1
|
Saavedra J. Beneficial effects of Angiotensin II receptor blockers in brain disorders. Pharmacol Res 2017; 125:91-103. [DOI: 10.1016/j.phrs.2017.06.017] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 06/17/2017] [Accepted: 06/28/2017] [Indexed: 12/11/2022]
|
2
|
Jiang B, Zhang H, Bi J, Zhang XL. Neuroprotective activities of catalpol on MPP+/MPTP-induced neurotoxicity. Neurol Res 2013; 30:639-44. [DOI: 10.1179/174313208x289543] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
|
3
|
Millan MJ. From the cell to the clinic: a comparative review of the partial D₂/D₃receptor agonist and α2-adrenoceptor antagonist, piribedil, in the treatment of Parkinson's disease. Pharmacol Ther 2010; 128:229-73. [PMID: 20600305 DOI: 10.1016/j.pharmthera.2010.06.002] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/02/2010] [Indexed: 12/16/2022]
Abstract
Though L-3,4-dihydroxyphenylalanine (L-DOPA) is universally employed for alleviation of motor dysfunction in Parkinson's disease (PD), it is poorly-effective against co-morbid symptoms like cognitive impairment and depression. Further, it elicits dyskinesia, its pharmacokinetics are highly variable, and efficacy wanes upon long-term administration. Accordingly, "dopaminergic agonists" are increasingly employed both as adjuncts to L-DOPA and as monotherapy. While all recognize dopamine D(2) receptors, they display contrasting patterns of interaction with other classes of monoaminergic receptor. For example, pramipexole and ropinirole are high efficacy agonists at D(2) and D(3) receptors, while pergolide recognizes D(1), D(2) and D(3) receptors and a broad suite of serotonergic receptors. Interestingly, several antiparkinson drugs display modest efficacy at D(2) receptors. Of these, piribedil displays the unique cellular signature of: 1), signal-specific partial agonist actions at dopamine D(2)and D(3) receptors; 2), antagonist properties at α(2)-adrenoceptors and 3), minimal interaction with serotonergic receptors. Dopamine-deprived striatal D(2) receptors are supersensitive in PD, so partial agonism is sufficient for relief of motor dysfunction while limiting undesirable effects due to "over-dosage" of "normosensitive" D(2) receptors elsewhere. Further, α(2)-adrenoceptor antagonism reinforces adrenergic, dopaminergic and cholinergic transmission to favourably influence motor function, cognition, mood and the integrity of dopaminergic neurones. In reviewing the above issues, the present paper focuses on the distinctive cellular, preclinical and therapeutic profile of piribedil, comparisons to pramipexole, ropinirole and pergolide, and the core triad of symptoms that characterises PD-motor dysfunction, depressed mood and cognitive impairment. The article concludes by highlighting perspectives for clarifying the mechanisms of action of piribedil and other antiparkinson agents, and for optimizing their clinical exploitation.
Collapse
Affiliation(s)
- Mark J Millan
- Dept of Psychopharmacology, Institut de Recherches Servier, 125 Chemin de Ronde, 78290 Croissy/Seine (Paris), France.
| |
Collapse
|
4
|
Li Y, Fawcett JP, Zhang H, Tucker IG. Transport and metabolism of MitoQ10, a mitochondria-targeted antioxidant, in Caco-2 cell monolayers. J Pharm Pharmacol 2010; 59:503-11. [PMID: 17430633 DOI: 10.1211/jpp.59.4.0004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Abstract
Mitoquinone (MitoQ10 mesylate) is a mitochondria-targeted antioxidant formulated for oral administration in the treatment of neurodegenerative diseases. We have investigated the absorption and metabolism of MitoQ10 in Caco-2 cell monolayers. The intracellular accumulation of MitoQ10 was 18–41% of the total amount of MitoQ10 added. Some of the intracellular MitoQ10 was reduced to mitoquinol and subsequently metabolized to glucuronide and sulfate conjugates. Transport of MitoQ10 was polarized with the apparent permeability (Papp) from basolateral (BL) to apical (AP) (PappBL→AP) being >2.5-fold the Papp from apical to basolateral (PappAP→BL). In the presence of 4% bovine serum albumin on the basolateral side, the PappAP→BL value increased 7-fold compared with control. The PappBL→AP value decreased by 26, 31 and 61% in the presence of verapamil 100 μM, ciclosporin 10 and 30 μM, respectively, whereas the PappAP→BL value increased 71% in the presence of ciclosporin 30 μM. Apical efflux of mitoquinol sulfate and mitoquinol glucuronide conjugates was significantly decreased by ciclosporin 30 μM and the breast cancer receptor protein (BCRP) inhibitor, reserpine 25 μM, respectively. These results suggested that the bioavailability of MitoQ10 may be limited by intracellular metabolism and the action of P-glycoprotein and BCRP. However, the dramatic increase in absorptive Papp in the presence of bovine serum albumin on the receiver side suggests these barrier functions may be less significant in-vivo.
Collapse
Affiliation(s)
- Yan Li
- School of Pharmacy, University of Otago, Dunedin, PO Box 913, New Zealand.
| | | | | | | |
Collapse
|
5
|
Crespo C, Gallego J, Cot A, Falcón C, Bullich S, Pareto D, Aguiar P, Sempau J, Lomeña F, Calviño F, Pavía J, Ros D. Quantification of dopaminergic neurotransmission SPECT studies with 123I-labelled radioligands. A comparison between different imaging systems and data acquisition protocols using Monte Carlo simulation. Eur J Nucl Med Mol Imaging 2008; 35:1334-42. [DOI: 10.1007/s00259-007-0711-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2007] [Accepted: 12/26/2007] [Indexed: 11/29/2022]
|
6
|
Powell PR, Paxon TL, Han KA, Ewing AG. Analysis of biogenic amine variability among individual fly heads with micellar electrokinetic capillary chromatography-electrochemical detection. Anal Chem 2007; 77:6902-6908. [PMID: 16255588 PMCID: PMC1362073 DOI: 10.1021/ac050963m] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Neurochemical variability among individual Drosophila heads has been examined with the sensitivity of electrochemical detection and the selectivity of micellar electrokinetic capillary chromatography. Homogenization of single Drosophila heads in volumes as small as 100 nL has been accomplished. Here we demonstrate reproducible separations for single fly heads in 250-nL volumes providing a 4-fold increase in sensitivity without overloading the electrochemical detector. This increase in sensitivity allows detection of previously undetected analytes, such as N-acetyltyramine (naTA) and octopamine (OA). Analytes including L-3,4-dihydroxyphenylalanine, N-acetyl octopamine, N-acetyldopamine, naTA, N-acetylserotonin, OA, dopamine, tyramine, and serotonin also have been consistently identified in single-head homogenates and observed with homogenates representing populations of Drosophila. Neurochemical variation between individual flies as well as the consistency within a population indicates varying amounts of neurotransmitter turnover. The inception, design, and fabrication of a miniature tissue homogenizer has enabled the separation of biogenic amines and metabolites from these severely volume-limited single Drosophila head homogenates.
Collapse
Affiliation(s)
- Paula R Powell
- Department of Chemistry, 104 Chemistry Research Building, InterCollege Graduate Program in Genetics, and Department of Biology, 208 Mueller Laboratory, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Tracy L Paxon
- Department of Chemistry, 104 Chemistry Research Building, InterCollege Graduate Program in Genetics, and Department of Biology, 208 Mueller Laboratory, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Kyung-An Han
- Department of Chemistry, 104 Chemistry Research Building, InterCollege Graduate Program in Genetics, and Department of Biology, 208 Mueller Laboratory, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Andrew G Ewing
- Department of Chemistry, 104 Chemistry Research Building, InterCollege Graduate Program in Genetics, and Department of Biology, 208 Mueller Laboratory, Pennsylvania State University, University Park, Pennsylvania 16802
| |
Collapse
|
7
|
|
8
|
Neurotoxins and medicinals for the treatment of Parkinson’s disease. Part 3: Drugs indirectly influencing the dopaminergic system (a review). Pharm Chem J 2005. [DOI: 10.1007/s11094-006-0022-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
9
|
Bo J, Ming BY, Gang LZ, Lei C, Jia AL. Protection by puerarin against MPP+-induced neurotoxicity in PC12 cells mediated by inhibiting mitochondrial dysfunction and caspase-3-like activation. Neurosci Res 2005; 53:183-8. [PMID: 16112764 DOI: 10.1016/j.neures.2005.06.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2005] [Revised: 06/12/2005] [Accepted: 06/17/2005] [Indexed: 10/25/2022]
Abstract
Puerarin, a main isoflavone glycoside distributed in Pueraria lobata (Willd.) Ohwi, showed inhibitory activity on H2O2-induced PC12 cells damage in our previous work. However, there is insufficient evidence in protective mechanism of puerarin, especially that relating to the mitochondrial function. In this study, when cells were pretreated with puerarin prior to 0.4 mM MPP+, protective roles were accompanied by a reduction of cell viability loss, morphological changes of apoptosis and apoptotic rate. To explore the protective mechanism of puerarin in MPP+-induced PC12 cells, mitochondrial function and caspase-3-like activity were measured. The results indicated that puerarin inhibited the release of mitochondrial cytochrome c to cytosol and the loss of mitochondrial membrane potentials. In addition, puerarin also reduced MPP+-induced caspase-3-like activation. Taken together, the above results suggest that pretreatment of PC12 cells with puerarin could block MPP+-mediated apoptosis by mitochondria-dependent caspase cascade.
Collapse
Affiliation(s)
- Jiang Bo
- School of Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024, China.
| | | | | | | | | |
Collapse
|
10
|
Neurotoxins and Drugs for the Treatment of Parkinson's Disease. Part I: Neurotoxins, Levodopa, and Agents Influencing Dopamine Metabolism (A Review). Pharm Chem J 2005. [DOI: 10.1007/s11094-006-0001-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
11
|
Abstract
Interest is increasing rapidly in the use of surrogate markers as primary measures of the effectiveness of investigational drugs in definitive drug trials. Many such surrogate markers have been proposed as potential candidates for use in definitive effectiveness trials of agents to treat neurologic or psychiatric disease, but as of this date, there are no such markers that have been adequately "validated," that is, shown to predict the effect of the treatment on the clinical outcome of interest. While the current law and regulations permit the United States Food and Drug Administration to base the approval of a drug product on a determination the effect of the drug on an unvalidated surrogate marker (that is, one for which it is not known that an effect on the surrogate actually predicts the desired clinical benefit), there are a number of difficulties in interpreting trials that use surrogate markers as primary measures of drug effect. In this article, the relevant regulatory context will be discussed, as well as the epistemological problems related to the interpretation of clinical trials in which unvalidated surrogate markers are used as primary outcomes.
Collapse
Affiliation(s)
- Russell Katz
- Division of Neuropharmacological Drug Products, United States Food and Drug Administration, Rockville, Maryland 20852, USA.
| |
Collapse
|
12
|
Abstract
Neurodegenerative diseases pose specific challenges for drug development. These diseases typically have a slow and variable clinical course, an insidious onset, and symptom expression is only observed when a significant proportion of neurons are already lost. It is important to identify vulnerability factors and other determinants of clinical course in order to be able in the future to select patient populations for clinical trials with a predictable prognosis. The neurodegenerative process itself is not amenable to direct observation and, thus, cannot be monitored in clinical trials. For this reason, surrogate biomarkers are required for use as outcome parameters. In this respect, magnetic resonance imaging has proved valuable for assessing disease activity and progression in multiple sclerosis. Rating scales are of use as outcome measures but, as these generally measure symptom severity, they are most appropriate for use in assessing symptomatic treatments. Survival has been used with success as an outcome measure in trials in amyotrophic lateral sclerosis, where disease progression is rapid. The optimal outcome measure, the sample size required and the treatment duration need to be chosen in relation to the phase of the disease. Potential new treatments can be chosen based upon new knowledge of the genetics and physiopathology of neurodegenerative diseases and, in some cases, screened in transgenic mouse models, although it should be recognised that the validity of these models in terms of treatment response has yet to be established empirically.
Collapse
Affiliation(s)
- Michel Dib
- Service de Neurologie, Hôpital de la Salpêtrière, Paris, France.
| |
Collapse
|
13
|
Leal-Cardoso JH, Matos-Brito BG, Lopes-Junior JEG, Viana-Cardoso KV, Sampaio-Freitas AB, Brasil RO, Coelho-De-Souza AN, Albuquerque AAC. Effects of estragole on the compound action potential of the rat sciatic nerve. Braz J Med Biol Res 2004; 37:1193-8. [PMID: 15273820 DOI: 10.1590/s0100-879x2004000800009] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Estragole, a relatively nontoxic terpenoid ether, is an important constituent of many essential oils with widespread applications in folk medicine and aromatherapy and known to have potent local anesthetic activity. We investigated the effects of estragole on the compound action potential (CAP) of the rat sciatic nerve. The experiments were carried out on sciatic nerves dissected from Wistar rats. Nerves, mounted in a moist chamber, were stimulated at a frequency of 0.2 Hz, with electric pulses of 50-100-micros duration at 10-20 V, and evoked CAP were monitored on an oscilloscope and recorded on a computer. CAP control parameters were: peak-to-peak amplitude (PPA), 9.9 +/- 0.55 mV (N = 15), conduction velocity, 92.2 +/- 4.36 m/s (N = 15), chronaxy, 45.6 +/- 3.74 micros (N = 5), and rheobase, 3.9 +/- 0.78 V (N = 5). Estragole induced a dose-dependent blockade of the CAP. At 0.6 mM, estragole had no demonstrable effect. At 2.0 and 6.0 mM estragole, PPA was significantly reduced at the end of 180-min exposure of the nerve to the drug to 85.6 +/- 3.96 and 13.04 +/- 1.80% of control, respectively. At 4.0 mM, estragole significantly altered PPA, conduction velocity, chronaxy, and rheobase (P < or = 0.05, ANOVA; N = 5) to 49.3 +/- 6.21 and 77.7 +/- 3.84, 125.9 +/- 10.43 and 116.7 +/- 4.59%, of control, respectively. All of these effects developed slowly and were reversible upon a 300-min wash-out. The data show that estragole dose-dependently blocks nerve excitability.
Collapse
Affiliation(s)
- J H Leal-Cardoso
- Centro de Ciências da Saúde, Universidade Estadual do Ceará, Fortaleza, CE, Brazil
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Complexes of the fac-{Re(CO)3}+ core with tridentate ligands derived from arylpiperazines. Inorganica Chim Acta 2004. [DOI: 10.1016/j.ica.2003.11.027] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
15
|
Joyce JN, Presgraves S, Renish L, Borwege S, Osredkar T, Hagner D, Replogle M, PazSoldan M, Millan MJ. Neuroprotective effects of the novel D3/D2 receptor agonist and antiparkinson agent, S32504, in vitro against 1-methyl-4-phenylpyridinium (MPP+) and in vivo against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP): a comparison to ropinirole. Exp Neurol 2003; 184:393-407. [PMID: 14637109 DOI: 10.1016/s0014-4886(03)00353-4] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The novel naphtoxazine derivative and preferential D(3) vs D(2) receptor agonist, S32504, restores perturbed motor function in rodent and primate models of antiparkinsonian activity with a potency superior to those of two further, preferential D(3) receptor agonists, pramipexole and ropinirole. However, potential neuroprotective properties of S32054 have not, to date, been evaluated. Herein, employing several measures of cellular integrity, we demonstrate that S32504 robustly, concentration-dependently and completely protects terminally differentiated SH-SY5Y cells against 1-methyl-4-phenylpyridinium (MPP+)-induced cell death in vitro. Further, S32504 was substantially more potent than pramipexole and ropinirole, the latter of which was neurotoxic at high concentrations. In vivo, subchronic treatment with low (0.25 mg/kg) and high (2.5 mg/kg) doses of S32504 prior to and during treatment of mice with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, MPTP, provided complete protection against MPTP-induced tyrosine hydroxylase immunoreactive (TH-IR) neuronal death in the substantia nigra pars compacta and ventral tegmental area. A high dose of ropinirole (2.5 mg/kg) provided some protection but statistical significance was not attained, and a low dose (0.25 mg/kg) was ineffective. Neither drug afforded protection against the MPTP-induced loss of DA fibers in the striatum, as measured by TH-IR and dopamine transporter immunoreactive fiber counts. In conclusion, the novel naphotoxazine and dopaminergic agonist, S32504, robustly protects dopaminergic neurones against the neurotoxic effects of MPP(+) and MPTP in in vitro and in vivo models, respectively. The underlying mechanisms and therapeutic pertinence of these actions will be of interest to further evaluate in view of its potent actions in behavioral models of antiparkinson activity.
Collapse
Affiliation(s)
- Jeffrey N Joyce
- Thomas H. Christopher Center for Parkinson's Disease Research, Sun Health Research Institute, 852622, Sun City, AZ, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Kagawa S, Nakano T, Inoue O, Nishimura T. Effect of glutamatergic systems on in vivo binding of [(125)I]beta-CIT in the brain of a rat model of Parkinson's disease. Synapse 2002; 46:38-44. [PMID: 12211097 DOI: 10.1002/syn.10096] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The effect of MK-801, a noncompetitive NMDA receptor antagonist, on both in vivo and in vitro binding of [(125)I]beta-CIT (RTI-55) was investigated in a rat model of Parkinson's disease. The binding experiments were performed 2 weeks after unilateral intranigral microinjection of 6-hydroxydopamine (6-OHDA). In the in vitro binding study, no alterations in [(125)I]beta-CIT binding in rat brain sections were observed after addition of MK-801, 0.03 microM or 3 microM, to the incubation medium. However, in vivo [(125)I]beta-CIT binding to the dopamine transporter in both nonlesioned and 6-OHDA-lesioned striatum was significantly increased by pretreatment with MK-801. In vivo [(125)I]beta-CIT binding to the serotonin (5HT) transporter in nonlesioned cerebral cortex, hypothalamus, and thalamus was also significantly increased by MK-801. However, the degree of change in the specific binding of [(125)I]beta-CIT induced by MK-801 was smaller in the lesioned cerebral cortex. Kinetic analysis, by a simplified three-compartment model with the cerebellum as the reference region, revealed that these alterations in the in vivo [(125)I]beta-CIT binding induced by MK-801 were mainly due to changes in the rate constants of in vivo binding, the input rate constant, k(3), and the output rate constant, k(4). These results indicate that the glutamatergic system significantly affects the function of dopamine transporters in the degenerated dopaminergic neurons in Parkinson's disease.
Collapse
Affiliation(s)
- Shinya Kagawa
- Division of Tracer Kinetics, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan.
| | | | | | | |
Collapse
|
17
|
Leal-Cardoso JH, Lahlou S, Coelho-de-Souza AN, Criddle DN, Pinto Duarte GIB, Santos MAV, Magalhães PJC. Inhibitory actions of eugenol on rat isolated ileum. Can J Physiol Pharmacol 2002; 80:901-6. [PMID: 12430985 DOI: 10.1139/y02-117] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effects of eugenol (1-2000 microM) on rat isolated ileum were studied. Eugenol relaxed the basal tonus (IC50 83 microM) and the ileum precontracted with 60 mM KCl (IC50 162 microM), an action unaltered by 0.5 microM tetrodotoxin, 0.2 mM N(G)-nitro-L-arginine methyl ester, 0.5 mM hexamethonium, and 1 microM indomethacin. Eugenol did not alter the resting transmembrane potential (Em) of the longitudinal muscle layer under normal conditions (5.0 mM K+) or in depolarised tissues. Eugenol reversibly inhibited contractions induced by submaximal concentrations of acetylcholine (ACh) and K+ (40 mM) with IC50 values of approximately 228 and 237 microM, respectively. Eugenol blocked the component of ACh-induced contraction obtained in Ca(2+)-free solution (0.2 mM EGTA) or in the presence of nifedipine (1 microM). Our results suggest that eugenol induces relaxation of rat ileum by a direct action on smooth muscle via a mechanism largely independent of alterations of Em and extracellular Ca2+ influx.
Collapse
|
18
|
Bannon MJ, Michelhaugh SK, Wang J, Sacchetti P. The human dopamine transporter gene: gene organization, transcriptional regulation, and potential involvement in neuropsychiatric disorders. Eur Neuropsychopharmacol 2001; 11:449-55. [PMID: 11704422 DOI: 10.1016/s0924-977x(01)00122-5] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The dopamine transporter is a plasma membrane protein that controls the spatial and temporal domains of dopamine neurotransmission through the accumulation of extracellular dopamine. The dopamine transporter may play a role in numerous dopamine-linked neuropsychiatric disorders. We review the cloning and organization of the human dopamine transporter gene, polymorphisms in its coding and noncoding sequence, and emerging data on its transcriptional regulation.
Collapse
Affiliation(s)
- M J Bannon
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Rm 2309 Scott Hall, 540 E. Canfield Ave., 48201, Detroit, MI, USA.
| | | | | | | |
Collapse
|
19
|
Catafau AM. Brain SPECT of dopaminergic neurotransmission: a new tool with proved clinical impact. Nucl Med Commun 2001; 22:1059-60. [PMID: 11567176 DOI: 10.1097/00006231-200110000-00001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
20
|
Berendse HW, Booij J, Francot CM, Bergmans PL, Hijman R, Stoof JC, Wolters EC. Subclinical dopaminergic dysfunction in asymptomatic Parkinson's disease patients' relatives with a decreased sense of smell. Ann Neurol 2001; 50:34-41. [PMID: 11456307 DOI: 10.1002/ana.1049] [Citation(s) in RCA: 224] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
By the time a clinical diagnosis of Parkinson's disease (PD) is made, a significant loss of dopaminergic neurons has already occurred. Identifying patients in the period between the presumed onset of dopaminergic cell loss and the appearance of clinical parkinsonism may be of major importance in the development of effective neuroprotective treatment strategies. In an effort to develop a feasible strategy to detect preclinical PD, a combination of olfactory processing tasks, including odor detection, odor identification, and odor discrimination was used to select groups of hyposmic and normosmic individuals from a total of 250 relatives (parents, siblings, or children) of subjects with PD. Single photon emission computed tomography (SPECT) with [123I]beta-CIT as a dopamine transporter ligand was used to assess nigrostriatal dopaminergic function in 25 hyposmic and 23 normosmic relatives of PD patients. An abnormal reduction in striatal dopamine transporter binding was found in 4 out of 25 hyposmic relatives of PD patients, two of whom subsequently developed clinical parkinsonism, and in none of the 23 normosmic relatives. These observations demonstrate that subclinical reductions in dopamine transporter binding can be detected in asymptomatic relatives of sporadic PD patients by means of [123I]beta-CIT and SPECT. The results further indicate that olfactory deficits may precede clinical motor signs in PD.
Collapse
Affiliation(s)
- H W Berendse
- Department of Neurology, Research Institute Neurosciences, Vrije Universiteit, Amsterdam, The Netherlands.
| | | | | | | | | | | | | |
Collapse
|
21
|
Abstract
Parkinsonism is a feature of various neurodegenerative diseases. Since it is well known that the dopaminergic system plays a major role in parkinsonism, numerous reports have focused on the assessment of the dopaminergic system in vivo. While the use of positron emission tomography (PET) for routine application is still hampered by its limited availability, single photon emission tomography (SPET) has been shown to deliver comparable results to PET in clinical settings. In recent years SPET investigations of the dopamine transporter and of the dopamine D2-like receptors have provided valuable information about the pre- and postsynaptic dopaminergic system in parkinsonism. This article briefly reviews the literature dealing with SPET imaging in parkinsonism and specifically addresses the ligands used, the methodology applied, and the current major clinical applications.
Collapse
Affiliation(s)
- K Tatsch
- Department of Nuclear Medicine, Klinikum Grosshadern, Ludwig-Maximilians-University Munich, Germany.
| |
Collapse
|
22
|
Romero-Ramos M, Venero JL, Santiago M, Rodriguez-Gómez JA, Vizuete ML, Cano J, Machado A. Decreased messenger RNA expression of key markers of the nigrostriatal dopaminergic system following vitamin E deficiency in the rat. Neuroscience 2001; 101:1029-36. [PMID: 11113352 DOI: 10.1016/s0306-4522(00)00424-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We have evaluated the effect of a vitamin E-deficient diet on the rat nigrostriatal dopaminergic system. After 15 days of deficient diet, the amount and activity of striatal and nigral tyrosine hydroxylase increased, which contrasted with a decreased messenger RNA expression for tyrosine hydroxylase and the dopamine transporter in the ventral mesencephalon. When we prolonged the deficiency of vitamin E for 30 days, dopamine levels did not differ in both areas. In contrast, messenger RNA levels for tyrosine hydroxylase and the dopamine transporter were markedly reduced in 30-day deficient rats. In addition, the number of oxidatively modified proteins significantly increased in the striatal and nigral areas studied. Overall, we propose that these changes suggest an important role of vitamin E in maintaining the normal equilibrium of the dopaminergic nigrostriatal system.
Collapse
Affiliation(s)
- M Romero-Ramos
- Departamento de Bioquímica, Bromatología, Toxicología y Medicina Legal, Facultad de Farmacia, Universidad de Sevilla, Calle Profesor García González s/n, 41012, Sevilla, Spain
| | | | | | | | | | | | | |
Collapse
|