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)

Oxygen free radicals and other oxygen derived species (Superoxide, O2-; Hydroperoxide, HOO; Singlet oxygen, 1O2-; Hydroxyl radical, OH; and Hydrogen peroxide, H2O2) including lipid peroxides have been suggested as important causative agents of aging and several human diseases, including cancer, multiple sclerosis, Parkinson's disease, autoimmune disease, ischemia, anemia, senile dementia, asbestosis and in thalassemia. This paper aims to communicate some of the theories and rationales in aging process and thalassemia.
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PMID:Role of lipid peroxidation and antioxidants in aging process and thalassemia. 134 11

L-3-(3-Hydroxy-4-pivaloyloxyphenyl)alanine (1, NB-355) is a novel L-dopa prodrug. After oral administration with carbidopa in rats, 1 demonstrated 2.3 times longer duration (MRT) and 1.4 times larger bioavailability (AUC) on plasma L-dopa concentrations than those of L-dopa itself. Similar results were obtained in dogs. The prolonged profile of L-dopa was parallel to that of carbidopa, and the intact ester was undetectable in rat plasma. After intravenous administration in rats, 1 was converted quickly and completely to L-dopa in the systemic circulation. It was also noted that the oral LD50 value of 1 was greater than 6 g/kg in mice. These data suggest that 1 will offer long-lasting L-dopa therapy for the treatment of Parkinson's disease with little concern about toxicity.
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PMID:A new potential prodrug to improve the duration of L-dopa: L-3-(3-hydroxy-4-pivaloyloxyphenyl)alanine. 277 50

Oxygen-based free radicals have been shown to play a major role in the acute destruction of neurons following cerebral ischemia and may be involved in the chronic neurodegeneration seen in Parkinson's disease, Alzheimer's disease, and other conditions characterized by the progressive death of neurons in the central nervous system. Drugs belonging to a group of antioxidant compounds, collectively known as the lazaroids, have strong neuroprotective effects in experimental models of acute ischemia. However, the specific mechanisms by which these drugs reduce the harmful actions of free radicals have not been established. Using electron paramagnetic resonance (EPR) spectroscopy with spin trapping, we investigated the interaction of U-74500A, a first-generation lazaroid, and U-78517F, a second-generation lazaroid, with two species of oxygen-based free radicals in aqueous solution and with the stable nitrogen-based free radical diphenylpicrylhydrazyl in dimethyl sulfoxide. Superoxide radicals were generated by the action of xanthine oxidase on hypoxanthine. Hydroxyl radicals were generated by the Fenton reaction involving aqueous ferrous iron and hydrogen peroxide. Both lazaroids reduce the EPR signal of all three radicals, but the drugs differ in potency and relative radical selectivity. These observations are consistent with the lazaroids being scavengers of oxygen-based and nitrogen-based free radicals and suggest that the neuroprotective actions of the lazaroids in cerebral ischemia may involve direct interactions of the lazaroids with several different species of free radicals.
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PMID:An in vitro EPR study of the free-radical scavenging actions of the lazaroid antioxidants U-74500A and U-78517F. 763 55

It has been suggested that free radicals may adversely influence the pathogenesis of Parkinson's disease. We conducted this study to determine whether bromocriptine, an agent widely used for treating parkinsonism, possesses antioxidant effects. Bromocriptine scavenged superoxide produced from a superoxide generating system (hypoxanthine-xanthine oxidase) by the spin-trapping method using electron spin resonance. Bromocriptine had a strong scavenging effect on the 5,5-dimethyl-1-pyrroline-N-oxide hydroxide signal produced from Fenton's reaction. Bromocriptine also attenuated the stable free radical diphenyl-p-picrylhydrazyl signal. This drug inhibited the autooxidation of rat brain homogenates in a dose-dependent manner in vitro. Autooxidation of brain homogenates collected from rats treated with bromocriptine (2.5 mg/kg, i.p., daily for 3 days) was significantly reduced as compared with values in untreated rat homogenates. These observations suggest that bromocriptine is a free radical scavenger and a potent antioxidant.
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PMID:Antioxidant properties of bromocriptine, a dopamine agonist. 811 89

There is growing evidence that oxidative stress and mitochondrial respiratory failure with attendant decrease in energy output are implicated in nigral neuronal death in Parkinson disease (PD). It is not known, however, which cellular elements (neurons or glial cells) are major targets of oxygen-mediated damage. 4-Hydroxy-2-nonenal (HNE) was shown earlier to react with proteins to form stable adducts that can be used as markers of oxidative stress-induced cellular damage. We report here results of immunochemical studies using polyclonal antibodies directed against HNE-protein conjugates to label the site of oxidative damage in control subjects (ages 18-99 years) and seven patients that died of PD (ages 57-78 years). All the nigral melanized neurons in one of the midbrain sections were counted and classified into three groups according to the intensity of immunostaining for HNE-modified proteins--i.e., no staining, weak staining, and intensely positive staining. On average, 58% of nigral neurons were positively stained for HNE-modified proteins in PD; in contrast only 9% of nigral neurons were positive in the control subjects; the difference was statistically significant (Mann-Whitney U test; P < 0.01). In contrast to the substantia nigra, the oculomotor neurons in the same midbrain sections showed no or only weak staining for HNE-modified proteins in both PD and control subjects; young control subjects did not show any immunostaining; however, aged control subjects showed weak staining in the oculomotor nucleus, suggesting age-related accumulation of HNE-modified proteins in the neuron. Our results indicate the presence of oxidative stress within nigral neurons in PD, and this oxidative stress may contribute to nigral cell death.
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PMID:Immunohistochemical detection of 4-hydroxynonenal protein adducts in Parkinson disease. 861 Jan 3

(E)-4-Hydroxy-2-nonenal (HNE) is a highly reactive product of the free radical-stimulated lipid peroxidation of phospholipid-bound arachidonic acid in cellular membranes. We describe a sensitive and specific method for the determination of HNE in clinical samples. The method is based on the formation of the O-pentafluorobenzyl (O-PFB) oxime derivative of HNE, which is then extracted and cleaned up by solid-phase extraction. The HNE O-PFB oxime is then analysed without further derivatisation by capillary column gas chromatography-negative ion chemical ionisation mass spectrometry (GC-NICI-MS) using selected-ion monitoring. Concentrations down to the pmol range were achieved using deuterated HNE as an internal standard. The method was used to determine HNE in the cerebrospinal fluid and plasma of patients with Parkinson's disease, the plasma of patients with HIV-1 infection and AIDS and in inflamed mucosal biopsy specimens from patients with inflammatory bowel disease.
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PMID:Determination of the lipid peroxidation product (E)-4-hydroxy-2-nonenal in clinical samples by gas chromatography--negative-ion chemical ionisation mass spectrometry of the O-pentafluorobenzyl oxime. 917 61

In this study a chronic cerebral iron-loaded model was established by feeding mice with high iron diet. Data indicated that brain iron concentrations were significantly increased in iron-fed mice compared with those of controls. A significant increase in oxidized glutathione (GSSG), decrease in total glutathione (oxidized and reduced glutathione, GSSG + GSH), and therefore increase in the GSSG/(GSSG + GSH) ratios were observed in iron-loaded mice. Hydroxyl radical (.OH) levels in striatum and brainstem were also significantly increased. Excessive iron alone did not change either dopamine (DA) or lipid peroxidation (LPO) concentrations in striatum. However, a single injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, 30 mg/kg, i.p.) into the iron-loaded mice caused a great enhancement in all these biochemical abnormalities. These findings suggest that iron does induce oxidative stress, but not severely injury neurons per sc. Excessive iron accumulation in the brain, however, is a potential risk for neuronal damage, which may promote by triggering factor(s). This supports the hypothesis that excessive cerebral iron may contribute to the aetiology of Parkinson's disease (PD).
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PMID:Excessive iron accumulation in the brain: a possible potential risk of neurodegeneration in Parkinson's disease. 944 65

1. The disposition and metabolic fate of ropinirole, a novel compound indicated for the symptomatic treatment of Parkinson's disease, was studied in the mouse, rat, cynomolgus monkey and man, following oral and intravenous administration of ropinirole hydrochloride. 2. In all species, nearly all of the p.o. administered dose (94%) was rapidly absorbed from the gastrointestinal tract following administration of 14C-ropinirole hydrochloride. In rat and monkey, the compound distributed rapidly beyond total body water and was shown to cross the blood-brain barrier. Blood clearance of the compound was high, approximately equal to one-half the hepatic blood flow in the monkey and similar to the hepatic blood flow in rat. Terminal phase elimination half-lives for the compound were relatively short (0.5 and 1.3 h in rat and monkey respectively), although there was evidence of a second elimination phase in the monkey with an elimination half-life of approximately 5-11 h. Plasma concentrations of ropinirole after the intravenous dose were not determined in the mouse and were below the lower limit of quantification in man (0.08 ng/ml) at the doses used in the studies described in this paper. 3. In both animals and man, ropinirole was extensively metabolized. In the rat, the major metabolic pathway was via hydroxylation of the aromatic ring to form 7-hydroxy ropinirole. In mouse, monkey and man, the major pathway was via N-depropylation. The N-despropyl metabolite was metabolized further to form 7-hydroxy and carboxylic acid derivatives. Metabolites formed in all species were generally metabolized further by glucuronidation. 7-Hydroxy ropinirole is the only metabolite of ropinirole previously shown to possess significant dopamine agonist activity in vivo. In all species, the major route of excretion of ropinirole-related material after oral or intravenous administration of the compound was renal (60-90% of dose).
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PMID:Disposition of ropinirole in animals and man. 1021 70

Hydroxyl radical (.OH) levels in blood, superoxide dismutase (SOD) activity in plasma (plasma-SOD) and in red blood cells (RBC) relative to Cu,Zn-SOD (SOD1) protein (RBC-SOD/SOD1), SOD1 protein in RBC (SOD1/RBC) and plasma (SOD1/plasma), and Mn-SOD protein in plasma (SOD2/plasma) were measured in patients with Parkinson's disease (PD), multiple-system atrophy (MSA) with parkinsonism, and in control subjects. Patients with PD had significantly higher.OH and plasma-SOD values and significantly lower RBC-SOD/SOD1 and SOD1/RBC values than the corresponding MSA and control values. In PD, RBC-SOD/SOD1 values were significantly lower in older patients and were negatively correlated with age.OH levels were significantly higher in PD patients with early onset, a long period of illness or severe Yahr stage, and were negatively correlated with onset and positively correlated with duration of illness. RBC-SOD/SOD1 values in PD patients who received pergolide therapy were significantly higher than those in PD patients who received neither pergolide nor bromocriptine therapy. Therefore, the higher.OH level and the lower SOD1 activity may play a role in the onset and progression of PD, and pergolide may act neuroprotectively by inducing SOD1 activity.
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PMID:Hydroxyl radical and superoxide dismutase in blood of patients with Parkinson's disease: relationship to clinical data. 1056 21

Hydroxyl free radical production seems to play an important role in the pathogenesis of Parkinson's disease. In the present study, we investigated the dopamine agonists pramipexole and pergolide as well as the nitrone compound S-PBN (N-tert-butyl-alpha-(2-sulfophenyl)nitrone) to reduce hydroxyl radical formation. Microdialysis experiments were carried out in non-anaesthetized Wistar rats. Salicylate was incorporated into the perfusion fluid to measure indirectly hydroxyl radicals indicated by 2,3-dihydroxybenzoic acid (2,3-DHBA). Local perfusion with 0.2 or 2 nmol/2 microl/min 6-hydroxydopamine (6-OHDA) via the microdialysis probe significantly increased 2,3-DHBA levels 14-fold and 47-fold, respectively. Systemic application of either pergolide (0.05 mg/kg) or pramipexole (1 mg/kg) failed to significantly reduce 6-OHDA-induced hydroxyl radical production. In contrast, a 40 min pretreatment with pramipexole (2 and 10 nmol/2 microl/min via the probe) before onset of 6-OHDA perfusion, significantly attenuated 2, 3-DHBA levels compared with vehicle controls. S-PBN pretreatment (2 nmol/2 microl/min) was not effective to reduce 2,3-DHBA levels. In conclusion, pramipexole was able to reduce hydroxyl radical levels induced by 6-OHDA in vivo after local application. This property of pramipexole may be beneficial under conditions of enhanced hydroxyl radical formation in parkinsonian brains and may add to its well known dopamine D(2)-like receptor agonistic effects.
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PMID:The dopamine agonist pramipexole scavenges hydroxyl free radicals induced by striatal application of 6-hydroxydopamine in rats: an in vivo microdialysis study. 1107 50


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