1
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Robertson AS, Majchrzak MJ, Smith CM, Gagnon RC, Devidze N, Banks GB, Little SC, Nabbie F, Bounous DI, DiPiero J, Jacobsen LK, Bristow LJ, Ahlijanian MK, Stimpson SA. Dramatic elevation in urinary amino terminal titin fragment excretion quantified by immunoassay in Duchenne muscular dystrophy patients and in dystrophin deficient rodents. Neuromuscul Disord 2017; 27:635-645. [PMID: 28554556 DOI: 10.1016/j.nmd.2017.05.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 04/29/2017] [Accepted: 05/09/2017] [Indexed: 11/27/2022]
Abstract
Enzyme-linked and electrochemiluminescence immunoassays were developed for quantification of amino (N-) terminal fragments of the skeletal muscle protein titin (N-ter titin) and qualified for use in detection of urinary N-ter titin excretion. Urine from normal subjects contained a small but measurable level of N-ter titin (1.0 ± 0.4 ng/ml). A 365-fold increase (365.4 ± 65.0, P = 0.0001) in urinary N-ter titin excretion was seen in Duchene muscular dystrophy (DMD) patients. Urinary N-ter titin was also evaluated in dystrophin deficient rodent models. Mdx mice exhibited low urinary N-ter titin levels at 2 weeks of age followed by a robust and sustained elevation starting at 3 weeks of age, coincident with the development of systemic skeletal muscle damage in this model; fold elevation could not be determined because urinary N-ter titin was not detected in age-matched wild type mice. Levels of serum creatine kinase and serum skeletal muscle troponin I (TnI) were also low at 2 weeks, elevated at later time points and were significantly correlated with urinary N-ter titin excretion in mdx mice. Corticosteroid treatment of mdx mice resulted in improved exercise performance and lowering of both urinary N-ter titin and serum skeletal muscle TnI concentrations. Low urinary N-ter titin levels were detected in wild type rats (3.0 ± 0.6 ng/ml), while Dmdmdx rats exhibited a 556-fold increase (1652.5 ± 405.7 ng/ml, P = 0.002) (both at 5 months of age). These results suggest that urinary N-ter titin is present at low basal concentrations in normal urine and increases dramatically coincident with muscle damage produced by dystrophin deficiency. Urinary N-ter titin has potential as a facile, non-invasive and translational biomarker for DMD.
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Affiliation(s)
- Alan S Robertson
- Genetically Defined Diseases, Bristol-Myers Squibb, Wallingford, CT, USA
| | - Mark J Majchrzak
- Genetically Defined Diseases, Bristol-Myers Squibb, Wallingford, CT, USA
| | | | - Robert C Gagnon
- Non-Clinical Biostatistics, Bristol-Myers Squibb, Lawrenceville, NJ, USA
| | - Nino Devidze
- Genetically Defined Diseases, Bristol-Myers Squibb, Wallingford, CT, USA
| | - Glen B Banks
- Genetically Defined Diseases, Bristol-Myers Squibb, Wallingford, CT, USA
| | - Sean C Little
- Genetically Defined Diseases, Bristol-Myers Squibb, Wallingford, CT, USA
| | - Fizal Nabbie
- Genetically Defined Diseases, Bristol-Myers Squibb, Wallingford, CT, USA
| | - Denise I Bounous
- Discovery Toxicology Clinical Pathology Laboratory, Bristol-Myers Squibb, Lawrenceville, NJ, USA
| | - Janet DiPiero
- Discovery Toxicology Clinical Pathology Laboratory, Bristol-Myers Squibb, Lawrenceville, NJ, USA
| | - Leslie K Jacobsen
- Genetically Defined Diseases, Bristol-Myers Squibb, Wallingford, CT, USA
| | - Linda J Bristow
- Genetically Defined Diseases, Bristol-Myers Squibb, Wallingford, CT, USA
| | | | - Stephen A Stimpson
- Genetically Defined Diseases, Bristol-Myers Squibb, Wallingford, CT, USA
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2
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Wager TT, Chappie T, Horton D, Chandrasekaran RY, Samas B, Dunn-Sims ER, Hsu C, Nawreen N, Vanase-Frawley MA, O’Connor RE, Schmidt CJ, Dlugolenski K, Stratman NC, Majchrzak MJ, Kormos BL, Nguyen DP, Sawant-Basak A, Mead AN. Dopamine D3/D2 Receptor Antagonist PF-4363467 Attenuates Opioid Drug-Seeking Behavior without Concomitant D2 Side Effects. ACS Chem Neurosci 2017; 8:165-177. [PMID: 27715007 DOI: 10.1021/acschemneuro.6b00297] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Dopamine receptor antagonism is a compelling molecular target for the treatment of a range of psychiatric disorders, including substance use disorders. From our corporate compound file, we identified a structurally unique D3 receptor (D3R) antagonist scaffold, 1. Through a hybrid approach, we merged key pharmacophore elements from 1 and D3 agonist 2 to yield the novel D3R/D2R antagonist PF-4363467 (3). Compound 3 was designed to possess CNS drug-like properties as defined by its CNS MPO desirability score (≥4/6). In addition to good physicochemical properties, 3 exhibited low nanomolar affinity for the D3R (D3 Ki = 3.1 nM), good subtype selectivity over D2R (D2 Ki = 692 nM), and high selectivity for D3R versus other biogenic amine receptors. In vivo, 3 dose-dependently attenuated opioid self-administration and opioid drug-seeking behavior in a rat operant reinstatement model using animals trained to self-administer fentanyl. Further, traditional extrapyramidal symptoms (EPS), adverse side effects arising from D2R antagonism, were not observed despite high D2 receptor occupancy (RO) in rodents, suggesting that compound 3 has a unique in vivo profile. Collectively, our data support further investigation of dual D3R and D2R antagonists for the treatment of drug addiction.
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Affiliation(s)
- Travis T. Wager
- Pfizer Worldwide Research and Development, Neuroscience
Medicinal Chemistry and Neuroscience Research Unit, 610 Main Street, Cambridge, Massachusetts 02139, United States
| | - Thomas Chappie
- Pfizer Worldwide Research and Development, Neuroscience
Medicinal Chemistry and Neuroscience Research Unit, 610 Main Street, Cambridge, Massachusetts 02139, United States
| | - David Horton
- Pfizer Worldwide Research and Development, Chemistry
and Biology, Eastern Point
Road, Groton, Connecticut 06340, United States
| | - Ramalakshmi Y. Chandrasekaran
- Pfizer Worldwide Research and Development, Chemistry
and Biology, Eastern Point
Road, Groton, Connecticut 06340, United States
| | - Brian Samas
- Pfizer Worldwide Research and Development, Chemistry
and Biology, Eastern Point
Road, Groton, Connecticut 06340, United States
| | - Elizabeth R. Dunn-Sims
- Pfizer Worldwide Research and Development, Chemistry
and Biology, Eastern Point
Road, Groton, Connecticut 06340, United States
| | - Cathleen Hsu
- Pfizer Worldwide Research and Development, Chemistry
and Biology, Eastern Point
Road, Groton, Connecticut 06340, United States
| | - Nawshaba Nawreen
- Pfizer Worldwide Research and Development, Chemistry
and Biology, Eastern Point
Road, Groton, Connecticut 06340, United States
| | - Michelle A. Vanase-Frawley
- Pfizer Worldwide Research and Development, Chemistry
and Biology, Eastern Point
Road, Groton, Connecticut 06340, United States
| | - Rebecca E. O’Connor
- Pfizer Worldwide Research and Development, Chemistry
and Biology, Eastern Point
Road, Groton, Connecticut 06340, United States
| | - Christopher J. Schmidt
- Pfizer Worldwide Research and Development, Neuroscience
Medicinal Chemistry and Neuroscience Research Unit, 610 Main Street, Cambridge, Massachusetts 02139, United States
| | - Keith Dlugolenski
- Pfizer Worldwide Research and Development, Neuroscience
Medicinal Chemistry and Neuroscience Research Unit, 610 Main Street, Cambridge, Massachusetts 02139, United States
| | - Nancy C. Stratman
- Pfizer Worldwide Research and Development, Neuroscience
Medicinal Chemistry and Neuroscience Research Unit, 610 Main Street, Cambridge, Massachusetts 02139, United States
| | - Mark J. Majchrzak
- Pfizer Worldwide Research and Development, Chemistry
and Biology, Eastern Point
Road, Groton, Connecticut 06340, United States
| | - Bethany L. Kormos
- Pfizer Worldwide Research and Development, Neuroscience
Medicinal Chemistry and Neuroscience Research Unit, 610 Main Street, Cambridge, Massachusetts 02139, United States
| | - David P. Nguyen
- Pfizer Worldwide Research and Development, Pharmacokinetics,
Dynamics, and Metabolism, 610 Main Street, Cambridge, Massachusetts 02139, United States
| | - Aarti Sawant-Basak
- Pfizer Worldwide Research and Development, Pharmacokinetics,
Dynamics, and Metabolism, 610 Main Street, Cambridge, Massachusetts 02139, United States
| | - Andy N. Mead
- Pfizer Worldwide Research and Development, Chemistry
and Biology, Eastern Point
Road, Groton, Connecticut 06340, United States
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3
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Modi ME, Majchrzak MJ, Fonseca KR, Doran A, Osgood S, Vanase-Frawley M, Feyfant E, McInnes H, Darvari R, Buhl DL, Kablaoui NM. Peripheral Administration of a Long-Acting Peptide Oxytocin Receptor Agonist Inhibits Fear-Induced Freezing. J Pharmacol Exp Ther 2016; 358:164-72. [PMID: 27217590 PMCID: PMC4959095 DOI: 10.1124/jpet.116.232702] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 05/11/2016] [Indexed: 01/05/2023] Open
Abstract
Oxytocin (OT) modulates the expression of social and emotional behaviors and consequently has been proposed as a pharmacologic treatment of psychiatric diseases, including autism spectrum disorders and schizophrenia; however, endogenous OT has a short half-life in plasma and poor permeability across the blood-brain barrier. Recent efforts have focused on the development of novel drug delivery methods to enhance brain penetration, but few efforts have aimed at improving its half-life. To explore the behavioral efficacy of an OT analog with enhanced plasma stability, we developed PF-06655075 (PF1), a novel non–brain-penetrant OT receptor agonist with increased selectivity for the OT receptor and significantly increased pharmacokinetic stability. PF-06478939 was generated with only increased stability to disambiguate changes to selectivity versus stability. The efficacy of these compounds in evoking behavioral effects was tested in a conditioned fear paradigm. Both central and peripheral administration of PF1 inhibited freezing in response to a conditioned fear stimulus. Peripheral administration of PF1 resulted in a sustained level of plasma concentrations for greater than 20 hours but no detectable accumulation in brain tissue, suggesting that plasma or cerebrospinal fluid exposure was sufficient to evoke behavioral effects. Behavioral efficacy of peripherally administered OT receptor agonists on conditioned fear response opens the door to potential peripheral mechanisms in other behavioral paradigms, whether they are mediated by direct peripheral activation or feed-forward responses. Compound PF1 is freely available as a tool compound to further explore the role of peripheral OT in behavioral response.
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Affiliation(s)
- Meera E Modi
- Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.)
| | - Mark J Majchrzak
- Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.)
| | - Kari R Fonseca
- Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.)
| | - Angela Doran
- Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.)
| | - Sarah Osgood
- Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.)
| | - Michelle Vanase-Frawley
- Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.)
| | - Eric Feyfant
- Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.)
| | - Heather McInnes
- Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.)
| | - Ramin Darvari
- Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.)
| | - Derek L Buhl
- Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.)
| | - Natasha M Kablaoui
- Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.)
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4
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Hanks AN, Dlugolenski K, Hughes ZA, Seymour PA, Majchrzak MJ. Pharmacological disruption of mouse social approach behavior: Relevance to negative symptoms of schizophrenia. Behav Brain Res 2013; 252:405-14. [DOI: 10.1016/j.bbr.2013.06.017] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 06/03/2013] [Accepted: 06/07/2013] [Indexed: 12/26/2022]
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5
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Kleiman RJ, Chapin DS, Christoffersen C, Freeman J, Fonseca KR, Geoghegan KF, Grimwood S, Guanowsky V, Hajós M, Harms JF, Helal CJ, Hoffmann WE, Kocan GP, Majchrzak MJ, McGinnis D, McLean S, Menniti FS, Nelson F, Roof R, Schmidt AW, Seymour PA, Stephenson DT, Tingley FD, Vanase-Frawley M, Verhoest PR, Schmidt CJ. Phosphodiesterase 9A regulates central cGMP and modulates responses to cholinergic and monoaminergic perturbation in vivo. J Pharmacol Exp Ther 2012; 341:396-409. [PMID: 22328573 DOI: 10.1124/jpet.111.191353] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Cyclic nucleotides are critical regulators of synaptic plasticity and participate in requisite signaling cascades implicated across multiple neurotransmitter systems. Phosphodiesterase 9A (PDE9A) is a high-affinity, cGMP-specific enzyme widely expressed in the rodent central nervous system. In the current study, we observed neuronal staining with antibodies raised against PDE9A protein in human cortex, cerebellum, and subiculum. We have also developed several potent, selective, and brain-penetrant PDE9A inhibitors and used them to probe the function of PDE9A in vivo. Administration of these compounds to animals led to dose-dependent accumulation of cGMP in brain tissue and cerebrospinal fluid, producing a range of biological effects that implied functional significance for PDE9A-regulated cGMP in dopaminergic, cholinergic, and serotonergic neurotransmission and were consistent with the widespread distribution of PDE9A. In vivo effects of PDE9A inhibition included reversal of the respective disruptions of working memory by ketamine, episodic and spatial memory by scopolamine, and auditory gating by amphetamine, as well as potentiation of risperidone-induced improvements in sensorimotor gating and reversal of the stereotypic scratching response to the hallucinogenic 5-hydroxytryptamine 2A agonist mescaline. The results suggested a role for PDE9A in the regulation of monoaminergic circuitry associated with sensory processing and memory. Thus, PDE9A activity regulates neuronal cGMP signaling downstream of multiple neurotransmitter systems, and inhibition of PDE9A may provide therapeutic benefits in psychiatric and neurodegenerative diseases promoted by the dysfunction of these diverse neurotransmitter systems.
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Affiliation(s)
- Robin J Kleiman
- SystaMedic Inc., 1084 Shennecossett Drive, Groton, CT 06340, USA.
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6
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Strick CA, Li C, Scott L, Harvey B, Hajós M, Steyn SJ, Piotrowski MA, James LC, Downs JT, Rago B, Becker SL, El-Kattan A, Xu Y, Ganong AH, Tingley FD, Ramirez AD, Seymour PA, Guanowsky V, Majchrzak MJ, Fox CB, Schmidt CJ, Duplantier AJ. Modulation of NMDA receptor function by inhibition of D-amino acid oxidase in rodent brain. Neuropharmacology 2011; 61:1001-15. [PMID: 21763704 DOI: 10.1016/j.neuropharm.2011.06.029] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Revised: 06/28/2011] [Accepted: 06/29/2011] [Indexed: 01/16/2023]
Abstract
Observations that N-Methyl-D-Aspartate (NMDA) antagonists produce symptoms in humans that are similar to those seen in schizophrenia have led to the current hypothesis that schizophrenia might result from NMDA receptor hypofunction. Inhibition of D-amino acid oxidase (DAAO), the enzyme responsible for degradation of D-serine, should lead to increased levels of this co-agonist at the NMDA receptor, and thereby provide a therapeutic approach to schizophrenia. We have profiled some of the preclinical biochemical, electrophysiological, and behavioral consequences of administering potent and selective inhibitors of DAAO to rodents to begin to test this hypothesis. Inhibition of DAAO activity resulted in a significant dose and time dependent increase in D-serine only in the cerebellum, although a time delay was observed between peak plasma or brain drug concentration and cerebellum D-serine response. Pharmacokinetic/pharmacodynamic (PK/PD) modeling employing a mechanism-based indirect response model was used to characterize the correlation between free brain drug concentration and D-serine accumulation. DAAO inhibitors had little or no activity in rodent models considered predictive for antipsychotic activity. The inhibitors did, however, affect cortical activity in the Mescaline-Induced Scratching model, produced a modest but significant increase in NMDA receptor-mediated synaptic currents in primary neuronal cultures from rat hippocampus, and resulted in a significant increase in evoked hippocampal theta rhythm, an in vivo electrophysiological model of hippocampal activity. These findings demonstrate that although DAAO inhibition did not cause a measurable increase in D-serine in forebrain, it did affect hippocampal and cortical activity, possibly through augmentation of NMDA receptor-mediated currents.
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MESH Headings
- Animals
- Brain/drug effects
- Brain/metabolism
- Central Nervous System Stimulants/metabolism
- Central Nervous System Stimulants/pharmacology
- Cyclic GMP/analysis
- Cyclic GMP/biosynthesis
- D-Amino-Acid Oxidase/antagonists & inhibitors
- D-Amino-Acid Oxidase/metabolism
- D-Amino-Acid Oxidase/physiology
- Drug Evaluation, Preclinical
- Electroencephalography
- Habituation, Psychophysiologic/drug effects
- Habituation, Psychophysiologic/physiology
- Harmaline/metabolism
- Hippocampus/drug effects
- Hippocampus/metabolism
- Male
- Maze Learning/drug effects
- Maze Learning/physiology
- Memory, Short-Term/drug effects
- Memory, Short-Term/physiology
- Mescaline/pharmacology
- Mice
- Miniature Postsynaptic Potentials/drug effects
- Miniature Postsynaptic Potentials/physiology
- Models, Biological
- Models, Chemical
- Molecular Targeted Therapy
- Motor Activity/drug effects
- Motor Activity/physiology
- Pruritus/chemically induced
- Pruritus/prevention & control
- Psychomotor Agitation/drug therapy
- Rats
- Rats, Long-Evans
- Rats, Sprague-Dawley
- Receptors, N-Methyl-D-Aspartate/drug effects
- Receptors, N-Methyl-D-Aspartate/metabolism
- Sensory Gating/drug effects
- Sensory Gating/physiology
- Serine/blood
- Serotonin Receptor Agonists/pharmacology
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7
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Kleiman RJ, Lanz TA, Finley JE, Bove SE, Majchrzak MJ, Becker SL, Carvajal-Gonzales S, Kuhn AM, Wood KM, Mariga A, Nelson FR, Verhoest PR, Seymour PA, Stephenson DT. P3‐380: Dendritic spine density deficits in the hippocampal CA1 region of young Tg2576 mice are ameliorated with the PDE9A inhibitor PF‐04447943. Alzheimers Dement 2010. [DOI: 10.1016/j.jalz.2010.05.1922] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
| | | | | | | | | | | | | | - A. Max Kuhn
- Pfizer Global Research and DevelopmentGroton CT USA
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8
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Rollema H, Hajós M, Seymour PA, Kozak R, Majchrzak MJ, Guanowsky V, Horner WE, Chapin DS, Hoffmann WE, Johnson DE, McLean S, Freeman J, Williams KE. Preclinical pharmacology of the alpha4beta2 nAChR partial agonist varenicline related to effects on reward, mood and cognition. Biochem Pharmacol 2009; 78:813-24. [PMID: 19501054 DOI: 10.1016/j.bcp.2009.05.033] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2009] [Revised: 05/23/2009] [Accepted: 05/26/2009] [Indexed: 12/12/2022]
Abstract
The pharmacological properties and pharmacokinetic profile of the alpha4beta2 nicotinic acetylcholine receptor (nAChR) partial agonist varenicline provide an advantageous combination of free brain levels and functional potencies at the target receptor that for a large part explain its efficacy as a smoking cessation aid. Since alpha4beta2 and other nAChR subtypes play important roles in mediating central processes that control reward, mood, cognition and attention, there is interest in examining the effects of selective nAChR ligands such as varenicline in preclinical animal models that assess these behaviors. Here we describe results from studies on varenicline's effects in animal models of addiction, depression, cognition and attention and discuss these in the context of recently published preclinical and preliminary clinical studies that collected data on varenicline's effects on mood, cognition and alcohol abuse disorder. Taken together, the preclinical and the limited clinical data show beneficial effects of varenicline, but further clinical studies are needed to evaluate whether the preclinical effects observed in animal models are translatable to the clinic.
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Affiliation(s)
- Hans Rollema
- Department of Neuroscience Biology, Pfizer Global Research and Development, Groton, CT 06340, USA.
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9
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Schmidt CJ, Chapin DS, Cianfrogna J, Corman ML, Hajos M, Harms JF, Hoffman WE, Lebel LA, McCarthy SA, Nelson FR, Proulx-LaFrance C, Majchrzak MJ, Ramirez AD, Schmidt K, Seymour PA, Siuciak JA, Tingley FD, Williams RD, Verhoest PR, Menniti FS. Preclinical characterization of selective phosphodiesterase 10A inhibitors: a new therapeutic approach to the treatment of schizophrenia. J Pharmacol Exp Ther 2008; 325:681-90. [PMID: 18287214 DOI: 10.1124/jpet.107.132910] [Citation(s) in RCA: 230] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
We have recently proposed the hypothesis that inhibition of the cyclic nucleotide phosphodiesterase (PDE) 10A may represent a new pharmacological approach to the treatment of schizophrenia (Curr Opin Invest Drug 8:54-59, 2007). PDE10A is highly expressed in the medium spiny neurons of the mammalian striatum (Brain Res 985:113-126, 2003; J Histochem Cytochem 54:1205-1213, 2006; Neuroscience 139:597-607, 2006), where the enzyme is hypothesized to regulate both cAMP and cGMP signaling cascades to impact early signal processing in the corticostriatothalamic circuit (Neuropharmacology 51:374-385, 2006; Neuropharmacology 51:386-396, 2006). Our current understanding of the physiological role of PDE10A and the therapeutic utility of PDE10A inhibitors derives in part from studies with papaverine, the only pharmacological tool for this target extensively profiled to date. However, this agent has significant limitations in this regard, namely, relatively poor potency and selectivity and a very short exposure half-life after systemic administration. In the present report, we describe the discovery of a new class of PDE10A inhibitors exemplified by TP-10 (2-{4-[-pyridin-4-yl-1-(2,2,2-trifluoro-ethyl)-1H-pyrazol-3-yl]-phenoxymethyl}-quinoline succinic acid), an agent with greatly improved potency, selectivity, and pharmaceutical properties. These new pharmacological tools enabled studies that provide further evidence that inhibition of PDE10A represents an important new target for the treatment of schizophrenia and related disorders of basal ganglia function.
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Affiliation(s)
- C J Schmidt
- Neuroscience, Pfizer Global Research and Development, Pfizer, Inc., Eastern Point Road, Groton, CT 06340, USA.
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10
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Sanner MA, Chappie TA, Dunaiskis AR, Fliri AF, Desai KA, Zorn SH, Jackson ER, Johnson CG, Morrone JM, Seymour PA, Majchrzak MJ, Faraci WS, Collins JL, Duignan DB, Prete Di CC, Lee JS, Trozzi A. Synthesis, SAR and pharmacology of CP-293,019: a potent, selective dopamine D4 receptor antagonist. Bioorg Med Chem Lett 1998; 8:725-30. [PMID: 9871530 DOI: 10.1016/s0960-894x(98)00108-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A series of novel, potent and selective pyrido[1,2-a]pyrazine dopamine D4 receptor antagonists are reported including CP-293,019 (D4 Ki = 3.4 nM, D2 Ki > 3,310 nM), which also inhibits apomorphine-induced hyperlocomotion in rats after oral dosing.
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Affiliation(s)
- M A Sanner
- Pfizer Central Research, Groton, CT 06340, USA
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11
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Decker MW, Majchrzak MJ, Cadman ED, Arneri? SP. Effects of chlorisondamine on nicotinic receptor binding in whole brain and nicotine-induced changes in locomotor activity in rats. Drug Dev Res 1994. [DOI: 10.1002/ddr.430310202] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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12
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Decker MW, Majchrzak MJ. Effects of central nicotinic cholinergic receptor blockade produced by chlorisondamine on learning and memory performance in rats. Behav Neural Biol 1993; 60:163-71. [PMID: 8117240 DOI: 10.1016/0163-1047(93)90271-i] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The effects of chronic nicotinic receptor blockade on the performance of learning and memory tasks were determined using chlorisondamine, a compound which produces central nicotinic cholinergic receptor blockade that lasts for several weeks after a single icv administration. Chlorisondamine treatment did not affect the acquisition of spatial information in the Morris water maze or in the radial arm maze, tasks in which performance is reportedly disrupted by acute administration of the nicotinic antagonist, mecamylamine. Chlorisondamine also did not affect performance in the inhibitory avoidance task and did not alter the memory enhancement found in this task after post-training administration of nicotine. Mecamylamine, however, completely blocked the memory-enhancing effects of nicotine. In contrast to the differential ability to chlorisondamine and mecamylamine to block nicotine's memory-enhancing effects, these antagonists produced comparable blockade of nicotine's effects on open field behavior. It is unlikely that the different effects of systemically administered mecamylamine and centrally administered chlorisondamine on nicotine-induced memory enhancement are due to mecamylamine's peripheral effects, since hexamethonium, a peripherally active nicotinic antagonist, did not block nicotine-induced memory enhancement. The different pattern of effects of mecamylamine and chlorisondamine may be related to compensatory mechanisms being selectively induced by chronic blockade produced by chlorisondamine and not by acute blockade produced by mecamylamine. Alternatively, different effects of these two nicotinic cholinergic antagonists on the performance of learning and memory tasks might be related to selective actions of these compounds at nicotinic receptor subtypes or at nonnicotinic receptors.
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Affiliation(s)
- M W Decker
- Neuroscience Research-47W, Pharmaceutical Products Division, Abbott Laboratories, Abbott Park, Illinois 60064
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13
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Abstract
The effects of (-)-lobeline were assessed in two learning and memory tasks in which nicotine-induced enhancement of performance has previously been demonstrated. Lobeline (19 mumol/kg, IP) administered immediately after inhibitory (passive) avoidance training improved retention performance assessed 24 h later, as rats that received this dose of lobeline took significantly longer to enter the shock compartment on the test day than rats that had been treated with vehicle. Pretraining lobeline treatment (1.9 mumol/kg, IP) significantly improved performance of rats with septal lesions in a spatial discrimination water maze, a finding confirmed when rats were retrained using new spatial locations and vehicle and lobeline treatments were reversed in a crossover design. The effective dose of lobeline in the inhibitory avoidance task was about 10-fold higher than that generally reported for nicotine, and direct comparison of the suppression of locomotor activity shortly after administration of nicotine or lobeline also revealed a 10-fold greater potency for nicotine. In contrast, no difference was found between the effective dose of lobeline in the current study and that we previously found with nicotine in the water maze. These findings suggest that lobeline's effects on the performance of learning and memory tasks may be similar to those of nicotine. Coupled with previous reports that lobeline does not produce the nicotine cue in drug discrimination experiments, this study also suggests that nicotinic receptors involved in the modulation of memory processes may be distinct from those involved in producing the nicotine cue.
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Affiliation(s)
- M W Decker
- Neuroscience Research, Pharmaceutical Products Division, Abbott Laboratories, Abbott Park, IL 60064
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14
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Abstract
Impaired septohippocampal function has been implicated in the memory deficits associated with Alzheimer's disease (AD), and septal lesions have been used to model the cognitive deficits associated with AD. In this study, we assessed the effects of systemic administration of nicotine on lesion-induced deficits in the acquisition of a spatial discrimination version of the Morris water maze. Rats with radiofrequency lesions of the medial septum were required to learn which of two visible platforms in a pool of water provided a means of escape. On each of the first 4 days of training, the rats received an injection of (-)nicotine (0, 0.1 or 0.3 mg/kg, i.p.) before training. Nicotine markedly improved the performance of septal rats. This enhanced performance was maintained in rats subsequently tested 1 and 15 days later without additional drug treatment. Septal rats initially trained under nicotine were impaired, however, when the platform locations were reversed and training was conducted under saline. Our findings suggest that nicotinic receptor stimulation might be useful in the treatment of cognitive deficits.
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Affiliation(s)
- M W Decker
- Pharmaceutical Products Division, Abbott Laboratories, Abbott Park, IL 60064
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15
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Decker MW, Majchrzak MJ. Effects of systemic and intracerebroventricular administration of mecamylamine, a nicotinic cholinergic antagonist, on spatial memory in rats. Psychopharmacology (Berl) 1992; 107:530-4. [PMID: 1603896 DOI: 10.1007/bf02245267] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The effects of both systemic and intracerebroventricular administration of mecamylamine, a nicotinic antagonist, were tested on the Morris water maze performance of rats. In experiment 1, mecamylamine (0, 3, and 10 mg/kg, IP) was administered before daily training sessions on the Morris water maze, a task in which rats use environmental cues to learn the location of an invisible escape platform in a large pool of water. The escape latencies of rats given the higher dose of mecamylamine were significantly longer than the latencies of rats given either saline or the peripherally-acting nicotinic antagonist hexamethonium (10 mg/kg). Analysis of search patterns during a free swim trial conducted in the absence of an escape platform confirmed the disruptive effects of the higher dose of mecamylamine. Similar drug effects were not observed when these rats were trained to a visible platform, and mecamylamine did not affect the retrieval of spatial information in well-trained rats. In experiment 2, similar effects were observed with ICV administration of mecamylamine (0, 10, 30, and 100 micrograms). The two higher doses increased escape latencies during the last day of place training and all three doses significantly impaired performance on a free swim. No significant effects were noted on subsequent training to a visible platform, and only the highest dose marginally impaired the retrieval of spatial information in well-trained animals. Thus, mecamylamine appears to impair the acquisition of spatial information in the Morris water maze but does not affect retrieval of previously acquired spatial information at comparable doses.
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Affiliation(s)
- M W Decker
- Neuroscience Research, Abbott Laboratories, Abbott Park, IL 60064
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16
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Abstract
1. Ethanol decreases the release of acetylcholine through effects on presynaptic neurons at both muscarinic and nicotinic junctions. 2. Blockade of the release of acetylcholine should produce denervation supersensitivity at both muscarinic and nicotinic cholinergic junctions. 3. Chronic but not acute treatment with ethanol produces supersensitivity to the hypothermic effects of a muscarinic agonist in the rat. 4. The authors now report that chronic treatment with orally administered ethanol blunts (rather than enhances) the hypothermic response to nicotine in the rat. 5. This could have major public health implications. 6. Smoking and the use of ethanol containing beverages positively covary. 7. Ethanol induced reduction in sensitivity to nicotine suggests that the heavy consumption of ethanol may necessitate that one drink more than otherwise in order to obtain the desired effects of nicotine.
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Dilsaver SC, Majchrzak MJ, Snider RM, Davidson RK. A nicotinic receptor antagonist enhances the hypothermic response to a muscarinic agonist. Prog Neuropsychopharmacol Biol Psychiatry 1991; 15:539-49. [PMID: 1749830 DOI: 10.1016/0278-5846(91)90029-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
1. Chronic treatment with amitriptyline produces supersensitivity to the hypothermic effects of the muscarinic agonist oxotremorine. 2. Chronic treatment with amitriptyline also produces supersensitivity to the hypothermic effects of nicotine. 3. Oxotremorine and other naturally occurring muscarinic agonists are also nicotinic agonists. 4. Chronic treatment with amitriptyline produces time-dependent and reversible supersensitivity to the hypothermic effects of nicotine. 5. The authors assessed the possibility that the development of supersensitivity to oxotremorine following chronic treatment with amitriptyline is related to an effect of this antidepressant on a nicotinic mechanism. 6. A nicotinic receptor antagonist would blunt (though not necessarily eliminate) enhanced sensitivity to the thermic effects of oxotremorine if the nicotinic effects of the latter are significant. 7. The simultaneous administration of mecamylamine (a peripherally and centrally active nicotinic receptor antagonist) greatly augments (rather than blunts) the hypothermic response to oxotremorine. 8. The data suggest that the oxotremorine may activate a nicotinic mechanism counterbalancing its effect on a muscarinic mechanism. 9. This is consistent with previously published reports that the activation of nicotinic and muscarinic mechanisms can exert opposite effects.
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Affiliation(s)
- S C Dilsaver
- Department of Psychiatry, University of Texas, Houston
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18
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Abstract
It has been reported that morphine causes a selective increase in the intake of dietary fat. Because we have noted considerable variability among rats in their preferences for carbohydrate and fat, we reasoned that the effect of morphine on diet selection may differ in fat-preferring vs. carbohydrate-preferring rats. Male Sprague-Dawley rats were given ad lib access to separate sources of carbohydrate, fat and protein (Experiment 1), or to a carbohydrate/protein and a fat/protein diet (Experiment 2). After daily baseline intakes of the diets were determined, all rats were tested for feeding responses to subcutaneous injections of morphine (0, 2 and 10 mg/kg). Significant positive correlations were found between baseline daily intake of a given diet and the effect of morphine on the intake of that diet. Generally, morphine increased carbohydrate intake in carbohydrate-preferring rats, and increased fat intake in fat-preferring rats. These results suggest that the effect of morphine is to increase intake of a preferred diet rather than to increase intake of a specific macronutrient.
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Affiliation(s)
- B A Gosnell
- University of Michigan, Department of Psychiatry, University Hospital, Ann Arbor 48109-0116
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Abstract
Intracerebroventricular (icv) administration of corticotropin-releasing hormone (CRH) or exposure to a restraint stressor causes acute anorexia in rats. However, the effects on food intake of repeated injections of CRH or repeated exposures to restraint stress have not been previously reported. As the effects of these more chronic CRH and stress treatments may be of greater relevance to emerging hypotheses of the pathogenesis of human eating and affective disorders, we measured the changes in food intake and body weight of rats after repeated central injections of CRH. In two experiments using two different daily dosages of CRH and two different schedules of administration, we found that the anorectic effect of CRH decreased over repeated injections. Weight gain was slowed significantly only in the high-dose experiment. Rats may become tolerant to the anorectic effects of CRH delivered by repeated icv injections. These findings have important implications for hypothesized mechanisms of anorexia nervosa and/or depression.
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Affiliation(s)
- D D Krahn
- University of Michigan Medical Center, Department of Psychiatry, Ann Arbor 48109-0116
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20
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Abstract
A previous study has implicated central mu opioid receptors in the preference for salt solutions. Because mu, kappa and delta receptors are all thought to play a role in food intake and/or the mediation of palatability, we performed a series of experiments to determine whether preferential agonists at kappa and delta receptors might also stimulate the intake of salt solutions. When injected centrally into nondeprived rats, two selective agonists at delta receptors caused increases in the intake of 0.6% saline; the intake of concurrently available water was either unchanged or slightly increased. The selective kappa agonist U-50,488H had no effect on water or saline intake, whereas the preferential kappa agonist DAFPHEDYN caused a delayed increase in saline intake. These results indicate a role for central delta receptors in the preference for salt solutions, and are consistent with the suggestion that opioids play a role in the mediation of palatability.
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MESH Headings
- 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer
- Animals
- Drinking/drug effects
- Dynorphins/analogs & derivatives
- Dynorphins/pharmacology
- Eating/drug effects
- Enkephalin, D-Penicillamine (2,5)-
- Enkephalins/pharmacology
- Food Preferences/drug effects
- Hypotonic Solutions
- Injections, Intraventricular
- Male
- Oligopeptides/pharmacology
- Peptide Fragments/pharmacology
- Pyrrolidines/pharmacology
- Rats
- Rats, Inbred Strains
- Receptors, Opioid/drug effects
- Receptors, Opioid, delta
- Receptors, Opioid, kappa
- Taste
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Affiliation(s)
- B A Gosnell
- University of Michigan, Department of Psychiatry, University Hospital, Ann Arbor 48109-0116
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21
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Abstract
1. Core temperature was telemetrically measured in 15 rats before (i.e., at baseline) and at 10-min intervals for 120 min following the injection of normal saline (1 ml/kg ip) or "no injection." 2. The sample exhibited a mean temperature increase of 0.60 +/- 0.10 degree C (mean +/- SEM) following injection. 3. This differed significantly from the mean increase of 0.13 +/- 0.03 degree C following "no injection" (p less than 0.001). 4. The injection of saline (1 ml/kg) affected a mean rise in core temperature of 0.55 +/- 0.07 degree C (p greater than 0.000001) in 46 animals in a second experiment. 5. These data indicate that routine handling and a simple injection comprise significant and measurable stress which must be controlled in neuropharmacological studies employing a thermoregulation paradigm.
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Affiliation(s)
- S C Dilsaver
- Department of Psychiatry, University of Michigan, Ann Arbor
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Abstract
The Fagerström Tolerance Questionnaire (TQ) is often used in both research and treatment contexts to evaluate nicotine tolerance and physiological dependence in cigarette smokers. Recently, however, questions about its validity and its usefulness in comparison to other easily collected measures have been raised. In the present study, 100 male subjects reporting for experimental sessions (Sample I) and 50 male and female subjects entering a smoking cessation clinic program (Sample II) were administered the TQ and determinations of plasma cotinine during ad libitum smoking were made. TQ scores were found to be correlated with cotinine levels in both samples, and several of the individual items proved to have statistically significant discriminatory value. Other schemes for determining degree of dependence were considered and found not to be superior to the TQ. Suggestions for further refining the TQ are reviewed.
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Affiliation(s)
- C S Pomerleau
- Department of Psychiatry, University of Michigan, Ann Arbor 48105
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23
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Abstract
1. The effect of chronic treatment with ethanol (14% v:v in drinking water) on the physiological endpoint core temperature which is partially regulated by a muscarinic mechanism was measured in adult male rats (n = 8). 2. One and two weeks of treatment were associated with enhancement of the hypothermic response to oxotremorine, 0.25 mg/kg ip (p = 0.0005 and p = 0.0001, respectively). 3. The sample remained supersensitive to this muscarinic agonist 48 and 96 hours after the discontinuation of treatment (p = 0.0014 and p = 0.013 respectively). 4. Repeated injections of oxotremorine, 0.25 mg/kg ip, every other day for 10 days did not produce carry-over effects in a control experiment. 5. The results suggest that ethanol renders muscarinic mechanisms supersensitive during chronic treatment and that supersensitivity remains up to 96 hours following withdrawal.
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Affiliation(s)
- M J Majchrzak
- Department of Psychiatry, University of Michigan, Ann Arbor
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Abstract
Endogenous opioid peptides are thought to play a role in mediating the palatability or rewarding aspects of sweet tastes. There is also evidence, however, which suggests that opioids may influence the preference for the taste of salt as well. In the present studies, we measured the effects of central administration of naloxone and the mu agonist [D-Ala2,MePhe4,Gly-ol5]enkephalin (DAGO) on the ingestion of salt solutions. In non-deprived rats given a choice of water and 0.6% saline, ICV injections of DAGO (1 and 3 nmol) significantly increased the intake of 0.6% saline; baseline water intake was minimal and was unaffected by DAGO. When rats were given a choice between water and 1.7% saline, DAGO stimulated both water and saline intake. Because 1.7% saline is a hypertonic solution, the increase in water intake may have been secondary to saline intake. In rats on a deprivation schedule in which water and 0.6% saline were available for only 2-3 h/day, there was a tendency for DAGO to increase 0.6% saline intake and decrease water intake, though these effects were not significant. In rats given water and 1.7% saline, DAGO increased saline intake and had no effect on water intake. Naloxone was also tested in water-deprived rats. Naloxone (20 and 50 micrograms) significantly decreased 0.6% saline intake; baseline water intake was low (3-5 ml) and was unaffected by naloxone. When rats were given a choice between water and 1.7% saline, naloxone (50 micrograms) significantly reduced water intake, while intake of 1.7% saline was slightly increased. These results suggest a role for central mu opioid receptors in mediating the preference for salt solutions.
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Affiliation(s)
- B A Gosnell
- University of Michigan, Department of Psychiatry, Ann Arbor 48109-0116
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25
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Abstract
1. The authors present data establishing the reliability and validity of a method for telemetrically measuring core temperature. 2. The method is designed to be of particular utility to psychobiological researchers.
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Affiliation(s)
- S C Dilsaver
- Department of Psychiatry, University of Michigan, Ann Arbor
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26
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Affiliation(s)
- S C Dilsaver
- Department of Psychiatry Ohio State University, Columbus 43210-1221
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Abstract
Endogenous opioid peptides are thought to play a role in mediating the pleasurable or rewarding aspects of the ingestion of certain foods and liquids. We therefore measured the effects of central administration of selective opioid agonists and naloxone on the intake of two concentrations of saccharin solution. All tests were performed on nondeprived rats, such that the taste of the solutions provided the primary incentive to consume. Intracerebroventricular (ICV) administration of the selective mu agonist [D-Ala2,MePhe4,Gly-ol5]enkephalin (DAGO) and the selective delta agonist Tyr-D-Thr-Gly-Phe-Leu-Thr (DTLET) (3 nmol) increased intake of a 0.15% saccharin solution by approximately 10 ml over 3 hr. Water was available simultaneously, but intake was minimal. The selective kappa agonist U-50,488H did not increase intake of the saccharin solution. Naloxone (30 and 100 micrograms, ICV) caused a 44% reduction in saccharin solution intake in the first hour; two- and three-hour cumulative intakes were not different from control. DAGO and DTLET were also tested when rats were given a weaker saccharin solution (0.006%) along with water. Both agonists caused small increases in saccharin and water intake, but the increases above baseline were much smaller than those observed with the more palatable 0.15% saccharin solution. These results are consistent with reports by others which suggest that endogenous opioids influence taste preferences or palatability. Further, they indicate a role for central mu and delta opioid receptors in the mediation of this influence.
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Affiliation(s)
- B A Gosnell
- University of Michigan, Department of Psychiatry, University Hospital, Ann Arbor 48109-0116
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Abstract
Smokers' ability to regulate nicotine intake by varying topographical parameters such as depth of inhalation and number of puffs makes it difficult to administer standardized doses of nicotine as delivered from smoking. A number of studies have claimed to control these parameters without confirming the effectiveness of such procedures by measures of plasma nicotine. The purpose of the present study was to determine whether specifying onset and duration of each puff would result in accurate dosing. Plasma nicotine boosts for five "paced puffers" were compared across two sessions and with similar data for five "free smokers." Neither between-subject consistency nor within-subject reproducibility was improved by this paced puffing procedure, despite apparent topographical control.
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Affiliation(s)
- C S Pomerleau
- University of Michigan, Department of Psychiatry, Ann Arbor 48105
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30
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Majchrzak MJ, Dilsaver SC. Effects of bright light on adrenergic and cholinergic systems. Am J Psychiatry 1988; 145:1608. [PMID: 3195686 DOI: 10.1176/ajp.145.12.1608a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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31
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Meador-Woodruff JH, Majchrzak MJ. Doxepin-induced cardiac dysrhythmia. J Clin Psychopharmacol 1988; 8:144-5. [PMID: 2453531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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32
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Abstract
The authors used a thermoregulation paradigm to evaluate effects of amitriptyline (AMI) on the sensitivity of a nicotinic mechanism involved in the regulation of core temperature in rats. Treatment with this tricyclic was associated with a significant increase in the hypothermic response to nicotine. Supersensitivity persisted for a minimum of 7.5 days following the last dose of AMI, and a significant proportion of animals displayed increased sensitivity after 14.5 days of abstinence. Implications for the mechanism of action of AMI are highlighted.
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Affiliation(s)
- S C Dilsaver
- Department of Psychiatry, University of Michigan, Ann Arbor 48109
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33
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Abstract
The authors used a thermoregulation paradigm to test the hypothesis that chronic treatment with bright artificial light produces subsensitivity to the hypothermic effects of clonidine, an alpha 2-agonist. One week of treatment produced blunting of the hypothermic response to clonidine (p less than 0.00001). These findings are consistent with previous reports that somatic treatments for depression produce subsensitivity of the alpha 2-receptor.
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Affiliation(s)
- S C Dilsaver
- Department of Psychiatry, College of Medicine, Ohio State University, Columbus 43201-1228
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34
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Abstract
Bright artificial light is a treatment for seasonal depression. Eleven (11) rats were exposed to bright artificial light (11,500 lux) for two consecutive weeks. The thermic response to nicotine was measured prior to light exposure and after one and two weeks of treatment. The thermic response to nicotine at baseline was -1.69 +/- 0.25 degrees C (mean +/- SEM). The thermic response to nicotine was -0.66 +/- 0.12 degrees C (p less than 0.002) after one and +0.31 +/- 0.14 degrees C (p less than 0.000025) after two weeks of light exposure. The change in temperature was different between weeks one and two (p less than 0.000025). The exposure of animals to constant light at an intensity of 300 lux did not blunt the hypothermic response to nicotine. These findings suggest that bright artificial light, like other antidepressant treatments, produces subsensitivity of a nicotinic mechanism involved in the regulation of core temperature.
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Affiliation(s)
- S C Dilsaver
- Department of Psychiatry, Ohio State University, Columbus 43210-1228
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35
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Abstract
Supersensitivity of a muscarinic mechanism is implicated in the pathophysiology of depression. Bright artificial light is efficacious in the treatment of Seasonal Affective Disorder (SAD). We studied the effect of constant bright light (11,500 lux) on the sensitivity of adult, male rats to oxotremorine, 1.5 mg/kg ip, using a repeated measures design. Oxotremorine challenges were proceeded by the injection of methylscopolamine, 1 mg/kg ip, by 30 minutes. Temperature was telemetrically measured every 10 minutes for 120 minutes starting 10 minutes after the injection of oxotremorine. Prior to and after 7 continuous days of exposure to bright light, the sample exhibited a hypothermic response of 2.50 +/- 0.48 degrees C (mean +/- SEM) and 0.29 +/- 0.31 degrees C (mean +/- SEM), respectively (p less than 0.0014). All 7 animals exhibited blunting to the thermic response to oxotremorine. Bright light also blocked the capacity of amitriptyline to supersensitize a central muscarinic mechanism. Exposure to light at an intensity of 300 lux for 7 days had no effect on the thermic response to oxotremorine. These data are consistent with the hypotheses that the biology of depression involves supersensitivity of central muscarinic mechanisms and that the effects of bright artificial light are not the consequence of shifting circadian rhythms.
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Affiliation(s)
- S C Dilsaver
- Department of Psychiatry, University of Michigan, Ann Arbor 48109
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36
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Affiliation(s)
- S C Dilsaver
- Department of Psychiatry, University of Michigan, Ann Arbor
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37
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Pomerleau CS, Pomerleau OF, Majchrzak MJ. Mecamylamine pretreatment increases subsequent nicotine self-administration as indicated by changes in plasma nicotine level. Psychopharmacology (Berl) 1987; 91:391-3. [PMID: 3104964 DOI: 10.1007/bf00518198] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Acute administration of mecamylamine, a centrally active nicotinic cholinergic agonist, has been shown to increase amount of smoking as indicated by smoking topography (e.g., puff rate, puff duration), expired carbon monoxide changes, and other inferential measures. In the present study, subjects showed significantly greater increases in plasma nicotine following smoking of two high-nicotine research cigarettes when pretreated with mecamylamine than when pretreated with placebo, even though no significant differences in puff volume or puff number were detected. Interestingly, none of our subjects reported nausea, although some achieved plasma nicotine levels at which nausea would typically be expected. We attribute the observed increases in nicotine intake to compensatory behavior designed to overcome mecamylamine's blocking effects.
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