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The highly-selective 5-HT(1A) agonist F15599 reduces L-DOPA-induced dyskinesia without compromising anti-parkinsonian benefits in the MPTP-lesioned macaque. Neuropharmacology 2015; 97:306-11. [PMID: 26071982 DOI: 10.1016/j.neuropharm.2015.05.033] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 05/13/2015] [Accepted: 05/22/2015] [Indexed: 11/23/2022]
Abstract
L-3,4-dihydroxyphenylalanine (L-DOPA) is the most effective anti-parkinsonian agent available, but upon chronic administration, patients with Parkinson's disease (PD) experience abnormal involuntary movements, dyskinesia. Modulation of serotonin 1A (5-HT1A) receptors is regarded as an effective way to alleviate dyskinesia, yet this approach has been marred by a reduction of the therapeutic effectiveness of L-DOPA. We hypothesised that highly-selective 5-HT1A stimulation might be a way to alleviate dyskinesia without compromising L-DOPA anti-parkinsonian action. F15599 (also known as NLX-101) is a highly-selective 5-HT1A agonist that displays over 1000 × selectivity over off-target receptors. Seven cynomolgus macaques were administered MPTP and developed severe parkinsonism. Following chronic administration of L-DOPA, they developed severe and reproducible dyskinesia. F15599 (0.003, 0.01, 0.03 and 0.1 mg/kg) or vehicle was administered in combination with L-DOPA and its effect on dyskinesia and L-DOPA anti-parkinsonian was assessed. In combination with L-DOPA, F15599 (0.1 mg/kg) reduced the severity of peak-dose dyskinesia, by ≈45% (P < 0.001), compared to L-DOPA alone. F15599 (any dose) had no effect on duration of on-time or motor activity counts compared to L-DOPA alone. F15599 at 0.03 and 0.1 mg/kg significantly reduced duration of on-time with disabling dyskinesia (by ≈49% and ≈71%, P < 0.05 and P < 0.001, respectively). These results suggest that F15599, a highly-selective 5-HT1A receptor agonist, alleviates dyskinesia without exerting a deleterious effect on L-DOPA anti-parkinsonian action.
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152
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Cerasa A, Koch G, Fasano A, Morgante F. Future scenarios for levodopa-induced dyskinesias in Parkinson's disease. Front Neurol 2015; 6:76. [PMID: 25883587 PMCID: PMC4381644 DOI: 10.3389/fneur.2015.00076] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 03/19/2015] [Indexed: 11/13/2022] Open
Affiliation(s)
| | - Giacomo Koch
- Laboratorio di Neurologia Clinica e Comportamentale, Fondazione Santa Lucia IRCCS , Rome , Italy
| | - Alfonso Fasano
- Morton and Gloria Shulman Movement Disorders Clinic and the Edmond J. Safra Program in Parkinson's Disease, Division of Neurology, Toronto Western Hospital, UHN, University of Toronto , Toronto, ON , Canada
| | - Francesca Morgante
- Dipartimento di Medicina Clinica e Sperimentale, Università di Messina , Messina , Italy
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153
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L-Dopa and Brain Serotonin System Dysfunction. TOXICS 2015; 3:75-88. [PMID: 29056652 PMCID: PMC5634697 DOI: 10.3390/toxics3010075] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 02/16/2015] [Accepted: 02/26/2015] [Indexed: 12/30/2022]
Abstract
L-dopa is used to treat the motor symptoms associated with Parkinson's disease, a neurodegenerative movement disorder characterized by a loss of dopamine neurons. L-dopa is the precursor to dopamine and crosses the blood-brain barrier to increase dopamine neurotransmission. This review will focus on the findings that dopamine produced from L-dopa is mediated in part by serotonin neurons. Direct evidence will be provided that increases in dopamine cause oxidative stress and damage serotonin neurons. Similarly, chronic L-dopa produces deficits in serotonin neurotransmission, including decreases in both serotonin cell bodies within the dorsal raphe and serotonin neurotransmitter concentrations in several forebrain regions. Since serotonin is involved in many important physiological processes including mood and cognition, L-dopa induced serotonin deficits may play a role in the side-effect symptoms observed in Parkinson's disease patients treated with L-dopa.
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154
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Iderberg H, Maslava N, Thompson AD, Bubser M, Niswender CM, Hopkins CR, Lindsley CW, Conn PJ, Jones CK, Cenci MA. Pharmacological stimulation of metabotropic glutamate receptor type 4 in a rat model of Parkinson's disease and L-DOPA-induced dyskinesia: Comparison between a positive allosteric modulator and an orthosteric agonist. Neuropharmacology 2015; 95:121-9. [PMID: 25749357 DOI: 10.1016/j.neuropharm.2015.02.023] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Revised: 02/16/2015] [Accepted: 02/18/2015] [Indexed: 12/21/2022]
Abstract
Metabotropic glutamate receptor 4 (mGlu4) negatively modulates GABA and glutamate release in the 'indirect pathway' of the basal ganglia, and has thus been proposed as a potential target to treat motor symptoms in Parkinson's disease. Here, we present an extensive comparison of the behavioural effects produced by the mGlu4 positive allosteric modulator (PAM), VU0364770, and the mGlu4 orthosteric agonist, LSP1-2111, in rats with unilateral 6-OHDA lesions. The compounds' activity was initially assessed in a test of haloperidol-induced catalepsy in intact rats, and effective doses were then evaluated in the hemiparkinsonian animal model. Neither of the two compounds modified the development of dyskinetic behaviours elicited by chronic treatment with full doses of l-DOPA. When given together with l-DOPA to rats with already established dyskinesias, neither VU0364770 nor LSP1-2111 modified the abnormal involuntary movement scores. VU0364770 potentiated, however, the motor stimulant effect of a subthreshold l-DOPA dose in certain behavioural tests, whereas LSP1-2111 lacked this ability. Taken together, these results indicate that a pharmacological stimulation of mGlu4 lacks intrinsic antidyskinetic activity, but may have DOPA-sparing activity in Parkinson's disease. For the latter indication, mGlu4 PAMs appear to provide a better option than orthosteric agonists.
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Affiliation(s)
- Hanna Iderberg
- Basal Ganglia Pathophysiology Unit, Department of Experimental Medical Science, Lund University, Sweden.
| | - Natallia Maslava
- Basal Ganglia Pathophysiology Unit, Department of Experimental Medical Science, Lund University, Sweden
| | - Analisa D Thompson
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN, USA; Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
| | - Michael Bubser
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN, USA; Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
| | - Colleen M Niswender
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN, USA; Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
| | - Corey R Hopkins
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN, USA; Department of Pharmacology, Vanderbilt University, Nashville, TN, USA; Department of Chemistry, Vanderbilt University, Nashville, TN 37232, USA
| | - Craig W Lindsley
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN, USA; Department of Pharmacology, Vanderbilt University, Nashville, TN, USA; Department of Chemistry, Vanderbilt University, Nashville, TN 37232, USA
| | - P Jeffrey Conn
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN, USA; Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
| | - Carrie K Jones
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN, USA; Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
| | - M Angela Cenci
- Basal Ganglia Pathophysiology Unit, Department of Experimental Medical Science, Lund University, Sweden.
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155
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Jenner P. Treatment of the later stages of Parkinson's disease - pharmacological approaches now and in the future. Transl Neurodegener 2015; 4:3. [PMID: 25973178 PMCID: PMC4429454 DOI: 10.1186/2047-9158-4-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 02/01/2015] [Indexed: 11/10/2022] Open
Abstract
The problems associated with the pharmacological treatment of the later stages of Parkinson's disease (PD) remain those seen over many years. These centre on a loss of drug effect ('wearing off') with disease progression, the occurrence of dyskinesia, notably with L-dopa use and the appearance of non-motor symptoms that are largely refractory to dopaminergic medication. Treatment strategies in late PD have been dominated by the use of drug combinations and the subtle manipulation of drug dosage. However, change is occurring as the understanding of the basis of motor complications and fluctuations and non-motor symptoms improves. New pharmacological options are expanding with the advent of longer acting versions of existing dopaminergic drugs, new drug delivery systems and the introduction of non-dopaminergic agents able to manipulate motor function both within the basal ganglia and in other brain regions. Non-dopaminergic agents are also being investigated for the treatment of dyskinesia and for the relief of non-motor symptoms. However, while therapy continues to improve, the treatment of late stage PD remains problematic with non-motor symptoms dominating the unmet need in this patient group.
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Affiliation(s)
- Peter Jenner
- Neurodegenerative Diseases Research Group, Institute of Pharmaceutical Sciences, Faculty of Health Sciences and Medicine, King's College, London, SE1 1UL UK
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