1
|
Park G, Park YJ, Yang HO, Oh MS. Ropinirole protects against 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-induced neurotoxicity in mice via anti-apoptotic mechanism. Pharmacol Biochem Behav 2013; 104:163-8. [DOI: 10.1016/j.pbb.2013.01.017] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Revised: 01/10/2013] [Accepted: 01/12/2013] [Indexed: 10/27/2022]
|
2
|
Ho G, Kumar S, Zhang C, Kng YL, Zhuo L. Molecular imaging reveals a correlation between 2'-CH3-MPTP-induced neonatal neurotoxicity and dopaminergic neurodegeneration in adult transgenic mice. Int J Dev Neurosci 2008; 26:673-81. [PMID: 18703131 DOI: 10.1016/j.ijdevneu.2008.07.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2008] [Revised: 07/21/2008] [Accepted: 07/21/2008] [Indexed: 11/30/2022] Open
Abstract
We previously reported that a single subcutaneous (s.c.) injection of the neurotoxicant, 1-methyl-4-(2'-methylphenyl)-1,2,3,6-tetrahydropyridine or 2'-CH(3)-MPTP, to postnatal day 4 (PD4) mice caused acute and transient gliosis in the brain, which can be noninvasively monitored during a course of 8 h immediately after the dosing [Ho, G., Zhang, C.Y., Zhuo, L., 2007. Non-invasive fluorescent imaging of gliosis in transgenic mice for profiling developmental neurotoxicity. Toxicol. Appl. Pharmacol. 221, 76-85]. In the current study, we examined the consequence of PD4 mice receiving multiple injections (4 x 8 mg/kg, s.c. in 2 h intervals) of the same neurotoxicant 24-72 h after the last injection. Here we showed that the multiple dosing scheme (with a higher cumulative dose) triggered a severe gliosis not only in the striatum and substantia nigra pars compacta (SNpc), but also in hippocampus and cerebellum when examined by noninvasive in vivo imaging and by immunohistochemistry (IHC), respectively, in the PD5 to PD7 mice. When neonates treated with the neurotoxicant at PD4 were allowed to develop to 10 weeks of age and examined with IHC, a majority of the dopaminergic (DA) neurons were found to be permanently depleted from the adult SNpc. Our findings suggest that neurotoxicant-elicited neonatal gliosis can be used as an early molecular signature to predict the permanent loss of DA neurons in the developed brain. Since 2'-CH(3)-MPTP is an inducer of Parkinsonism in mice, the molecular imaging method described here is a relatively simple and powerful tool for longitudinally studying the developmental aspect of Parkinsonism.
Collapse
Affiliation(s)
- Gideon Ho
- Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, #04-01, Singapore 138669
| | | | | | | | | |
Collapse
|
3
|
Unger EL, Mazzola-Pomietto P, Murphy DL, Andrews AM. 2'-NH(2)-MPTP [1-methyl-4-(2'-aminophenyl)-1,2,3,6-tetrahydropyridine] depletes serotonin and norepinephrine in rats: a comparison with 2'-CH(3)-MPTP [1-methyl-4-(2'-methylphenyl)-1,2,3,6-tetrahydropyridine]. J Pharmacol Exp Ther 2002; 303:527-33. [PMID: 12388632 DOI: 10.1124/jpet.102.037614] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) analog, 1-methyl-4-(2'-aminophenyl)-1,2,3,6-tetrahydropyridine (2'-NH(2)-MPTP), depletes brain serotonin and norepinephrine in mice without affecting striatal dopamine. The present study was conducted to determine whether 2'-NH(2)-MPTP would be similarly neurotoxic to rats. Four injections of 20 mg/kg 2'-NH(2)-MPTP caused 80 to 90% depletions in serotonin and norepinephrine in frontal cortex and hippocampus in rats 1 week post-treatment. A lower dose of 2'-NH(2)-MPTP (4 x 15 mg/kg) also produced large decrements in serotonin and norepinephrine levels and in serotonin transporter density measured 3 weeks after neurotoxin administration. Furthermore, this lower dose of 2'-NH(2)-MPTP altered functional serotonin neurotransmission as evidenced by a 2-fold potentiation of 1-(3-chlorophenyl)-piperazine.2HCl-induced hyperthermia, an index of serotonergic denervation supersensitivity. At both doses, 2'-NH(2)-MPTP was without effect on striatal dopamine. For comparison, additional rats were treated with a second 2'-substituted analog of MPTP, 1-methyl-4-(2'-methylphenyl)-1,2,3,6-tetrahydropyridine (2'-CH(3)-MPTP), at 2 x 20 mg/kg. This dosing regimen causes substantial striatal dopamine depletion in mice. 2'-CH(3)-MPTP had no effect on brain levels of serotonin, norepinephrine, or dopamine in rats. Together, these results demonstrate that rats are sensitive to the toxic effects of 2'-NH(2)-MPTP but not to 2'-CH(3)-MPTP at doses known to cause neurotoxicity in mice. Moreover, this study clearly shows that 2'-NH(2)-MPTP can be utilized in rats as a tool to study the serotonergic and noradrenergic neurotransmitter systems.
Collapse
Affiliation(s)
- Erica L Unger
- 152 Davey Laboratory, Department of Chemistry, Pennsylvania State University, University Park, PA 16802, USA
| | | | | | | |
Collapse
|
4
|
Abstract
MPTP burst upon the medical landscape two decades ago, first as a mysterious parkinsonian epidemic, triggering an unparalleled quest for the toxin's identity, and closely followed by an intense pursuit of its cellular mechanisms of action. MPTP treatment created an animal model of many features of Parkinson's disease (PD), used primarily in primates and later in mice. The critical role of oxidative stress damage to vulnerable dopamine neurons, as well as for neurodegenerative diseases in general, emerged from MPTP neurotoxicity. A remarkable cross-fertilization of basic and clinical findings, including genetic and epidemiologic studies, has greatly advanced our understanding of PD and revealed multiple factors contributing to the parkinsonian phenotypes. Brain imaging localizes sites of action and provides potential presymptomatic diagnostic testing. Epidemiologic reports linking PD with pesticide exposure were complimented by supportive evidence from biochemical studies of MPTP and structurally related compounds, especially after low-level, long-term exposure. Genetic studies on the role of risk genes, such as alpha-synuclein or parkin, have been validated by biochemical, anatomical and neurochemical investigations showing factors interacting to produce pathophysiology in the animal model. Focusing on the pivotal role of mitochondria, subcellular pathways participating in cell death have been clarified by unraveling similar sites of action of MPTP. Along the way, compounds antagonizing or potentiating MPTP effects indicated new PD therapies, some of the former achieving clinical trials. The future is encouraging for combating PD and will continue to benefit from the MPTP neurotoxicity model.
Collapse
Affiliation(s)
- Samuel G Speciale
- Department of Psychiatry, University of Texas Southwestern Medical School, Dallas, TX 75390, USA.
| |
Collapse
|
5
|
Sundström E, Samuelsson EB. Comparison of key steps in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) neurotoxicity in rodents. PHARMACOLOGY & TOXICOLOGY 1997; 81:226-31. [PMID: 9396088 DOI: 10.1111/j.1600-0773.1997.tb00051.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Three steps in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) neurotoxicity were compared with the neurodegenerative effects of the toxin in mice and rats. Firstly, we compared the neurotoxicity of MPTP, mediated by monoamine oxidase (MAO)-B, to that of 1-methyl-4-(2'-methylphenyl)-1,2,3,6-tetrahydropyridine (2'-CH3-MPTP), an analogue oxidized by MAO-A and MAO-B. Both toxins caused degeneration of dopamine terminals in mice but not in rats. In NMRI mice noradrenaline terminals were also affected by both toxins. Pretreatment with deprenyl to prevent MAO-B-mediated oxidation in the capillary endothelium enhanced dopamine toxicity to 2'-CH3-MPTP in nucleus accumbens but no potentiation was seen in striatum and the olfactory tubercle. Secondly, synaptosomal uptake of the 1-methyl-4-phenylpyridinium ion (MPP+) was studied. Uptake in rats was not significantly different from that in the two mice strains. Thirdly, no significant differences were found in MPP(+)-induced lactate production in striatal slices or synaptosomes. We conclude that the lack of effect of MPTP in rats is not due to mechanisms specific for MPTP but probably to the ability of rat catecholamine neurons to cope with, and survive, impaired energy metabolism.
Collapse
MESH Headings
- 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine/analogs & derivatives
- 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine/metabolism
- 1-Methyl-4-phenylpyridinium/metabolism
- Animals
- Brain/drug effects
- Brain/metabolism
- Dopamine/metabolism
- Lactic Acid/metabolism
- MPTP Poisoning
- Male
- Mice
- Mice, Inbred C57BL
- Norepinephrine/metabolism
- Parkinson Disease, Secondary/chemically induced
- Parkinson Disease, Secondary/metabolism
- Rats
- Rats, Sprague-Dawley
- Synaptosomes/drug effects
- Synaptosomes/metabolism
Collapse
Affiliation(s)
- E Sundström
- Division of Geriatric Medicine, Karolinska Institutet, Huddinge University Hospital, Sweden
| | | |
Collapse
|
6
|
Irwin I, Delanney L, Chan P, Sandy MS, Di Monte DA, Langston JW. Nigrostriatal monoamine oxidase A and B in aging squirrel monkeys and C57BL/6 mice. Neurobiol Aging 1997; 18:235-41. [PMID: 9258902 DOI: 10.1016/s0197-4580(97)00003-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In this study we assessed the two forms of monoamine oxidase (MAO) in the caudate, putamen, and substantia nigra of young (4-year-old), intermediate-aged (11-year-old), and aged (20-year-old) squirrel monkeys and in the striata of young (2-month-old) and older (10-month-old) C57Bl/6 mice. MAO A and B activities were determined by measuring the rate of oxidation of the specific substrates phenethylamine and serotonin. In squirrel monkey, the vast majority of MAO activity was MAO B with activity of this isoform 10 times greater than of MAO A, while in mice the activity of the two forms was approximately equivalent. Although mice demonstrated nearly twofold selective increases in striatal MAO B between 2 and 10 months of age, neither MAO B nor A showed statistically significant changes with age in squirrel monkeys. These results document the marked differences between nonhuman primates and rodents with respect to the relative activities and the effects of age on MAO A and B, and indicate that increased MAO is not an inevitable feature of aging.
Collapse
Affiliation(s)
- I Irwin
- Parkinson's Institute, Sunnyvale, CA 94089, USA
| | | | | | | | | | | |
Collapse
|
7
|
Sziráki I, Kardos V, Patthy M, Gaál J, Arányi P, Kollár E, Tömösközi Z, Király I. Novel sites of action for deprenyl in MPTP-parkinsonism: metabolite-mediated protection against striatal neurotoxicity and suppression of MPTP-induced increase of dopamine turnover in C57BL mice. PROGRESS IN BRAIN RESEARCH 1995; 106:155-71. [PMID: 8584651 DOI: 10.1016/s0079-6123(08)61212-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- I Sziráki
- Institute for Drug Research, Budapest, Hungary
| | | | | | | | | | | | | | | |
Collapse
|
8
|
Sziráki I, Kardos V, Patthy M, Pátfalusi M, Gaál J, Solti M, Kollár E, Singer J. Amphetamine-metabolites of deprenyl involved in protection against neurotoxicity induced by MPTP and 2'-methyl-MPTP. JOURNAL OF NEURAL TRANSMISSION. SUPPLEMENTUM 1994; 41:207-19. [PMID: 7931228 DOI: 10.1007/978-3-7091-9324-2_27] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The ability of 1-deprenyl to protect against the parkinsonian effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) has been attributed to the inhibition of conversion of MPTP to MPP+ (1-methyl-4-phenylpyridinium) catalyzed by MAO-B. We report here that deprenyl-treatment in mice has an additional neuroprotective element associated with the rapid metabolization of 1-deprenyl to 1-methamphetamine and 1-amphetamine. 1-Methamphetamine and 1-amphetamine inhibit MPP(+)-uptake into striatal synaptosomes prepared from rats. Post-treatment by 1-deprenyl, 1-methamphetamine, 1-amphetamine (at times when MPTP is no longer present in the striatum of mice) protects against neurotoxicity in C57BL mice by blocking the uptake of MPP+ into dopaminergic neurons, and even against the neurotoxicity induced by 2'CH3-MPTP, which is partly bioactivated by MAO-A. These findings may have clinical implications since deprenyl has recently been found to delay the progression of Parkinson's disease.
Collapse
MESH Headings
- 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine/analogs & derivatives
- 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine/antagonists & inhibitors
- 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine/pharmacology
- Amphetamines/metabolism
- Animals
- Corpus Striatum/metabolism
- Dopamine Antagonists/pharmacology
- Male
- Mice
- Mice, Inbred C57BL
- Monoamine Oxidase/metabolism
- Monoamine Oxidase Inhibitors/pharmacology
- Neurotoxins/antagonists & inhibitors
- Pargyline/pharmacology
- Rats
- Rats, Inbred Strains
- Selegiline/metabolism
Collapse
Affiliation(s)
- I Sziráki
- Institute for Drug Research, Budapest, Hungary
| | | | | | | | | | | | | | | |
Collapse
|
9
|
Andrews AM, Murphy DL. Sustained depletion of cortical and hippocampal serotonin and norepinephrine but not striatal dopamine by 1-methyl-4-(2'-aminophenyl)-1,2,3,6-tetrahydropyridine (2'-NH2-MPTP): a comparative study with 2'-CH3-MPTP and MPTP. J Neurochem 1993; 60:1167-70. [PMID: 8094744 DOI: 10.1111/j.1471-4159.1993.tb03271.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Unlike 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), which produces consistent decreases in levels of striatal dopamine (DA) with considerably smaller and more variable effects on mouse brain levels of serotonin (5-HT) and norepinephrine (NE), a novel amine-substituted MPTP analogue, 1-methyl-4-(2'-aminophenyl)-1,2,3,6-tetrahydropyridine (2'-NH2-MPTP), administered in a standard mouse dosing paradigm for MPTP (20 mg/kg x 4) did not affect striatal DA but led to marked reductions (60-70%) in levels of 5-HT, 5-hydroxyindoleacetic acid (5-HIAA), and NE measured in frontal cortex and hippocampus 1 week after treatment. Another 2'-substituted MPTP analogue, 1-methyl-4-(2'-methylphenyl)-1,2,3,6- tetrahydropyridine, affected cortical and hippocampal 5-HT, 5-HIAA, and NE only minimally, while markedly reducing the DA content in striatum (90%), thus indicating that the substituent (-NH2 versus -CH3) at the 2' position is important for the differential effects of these MPTP analogues. In a replication study with a 3-week end point, hippocampal and cortical 5-HT, 5-HIAA,, and NE levels remained depressed with no indication of recovery. These results suggest that 2'-NH2-MPTP may be a novel, regionally selective neurotoxin for serotonergic and noradrenergic nerve terminals.
Collapse
Affiliation(s)
- A M Andrews
- Laboratory of Clinical Science, National Institute of Mental Health, Bethesda, Maryland 20892
| | | |
Collapse
|
10
|
Devlin AJ, Bhatti AR, Williams AC, Ramsden DB. Activation of bovine plasma benzylamine oxidase (BzAO) by 1-methyl-4-(2-methylphenyl)-1,2,3,6-tetrahydropyridine. Toxicol Lett 1992; 61:305-10. [PMID: 1353643 DOI: 10.1016/0378-4274(92)90157-f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We have shown previously that certain analogues of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) are potent inhibitors of human and bovine plasma benzylamine oxidase (BzAO: EC 1.4.3.6). Inhibition was competitive, reversible and allosteric. Under certain conditions competitive inhibitors of allosteric enzymes can act as allosteric activators. In the present work, 1-methyl-4-(2-methylphenyl)-1,2,3,6-tetrahydropyridine (2'-CH3MPTP) was found to activate bovine plasma BzAO at low substrate and 2'-CH3MPTP concentrations. At higher 2'-CH3MPTP concentrations, the activation was negated.
Collapse
Affiliation(s)
- A J Devlin
- Department of Medicine, University of Birmingham, Queen Elizabeth Hospital, UK
| | | | | | | |
Collapse
|
11
|
Gupta M, Chen XL. Neurotoxicity of an MPTP analogue, 2'CH3-MPTP, on monoaminergic systems in the mouse brain. Ann N Y Acad Sci 1992; 648:283-5. [PMID: 1353331 DOI: 10.1111/j.1749-6632.1992.tb24557.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- M Gupta
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Kentucky 40292
| | | |
Collapse
|
12
|
|
13
|
Hemrick-Luecke SK, Robertson DW, Krushinski JH, Fuller RW. Persistent depletion of striatal dopamine and cortical norepinephrine in mice by 1-methyl-4-phenyl-1,2,3,6-tetrahydro-3-pyridinol (MPTP-3-OL), an analog of MPTP. Life Sci 1992; 50:573-82. [PMID: 1736028 DOI: 10.1016/0024-3205(92)90369-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
MPTP-3-ol injected s.c. once daily for 4 days resulted in a dose-dependent depletion of striatal dopamine and cortical norepinephrine one week after the last dose. MPTP-3-ol was approximately one-fourth as potent as MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) in causing these effects. MPTP-3-ol was oxidized by monoamine oxidase in mouse brain in vitro and resulted in MPP+ (1-methyl-4-phenylpyridinium) formation in brain in vivo, both at about one-fourth the rates with MPTP. The in vitro metabolism of MPTP-3-ol was inhibited by deprenyl, a selective inhibitor of monoamine oxidase type B, and deprenyl pretreatment also blocked the depletion of striatal dopamine and cortical norepinephrine in vivo. Pretreatment with EXP 561, an inhibitor of catecholamine uptake, also prevented the dopamine- and norepinephrine-depleting effects of MPTP-3-ol. Thus, substitution of a hydroxy group on the 3-position of MPTP retains its neurotoxic potential toward catecholamine neurons but reduces potency by decreasing the rate of oxidation via monoamine oxidase type B.
Collapse
MESH Headings
- 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine/analogs & derivatives
- 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine/metabolism
- 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine/pharmacology
- 1-Methyl-4-phenylpyridinium/metabolism
- Animals
- Brain Chemistry/drug effects
- Catecholamines/metabolism
- Cerebral Cortex/drug effects
- Cerebral Cortex/metabolism
- Corpus Striatum/drug effects
- Corpus Striatum/metabolism
- Dopamine/metabolism
- Dose-Response Relationship, Drug
- In Vitro Techniques
- Male
- Mice
- Norepinephrine/metabolism
- Selegiline/pharmacology
Collapse
Affiliation(s)
- S K Hemrick-Luecke
- Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, IN 46285
| | | | | | | |
Collapse
|
14
|
Efange SM, Boudreau RJ. Molecular determinants in the bioactivation of the dopaminergic neurotoxin N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). J Comput Aided Mol Des 1991; 5:405-17. [PMID: 1685185 DOI: 10.1007/bf00125661] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Nineteen analogs of the dopaminergic neurotoxin N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) have been used as probes to study the structural parameters that influence MAO-catalyzed oxidation. In this study, the efficiency of enzyme-catalyzed substrate oxidation was found to be unrelated to parameters such as the ionization potential, dipole moment, net atomic charge at C5 and the dihedral angle between the phenyl ring and the tetrahydropyridine moiety. Conformational analysis revealed that substitution at the C2' position of MPTP yields atropisomers. It is suggested that one of these atropisomers would be either inactive or substantially less active than the other. Therefore, the relative oxidative efficiency and toxicity of these compounds reported earlier may have been significantly underestimated. Based on the conformational analysis and other data, a rudimentary model of the MAO substrate site has been developed which partially explains the substrate specificities of MAO A and MAO B. Each substrate binding site can be divided into two regions, (a) an amine-binding pocket (for the tetrahydropyridine moiety), and (b) a 'bulky substituent' region (for the phenyl group and its substituents). The length of the substrate binding site (measured along the long axis of MPTP) is approximately 8.5 A, and the width of the 'amine-binding' pocket is approximately 2.5 A (from C3 to C5). The 'bulky substituent' region contains a central area for binding the phenyl group of MPTP. This central area is flanked by two hydrophobic pockets, P2' and P3'. In MAO A, the pocket P2'-A is oriented 45-135 degrees relative to the plane of the tetrahydropyridine moiety, with a radius of 3.1 A from C2' of the phenyl ring. The radius of a similar but smaller pocket, P2'-B, in MAO B, is approximately 2.7 A. In MAO B, the pocket P3'-B (radius 2.36 A from C3') is larger than a similar pocket P3'-A (radius 1.70 A from C3') in MAO A. The foregoing characterization suggests that differences in the size and topography of both of the substituent pockets play an important role in determining the substrate specificities of these two isozymes.
Collapse
MESH Headings
- 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine/analogs & derivatives
- 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine/chemistry
- 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine/pharmacokinetics
- Binding Sites
- Biotransformation
- Computer Simulation
- Dopamine Agents/chemistry
- Dopamine Agents/pharmacokinetics
- Models, Molecular
- Molecular Conformation
- Molecular Probes
- Molecular Structure
- Monoamine Oxidase/metabolism
- Neurotoxins/chemistry
- Neurotoxins/pharmacokinetics
- Oxidation-Reduction
- Substrate Specificity
Collapse
Affiliation(s)
- S M Efange
- Department of Radiology, University of Minnesota, Minneapolis 55455
| | | |
Collapse
|
15
|
Johannessen JN, Sobotka TJ, Weise VK, Markey SP. Prolonged alterations in canine striatal dopamine metabolism following subtoxic doses of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and 4'-amino-MPTP are linked to the persistence of pyridinium metabolites. J Neurochem 1991; 57:981-90. [PMID: 1677682 DOI: 10.1111/j.1471-4159.1991.tb08247.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Single toxic doses of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP).HCl (2.5 mg/kg i.v.) and 4'-amino-MPTP.2HCl (22.5 mg/kg) induce loss of striatal dopamine (DA) and tyrosine hydroxylase (TH) activity and of nigral DA neurons in the dog. To examine the subacute neurochemical changes induced by low doses of MPTP and 4'-amino-MPTP, dose-response studies of these compounds were carried out in the dog, using 6- and 3-week survival times for these two compounds, respectively. Low single doses of MPTP (1.0, 0.5, and 0.1 mg/kg i.v.) and 4'-amino-MPTP (15, 7.5, and 3.75 mg/kg i.v.) did not cause depletion of canine striatal DA or TH or a loss of nigral neurons. However, levels of the DA metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) were decreased in a dose-related fashion, with significant loss of DOPAC being evident 6 weeks after the lowest administered dose of MPTP and 3 weeks after 4'-amino-MPTP. This selective loss of DA metabolites following nontoxic doses of MPTP and 4'-amino-MPTP led to a shift in the ratio of DA to DOPAC or HVA, which was characteristic for each compound. The measurement of striatal 1-methyl-4-phenylpyridinium (MPP+) and 4'-amino-MPP+ levels revealed that high concentrations (up to 150 microM) persist in the striatum for weeks following administration of a single nontoxic dose of MPTP or 4'-amino-MPTP. A causal relationship between the striatal concentration of MPP+ or 4'-amino-MPP+ and the change in DA metabolism as reflected in the DA/DOPAC ratio is suggested by a significant correlation between these measures. It is suggested that presynaptic sequestration and retention of MPP+ and 4'-amino-MPP+ by striatal DA terminals result in the inhibition of the monoamine oxidase contained within these terminals.
Collapse
Affiliation(s)
- J N Johannessen
- Laboratory of Clinical Science, National Institute of Mental Health, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland 20892
| | | | | | | |
Collapse
|
16
|
Miller DB, Reinhard JF, Daniels AJ, O'Callaghan JP. Diethyldithiocarbamate potentiates the neurotoxicity of in vivo 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine and of in vitro 1-methyl-4-phenylpyridinium. J Neurochem 1991; 57:541-9. [PMID: 1649252 DOI: 10.1111/j.1471-4159.1991.tb03784.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Diethyldithiocarbamic acid (DDC) potentiates in vivo neurotoxicity of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and in vitro neurotoxicity of 1-methyl-4-phenylpyridinium (MPP+). Male C57B1/6 mice were given two or five injections of MPTP (30 mg/kg i.p.) preceded 0.5 h by DDC (400 mg/kg i.p.). The mice were tested for catalepsy, akinesia, or motor activity during and after the period of dosing. Striatal and hippocampal tissues were obtained at 2 and 7 days following the last injection and evaluated for dopamine and norepinephrine levels, respectively. These same tissues were also analyzed for the levels of glial fibrillary acidic protein (GFAP), an astrocyte-localized protein known to increase in response to neural injury. Pretreatment with DDC potentiated the effect of MPTP in striatum and resulted in substantially greater dopamine depletion, as well as a more pronounced elevation in GFAP. In hippocampus, the levels of norepinephrine and GFAP were not different from controls in mice receiving only MPTP, but pretreatment with DDC resulted in a sustained depletion of norepinephrine and an elevation of GFAP, suggesting that damage was extended to this brain area by the combined treatment. Mice receiving MPTP preceded by DDC also demonstrated a more profound, but reversible, catalepsy and akinesia compared to those receiving MPTP alone. Systemically administered MPP+ decreased heart norepinephrine, but did not alter the striatal levels of dopamine or GFAP, and pretreatment with DDC did not alter these effects, but did increase lethality. DDC is known to increase brain levels of MPP+ after MPTP, but our data indicate that this is not due to a movement of peripherally generated MPP+ into CNS.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- D B Miller
- U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711
| | | | | | | |
Collapse
|
17
|
Kovel'man IR, Tochilkin AI, Gorkin VZ. Structure and action of reversible monoamine oxidase inhibitors (review). Pharm Chem J 1991. [DOI: 10.1007/bf00777412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
18
|
Devlin AJ, Bhatti AR, Williams AC, Ramsden DB. Inhibition of human benzylamine oxidase (BzAO) by analogues of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Toxicol Lett 1990; 54:135-42. [PMID: 1979697 DOI: 10.1016/0378-4274(90)90176-m] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A sensitive assay for human plasma BzAO, involving the conversion of 14C-benzylamine to 14C-benzaldehyde, was developed. MPTP and several of its analogues were found to be competitive inhibitors of the enzyme. Ki values for the MPTP analogues in the presence of human plasma BzAO were determined. The analogues had a different rank order of inhibition of human plasma BzAO compared with the rank order of inhibition of bovine plasma BzAO found previously. MPTP and 1-methyl-4-(2-methylphenyl)-1,2,3,6-tetrahydropyridine (2'-CH3-MPTP), which are potent nigrostriatal toxins, were weak inhibitors of human plasma BzAO.
Collapse
Affiliation(s)
- A J Devlin
- Department of Medicine, University of Birmingham, Queen Elizabeth Hospital, Edgbaston, U.K
| | | | | | | |
Collapse
|
19
|
Bernardini GL, Speciale SG, German DC. Increased midbrain dopaminergic cell activity following 2'CH3-MPTP-induced dopaminergic cell loss: an in vitro electrophysiological study. Brain Res 1990; 527:123-9. [PMID: 1980838 DOI: 10.1016/0006-8993(90)91069-s] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Several days after the administration of 1-methyl-4-(2'-methylphenyl)-1,2,3,6-tetrahydropyridine (2'CH3-MPTP) to the BALB/cJ mouse there is a loss of midbrain dopaminergic neurons, a reduction of forebrain dopamine (DA) content, and an elevation in forebrain DA turnover. The purpose of the present study was to determine whether the increase in forebrain DA turnover is related to an increase in dopaminergic neuronal activity. In vitro extracellular single unit recordings were made from midbrain dopaminergic neurons in the substantia nigra pars compacta (nucleus A9) and ventral tegmental area (nucleus A10) of BALB/cJ mice. The experimental animals were treated intraperitoneally with 40, 50 or 55 mg/kg 2'CH3-MPTP and killed 7-15 days later. Forebrain DA concentrations were decreased below control values by the two higher toxin doses in the caudate-putamen (67% and 78%, respectively), but not in the nucleus accumbens. DA turnover increased more than 2-fold in the caudate-putamen, but was unchanged in the nucleus accumbens. Nucleus A9 cells, in the 2'CH3-MPTP-treated animals, exhibited a 3-fold increase in the number of spontaneously active cells, and an 84% increase in basal firing rates. There was also a positive correlation between the A9 cell firing rates, and the DA turnover in the striatum of the toxin-treated mice. Nucleus A10 cells, in the 2'CH3-MPTP-treated animals, exhibited neither changes in number of spontaneously active cells nor changes in firing rates.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- G L Bernardini
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas 75235-9070
| | | | | |
Collapse
|
20
|
Abstract
The possibility that idiopathic Parkinson's disease may be linked to a deficiency of an important detoxifying enzyme such as the cytochrome P450 enzyme bufuralol hydroxylase is examined. A hypothetical model of how this might operate to produce early onset Parkinson's disease is suggested.
Collapse
Affiliation(s)
- G S Shahi
- Department of Physiology, National University of Singapore
| | | | | |
Collapse
|
21
|
Rose S, Nomoto M, Jackson EA, Gibb WR, Jenner P, Marsden CD. 1-Methyl-4-(2'-methylphenyl)-1,2,3,6-tetrahydropyridine (2'-methyl-MPTP) is less neurotoxic than MPTP in the common marmoset. Eur J Pharmacol 1990; 181:97-103. [PMID: 2117541 DOI: 10.1016/0014-2999(90)90249-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Four adult marmosets were treated with increasing doses of 1-methyl-4-(2'-methylphenyl)-1,2,3,6-tetrahydropyridine (2'-methyl-MPTP) in the range 0.23-4.3 mg/kg i.p. to give a cumulative dose of 11.0-11.6 mg/kg over a 6-10 day period. After 4 days of treatment, and as the dosage was gradually increased, the animals exhibited mild motor deficits. These abnormalities slowly declined over the following 1-6 week period. In contrast, similar treatment of common marmosets with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) (1-4 mg/kg i.p.) for 3-5 days in a cumulative dose of 6.9-9.2 mg/kg produced gross impairment of motor function which persisted throughout the 5 weeks period of observation. Administration of 2'-methyl-MPTP for 6-10 days caused some decrease in dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC), but not homovanillic acid (HVA) content in the caudate nucleus in animals 5-6 weeks after the start of treatment. There was a small decrease in [3H]dopamine uptake into putamen synaptosomes. This contrasted with the marked decreases in all these parameters observed after MPTP treatment of common marmosets. Histological examination of the substantia nigra from the four animals treated with 2'-methyl-MPTP did not show degeneration or loss of dopamine-containing cell bodies in the zona compacta. In contrast, MPTP caused severe destruction of these pigmented nigral neurones. In the common marmoset 2'-methyl-MPTP does not appear to show the same neurotoxic action as MPTP itself. This contrasts with findings in the mouse where 2'-methyl-MPTP is more toxic to dopamine-containing cells of substantia nigra than MPTP.
Collapse
Affiliation(s)
- S Rose
- Parkinson's Disease Society Experimental Research Laboratories, Biomedical Sciences Division, King's College, London, U.K
| | | | | | | | | | | |
Collapse
|
22
|
Maret G, Testa B, Jenner P, el Tayar N, Carrupt PA. The MPTP story: MAO activates tetrahydropyridine derivatives to toxins causing parkinsonism. Drug Metab Rev 1990; 22:291-332. [PMID: 2253555 DOI: 10.3109/03602539009041087] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- G Maret
- Institut de Chimie Thérapeutique, Ecole de Pharmacie Université de Lausanne, Switzerland
| | | | | | | | | |
Collapse
|
23
|
Tetrud JW, Langston JW. MPTP-induced parkinsonism as a model for Parkinson's disease. ACTA NEUROLOGICA SCANDINAVICA. SUPPLEMENTUM 1989; 126:35-40. [PMID: 2694734 DOI: 10.1111/j.1600-0404.1989.tb01780.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
It is now well recognized that 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) can induce a syndrome in human and non-human primates similar to Parkinson's disease. This highly selective neurotoxin, which affects specific catecholaminergic nuclei in the brainstem, has provided an important new tool for the study of Parkinson's disease. In this article we review several specific areas related to current research on MPTP, including the question of disease progression, issues regarding the validity of the animal model induced by MPTP, the role of aging in regard to its neurotoxicity and Parkinson's disease, and new therapeutic strategies that have evolved from basic research with the compound. We conclude that both clinical and basic research stemming from the discovery of MPTP have provided valuable insights regarding both the cause and treatment of Parkinson's disease.
Collapse
Affiliation(s)
- J W Tetrud
- California Parkinson's Foundation, San Jose
| | | |
Collapse
|
24
|
Efange SM, Mash D, Hefti F, Kung HF, Billings J. Selective visualization of rodent locus ceruleus by a radiolabeled N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine analog. J Neurochem 1989; 53:459-64. [PMID: 2787390 DOI: 10.1111/j.1471-4159.1989.tb07356.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The neurotoxic metabolite of N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), 1-methyl-4-phenylpyridinium, selectively accumulates in dopaminergic neurons via the dopamine reuptake system. Consequently, nontoxic radiolabeled MPTP analogs may be potentially useful for visualizing catecholaminergic neurons in vivo. N-Methyl-4-(4-hydroxy-3-[125I]iodobenzyl)-1,2,3,6-tetrahydropyridine [( 125I]MHTP), an analog of the nontoxic N-methyl-4-benzyl-1,2,3,6-tetrahydropyridine, has been studied in rats and mice. After intravenous administration of [125I]MHTP to rodents, the initial accumulation of radioactivity within the brain was found to be comparable to that of radiolabeled MPTP. Following intravenous administration of [125I]MHTP, in vivo autoradiographic visualization of the rodent brain revealed selective accumulation of [125I]MHTP-derived radioactivity within the locus ceruleus; there was no accumulation of the radiotracer within dopaminergic fibers and cell bodies. The accumulation of radioactivity within the locus ceruleus was blocked by pretreatment with pargyline, a result suggesting that an MHTP metabolite formed by monoamine oxidase was responsible for the localization of the radiotracer within this structure. The anatomical distribution of the radiolabel demonstrates selective accumulation of this metabolite within noradrenergic cell bodies and those fibers making up the locus ceruleus. These findings further suggest that nontoxic metabolites of MPTP may become useful for in vivo labeling of selected populations of catecholaminergic neurons.
Collapse
Affiliation(s)
- S M Efange
- Department of Radiology, University of Miami School of Medicine, Florida
| | | | | | | | | |
Collapse
|
25
|
Sayre LM. Biochemical mechanism of action of the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Toxicol Lett 1989; 48:121-49. [PMID: 2672418 DOI: 10.1016/0378-4274(89)90168-9] [Citation(s) in RCA: 98] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The various biochemical mechanisms considered to explain the selective dopaminergic neurotoxicity of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) are reviewed. MPTP is metabolized by monoamine oxidase in the brain, ultimately yielding 1-methyl-4-phenylpyridinium cation (MPP+), which is accumulated in dopamine cells by the high-affinity dopamine uptake pump. Cell death appears to reflect a compromise in energy production arising as a result of the Nernstian concentration of MPP+ inside mitochondria and persistent inhibition of Site 1 of the respiratory chain. The structural features underlying each biochemical step involved in the expression of neurotoxicity are described, and the implications of the MPTP phenomenon to efforts aimed at elucidating the pathogenesis of idiopathic parkinsonism are discussed.
Collapse
Affiliation(s)
- L M Sayre
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106
| |
Collapse
|
26
|
Manaye KF, Sonsalla PK, Barnett G, Heikkila RE, Woodward DJ, Smith WK, German DC. 1-Methyl-4-(2'-methylphenyl)-1,2,3,6-tetrahydropyridine (2'CH3-MPTP)-induced degeneration of mesostriatal dopaminergic neurons in the mouse: biochemical and neuroanatomical studies. Brain Res 1989; 491:307-15. [PMID: 2765888 DOI: 10.1016/0006-8993(89)90065-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The neurotoxic effects of 1-methyl-4-(2'-methylphenyl)-1,2,3,6-tetrahydropyridine (2'CH3-MPTP), a substituted analog of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, were studied in BALB/cJ mice. Moderate doses of 2'CH3-MPTP produced a greater depletion of dopamine (DA) in the striatum (45%) than in the nucleus accumbens (23%), and in these same animals, there was a 35% loss of midbrain DA neurons. The greatest loss of DA cells occurred within the substantia nigra (43%), and there was also a significant loss of cells within the ventral tegmental area (28%). Higher doses of 2'CH3-MPTP decreased levels of DA more in the axon terminal/forebrain region (72%) than in the cell body/midbrain region (25%). Similar forebrain/midbrain DA depletion ratios were also found in mice that received an electrolytic lesion of the midbrain DA neurons; there was a greater Da depletion in the forebrain (29%) than in the midbrain (8%). In both 2'CH3-MPTP and electrolytically lesioned animals there was a significant increase in DA turnover in the forebrain region, as measured by the homovanillic acid/DA ratio. These data indicate that 2'CH3-MPTP: (1) destroys DA neurons within two midbrain regions containing cells which project to the striatum (i.e. mesostriatal DA neurons), rather than just nigrostriatal DA neurons; (2) produces a greater loss of DA in the axon terminal region than in the cell body region; and (3) influences the mesostriatal DA neurons in the same way as does a lesion to the cell bodies. These data are discussed with regard to the pathophysiology of 2'CH3-MPTP.
Collapse
Affiliation(s)
- K F Manaye
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, 75235-9070
| | | | | | | | | | | | | |
Collapse
|
27
|
Heikkila RE, Sieber BA, Manzino L, Sonsalla PK. Some features of the nigrostriatal dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in the mouse. MOLECULAR AND CHEMICAL NEUROPATHOLOGY 1989; 10:171-83. [PMID: 2669769 DOI: 10.1007/bf03159727] [Citation(s) in RCA: 122] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- R E Heikkila
- Department of Neurology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway, NJ 08854
| | | | | | | |
Collapse
|
28
|
Abstract
Recent developments have focused attention on the possibility that a toxic environmental factor may be the cause of Parkinson's disease (PD). A hypothesis seeking to explain the cause of PD must explain its worldwide distribution, the small percentage of the population affected, geographic variations in prevalence and why PD was unrecognized prior to the early nineteenth century. The difficulties in finding a ubiquitous environmental agent which could account for these observations, may be illustrated by considering the hypothesis that such an agent may be a constituent of a common plant such as the tomato. This hypothesis meets all the necessary prerequisites. It is testable and appears to be an excellent starting point from which to search for the cause of PD.
Collapse
Affiliation(s)
- J I Sage
- Department of Neurology, UMDNJ-Robert Wood Johnson Medical School, New Brunswick 08903-0019
| |
Collapse
|
29
|
Heikkila RE, Youngster SK, Panek DU, Giovanni A, Sonsalla PK. Studies with the neurotoxicant 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and several of its analogs. Toxicology 1988; 49:493-501. [PMID: 3259742 DOI: 10.1016/0300-483x(88)90035-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The nigrostriatal dopaminergic neurotoxicity of MPTP was prevented in mice in a dose-dependent manner by the monoamine oxidase-B (MAO-B) inhibitor deprenyl. This finding, combined with other observations, points out the important role of MAO-B in the bioactivation of MPTP. In the present study, some comparisons between MPTP and several of its structural analogs will be presented.
Collapse
Affiliation(s)
- R E Heikkila
- Department of Neurology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway 08854
| | | | | | | | | |
Collapse
|
30
|
Bhatti AR, Burdon J, Williams AC, Pall HS, Ramsden DB. Synthesis and nuclear magnetic resonance spectroscopic, mass spectroscopic, and plasma amine oxidase inhibitory properties of analogues of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. J Neurochem 1988; 50:1097-104. [PMID: 3258016 DOI: 10.1111/j.1471-4159.1988.tb10578.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Seventeen analogues of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine were synthesized using three reaction pathways: condensation of phenols with 1-methyl-4-piperidone, reaction of Grignard reagents with 1-methyl-4-piperidone followed by dehydration of the product, and aminomethylation of olefins. The identity of the products of synthesis was established by nuclear magnetic resonance spectroscopy, mass spectroscopy, and elemental analysis. Thirteen analogues were shown to inhibit the oxidation of benzylamine by bovine plasma amine oxidase. Increasing the length of the aliphatic chain of N-substituted analogues resulted in increased inhibition. In 4-phenyl-substituted analogues, both the position and electronic character of the substituent group affected the degree of inhibition.
Collapse
Affiliation(s)
- A R Bhatti
- Department of Medicine, University of Birmingham, Queen Elizabeth Hospital, England
| | | | | | | | | |
Collapse
|
31
|
Kindt MV, Youngster SK, Sonsalla PK, Duvoisin RC, Heikkila RE. Role for monoamine oxidase-A (MAO-A) in the bioactivation and nigrostriatal dopaminergic neurotoxicity of the MPTP analog, 2'Me-MPTP. Eur J Pharmacol 1988; 146:313-8. [PMID: 3131149 DOI: 10.1016/0014-2999(88)90308-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) administration leads to the selective destruction of the dopaminergic neurons of the nigrostriatal pathway in experimental animals including monkeys and mice. The neurotoxicity of MPTP is dependent upon its monoamine oxidase-B (MAO-B)-catalyzed conversion to the 1-methyl-4-phenylpyridinium species (MPP+). A methylated analog of MPTP. A methylated analog of MPTP, namely 1-methyl-4-(2'-methylphenyl)-1,2,3,6-tetrahydropyridine (2'Me-MPTP), is a more potent dopaminergic neurotoxin than MPTP in mice. Although the selective inhibition of MAO-B is sufficient to protect mice against MPTP-induced neurotoxicity, it is reported here that complete inhibition of MAO-B failed to prevent 2'Me-MPTP-induced dopaminergic neurotoxicity. However, the neurotoxicity of 2'Me-MPTP was completely prevented and 2'Me-MPP+ formation was markedly attenuated in mice in which both MAO-A and MAO-B were almost totally inhibited. This information about the role of MAO-A in the bioactivation of 2'Me-MPTP may be of relevance to those who speculate that the MAO-B catalyzed bioactivation of MPTP or a similar compound may be the cause of idiopathic Parkinson's disease.
Collapse
Affiliation(s)
- M V Kindt
- Department of Neurology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway 08854
| | | | | | | | | |
Collapse
|
32
|
Schultz W. MPTP-induced parkinsonism in monkeys: mechanism of action, selectivity and pathophysiology. GENERAL PHARMACOLOGY 1988; 19:153-61. [PMID: 3127268 DOI: 10.1016/0306-3623(88)90055-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- W Schultz
- Institut de Physiologie, Université de Fribourg, Switzerland
| |
Collapse
|
33
|
Reinhard JF, Diliberto EJ, Viveros OH, Daniels AJ. Subcellular compartmentalization of 1-methyl-4-phenylpyridinium with catecholamines in adrenal medullary chromaffin vesicles may explain the lack of toxicity to adrenal chromaffin cells. Proc Natl Acad Sci U S A 1987; 84:8160-4. [PMID: 2891137 PMCID: PMC299498 DOI: 10.1073/pnas.84.22.8160] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Cultures of bovine adrenomedullary chromaffin cells accumulated 1-methyl-4-phenylpyridinium (MPP+) in a time- and concentration-dependent manner by a process that was prevented by desmethylimipramine. The subcellular localization of the incorporated [methyl-3H]MPP+ was examined by differential centrifugation and sucrose density gradient fractionation and was found to be predominantly colocalized with catecholamines in chromaffin vesicles, and negligible amounts were detected within the mitochondrial fraction. When chromaffin cell membranes were made permeable with the detergent digitonin in the absence of calcium, there was no increase in the release of [3H]MPP+, indicating that there is negligible accumulation of the neurotoxin in the cytosol. Simultaneous exposure to digitonin and calcium induced cosecretion of MPP+ and catecholamines. Stimulation of the cells with nicotine released both catecholamines and MPP+ at identical rates and percentages of cellular content in a calcium-dependent manner. Last, when cells were incubated with MPP+ in the presence of tetrabenazine (an inhibitor of vesicular uptake), the chromaffin cell toxicity of MPP+ was potentiated. We submit that the ability of the chromaffin cells to take up and store MPP+ in the chromaffin vesicle prevents the toxin's interaction with other structures and, thus, prevents cell damage. As an extension of this hypothesis, the relative resistance of some brain monoaminergic neurons to the toxic actions of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine may result from the subcellular sequestration of MPP+ in the storage vesicle.
Collapse
Affiliation(s)
- J F Reinhard
- Department of Medicinal Biochemistry, Wellcome Research Laboratories, Research Triangle Park, NC 27709
| | | | | | | |
Collapse
|
34
|
Irwin I, Wu EY, DeLanney LE, Trevor A, Langston JW. The effect of diethyldithiocarbamate on the biodisposition of MPTP: an explanation for enhanced neurotoxicity. Eur J Pharmacol 1987; 141:209-17. [PMID: 2824216 DOI: 10.1016/0014-2999(87)90265-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Diethyldithiocarbamate (DDC) has been reported to exacerbate the neurotoxic effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in mice. In this study, the effects of DDC on the biotransformation and distribution of MPTP and 1-methyl-4-phenylpyridinium ion (MPP+, the putative toxic metabolite of MPTP) were investigated. When DDC was administered prior to a standardized dosage of MPTP, the initial concentrations of MPTP in striatum, ventral mesencephalon and frontal cortex were markedly increased when compared to animals given MPTP alone. The pre-administration of DDC also produced increased concentrations of MPP+ in these regions at all time points studied. Further, the rate of disappearance of MPP+ from brain was significantly less in DDC pretreated animals, when compared to animals given MPTP alone. In vitro studies, using either brain homogenates or partially purified MAO-B, showed that DDC enhanced the biotransformation of MPTP. These results suggest that DDC enhances MPTP-induced neurotoxicity by increasing brain concentrations of MPP+. Factors contributing to this increase appear to include greater delivery of MPTP to the central nervous system (CNS), increased biotransformation of MPTP to MPP+ via MAO, and possibly reduced clearance of MPP+ from the brain.
Collapse
Affiliation(s)
- I Irwin
- Institute for Medical Research, San Jose, CA 95128
| | | | | | | | | |
Collapse
|
35
|
Youngster SK, Saari WS, Heikkila RE. 1-Methyl-4-cyclohexyl-1,2,3,6-tetrahydropyridine (MCTP): an alicyclic MPTP-like neurotoxin. Neurosci Lett 1987; 79:151-6. [PMID: 3499585 DOI: 10.1016/0304-3940(87)90688-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
1-Methyl-4-cyclohexyl-1,2,3,6-tetrahydropyridine (MCTP), an analog of MPTP, was found to be an MPTP-like neurotoxin. MCTP administration caused extensive losses of neostriatal dopamine and its major metabolites in male Swiss-Webster mice. Under similar experimental conditions, MCTP was approximately as potent as MPTP. Like MPTP, MCTP was a good substrate for monoamine oxidase-B (MAO-B) and its neurotoxicity was prevented in mice by AGN-1135, a selective inhibitor of MAO-B. The neurotoxicity of MCTP and of MPTP was also prevented by the dopamine uptake inhibitor mazindol. 1-Methyl-4-cyclohexylpyridinium ion (MCP+), the 4-electron oxidation product of MCTP, caused release of previously accumulated [3H]dopamine from mouse neostriatal synaptosomes. This release was blocked by mazindol, which indicates that MCP+, like 1-methyl-4-phenylpyridinium ion (MPP+), the 4-electron oxidation product of MPTP, is a substrate for the dopamine transport system. Like MPP+, MCP+ was found to inhibit the mitochondrial oxidation of NADH-linked substrates. It appears that conjugation between the tetrahydropyridine ring and a 4-substituent is not a requirement for an MPTP analog to possess neurotoxicity.
Collapse
Affiliation(s)
- S K Youngster
- Department of Neurology, University of Medicine and Dentistry, New Jersey-Robert Wood Johnson, Medical School, Piscataway 08854-5635
| | | | | |
Collapse
|
36
|
Abstract
The MPTP-treated mouse has proven to be a valuable model of parkinsonism. For example, C57 black mice treated with MPTP exhibit a large decrement in the neostriatal content of dopamine and its metabolites, a marked reduction in the capacity of neostriatal synaptosomal preparations to accumulate [3H]dopamine, a large decrease in neostriatal tyrosine hydroxylase activity, a marked loss of nerve cells in the zona compacta of the substantia nigra, and pronounced behavioral deficits. These biochemical, pathological and behavioral deficits are similarly observed in MPTP-treated primates and in humans with idiopathic parkinsonism. A great deal of our current knowledge concerning MPTP has come from experimentation carried out in the mouse.
Collapse
Affiliation(s)
- R E Heikkila
- Department of Neurology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway 08854
| | | |
Collapse
|
37
|
Fuller RW, Hemrick-Luecke SK. Persistent depletion of striatal dopamine and its metabolites in mice by TMMP, an analogue of MPTP. J Pharm Pharmacol 1987; 39:667-9. [PMID: 2888865 DOI: 10.1111/j.2042-7158.1987.tb03453.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
TMMP (1-methyl-4-[methylpyrrol-2-yl]-1,2,3,6-tetrahydropyridine) mimicked MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) in causing persistent depletion of striatal dopamine and its metabolites one week after the last of four daily subcutaneous injections in mice. MMPP (1-methyl-4-[1-methylpyrrol-2-yl]-4-piperidinol) produced no depletion of dopamine or its metabolites under these conditions. None of the three compounds affected dopamine or its metabolites when administered orally. TMMP was even more rapidly oxidized by type B monoamine oxidase in-vitro than was MPTP, but MMPP was a very poor substrate for the enzyme. The lack of neurotoxicity of MMPP toward nigrostriatal dopamine neurons when it was given orally or subcutaneously to mice contrasts with previously reported results in monkeys, in which case MMPP was reported to be neurotoxic.
Collapse
Affiliation(s)
- R W Fuller
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana 46285
| | | |
Collapse
|
38
|
Gibb C, Willoughby J, Glover V, Sandler M, Testa B, Jenner P, Marsden CD. Analogues of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine as monoamine oxidase substrates: a second ring is not necessary. Neurosci Lett 1987; 76:316-22. [PMID: 3495757 DOI: 10.1016/0304-3940(87)90422-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is oxidised to a neurotoxic metabolite by monoamine oxidase B (MAO B). Using two colorimetric assays, we have examined a range of its structural analogues as possible further substrates of this enzyme in order to identify the types of environmental or endogenous compounds that might also be neurotoxic. Compounds with fully saturated or unsaturated pyridine rings were not substrates; nor were a range of tetrahydro-beta-carbolines or isoquinolines. Four substrates for MAO were found, 1-methyl-4-(2'-methylphenyl)-1,2,3,6-tetrahydropyridine (2'-Me-MPTP), 4-phenyl-1,2,3,6-tetrahydropyridine (PTP), 4-(p-chlorophenyl)-1,2,3,6-tetrahydropyridine (Cl-PTP) and ethyl-1-methyl-1,2,3,6-tetrahydro-4-pyridine-carboxylate (ethyl-MTP-carboxylate). Ethyl-MTP-carboxylate is of particular interest as it shows that a tetrahydropyridine without a phenyl ring can also be a substrate. Cl-PTP, PTP and ethyl-MTP-carboxylate appeared to be partially metabolised by MAO A. The inhibitor sensitivity of 2'-Me-MPTP oxidation was more complex.
Collapse
|
39
|
Perry TL, Jones K, Hansen S, Wall RA. 4-phenylpyridine and three other analogues of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine lack dopaminergic nigrostriatal neurotoxicity in mice and marmosets. Neurosci Lett 1987; 75:65-70. [PMID: 3106859 DOI: 10.1016/0304-3940(87)90076-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
C57 black mice were injected repeatedly with maximal tolerated doses of 2 chemical analogues of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP); 4-phenylpyridine and 4-phenyl-1,2,3,6-tetrahydropyridine. Although both compounds were clearly acutely toxic to mice, neither caused any reduction in striatal dopamine content after chronic exposure. Two MPTP analogues which may be formed endogenously during the metabolism of brain monoamines, 2-methyl-1,2,3,4-tetrahydroisoquinoline and 2-methyl-1,2,3,4-tetrahydro-beta-carboline, were injected repeatedly into common marmosets. Again, although both compounds appeared highly toxic, neither caused any reduction in striatal dopamine content. It appears unlikely that any of these 4 MPTP analogues causes idiopathic Parkinson's disease.
Collapse
|
40
|
Irwin I, Langston JW, DeLanney LE. 4-Phenylpyridine (4PP) and MPTP: the relationship between striatal MPP+ concentrations and neurotoxicity. Life Sci 1987; 40:731-40. [PMID: 3492652 DOI: 10.1016/0024-3205(87)90300-6] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Because of the chemical and structural similarity between 4-phenylpyridine (4PP) and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), the effects of 4PP alone and in combination with MPTP on striatal dopamine (DA) concentrations were studied in mice. 4PP did not deplete striatal DA, even when given in maximally tolerated doses (five times that required for MPTP neurotoxicity). However, when 4PP was administered prior to MPTP, it provided significant protection against the DA-depleting effects of MPTP. Additional experiments showed that 4PP pretreatment reduced striatal concentrations of 1-methyl-4-phenylpyridinium ion (MPP+) - the putative toxic biotransformation product of MPTP, and that the concentration of this metabolite closely mirrored striatal DA depletion in MPTP-treated mice. In vitro studies established that 4PP probably lowers MPP+ concentrations by inhibiting the biotransformation of MPTP to MPP+. These observations could be of clinical interest in view of the lower incidence of cigarette smoking among Parkinson's disease patients, and the fact that 4PP is known to be present in cigarettes.
Collapse
|
41
|
Abstract
1-Methyl-4-phenylpyridinium (MPP+), the putative toxic metabolite of the neurotoxin, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), inhibited NAD(H)-linked mitochondrial oxidation at the level of Complex I of the electron transport system. MPTP and MPP+ inhibited aerobic glycolysis in mouse striatal slices, as measured by increased lactate production; MPTP-induced effects were prevented by inhibition of monoamine oxidase B activity. Several neurotoxic analogs of MPTP also form pyridinium metabolites via MAO; these MPP+ analogs were all inhibitors of NAD(H)-linked oxidation by isolated mitochondria. 2'-Methyl-MPTP, a more potent neurotoxin in mice than MPTP, was also more potent than MPTP in inducing lactate accumulation in mouse brain striatal slices. Overall, the studies support the hypothesis that compromise of mitochondrial oxidative capacity is an important factor in the mechanisms underlying the toxicity of MPTP and similar compounds.
Collapse
|
42
|
Johannessen JN, Savitt JM, Markey CJ, Bacon JP, Weisz A, Hanselman DS, Markey SP. The development of amine substituted analogues of MPTP as unique tools for the study of MPTP toxicity and Parkinson's disease. Life Sci 1987; 40:697-704. [PMID: 2433563 DOI: 10.1016/0024-3205(87)90296-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We are currently developing amino-substituted MPTP analogues as useful probes for understanding the mechanism of MPTP toxicity and Parkinson's disease. One analogue, 4'-amino MPTP, induces a loss of striatal dopamine and is thus a suitable substitute for MPTP. This probe will be used as a histologically fixable MPTP which can be used to answer detailed anatomical questions concerning the sites of MPTP, MPP+ uptake and storage. In addition, antibodies have been raised against MPTP and MPP+ in rabbits using diazo-linked bovine serum albumin conjugates. The antibodies have been characterized with regard to their recognition of relevant structural analogues using an enzymelinked immunoassay (ELISA) procedure. Antibodies to MPTP detected MPTP in mouse brain extracts derived from as little as 5 micrograms of tissue. The antibodies will be used for immunohistochemical localization of 4'-NH2-MPTP and 4'-NH2-MPP+ in brain, as well as probes for the screening of parkinsonian brain tissue for any MPTP- or MPP+-like materials which might exist.
Collapse
|
43
|
|
44
|
Trevor AJ, Singer TP, Ramsay RR, Castagnoli N. Processing of MPTP by monoamine oxidases: implications for molecular toxicology. JOURNAL OF NEURAL TRANSMISSION. SUPPLEMENTUM 1987; 23:73-89. [PMID: 3295117 DOI: 10.1007/978-3-7091-8901-6_5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine), a selective nigrostriatal neurotoxin, is bioactivated by MAO-B (and less effectively by MAO-A) to 2,3-MPDP+ and this intermediate undergoes further oxidation to MPP+, partly through the activity of MAO forms. MPTP and its two primary metabolites are competitive inhibitors of both A and B forms of MAO. MPTP and 2,3-MPDP+ are also mechanism-based inactivators of both forms of the enzyme. A catalytic mechanism, involving the formation of radical intermediates, is proposed for the MAO-mediated oxidation of MPTP. Post-oxidation biochemical sequelae, possibly involved in the expression of neurotoxicity, include the active accumulation of MPP+ via dopamine reuptake systems, the energy-driven uptake of MPP+ by mitochondria and the inhibition of NADH dehydrogenase by pyridine derivatives. A scheme linking these events as steps in the molecular mechanism of action of MPTP is proposed and discussed in terms of the selective toxicity of the neurotoxin towards nigrostriatal cells.
Collapse
|
45
|
The neurotoxicity of 1-methyl-4-phenyl-1,2,3,6,-tetrahydropyridine (mptp) and its relevance to parkinson's disease. Neurochem Int 1987; 11:359-73. [DOI: 10.1016/0197-0186(87)90024-6] [Citation(s) in RCA: 67] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
46
|
Arai Y, Hamamichi N, Kinemuchi H. Time-dependent inhibition of rat brain monoamine oxidase by an analogue of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), 4-(4-chlorophenyl)-1,2,3,6-tetrahydropyridine. Neurosci Lett 1986; 70:255-60. [PMID: 3490636 DOI: 10.1016/0304-3940(86)90473-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Inhibitory effects of some MPTP and MPP+ analogues on rat brain MAO activity were studied to further clarify the structure-activity relationships of MPTP neurotoxicity. Of the analogues tested, 4-(4-chlorophenyl)-1,2,3,6-tetrahydropyridine (CPTP), 4-(4-chlorobenzyl)-pyridine (CBP), 4-benzylpyridine (BPY) and 4-benzylpiperidine (BPIP) dose-dependently inhibited both MAO-A and -B activities. CPTP, BPY and BPIP showed a higher MAO-A selectivity, while CBP was a selective MAO-B inhibitor. In preincubation studies, only CPTP greatly enhanced the degree of inhibition of MAO-B when the preincubation time was increased, but inhibition of MAO-A was not enhanced. Together with our previous MPTP and MPP+ analogue findings, the present results indicate that, in these chemical structures, a 4-phenyl-1,2,3,6-tetrahydropyridine ring is most essential for time-dependent inhibition of MAO. This chemical requirement is consistent with the ability to cause nigrostriatal dopaminergic neurotoxicity.
Collapse
|
47
|
Kindt M, Nicklas WJ, Sonsalla PK, Heikkila RE. Mitochondria and the neurotoxicity of MPTP. Trends Pharmacol Sci 1986. [DOI: 10.1016/0165-6147(86)90426-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|