental and Clinical Pharmacology, University of Graz, Graz, Austria.
| | | |
Collapse
|
48
|
Cheng Y, Planta F, Ladure P, Julien C, Barrès C. Acute cardiovascular effects of the alpha2-adrenoceptor antagonist, idazoxan, in rats: influence of the basal sympathetic tone. J Cardiovasc Pharmacol 2000; 35:156-63. [PMID: 10630747 DOI: 10.1097/00005344-200001000-00021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Intravenous administration of the alpha2-adrenoceptor antagonist, idazoxan, elicits variable cardiovascular effects, depending on experimental conditions. In this study, the effects of idazoxan were investigated in rats with high, low, or no basal sympathetic tone. In a group of conscious Sprague-Dawley rats (n = 9), mean arterial pressure (MAP), heart rate (HR), and renal sympathetic nervous activity (RSNA) were recorded. Idazoxan (250 microg/kg, i.v.) induced a transient decrease in MAP (-12+/-3 mm Hg) that was accompanied by increases in HR (49+/-14 beats/min) and RSNA (53+/-14%). In six of nine rats, a light pentobarbitone anesthesia was given. Basal RSNA was decreased (6.0+/-1.3 microV from 12.8+/-4.1 microV; p<0.05), and the depressor effect of idazoxan was reversed to a pressor effect (21+/-6 mm Hg) associated with bradycardia (-16+/-8 beats/min) and sympathoinhibition (-56+/-15%). In eight conscious intact rats, idazoxan (250 microg/kg, i.v.) attenuated by approximately 40% the pressor response to the selective alpha1-adrenoceptor agonist, cirazoline (0.5 microg/kg, i.v.). In three groups of six to seven ganglion-blocked (chlorisondamine, 2.5 mg/kg, i.v.) conscious rats, idazoxan dose-dependently increased mean arterial pressure (MAP: 39+/-2, 55+/-3, and 69+/-4 mm Hg at 125, 250, and 500 microg/kg, i.v., respectively) with minimal changes in HR. In contrast, the noradrenaline-releasing agent, tyramine (62.5, 125, and 250 microg/kg, i.v.), dose-dependently increased both MAP and HR. The alpha1-adrenoceptor antagonist, prazosin (1 mg/kg, i.v.; n = 8) blunted by approximately 70% (p<0.01) the pressor effect of 250 microg/kg idazoxan. It is concluded that in rats with high sympathetic tone, idazoxan has depressor effects, most likely related to its peripheral alpha-adrenoceptor antagonist properties. In rats with low or no sympathetic tone, idazoxan induced pressor responses mainly secondary to its partial agonist activity at vascular postjunctional alpha1-adrenoceptors.
Collapse
Affiliation(s)
- Y Cheng
- Département de Physiologie et Pharmacologie Clinique, CNRS ESA 5014, Faculté de Pharmacie, Lyon, France
| | | | | | | | | |
Collapse
|
49
|
Henry B, Fox SH, Peggs D, Crossman AR, Brotchie JM. The alpha2-adrenergic receptor antagonist idazoxan reduces dyskinesia and enhances anti-parkinsonian actions of L-dopa in the MPTP-lesioned primate model of Parkinson's disease. Mov Disord 1999; 14:744-53. [PMID: 10495035 DOI: 10.1002/1531-8257(199909)14:5<744::aid-mds1006>3.0.co;2-7] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Dopamine replacement therapy in patients with Parkinson's disease is plagued by the emergence of abnormal involuntary movements known as L-dopa-induced dyskinesias. It has been demonstrated that yohimbine can reduce L-dopa-induced dyskinesia in the MPTP-lesioned primate model of Parkinson's disease. Yohimbine is, among other things, an alpha-adrenergic receptor antagonist. In this study, we demonstrate that the selective and potent alpha2-adrenergic receptor antagonist idazoxan reduces L-dopa-induced dyskinesia in the MPTP-lesioned marmoset model of Parkinson's disease. The alpha2-adrenergic receptor antagonists rauwolscine and yohimbine also reduce L-dopa-induced dyskinesia. Furthermore, we demonstrate that coadministration of idazoxan with L-dopa can provide an anti-parkinsonian action more than twice the length of that seen with L-dopa alone. However, idazoxan as a monotherapy displayed no anti-parkinsonian actions. We propose that idazoxan in combination with L-dopa may provide a novel approach to the treatment of Parkinson's disease that will not only reduce the dyskinetic side effects, but extend the anti-parkinsonian actions of L-dopa. Idazoxan, as an adjunct to dopamine replacement, may prove useful in the treatment of parkinsonian patients at all stages of disease progression.
Collapse
Affiliation(s)
- B Henry
- Organon Laboratories Limited, Department of Pharmacology, Lanarkshire, Scotland, UK
| | | | | | | | | |
Collapse
|
50
|
Rosen MI, Kosten TR, Kreek MJ. The effects of naltrexone maintenance on the response to yohimbine in healthy volunteers. Biol Psychiatry 1999; 45:1636-45. [PMID: 10376126 DOI: 10.1016/s0006-3223(98)00259-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
BACKGROUND Preclinical research suggests that opiate antagonists may alter stress responsiveness. This study describes the effect of pretreatment with the opioid antagonist naltrexone on the response to a noradrenergic stressor, the alpha-2-receptor-antagonist, yohimbine, in healthy subjects. The current study was designed to compare the change in responses to yohimbine after 2 weeks of treatment with naltrexone to the response after at least 2 weeks of treatment with placebo. METHODS After a week of placebo naltrexone treatment, ten subjects were randomized into a double-blind cross-over to placebo or active naltrexone (50 mg p.o. daily) on weeks 2 to 4, and the converse condition for weeks 5 to 7. Subjects received challenges in a random, fixed sequence with placebo and active yohimbine (i.v., 0.2 mg/kg) on weeks 1, 4, and 7. The active-active combination generally had the strongest drug effects. RESULTS There were statistically significant (p < .05) interactions of naltrexone condition X yohimbine condition for subject ratings of "nervous," "not liking the drug effect," "talkative," and "urge to urinate," and a trend (p < .10) for cortisol levels. CONCLUSIONS The results suggest that clinically used naltrexone doses alter sensitivity to yohimbine.
Collapse
Affiliation(s)
- M I Rosen
- Yale University School of Medicine, VA Connecticut Healthcare System, Psychiatry Service, West Haven, CT 06516, USA
| | | | | |
Collapse
|