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Schifano F, Catalani V, Sharif S, Napoletano F, Corkery JM, Arillotta D, Fergus S, Vento A, Guirguis A. Benefits and Harms of 'Smart Drugs' (Nootropics) in Healthy Individuals. Drugs 2022; 82:633-647. [PMID: 35366192 DOI: 10.1007/s40265-022-01701-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/07/2022] [Indexed: 12/14/2022]
Abstract
'Smart drugs' (also known as 'nootropics' and 'cognitive enhancers' [CEs]) are being used by healthy subjects (i.e. students and workers) typically to improve memory, attention, learning, executive functions and vigilance, hence the reference to a 'pharmaceutical cognitive doping behaviour'. While the efficacy of known CEs in individuals with memory or learning deficits is well known, their effect on non-impaired brains is still to be fully assessed. This paper aims to provide an overview on the prevalence of use; putative neuroenhancement benefits and possible harms relating to the intake of the most popular CEs (e.g. amphetamine-type stimulants, methylphenidate, donepezil, selegiline, modafinil, piracetam, benzodiazepine inverse agonists, and unifiram analogues) in healthy individuals. CEs are generally perceived by the users as effective, with related enthusiastic anecdotal reports; however, their efficacy in healthy individuals is uncertain and any reported improvement temporary. Conversely, since most CEs are stimulants, the related modulation of central noradrenaline, glutamate, and dopamine levels may lead to cardiovascular, neurological and psychopathological complications. Furthermore, use of CEs can be associated with paradoxical short- and long-term cognitive decline; decreased potential for plastic learning; and addictive behaviour. Finally, the non-medical use of any potent psychotropic raises serious ethical and legal issues, with nootropics having the potential to become a major public health concern. Further studies investigating CE-associated social, psychological, and biological outcomes are urgently needed to allow firm conclusions to be drawn on the appropriateness of CE use in healthy individuals.
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Affiliation(s)
- Fabrizio Schifano
- Psychopharmacology, Drug Misuse and Novel Psychoactive Substances Research Unit, School of Life and Medical Sciences, University of Hertfordshire, College Lane Campus, Hatfield, UK.
| | - Valeria Catalani
- Psychopharmacology, Drug Misuse and Novel Psychoactive Substances Research Unit, School of Life and Medical Sciences, University of Hertfordshire, College Lane Campus, Hatfield, UK
| | - Safia Sharif
- Psychopharmacology, Drug Misuse and Novel Psychoactive Substances Research Unit, School of Life and Medical Sciences, University of Hertfordshire, College Lane Campus, Hatfield, UK
| | - Flavia Napoletano
- East London Foundation Trust (ELFT), Newham Early Intervention Service, London, UK
| | - John Martin Corkery
- Psychopharmacology, Drug Misuse and Novel Psychoactive Substances Research Unit, School of Life and Medical Sciences, University of Hertfordshire, College Lane Campus, Hatfield, UK
| | - Davide Arillotta
- Psychopharmacology, Drug Misuse and Novel Psychoactive Substances Research Unit, School of Life and Medical Sciences, University of Hertfordshire, College Lane Campus, Hatfield, UK
| | - Suzanne Fergus
- Psychopharmacology, Drug Misuse and Novel Psychoactive Substances Research Unit, School of Life and Medical Sciences, University of Hertfordshire, College Lane Campus, Hatfield, UK
| | - Alessandro Vento
- Department of Mental Health, ASL Roma 2, Rome, Italy
- Addictions' Observatory (ODDPSS), Rome, Italy
- Department of Psychology, Guglielmo Marconi University, Rome, Italy
| | - Amira Guirguis
- Psychopharmacology, Drug Misuse and Novel Psychoactive Substances Research Unit, School of Life and Medical Sciences, University of Hertfordshire, College Lane Campus, Hatfield, UK
- Swansea University Medical School, Institute of Life Sciences 2, Swansea University, Singleton Park, Swansea, UK
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2
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Cui K, Yang F, Tufan T, Raza MU, Zhan Y, Fan Y, Zeng F, Brown RW, Price JB, Jones TC, Miller GW, Zhu MY. Restoration of Noradrenergic Function in Parkinson's Disease Model Mice. ASN Neuro 2021; 13:17590914211009730. [PMID: 33940943 PMCID: PMC8114769 DOI: 10.1177/17590914211009730] [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: 12/19/2022] Open
Abstract
Dysfunction of the central noradrenergic and dopaminergic systems is the primary neurobiological characteristic of Parkinson’s disease (PD). Importantly, neuronal loss in the locus coeruleus (LC) that occurs in early stages of PD may accelerate progressive loss of dopaminergic neurons. Therefore, restoring the activity and function of the deficient noradrenergic system may be an important therapeutic strategy for early PD. In the present study, the lentiviral constructions of transcription factors Phox2a/2b, Hand2 and Gata3, either alone or in combination, were microinjected into the LC region of the PD model VMAT2 Lo mice at 12 and 18 month age. Biochemical analysis showed that microinjection of lentiviral expression cassettes into the LC significantly increased mRNA levels of Phox2a, and Phox2b, which were accompanied by parallel increases of mRNA and proteins of dopamine β-hydroxylase (DBH) and tyrosine hydroxylase (TH) in the LC. Furthermore, there was considerable enhancement of DBH protein levels in the frontal cortex and hippocampus, as well as enhanced TH protein levels in the striatum and substantia nigra. Moreover, these manipulations profoundly increased norepinephrine and dopamine concentrations in the striatum, which was followed by a remarkable improvement of the spatial memory and locomotor behavior. These results reveal that over-expression of these transcription factors in the LC improves noradrenergic and dopaminergic activities and functions in this rodent model of PD. It provides the necessary groundwork for the development of gene therapies of PD, and expands our understanding of the link between the LC-norepinephrine and dopamine systems during the progression of PD.
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Affiliation(s)
- Kui Cui
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, United States
| | - Fan Yang
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, United States.,Hong Kong Institute, Asia Metropolitan University, Hong Kong, China
| | - Turan Tufan
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, United States
| | - Muhammad U Raza
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, United States
| | - Yanqiang Zhan
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, United States.,Department of Neurology, Renmin Hospital of the Wuhan University, Wuhan, China
| | - Yan Fan
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, United States.,Department of Biochemistry, Nantong University College of Medicine, Nantong, China
| | - Fei Zeng
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, United States.,Department of Neurology, Renmin Hospital of the Wuhan University, Wuhan, China
| | - Russell W Brown
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, United States
| | - Jennifer B Price
- Department of Biological Sciences, College of Arts and Sciences; East Tennessee State University, Johnson City, United States
| | - Thomas C Jones
- Department of Biological Sciences, College of Arts and Sciences; East Tennessee State University, Johnson City, United States
| | - Gary W Miller
- Department of Environmental Health Sciences, Mailmen School of Public Health, Columbia University, New York, New York, United States
| | - Meng-Yang Zhu
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, United States
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Di Giovanni G, García I, Colangeli R, Pierucci M, Rivadulla ML, Soriano E, Chioua M, Della Corte L, Yáñez M, De Deurwaerdère P, Fall Y, Marco-Contelles J. N-(furan-2-ylmethyl)-N-methylprop-2-yn-1-amine (F2MPA): A potential cognitive enhancer with MAO inhibitor properties. CNS Neurosci Ther 2014; 20:633-40. [PMID: 24848125 DOI: 10.1111/cns.12284] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 04/07/2014] [Accepted: 04/22/2014] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND A considerable body of human and animal experimental evidence links monoaminergic systems and cognition. Monoamine oxidase inhibitors (MAOIs), being able to enhance monoaminergic transmission and having neuroprotective properties, might represent a promising therapeutic strategy in cognitive impairment in Alzheimer's disease (AD) and other dementias. METHODS The MAO-A and MAO-B inhibition profile of N-(furan-2-ylmethyl)-N-prop-2-yn-1-amine derivates (compounds 1-3) were evaluated by fluorimetric method and their absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties estimated. The effects of the selected compound 1, N-(furan-2-ylmethyl)-N-methylprop-2-yn-1-amine (F2MPA), were evaluated on the basic synaptic transmission, long-term potentiation (LTP), and excitability in the dentate gyrus (DG) of the hippocampus of anesthetized rats. RESULTS F2MPA is a partially reversible inhibitor of hMAO-B, with moderate to good ADMET properties and drug-likeness. Intraperitoneal administration of 1 mg/kg F2MPA greatly enhanced basic synaptic transmission, induced LTP, and potentiated electrically induced LTP in the dentate gyrus. Moreover, F2MPA did not modify seizure threshold of pilocarpine-induced convulsion in CD1 mice. CONCLUSION Our findings suggest that, the MAO-B inhibitor, F2MPA improves DG synaptic transmission without triggering pathological hyperexcitability. Therefore, F2MPA shows promise as a potential cognition-enhancing therapeutic drug.
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Affiliation(s)
- Giuseppe Di Giovanni
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta; School of Bioscience, Cardiff University, Cardiff, UK
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Amphetamine exposure selectively enhances hippocampus-dependent spatial learning and attenuates amygdala-dependent cue learning. Neuropsychopharmacology 2010; 35:1440-52. [PMID: 20200510 PMCID: PMC3055464 DOI: 10.1038/npp.2010.14] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Behaviorally sensitizing regimen of amphetamine (AMPH) exposure has diverse effects on learning, memory, and cognition that are likely to be a consequence of long-term neural adaptations occurring in the cortico-limbic-striatal circuitry. In particular, altered dopamine signaling in the nucleus accumbens and medial prefrontal cortex has been implicated to underlie AMPH-induced changes in behavior. This study sought to test the hypothesis that repeated AMPH exposure disrupts the regulation of limbic information processing and the balance of competing limbic control over appetitive behavior. Mice received seven intraperitoneal injections of D-AMPH (2.5 mg/kg or 5 mg/kg) or vehicle solution (saline) and were trained in (1) a simultaneous conditioned cue and place preference task using a six-arm radial maze, found to depend on the integrity of the hippocampus (HPC) and basolateral amygdala (BLA), respectively and (2) a conditional BLA-dependent cue, and HPC-dependent place learning task using an elevated T-maze. In both tasks, the vehicle pretreatment group initially acquired cue learning, followed by the emergence of significant place/spatial learning. In contrast, pretreatment with repeated AMPH caused marked deviations from normal acquisition patterns of place and cue conditioning, significantly facilitating HPC-dependent place conditioning in the first task while attenuating BLA-dependent cue conditioning in both tasks. These findings provide the first demonstration of an aberrant regulation of HPC- and BLA-dependent learning as a result of AMPH exposure, highlighting the importance of the meso-coticolimbic dopamine system in maintaining the balance of limbic control over appetitive behavior.
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Coccini T, Manzo L, Debes F, Steuerwald U, Weihe P, Grandjean P. No changes in lymphocyte muscarinic receptors and platelet monoamine oxidase-B examined as surrogate central nervous system biomarkers in a Faroese children cohort prenatally exposed to methylmercury and polychlorinated biphenyls. Biomarkers 2009; 14:67-76. [PMID: 19330584 DOI: 10.1080/13547500902783739] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Experimental evidence suggests that monoamine oxidase B (MAO-B) and muscarinic cholinergic receptors (mAChRs) are involved in the pathogenesis of neurotoxicity caused by methylmercury and polychlorinated biphenyls (PCBs). Blood samples from 7-year-old exposed children were analyzed for platelet MAO-B and lymphocyte mAChRs as potential markers of exposure to these neurotoxicants. The blood neurotoxicity biomarkers were compared with prenatal and current exposures and with neuropsychological test results. Both biomarkers showed homogeneous distributions within this cohort (mAChR, range 0.04-36.78 fmol/million cells; MAO-B, 0.95-14.95 nmol mg(-1) protein h(-1)). No correlation was found between the two biomarkers and either blood neurotoxicant concentrations or clinical findings. MAO-B and mAChR sensitivity may not be sufficiently high to assess early, subclinical responses to low/moderate methylmercury and/or PCB exposure, whereas these markers are significantly altered in sustained exposure scenarios, as shown by clinical studies in drug addicts or patients treated with psychopharmacological agents.
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Affiliation(s)
- Teresa Coccini
- IRCCS Salvatore Maugeri Foundation, Toxicology Division, Institute of Pavia, Italy.
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Pascual R, Zamora-León SP. Chronic (–)-Deprenyl Administration Attenuates Dendritic Developmental Impairment Induced by Early Social Isolation in the Rat. Dev Neurosci 2006; 29:261-7. [PMID: 17047320 DOI: 10.1159/000096413] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2006] [Accepted: 06/05/2006] [Indexed: 11/19/2022] Open
Abstract
It has been demonstrated that postweaning social isolation alters dendritic development in the medial prefrontal cortex (mPFC) of the rat. In addition, (-)-deprenyl, a monoamine oxidase B (MAO-B) inhibitor, promotes dendritic growth in prefrontocortical pyramidal cells. This study examined whether prefrontocortical dendritic developmental impairment induced by postweaning social isolation is attenuated by chronic (-)-deprenyl administration. Weanling Sprague-Dawley male rats were randomly reared in social and isolated environments between postnatal days 21 and 51 (P21-P51). At P52, half of the animals were behaviorally evaluated in the open-field test and sacrificed for histological analysis. The remaining isolated rats were subdivided into saline- and daily (-)-deprenyl-treated animals for 30 additional days (P52-P82). Socially-reared rats remained undisturbed except for daily saline administration. At P82, all animals were behaviorally evaluated and sacrificed for histological analysis. Dendritic quantification of the Golgi-Cox-Sholl-stained neurons indicated that chronic (-)-deprenyl administration partially compensated the dendritic growth impairment induced by social isolation. In addition, both isolated-saline- and (-)-deprenyl-treated rats showed a sustained locomotor hyperactivity in the open-field test.
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Affiliation(s)
- Rodrigo Pascual
- Instituto de Ciencias Básicas, Universidad Católica del Maule, Talca, Chile.
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Yasar S, Justinova Z, Lee SH, Stefanski R, Goldberg SR, Tanda G. Metabolic transformation plays a primary role in the psychostimulant-like discriminative-stimulus effects of selegiline [(R)-(-)-deprenyl]. J Pharmacol Exp Ther 2005; 317:387-94. [PMID: 16352699 DOI: 10.1124/jpet.105.096263] [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] [Indexed: 11/22/2022] Open
Abstract
l-Deprenyl [selegiline, (R)-(-)-deprenyl] is a selective inhibitor of monoamine oxidase B (MAO-B) used in the treatment of Parkinson's disease and proposed as an antidepressant and an aid for cigarette-smoking cessation and treatment of psychostimulant abuse. Beneficial therapeutic effects of (R)-(-)-deprenyl may also result from indirect actions. Brain levels of dopamine and beta-phenylethylamine (beta-PEA), a behaviorally active endogenous trace amine, increase after (R)-(-)-deprenyl treatment due to MAO-B blockade and (R)-(-)-deprenyl is metabolized to (R)-(-)-methamphetamine and (R)-(-)-amphetamine, suggesting that (R)-(-)-deprenyl may have psychostimulant-like behavioral effects. Indeed, (R)-(-)-deprenyl produces psychostimulant-like discriminative-stimulus effects in experimental animals. Here, we tested the hypothesis that psychostimulant-like behavioral effects of (R)-(-)-deprenyl are mainly mediated by its metabolites. Male Fisher F344 rats were trained to discriminate i.p. injection of 1.0 mg/kg (S)-(+)-methamphetamine or 10.0 mg/kg cocaine from injection of saline using two-lever choice schedules of food delivery or stimulus shock termination. When (R)-(-)-deprenyl was tested by substitution, it had (S)-(+)-methamphetamine- and cocaine-like discriminative-stimulus effects, but only at doses of 10 to 30 mg/kg, doses 10 to 20 times higher than those selective for MAO-B inhibition. Ro 16-6491 [N-(2-aminoethyl)-4-chlorobenzamide hydrochloride], a selective inhibitor of MAO-B enzyme activity without psychoactive metabolites, had no psychostimulant-like discriminative effects. In addition, blockade of (R)-(-)-deprenyl's metabolism with SKF 525A (beta-DEAE-diphenylpropylacetate hydrochloride; 50 mg/kg i.p.) reduced or eliminated (R)-(-)-deprenyl's psychostimulant-like discriminative effects. When beta-PEA synthesis was blocked by NSD 1015 (m-hydroxy-benzyl-hydrazine; 30 mg/kg i.p.), there was a modest reversal of (R)-(-)-deprenyl's psychostimulant-like discriminative effects under some conditions, indicating a facilitatory modulation of the psychostimulant-like discriminative effects of (R)-(-)-deprenyl metabolites by elevated levels of beta-PEA under certain conditions.
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Affiliation(s)
- Sevil Yasar
- Division of Geriatric Medicine and Gerontology, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA.
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Studzinski CM, Araujo JA, Milgram NW. The canine model of human cognitive aging and dementia: pharmacological validity of the model for assessment of human cognitive-enhancing drugs. Prog Neuropsychopharmacol Biol Psychiatry 2005; 29:489-98. [PMID: 15795058 DOI: 10.1016/j.pnpbp.2004.12.014] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/13/2004] [Indexed: 01/24/2023]
Abstract
For the past 15 years we have investigated the aged beagle dog as a model for human aging and dementia. We have shown that dogs develop cognitive deficits and neuropathology seen in human aging and dementia. These similarities increase the likelihood that the model will be able to accurately predict the efficacy of Alzheimer's disease (AD) treatments as well as detect therapeutics with limited or no efficacy. Better predictive validity of cognitive-enhancing therapeutics (CETs) could lead to enormous cost savings by reducing the number of failed human clinical trials and also may reduce the likelihood of negative outcomes such as those recently observed in the AN-1792 clinical trials. The current review assesses the pharmacological validity of the canine model of human aging and dementia. We tested the efficacy of (1) CP-118,954 and phenserine, two acetylcholinesterase inhibitors, (2) an ampakine, (3) selegiline hydrochloride, two drugs that have failed human AD trials, and (4) adrafinil, a putative CET. Our research demonstrates that dogs not only develop isomorphic changes in human cognition and brain pathology, but also accurately predict the efficacy of known AD treatments and the absence or limited efficacy of treatments that failed clinical trials. These findings collectively support the utilization of the dog model as a preclinical screen for identifying novel CETs for both age-associated memory disorder and dementia.
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Abstract
Evolution of the prefrontal cortex was an essential precursor to civilization. During the past decade, it became increasingly obvious that human prefrontal function is under substantial genetic control. In particular, heritability studies of frontal lobe-related neuropsychological function, electrophysiology and neuroimaging have greatly improved our insight. Moreover, the first genes that are relevant for prefrontal function such as catechol-O-methyltransferase (COMT) are currently discovered. In this review, we summarize the present knowledge on the genetics of human prefrontal function. For historical reasons, we discuss the genetics of prefrontal function within the broader concept of general cognitive ability (intelligence). Special emphasis is also given to methodological concerns that need to be addressed when conducting research on the genetics of prefrontal function in humans.
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Affiliation(s)
- Georg Winterer
- Clinical Brain Disorders Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA.
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10
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Buccafusco JJ, Terry AV, Goren T, Blaugrun E. Potential cognitive actions of (n-propargly-(3r)-aminoindan-5-yl)-ethyl, methyl carbamate (tv3326), a novel neuroprotective agent, as assessed in old rhesus monkeys in their performance of versions of a delayed matching task. Neuroscience 2003; 119:669-78. [PMID: 12809688 DOI: 10.1016/s0306-4522(02)00937-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
(N-propargyl-(3R)-aminoindan-5-yl)-ethyl, methyl carbamate (TV3326), a known neuroprotective agent exhibiting the properties of both an inhibitor of monoamine oxidase (brain selective) and an inhibitor of acetylcholinesterase was administered to seven old rhesus monkeys well trained to perform versions of a delayed matching-to-sample (DMTS) task. An increasing dose regimen of TV3326 was administered orally according to a schedule that allowed the animals to perform the standard DMTS task and a self-titrating version of the DMTS task each week during the study. A distractor version of the task was administered during two of the doses of TV3326. Under the conditions of this experiment TV3326 failed to significantly affect accuracy on the standard DMTS task; however, the drug was very effective in improving the ability of subjects to titrate to longer-duration delay intervals in the titrating version of the task. The maximal drug-induced extension of the self-titrated delay interval amounted to a 36.7% increase above baseline. This increase in maximum delay duration occurred without a significant change in overall task accuracy. TV3326 also significantly improved task accuracy during distractor (interference) sessions. The compound was effective enough to return group performance efficiency to standard DMTS vehicle levels of accuracy. These results were independent of whether trials were associated with a distractor or non-distractor delay interval, and they were independent of delay interval. The lack of delay selectivity in task improvement by TV3326 may not be consistent with a selective effect on attention. TV3326 was not associated with any obvious side effect or untoward reaction of the animals to the drug. Thus, TV3326 may be expected to offer a significant positive cognitive outcome in addition to its reported neuroprotective action.
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Affiliation(s)
- J J Buccafusco
- Alzheimer's Research Center, Medical College of Georgia, 30912-2300, Augusta, GA, USA.
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Dragoni S, Bellik L, Frosini M, Matteucci G, Sgaragli G, Valoti M. Cytochrome P450-dependent metabolism of l-deprenyl in monkey (Cercopithecus aethiops) and C57BL/6 mouse brain microsomal preparations. J Neurochem 2003; 86:1174-80. [PMID: 12911625 DOI: 10.1046/j.1471-4159.2003.01927.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The aim of the present investigation was to characterize the cytochrome P450 (CYP)-dependent metabolism of l-deprenyl by brain microsomal preparations obtained from two different animal models that have been extensively used in Parkinson's disease studies, namely monkey (Cercopithecus aethiops) and C57BL/6 mouse. In monkey brain microsomal fractions, the apparent Km values for methamphetamine formation from l-deprenyl were 67.8 +/- 1.0 and 72.0 +/- 1.6 microm, in the cortex and striatum, respectively. Similarly, for nordeprenyl formation from l-deprenyl, Km values in cortex and striatum were 21.3 +/- 3.2 and 27.3 +/- 4.0 microm, respectively. Both metabolic pathways appear to be more efficient in the cortex than in the striatum as the Vmax for microsomal preparation was lower in the striatum for the formation of both metabolites. The formation rate of l-methamphetamine was up to one order of magnitude greater than that of nordeprenyl. Inhibition analysis of both pathways in monkey brain suggested that l-methamphetamine formation is catalysed by CYP2A and CYP3A, whereas only CYP3A appears to be involved in nordeprenyl formation. With microsomal preparations from whole brain of C57BL/6 mice, the only l-deprenyl metabolite that could be detected was methamphetamine and the Km and Vmax values were similar to those determined in monkey cortex (53.6 +/- 2.9 microm and 33.9 +/- 0.4 pmol/min/mg protein, respectively). 4-Methylpyrazole selectively inhibited methamphetamine formation, suggesting the involvement of CYP2E1. In conclusion, the present study indicates that l-deprenyl is effectively metabolised by CYP-dependent oxidases in the brain, giving rise mainly to the formation of methamphetamine, which has been suggested to play a role in the pharmacological effects of the parent drug. The results also demonstrate that there are differences between species in CYP-dependent metabolism of l-deprenyl.
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Affiliation(s)
- Stefania Dragoni
- Istituto di Scienze Farmacologiche, Centro Interdipartimentale di Ricerca sul Metabolismo dei Farmaci Neuropsicotropi, Università di Siena, Siena, Italy
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12
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Russig H, Durrer A, Yee BK, Murphy CA, Feldon J. The acquisition, retention and reversal of spatial learning in the morris water maze task following withdrawal from an escalating dosage schedule of amphetamine in wistar rats. Neuroscience 2003; 119:167-79. [PMID: 12763078 DOI: 10.1016/s0306-4522(03)00045-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two experiments were carried out to evaluate the effects of amphetamine withdrawal in rats on spatial learning in the water maze. A schedule of repeated d-amphetamine administration lasting for 6 days, with three injections per day (1-5 mg/kg, i.p.), was employed. Experiment 1 demonstrated that amphetamine withdrawal did not impair the acquisition of the water maze task (third to fourth withdrawal days), but amphetamine-withdrawn rats made more target-zone visits and reached the former location of the platform quicker than controls during the probe test (fifth withdrawal day). In experiment 2, retention of the location of the escape platform was assessed in animals having been pre-trained on the water maze task before treatment. On the third withdrawal day, retention of the former platform location was assessed in a probe test. Retention was only clearly seen in the measure of target zone visits, and performance did not differ between groups. Next, the animals were trained to escape to a new location in the water maze on withdrawal days 4-5. A reversal effect could be discerned across the first four trials, as evident by the animals' tendency to search in the former target quadrant. This interfered with the new learning, but amphetamine-withdrawn animals appeared to overcome it more rapidly than saline-treated controls. This finding is consistent with the view that amphetamine withdrawal can enhance behavioural switching, which could be expressed as a reduction of proactive interference during learning; and, it is in line with our previous finding that latent inhibition is also attenuated during amphetamine withdrawal.
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Affiliation(s)
- H Russig
- Laboratory of Behavioural Neurobiology, Swiss Federal Institute of Technology (ETH Zurich), Schorenstrasse 16, CH-8603 Schwerzenbach, Switzerland
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Holschneider DP, Chen K, Seif I, Shih JC. Biochemical, behavioral, physiologic, and neurodevelopmental changes in mice deficient in monoamine oxidase A or B. Brain Res Bull 2001; 56:453-62. [PMID: 11750790 PMCID: PMC4109811 DOI: 10.1016/s0361-9230(01)00613-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The availability of mutant mice that lack either MAO A or MAO B has created unique profiles in the central and peripheral availability of serotonin, norepinephrine, dopamine, and phenylethylamine. This paper summarizes some of the current known phenotypic findings in MAO A knock-out mice and contrast these with those of MAO B knock-out mice. Differences are discussed in relation to the biochemical, behavioral, and physiologic changes investigated to date, as well as the role played by redundancy mechanisms, adaptational responses, and alterations in neurodevelopment.
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Affiliation(s)
- D. P. Holschneider
- Department of Psychiatry and the Behavioral Sciences, USC School of Medicine, Los Angeles, CA, USA
- Department of Neurology, USC School of Medicine, Los Angeles, CA, USA
- Greater Los Angeles VA Healthcare System, Los Angeles, CA, USA
- Address for correspondence: J. C. Shih, Ph.D., University of Southern California, School of Pharmacy, 1985 Zonal Ave., Rm. 528, Los Angeles, CA 90089, USA. Fax: (323) 442-3229;
| | - K. Chen
- Department of Molecular Pharmacology and Toxicology, USC School of Pharmacy, Los Angeles, CA, USA
| | - I. Seif
- Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 146, Institut Curie, Orsay, France
| | - J. C. Shih
- Department of Molecular Pharmacology and Toxicology, USC School of Pharmacy, Los Angeles, CA, USA
- Department of Cell and Neurobiology, USC School of Medicine, Los Angeles, CA, USA
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14
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Grasing K, Azevedo R, Karuppan S, Ghosh S. Biphasic effects of selegiline on striatal dopamine: lack of effect on methamphetamine-induced dopamine depletion. Neurochem Res 2001; 26:65-74. [PMID: 11358284 DOI: 10.1023/a:1007632700126] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We tested the hypothesis that selegiline can attenuate dopamine depletion if administered following high doses of methamphetamine that cause neurotoxicity in the striatum. Methamphetamine produced decreases of 50% or greater in both striatal concentrations of dopamine and combined concentrations of homovanillic acid and DOPAC in mice. For animals not exposed to methamphetamine, chronic treatment with selegiline over 18 days caused biphasic effects on striatal dopamine content, with decreases, no effect, or increases observed for mice receiving treatment with 0.02, 0.2, and 2.0 mg/kg, respectively. Selegiline failed to modify methamphetamine-induced reductions in striatal dopamine content or combined concentrations of homovanillic acid and DOPAC. Significant increases in mortality following the onset of selegiline treatment (24 hours after the initial dose of methamphetamine) occurred in methamphetamine-treated mice that received saline or 2.0 mg/kg of selegiline, but not for mice treated with 0.02 or 0.2 mg/kg of selegiline. These results indicate that selegiline fails to attenuate dopamine depletion when administered chronically following exposure to methamphetamine, but may attenuate methamphetamine-induced mortality. In control animals that did not receive methamphetamine, low doses of selegiline produced decreases the concentration of striatal dopamine, while high dose treatment caused increases in striatal dopamine content.
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Affiliation(s)
- K Grasing
- Veterans Administration Medical Center, Kansas City, Missouri 64128, USA.
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15
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D'Hooge R, De Deyn PP. Applications of the Morris water maze in the study of learning and memory. BRAIN RESEARCH. BRAIN RESEARCH REVIEWS 2001; 36:60-90. [PMID: 11516773 DOI: 10.1016/s0165-0173(01)00067-4] [Citation(s) in RCA: 1386] [Impact Index Per Article: 60.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The Morris water maze (MWM) was described 20 years ago as a device to investigate spatial learning and memory in laboratory rats. In the meanwhile, it has become one of the most frequently used laboratory tools in behavioral neuroscience. Many methodological variations of the MWM task have been and are being used by research groups in many different applications. However, researchers have become increasingly aware that MWM performance is influenced by factors such as apparatus or training procedure as well as by the characteristics of the experimental animals (sex, species/strain, age, nutritional state, exposure to stress or infection). Lesions in distinct brain regions like hippocampus, striatum, basal forebrain, cerebellum and cerebral cortex were shown to impair MWM performance, but disconnecting rather than destroying brain regions relevant for spatial learning may impair MWM performance as well. Spatial learning in general and MWM performance in particular appear to depend upon the coordinated action of different brain regions and neurotransmitter systems constituting a functionally integrated neural network. Finally, the MWM task has often been used in the validation of rodent models for neurocognitive disorders and the evaluation of possible neurocognitive treatments. Through its many applications, MWM testing gained a position at the very core of contemporary neuroscience research.
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Affiliation(s)
- R D'Hooge
- Laboratory of Neurochemistry and Behavior, Born-Bunge Foundation, and Department of Neurology/Memory Clinic, Middelheim Hospital, University of Antwerp, Universiteitsplein 1, B-2610, Antwerp, Belgium.
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16
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Puurunen K, Jolkkonen J, Sirviö J, Haapalinna A, Sivenius J. Selegiline combined with enriched-environment housing attenuates spatial learning deficits following focal cerebral ischemia in rats. Exp Neurol 2001; 167:348-55. [PMID: 11161623 DOI: 10.1006/exnr.2000.7563] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Selegiline (l-deprenyl) is an irreversible monoamine oxidase B (MAO-B) inhibitor that is suggested to have neuroprotective and neuronal rescuing properties. The present study investigated whether systemic administration of selegiline facilitates behavioral recovery after transient focal cerebral ischemia in rats using a combination of different behavioral tests (limb placing, foot slip, water maze, and Montoya's staircase test) to measure the outcome of recovery. Selegiline (0.5 mg/kg, SC) or 0.9% NaCl was administered once a day, beginning on the second day after induction of ischemia and continuing for 30 days. Selegiline administration combined with enriched-environment housing attenuated ischemia-induced spatial learning deficits in a water-maze task and enhanced performance of both the contralateral affected and ipsilateral nonaffected forelimbs in a staircase test. Selegiline administration alone was not beneficial in any of the tests. Subsequent histologic examination revealed that the infarct volumes were not different between the experimental ischemic groups. Thus, these results suggest that selegiline combined with enriched-environment housing reduces behavioral and cognitive deficits without affecting infarct size.
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Affiliation(s)
- K Puurunen
- Department of Neuroscience and Neurology, University of Kuopio, Kuopio, Finland
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17
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Hsieh MT, Wu CR, Wang WH, Lin LW. The ameliorating effect of the water layer of Fructus Schisandrae on cycloheximide-induced amnesia in rats: interaction with drugs acting at neurotransmitter receptors. Pharmacol Res 2001; 43:17-22. [PMID: 11207061 DOI: 10.1006/phrs.2000.0756] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Our previous study indicated that the water layer present in Fructus Schisandra(FS(w)) at 10 and 25 mg kg(-1)significantly counteracted cycloheximide (CXM)-induced amnesia. Therefore, the mechanism of action of the ameliorating effect of FS(w)on CXM-induced amnesia in the passive avoidance task was investigated in rats. The ameliorating effect of FS(w)on CXM-induced amnesia was depressed by scopolamine. The serotonin releaser, p -chloroamphetamine significantly antagonized the ameliorating effect of FS(w)on CXM-induced amnesia. Furthermore, the ameliorating effect was also inhibited by the 5-HT(1A)receptor agonist 8-OH-DPAT, but potentiated by the 5-HT(2)receptor antagonist ritanserin. Finally, the GABA(A)receptor antagonist bicuculline blocked the ameliorating effect of FS(w). These results suggest that the beneficial effect of FS(w)on CXM-induced amnesia is amplified by treatment with serotonergic 5-HT(2)receptor antagonists, but reduced by serotonergic 5-HT(1A)receptor agonists as well as GABA(A)and cholinergic receptor antagonists.
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Affiliation(s)
- M T Hsieh
- Institute of Chinese Pharmaceutical Sciences, China Medical College, 91 Hsueh Shih Road, Taichung, Taiwan, 40421, Republic of China.
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Holschneider DP, Scremin OU, Chen K, Shih JC. Lack of protection of monoamine oxidase B-deficient mice from age-related spatial learning deficits in the Morris water maze. Life Sci 1999; 65:1757-63. [PMID: 10576555 DOI: 10.1016/s0024-3205(99)00428-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Monoamine oxidase B (MAO-B) increases in brain in response to aging and neurodegeneration. Whether such increases represent a risk factor to further neuronal damage or simply represent epiphenomena remains unclear. L-deprenyl, an inhibitor of MAO-B, has been shown to improve learning in aged rodents. However, recent data suggests this may occur through mechanisms independent of its enzymatic inhibition. This study investigates visualspatial learning of MAO-B deficient mice and examines what effects absence of MAO-B has on age-related cognitive decline. Learning was tested in the Morris Water Maze in male transgenic MAO-B knockout mice (KO) ages 2 months (n = 9), 7 months (n = 7), and 17 months (n = 8). Performance was compared to that of wild type (WT) littermates. Animals were given four 60 second trials per day with the submerged platform in the "North" position. Animals received 7 days of learning in which they were introduced into the pool facing the wall, alternating between the "East" and "West" positions. A single probe trial followed on day 8, followed by continuation of the original learning paradigm on days 9 and 10. Subsequently, the platform position was changed to the diagonally opposite quadrant and learning continued on days 11-13, followed by a cue phase in which the platform was made visible. Total distance traveled and latency to the platform was increased in 7- and 17- month old mice, most significantly at the beginning of the acquisition phase. This effect reappeared again in 17- month old mice during the reversal phase. No predominant genotypic differences in latency or distance were observed during any phase of the experiment. Our results show that presence or absence of MAO-B does not appear to alter performance in the Morris water maze. Furthermore, presence or absence of MAO-B does not provide protection from the age-dependent deficits in spatial learning.
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Affiliation(s)
- D P Holschneider
- Dept. of Psychiatry and the Behavioral Sciences, School of Pharmacy, University of Southern California, Los Angeles 90033, USA.
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Churchyard A, Mathias CJ, Lees AJ. Selegiline-induced postural hypotension in Parkinson's disease: a longitudinal study on the effects of drug withdrawal. Mov Disord 1999; 14:246-51. [PMID: 10091617 DOI: 10.1002/1531-8257(199903)14:2<246::aid-mds1008>3.0.co;2-p] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
OBJECTIVES The United Kingdom Parkinson's Disease Research Group (UKPDRG) trial found an increased mortality in patients with Parkinson's disease (PD) randomized to receive 10 mg selegiline per day and L-dopa compared with those taking L-dopa alone. Recently, we found that therapy with selegiline and L-dopa was associated with selective systolic orthostatic hypotension which was abolished by withdrawal of selegiline. This unwanted effect on postural blood pressure was not the result of underlying autonomic failure. The aims of this study were to confirm our previous findings in a separate cohort of patients and to determine the time course of the cardiovascular consequences of stopping selegiline in the expectation that this might shed light on the mechanisms by which the drug causes orthostatic hypotension. METHODS The cardiovascular responses to standing and head-up tilt were studied repeatedly in PD patients receiving selegiline and as the drug was withdrawn. RESULTS Head-up tilt caused systolic orthostatic hypotension which was marked in six of 20 PD patients on selegiline, one of whom lost consciousness with unrecordable blood pressures. A lesser degree of orthostatic hypotension occurred with standing. Orthostatic hypotension was ameliorated 4 days after withdrawal of selegiline and totally abolished 7 days after discontinuation of the drug. Stopping selegiline also significantly reduced the supine systolic and diastolic blood pressures consistent with a previously undescribed supine pressor action. CONCLUSION This study confirms our previous finding that selegiline in combination with L-dopa is associated with selective orthostatic hypotension. The possibilities that these cardiovascular findings might be the result of non-selective inhibition of monoamine oxidase or of amphetamine and metamphetamine are discussed.
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Affiliation(s)
- A Churchyard
- Institute of Neurology and University Department of Clinical Neurology, National Hospital for Neurology and Neurosurgery, London, UK
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20
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Gelowitz DL, Paterson IA. Neuronal sparing and behavioral effects of the antiapoptotic drug, (-)deprenyl, following kainic acid administration. Pharmacol Biochem Behav 1999; 62:255-62. [PMID: 9972692 DOI: 10.1016/s0091-3057(98)00162-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
(-)Deprenyl is an irreversible inhibitor of monoamine oxidase B (MAO-B) frequently used as an adjunct therapy in the treatment of Parkinson's Disease. Recent evidence, however, has found that deprenyl's metabolites are associated with an antiapoptotic action within certain neuronal populations. Interestingly, deprenyl's antiapoptotic actions appear not to depend upon the inhibition of MAO-B. Due to a paucity of information surrounding (-)deprenyl's ability to spare neurons in vivo, a series of studies was conducted to further investigate this phenomenon within an apoptotic neuronal death model: kainic acid induced excitotoxicity. Results indicated that (-)deprenyl increased hippocampal neuronal survival compared to saline-matched controls following kainic acid insult. Furthermore, it was discovered that (-)deprenyl treatment could be stopped 14 days following CNS insult by kainate, with evidence of neuronal sparing still present by day 28. In open-field locomotor activity testing of kainate-treated animals, those given subsequent (-)deprenyl treatment showed habituation curves similar to control subjects, while saline-treated animals did not. Given deprenyl's antiapoptotic actions, it is proposed that (-)deprenyl may be beneficial in the treatment of a variety of neurodegenerative diseases where evidence of apoptosis exists, such as Parkinson's and Alzheimer's Disease, by slowing the disease process itself.
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Affiliation(s)
- D L Gelowitz
- Department of Psychiatry, University of Cincinnati, OH 45267-0559, USA
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21
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Churchyard A, Mathias CJ, Boonkongchuen P, Lees AJ. Autonomic effects of selegiline: possible cardiovascular toxicity in Parkinson's disease. J Neurol Neurosurg Psychiatry 1997; 63:228-34. [PMID: 9285463 PMCID: PMC2169684 DOI: 10.1136/jnnp.63.2.228] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVES The United Kingdom Parkinson's Disease Research Group (UKPDRG) trial found an increased mortality in patients with Parkinson's disease randomised to receive selegiline (10 mg/day) and levodopa compared with those taking levodopa alone. Unwanted effects of selegiline on cardiovascular regulation have been investigated as a potential cause for the unexpected mortality finding of the UKPDRG trial. METHODS The cardiovascular responses to a range of physiological stimuli, including standing and head up tilt, were studied in patients with Parkinson's disease receiving levodopa alone and a matched group on levodopa and selegiline. RESULTS Head up tilt caused selective and often severe orthostatic hypotension in nine of 16 patients taking selegiline and levodopa, but was without effect on nine patients receiving levodopa alone. Two patients taking selegiline lost consciousness with unrecordable blood pressures and a further four had severe symptomatic hypotension. The normal protective rises in heart rate and plasma noradrenaline were impaired. The abnormal response to head up tilt was reversed by discontinuation of selegiline. Drug withdrawal caused a pronounced deterioration in motor function in 13 of the 16 patients taking selegiline. CONCLUSION Therapy with selegiline and levodopa in combination may be associated with severe orthostatic hypotension not attributable to levodopa alone. Selegiline also has pronounced symptomatic motor effects in advanced Parkinson's disease. The possibilities that these cardiovascular and motor findings might be due either to non-selective inhibition of monoamine oxidase or to amphetamine and met-amphetamine are discussed.
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Affiliation(s)
- A Churchyard
- Institute of Neurology, National Hospital for Neurology and Neurosurgery, London, UK
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22
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Romero-Ramos M, Rodríguez-Gómez JA, Venero JL, Cano J, Machado A. Chronic inhibition of the high-affinity dopamine uptake system increases oxidative damage to proteins in the aged rat substantia nigra. Free Radic Biol Med 1997; 23:1-7. [PMID: 9165291 DOI: 10.1016/s0891-5849(96)00405-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The effect of chronic treatment of aged rats with nomifensine has been studied in the rat nigrostriatal dopaminergic system. The rat substantia nigra suffers an oxidative damage during aging that results in both an increase in carbonyl groups of its total proteins and the oxidative inactivation of tyrosine hydroxylase (TH) enzyme, which are partially reversed by chronic treatment with deprenyl. Different mechanisms may account for this effect, including inhibition of the high-affinity dopamine uptake system. We treated aged rats chronically with nomifensine for 2 months and found some significant effects. Nomifensine treatment significantly increased TH enzyme amount in substantia nigra (39.2%), which was accompanied by a significant increase in TH enzyme activity (47.8%). However, these effects were not observed in the terminal field (striatum). As a further step we quantified the oxidative level of proteins by measuring the number of carbonyl groups coupled either to total proteins or specifically to TH enzyme. The proteins of aged rat substantia nigra showed a significant increase of carbonyl groups following nomifensine treatment. The number of carbonyl groups coupled to nigral TH enzyme also increased in the nomifensine-treated animals. However, this increase was lower than that found in the total homogenate proteins. All these results show that the oxidative damage produced during aging in tyrosine hydroxylase enzyme and total proteins is not reduced by nomifensine treatment. On the contrary, the nomifensine treatment increased the oxidative damage to proteins. These results suggest the capability of deprenyl to induce TH enzyme could be due to inhibition of the high-affinity dopamine uptake system, but its ability to protect against oxidative damage is not produced by this mechanism.
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Affiliation(s)
- M Romero-Ramos
- Departamento de Bioquímica, Bromatología y Toxicología, Facultad de Farmacia, Universidad de Sevilla, Spain
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Head E, Hartley J, Kameka AM, Mehta R, Ivy GO, Ruehl WW, Milgram NW. The effects of L-deprenyl on spatial short term memory in young and aged dogs. Prog Neuropsychopharmacol Biol Psychiatry 1996; 20:515-30. [PMID: 8771606 DOI: 10.1016/0278-5846(96)00014-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
1. Young and aged dogs were tested on a spatial memory task using a delayed non matching to sample technique. Dogs were tested with 20, 70 and 110 second delay intervals. Animals were pretrained to a stable level of performance prior to treatment. 2. During treatment periods, dogs were orally administered a placebo or I-deprenyl in doses of 0.5 and 1.0 mg/kg in a repeated measures design. 3. Young dogs did not show any significant effects of I-deprenyl, however the sample size was limited. 4. L-deprenyl administration improved spatial memory in aged dogs. 5. The optimal dose or length of treatment time of I-deprenyl varied among individual dogs.
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Affiliation(s)
- E Head
- University of Toronto, Division of Life Sciences, Scarborough, Ontario, Canada
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Yasar S, Goldberg JP, Goldberg SR. Are metabolites of l-deprenyl (selegiline) useful or harmful? Indications from preclinical research. JOURNAL OF NEURAL TRANSMISSION. SUPPLEMENTUM 1996; 48:61-73. [PMID: 8988462 DOI: 10.1007/978-3-7091-7494-4_6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A frequent topic of controversy has been whether metabolism of l-deprenyl (selegiline) to active metabolites is a detriment to clinical use. This paper reviews possible roles of the metabolites of l-deprenyl in producing unwanted adverse side effects or in augmenting or mediating its clinically useful actions. Levels of l-amphetamine and l-methamphetamine likely to be reached, even with excessive intake of l-deprenyl, would be unlikely to produce neurotoxicity and there is no preclinical or clinical evidence of abuse liability of l-deprenyl. In contrast, there is evidence that l-amphetamine and l-methamphetamine have some qualitatively different actions than their d-isomer counterparts on EEG and cognitive functioning which might result in beneficial clinical effects and complement beneficial clinical actions of l-deprenyl itself.
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Affiliation(s)
- S Yasar
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Medical School, Baltimore, MD, USA
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26
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Berry MD, Juorio AV, Paterson IA. Possible mechanisms of action of (-)deprenyl and other MAO-B inhibitors in some neurologic and psychiatric disorders. Prog Neurobiol 1994; 44:141-61. [PMID: 7831475 DOI: 10.1016/0301-0082(94)90036-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- M D Berry
- Neuropsychiatric Research Unit, University of Saskatchewan, Saskatoon, Canada
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Abstract
Recent advances in neuroscience and molecular neurochemistry have substantially increased the knowledge of the neuropathobiology of senile dementia and Alzheimer's disease. On the basis of various hypotheses concerning degenerative processes in aging brains, new therapeutic strategies have been developed, including nootropic drugs with different mechanisms of action and heterogenous chemical structures. Mutual relationships exist between neuroscientific research and nootropic drug development. To date, such areas of research and drug development have involved deficits of brain neurotransmission (cholinergic, monoaminergic, peptidergic), free radical-induced damage, disturbances of calcium homeostasis and excitatory amino acid function, and deposition of amyloid protein.
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Affiliation(s)
- O Benesová
- Psychiatric Centre, Prague, Czech Republic
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