Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0030567 (Parkinson's disease)
 63,064 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Erythrocyte lipid peroxidation, oxidative hemolysis, erythrocyte antioxidant enzymes, viz. superoxide dismutase, glutathione reductase, glutathione peroxidase, catalase and plasma antioxidants, viz. vitamin A, vitamin E, vitamin C and ceruloplasmin have been determined by spectrophotometric methods in 15 patients with Parkinson's disease (PD) and in 50 controls. Lipid peroxidation, oxidative hemolysis and plasma ceruloplasmin were significantly higher in PD patients as compared to normals. Erythrocyte antioxidants in PD patients were not significantly different from the controls. However, plasma vitamin C in PD patients was significantly lower than the controls. It is concluded that these patients are under oxidative stress which points to a possible involvement of free radicals in PD.
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PMID:Free radical toxicity and antioxidants in Parkinson's disease. 1286 18

The diverse damaging effects of dopamine (DA) oxidation products on brain subcellular components including mitochondrial electron transport chain have been implicated in dopaminergic neuronal death in Parkinson's disease. It has been shown in this study that DA (50-200 microM) causes dose-dependent inhibition of Na+, K+-ATPase activity of rat brain crude synaptosomal-mitochondrial fraction during in vitro incubation up to 2 h. The enzyme inactivation is prevented by catalase and the metal-chelator (diethylenetriamine penta-acetic acid) but not by superoxide dismutase or hydroxyl-radical scavengers like mannitol and dimethylsulphoxide (DMSO). Further, reduced glutathione and cysteine, markedly prevent DA-mediated inactivation of Na+, K+-ATPase. Under similar conditions of incubation, DA (200 microM) leads to the formation of quinoprotein adducts (protein-cysteinyl catechol) with synaptosomal-mitochondrial proteins and the phenomenon is also prevented by glutathione (5 mM) or cysteine (5 mM). The available data imply that the inactivation of Na+, K+-ATPase in this system involves both H2O2 and metal ions. The reactive quinones by forming adducts with protein thiols also probably contribute to the process, since reduced glutathione and cysteine which scavenge quinones from the system protect Na+, K+-ATPase from DA-mediated damage. The inactivation of neuronal Na+, K+-ATPase by DA may give rise to various toxic sequelae with potential implications for dopaminergic cell death in Parkinson's disease.
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PMID:Dopamine oxidation products inhibit Na+, K+-ATPase activity in crude synaptosomal-mitochondrial fraction from rat brain. 1286 86

The effect of He-Ne laser radiation on activity of MAO B, Cu/Zn-SOD, Mn-SOD, and catalase in blood cells from patients with Parkinson's disease was studied in vivo and in vitro. The effects of intravenous in vivo irradiation (intravenous laser therapy) were more pronounced than those observed in similar in vitro experiments. It is concluded that generalized effect of laser therapy involves interaction between blood cells.
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PMID:Laser modification of the blood in vitro and in vivo in patients with Parkinson's disease. 1291 Feb 78

Apomorphine (APO) is considered to be a classical mixed type dopamine D(1) and D(2) receptor agonist. It has been used in the therapy of Parkinson's disease and, more recently, for the treatment of erectile dysfunction. Like other catechols (e.g. dopamine), APO easily autoxidizes, producing quinone and semiquinone derivatives that may lead to the formation of reactive oxygen species and induce neurotoxicity. We assayed mutagenicity, antimutagenicity, and cytotoxicity of these compounds by means of the Salmonella/microsome assay, WP2 Mutoxitest and sensitivity assay in Saccharomyces cerevisiae yeast strains lacking antioxidant defenses. In the absence of S9 mix both compounds Apomorphine and its oxidation derivative, 8-oxo-apomorphine-semiquinone (8-OASQ), both at doses ranging from 20 to 80 microg per plate, induced frameshift mutations in TA98 and TA97 S. typhimurium strains, with 8-OASQ being up to two times more mutagenic. However, for strains which detect oxidative mutagens, 8-OASQ acted as a mutagen while APO was an antimutagen, inhibiting H(2)O(2) and t-BOOH-induced mutagenicity in TA102 S. typhimurium and WP2-derived E. coli strains. The S9 mix inhibited all mutagenic effects, probably either by conjugation of APO and 8-OASQ to proteins or by quenching reactive oxygen species. In sensitivity assays with S. cerevisiae, APO was only clearly cytotoxic to some strains at higher doses (200 and 400 microg/ml), whereas 8-OASQ dose-dependently sensitized all the strains, mainly the mutants lacking catalase (deltactt1), superoxide dismutase (deltasod1) and Yap1 transcription factor (deltayap1), suggesting that 8-OASQ cytotoxicity towards S. cerevisiae results from its pro-oxidant properties. APO also tended to protect S. cerevisiae strains against oxidative damage induced by high concentrations of H(2)O(2) and t-BOOH, while 8-OASQ enhanced pro-oxidant effects and induced adaptation responses to these agents. These results suggest that the 8-OASQ oxidation product of APO might induce cytotoxic and genotoxic effects.
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PMID:Differential mutagenic, antimutagenic and cytotoxic responses induced by apomorphine and its oxidation product, 8-oxo-apomorphine-semiquinone, in bacteria and yeast. 1294 12

Age-related increases in brain monoamine oxidase B (MAO-B) and its ability to produce reactive oxygen species as a by-product of catalysis could contribute to neurodegeneration associated with Parkinson's disease. This may be via increased oxidative stress and/or mitochondrial dysfunction either on its own or through its interaction with endogenous or exogenous neurotoxic species. We have created genetically engineered dopaminergic PC12 cell lines with subtly increased levels of MAO-B mimicking those observed during normal aging. In our cells, increased MAO-B activity was found to result in increased H2O2 production. This was found to correlate with a decrease in mitochondrial complex I activity which may involve both direct oxidative damage to the complex itself as well as oxidative effects on the tricarboxylic acid cycle enzyme alpha-ketoglutarate dehydrogenase (KGDH) which provides substrate for the complex. Both complex I and KGDH activities have been reported to be decreased in the Parkinsonian brain. These in vitro events are reversible by catalase addition. Importantly, MAO-B elevation was found to abolish the spare KGDH threshold capacity, which can normally be significantly inhibited before it affects maximal mitochondrial oxygen consumption rates. Our data suggest that H2O2 production via subtle elevations in MAO-B levels can result in oxidative effects on KGDH that can compromise the ability of dopaminergic neurons to cope with increased energetic stress.
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PMID:Oxidative alpha-ketoglutarate dehydrogenase inhibition via subtle elevations in monoamine oxidase B levels results in loss of spare respiratory capacity: implications for Parkinson's disease. 1296 42

A series of naturally occurring isoquinoline alkaloids, besides their distribution in the environment and presence in certain food stuffs, have been detected in human tissues including particular regions of brain. An example is salsolinol (1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline) that not only induces neuronal cell death, but also causes DNA damage and genotoxicity. Tetrahydropapaveroline [THP; 6,7-dihydroxy-1-(3',4'-dihydroxybenzyl)-1,2,3,4-tetrahydroisoquinoline], a dopamine-derived tetrahydroisoquinoline alkaloid, has been reported to inhibit mitochondrial respiration and is considered to contribute to neurodegeneration implicated in Parkinson's disease. Since THP bears two catechol moieties, the compound may readily undergo redox cycling to produce reactive oxygen species (ROS) as well as toxic quinoids. In the present study, we have examined the capability of THP to cause oxidative DNA damage and cell death. Incubation of THP with phiX174 supercoiled DNA or calf thymus DNA in the presence of cupric ion caused substantial DNA damage as determined by strand scission or formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo), respectively. THP plus copper-induced DNA damage was ameliorated by some ROS scavengers/antioxidants and catalase. Treatment of C6 glioma cells with THP led to a concentration-dependent reduction in cell viability, which was prevented by the antioxidant N-acetyl-L-cysteine. When these cells were treated with 10microM THP, c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) were rapidly activated via phosphorylation, whereas activation of extracellular signal-regulated protein kinase (ERK) was inhibited. Furthermore, pretreatment with inhibitors of JNK and p38 MAPK rescued the glioma cells from THP-induced cytotoxicity, suggestive of the involvement of these kinases in THP-induced C6 glioma cell damage.
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PMID:Oxidative DNA damage and glioma cell death induced by tetrahydropapaveroline. 1464 15

We present for discussion a possible molecular mechanism explaining the formation of reactive oxygen species involved in the neurodegenerative process of dopaminergic system in Parkinson's disease. This new hypothesis involves one-electron reduction of aminochrome to o-semiquinone radical, which seems to be the reaction responsible for neurodegenerative process of dopaminergic system. Leukoaminochrome o-semiquinone is extremely reactive with oxygen, which reoxidizes by reducing oxygen to superoxide radicals. Superoxide radicals enzymatically or spontaneously dismutate to dioxygen and hydrogen peroxide which is a precursor of hydroxyl radicals. ESR-experiments have showed that aminochrome o-semiquinone is extremely reactive in the presence of oxygen compared to dopamine o-semiquinone. In addition, the antioxidant enzymes superoxide dismutase and catalase play a prooxidant role by increasing the autoxidation rate and formation of superoxide radicals. One electron reduction of aminochrome to o-semiquinone can be performed by flavoenzymes which use NADPH and NADH as electron donator. The ability of aminochrome o-semiquinone to autoxidize in the presence of oxygen gives rise to a redox cycling process which will continue until oxygen, NADH and/or NADPH are depleted. Depletion of NADPH will prevent glutathione reductase from reducing glutathione, which is one of the main antioxidants in the cell. In addition depletion of NADH will prevent the formation of ATP in the electron transport chain in the mitochondria. Two antioxidants, probably, neuroprotective reactions are also discussed.
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PMID:The possible role of one-electron reduction of aminochrome in the neurodegenerative process of the dopaminergic system. 1471 70

X-linked adrenoleukodystrophy (X-ALD) is a hereditary disorder of peroxisomal metabolism biochemically characterized by the accumulation of very long chain fatty acids (VLCFA), particularly hexacosanoic acid (C26:0) and tetracosanoic acid (C24:0) in different tissues and in biological fluids. The disease is clinically characterized by central and peripheral demyelination and adrenal insufficiency, which is closely related to the increased concentrations of these fatty acids. However, the mechanisms underlying the brain damage in X-ALD are poorly known. Considering that free radical generation is involved in various neurodegenerative disorders, like Parkinson disease, multiple sclerosis and Alzheimer's disease, in the present study we evaluated various oxidative stress parameters, namely chemiluminescence, thiobarbituric acid reactive species (TBA-RS), total radical-trapping antioxidant potential (TRAP), and total antioxidant reactivity (TAR) in plasma of X-ALD patients, as well as the activities of the antioxidant enzymes catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) in erythrocytes and fibroblasts from these patients. It was verified a significant increase of plasma chemiluminescence and TBA-RS, reflecting induction of lipid peroxidation, as well as a decrease of plasma TAR, indicating a deficient capacity to rapidly handle an increase of reactive species. We also observed a significant increase of erythrocytes GPx activity and of catalase and SOD activities in fibroblasts from the patients studied. It is therefore proposed that oxidative stress may be involved in pathophysiology of X-ALD.
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PMID:Evidence that oxidative stress is increased in patients with X-linked adrenoleukodystrophy. 1473 78

The neurotoxin, 6-hydroxydopamine (6-OHDA) has been implicated in the neurodegenerative process of Parkinson's disease. The current study was designed to elucidate the toxicological effects of 6-OHDA on energy metabolism in neuroblastoma (N-2A) cells. The toxicity of 6-OHDA corresponds to the total collapse of anaerobic/aerobic cell function, unlike other mitochondrial toxins such as MPP+ that target specific loss of aerobic metabolism. The toxicity of 6-OHDA paralleled the loss of mitochondrial oxygen (O2) consumption (MOC), glycolytic activity, ATP, H+ ion gradients, membrane potential and accumulation of the autoxidative product, hydrogen peroxide (H2O2). Removing H2O2 with nonenzymatic stoichiometric scavengers, such as carboxylic acids, glutathione and catalase yielded partial protection. The rapid removal of H2O2 with pyruvate or catalase restored only anaerobic glycolysis, but did not reverse the loss of MOC, indicating mitochondrial impairment is independent of H2O2. The H2O2 generated by 6-OHDA contributed toward the loss of anaerobic glycolysis through lipid peroxidation and lactic acid dehydrogenase inhibition. The ability of 6-OHDA to maintain oxidized cytochrome c (CYT-C-OX) in its reduced form (CYT-C-RED), appears to play a role in mitohondrial impairment. The reduction of CYT-C by 6-OHDA, was extensive, occurred within minutes, preceded formation of H2O2 and was unaffected by catalase or superoxide dismutase. At similar concentrations, 6-OHDA readily altered the valence state of iron [Fe(III)] to Fe(II), which would also theoretically sustain CYT-C in its reduced form. In isolated mitochondria, 6-OHDA had negligible effects on complex I, inhibited complex II and interfered with complex III by maintaining the substrate, CYT-C in a reduced state. 6-OHDA caused a transient and potent surge in isolated cytochrome oxidase (complex IV) activity, with rapid recovery as a result of 6-OHDA recycling CYT-C-OX to CYT-C-RED. Typical mitochondrial toxins such as MPP+, azide and antimycin appeared to inhibit the catalytic activity of ETC enzymes. In contrast, 6-OHDA alters the redox of the cytochromes, resulting in loss of substrate availability and obstruction of oxidation-reduction events. Complete cytoprotection against 6-OHDA toxicity and restored MOC was achieved by combining catalase with CYT-C (horse heart). In summary, CYT-C reducing properties are unique to catecholamine neurotransmitters, and may play a significant role in selective vulnerability of dopaminergic neurons to mitochondrial insults.
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PMID:The role of oxidative stress, impaired glycolysis and mitochondrial respiratory redox failure in the cytotoxic effects of 6-hydroxydopamine in vitro. 1503 17

The pathology of Parkinson's disease involves oxidative damage to dopaminergic neurons of the substantia nigra. Oxidation of the dopamine (DA) neurotransmitter itself may contribute to the generation of a reactive oxygen species (ROS) and subsequent neurodegeneration. Glia cells can either exacerbate injury or exert protective properties on local neurons in the brain. We investigate glial antioxidant enzyme systems relative to ROS generated during cytokine activation, monoamine oxidase (MAO) activity and autoxidation of DA in glioma cells. Rat C6 glioma cells stimulated with lipopolysaccharide Escherichia coli 0111:B4 and interferon gamma (LPS/IFN-g) produced high levels of nitric oxide (241 nmol mg(-1) protein 24 h(-1)) but not superoxide (O(-) (2)) or hydrogen peroxide (H(2)O(2)). Basal C6 cells exhibited a rapid and robust capacity to remove exogenous H(2)O(2) within minutes. Preincubation with sodium azide but not buthionine-[S, R]-sulfoximine attenuated this response, indicating catalase as the primary enzyme responsible for this effect. The glioma catalase reaction rate was slightly attenuated by exposure to LPS/IFN-g for 24 h. However, the reduction in catalase activity was not due to nitric oxide, because both the supernatant and sodium nitroprusside had no effect on isolated catalase enzyme activity. Hydrogen peroxide was produced only through substrate-driven MAO activity in prepared lysate. However, the quantity of H(2)O(2) produced per unit time (0.46 nmol mg(-1) protein min(-1)) was negligible compared with the enormous capacity for its removal by catalase (213.9 nmol mg(-1) protein min(-1)) (> or =462 x greater). Similarly, H(2)O(2) generated by DA autoxidation per unit time (0.28 nmol mg(-1) protein equiv. min(-1)), was rapidly dissolved by glioma cells at high capacity (> or =750 x greater). In conclusion, C6 cells produce nitric oxide under cytokine/endotoxin-stimulated conditions. Moreover, C6 cells exhibit a dynamic H(2)O(2) scavenging capacity, with ample facility to dispose of the peroxide generated by both MAO activity and spontaneous DA autoxidation.
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PMID:Glioma cell antioxidant capacity relative to reactive oxygen species produced by dopamine. 1505 4


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