Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.9.3.1 (cytochrome oxidase)
 8,822 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The dermal cells in grey, xanthic, and white goldfish integuments were cytochemically characterized for the following enzymatic activities: tyrosinase, DOPA-oxidase, cytochrome oxidase, monoamine oxidase, peroxidase, non-specific esterase, cholinesterase, NAD-diaphorase, NADP-diaphorase, aryl sulfatase, nucleotide phosphodiesterase, beta-glucuronidase, acid phosphatase, alkaline phosphatase, adenosine triphosphatase, thiamine pyrophosphatase, glucose-6-phosphatase, aldolase, as well as succinate, malate, isocitrate, glutamate, glucose-6-phosphate, 6-phosphogluconate, alpha-glycerophosphate, alcohol, lactate, and beta-hydroxybutyrate dehydrogenases. It was found that the epidermis was a significant barrier to the access of cytochemical reaction substrates. Removal of the epidermal barrier provided dermal cell localizations of enzymatic activities which were reproducible. Further, alterations in reaction times and temperatures from the mammalian methodology provided conditions fe various integumental cells were compared for possible interrelationships. The basic foundations for future work with the dermis of poikilothermic vertebrates on an experimental basis were established. In addition, a previously undescribed non-pigmented dermal cell, the "x"-cell, was found to have enzymatic characteristics similar to both melanophores and lipophores. The "x"-cell may be the common precursor of both types of pigment cells.
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PMID:Cytochemical characterization of goldfish (Carassius auratus L.) dermis with special reference to the pigment cells. 82 86

The indices of central hemodynamics and myocardial contractility were studied by poly- and mechanocardiography in 25 patients with stage I-IIA circulatory insufficiency prior to and after treatment with 1-dioxyphenlalanine. The content of lactic and pyruvic acids in the blood and erythrocyte permeability to 32P were determined at the same time. The activity of the redox enzymes was studied in rats with experimentally induced circulatory insufficiency on the background of 1-DOPA medication. It was established that contractility of the heart and indices of central hemodynamics improved due to the effect of 1-DOPA. A decrease in the lactate concentration and an elevation of the pyruvate level in the blood of patients were noted. In animal experiments increased activity of cytochrome oxidase, succinic dehydrogenase, and alkaline and acid phosphatase in the myocardium was demonstrated.
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PMID:[Clinico-experimental evaluation of therapeutic effectiveness of 1-dihydroxyphenylalanine in circulatory insufficiency]. 92 3

L-3,4-Dihydroxyphenylalanine (L-dopa) is toxic for human neuroblastoma cells NB69 and its toxicity is related to several mechanisms including quinone formation and enhanced production of free radicals related to the metabolism of dopamine via monoamine oxidase type B. We studied the effect of L-DOPA on activities of enzyme complexes in the electron transport chain (ETC) in homogenate preparations from the human neuroblastoma cell line NB69. As a preliminary step we compared the activity of ETC in cellular homogenates with that of purified mitochondria from NB69 cells and rat brain. Specific activities for complex I, complex II-III, and complex IV in NB69 cells were, respectively, 65, 96, and 32% of those in brain mitochondria. Complex I activity was inhibited in a dose-dependent way by 1-methyl-4-phenylpyridinium ion with an EC50 of approximately 150 microM. Treatment with 0.25 mM L-dopa for 5 days reduces complex IV activity to 74% of control values but does not change either complex I or citrate synthase. Ascorbic acid (1 mM), which protects NB69 cells from L-dopa-induced neurotoxicity, increases complex IV activity to 133% of the control and does not change other ETC complexes. Ascorbic acid also reverses L-dopa-induced reduction of complex IV activity in NB69 cells. This observation might indicate that the protection observed with ascorbic acid is related to complex IV activation. In vitro incubation with L-dopa (0.125-4 mM) for 2 min produced a dose-dependent reduction of complex IV without change in complex I and II-III activities.
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PMID:L-dopa inhibits complex IV of the electron transport chain in catecholamine-rich human neuroblastoma NB69 cells. 783 50

In order to examine the consequences of nigrostriatal denervation on metabolic and functional activity of the basal ganglia, we analysed the distribution of cytochrome oxidase, a metabolic marker for neuronal functional activity, throughout the different basal ganglia structures in parkinsonian syndromes. The study was performed using enzyme histochemistry and densitometric measurements in patients with Parkinson's disease and in monkeys rendered parkinsonian by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyrydine (MPTP) intoxication. In MPTP-intoxicated monkeys compared to control animals, enzyme activity was significantly increased in the subthalamic nucleus and in the output nuclei of the basal ganglia, e.g. the internal segment of the globus pallidus and the substantia nigra pars reticulata, but remained unchanged in the external segment of the globus pallidus and the striatum. L-DOPA treatment reversed the increased enzyme activity in all of the affected structures studied. In contrast, in parkinsonian patients, who had all been chronically treated with L-DOPA, no changes in enzyme activity were detected compared to control subjects. The results in MPTP-intoxicated monkeys are in agreement with the accepted model of basal ganglia organization, in which the output nuclei of the basal ganglia are considered to be overactive after nigrostriatal denervation, partly due to increased activity of excitatory afferents from the subthalamic nucleus. Since the increased enzyme activity in MPTP-intoxicated monkeys was reversed by L-DOPA therapy, the unchanged cytochrome oxidase activity observed in parkinsonian patients might result from L-DOPA treatment, combined with the chronicity of nigrostriatal denervation.
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PMID:Metabolic activity of the basal ganglia in parkinsonian syndromes in human and non-human primates: a cytochrome oxidase histochemistry study. 868 21

In Parkinson's disease, nigrostriatal denervation leads to an overactivity of the subthalamic nucleus and its target areas, which is responsible of the clinical manifestations of the disease. Because the subthalamic nucleus uses glutamate as neurotransmitter and is innervated by glutamatergic fibers, pharmacological blockade of glutamate transmission might be expected to restore the cascade of neurochemical changes induced by a dopaminergic denervation within the basal ganglia. To test this hypothesis, two types of glutamate antagonists, the NMDA receptor antagonist MK-801 and the alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptor antagonist LY293558, were administered systemically, either alone or in combination with L-DOPA, in rats with a unilateral 6-hydroxydopamine lesion of the nigrostriatal dopamine pathway. The effect of treatment was assessed neurochemically by analyzing at the cellular level the functional activity of basal ganglia output structures and the subthalamic nucleus using the expression levels of the mRNAs coding for glutamic acid decarboxylase and cytochrome oxidase, respectively, as molecular markers of neuronal activity. The present study shows that treatment with glutamate antagonists, and particularly with AMPA antagonists, alone or in combination with L-DOPA, reverses the overactivity of the subthalamic nucleus and its target areas induced by nigrostriatal denervation. These results furnish the neurochemical basis for the potential use of glutamate antagonists as therapeutic agents in Parkinson's disease.
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PMID:Systemic administration of NMDA and AMPA receptor antagonists reverses the neurochemical changes induced by nigrostriatal denervation in basal ganglia. 1038 87

We developed a primate model of striatonigral degeneration (SND), the neuropathology underlying levodopa-unresponsive parkinsonism associated with multiple systemic atrophy (MSA-P), by sequential systemic administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and 3-nitropropionic acid (3NP) in a Macaca fascicularis monkey. L-Dopa-responsive parkinsonian features emerged after MPTP injections. Subsequent chronic 3NP administration aggravated the motor symptoms and abolished the L-dopa response. In vivo magnetic resonance imaging revealed bilateral striatal lesions. Histopathologically, there was severe dopaminergic cell loss in the substantia nigra pars compacta compared with the control monkey. Furthermore, we observed circumscribed areas of severe neuronal degeneration in the motor striatum. These changes were absent in the control monkey, and they were associated with diffuse metabolic failure as demonstrated by cytochrome oxidase histochemistry. The striatal pathology predominantly involved output pre-pro-enkephalin A- and substance P-containing cells, whereas somatostatin (NADPH-diaphorase)-containing interneurons were relatively spared. Our model therefore reproduced levodopa-unresponsive parkinsonism and SND-like pathologic changes characteristic of MSA-P. The double-lesion primate model of SND may serve as a preclinical test-bed for the evaluation of novel therapeutic strategies in MSA-P.
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PMID:Toward a primate model of L-dopa-unresponsive parkinsonism mimicking striatonigral degeneration. 1083 Apr 20

Amyloid-beta peptide (Abeta) is the toxic agent in Alzheimer's disease (AD), although the mechanism causing the neurodegeneration is not known. We previously proposed a mechanism in which excessive Abeta binds to regulatory heme, triggering functional heme deficiency (HD), causing the key cytopathologies of AD. We demonstrated that HD triggers the release of oxidants (e.g., H(2)O(2)) from mitochondria due to the loss of complex IV, which contains heme-a. Now we add more evidence that Abeta binding to regulatory heme in vivo is the mechanism by which Abeta causes HD. Heme binds to Abeta, thus preventing Abeta aggregation by forming an Abeta-heme complex in a cell-free system. We suggest that this complex depletes regulatory heme, which would explain the increase in heme synthesis and iron uptake we observe in human neuroblastoma cells. The Abeta-heme complex is shown to be a peroxidase, which catalyzes the oxidation of serotonin and 3,4-dihydroxyphenylalanine by H(2)O(2). Curcumin, which lowers oxidative damage in the brain in a mouse model for AD, inhibits this peroxidase. The binding of Abeta to heme supports a unifying mechanism by which excessive Abeta induces HD, causes oxidative damage to macromolecules, and depletes specific neurotransmitters. The relevance of the binding of regulatory heme with excessive Abeta for mitochondrial dysfunction and neurotoxicity and other cytopathologies of AD is discussed.
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PMID:Amyloid-beta peptide binds with heme to form a peroxidase: relationship to the cytopathologies of Alzheimer's disease. 1649 52

Increasing evidence suggests a critical role for oxidative and nitrosative stress in the pathogenesis of most important neurodegenerative disorders. Parkinson's disease (PD) is a neurodegenerative disease characterized by a severe depletion in number of dopaminergic cells of the substantia nigra (SN). Administration of L-DOPA (LD) is the more effective treatment for patients with PD. However, the vast majority of patients suffer LD-related complications, which represent the major problem in the clinical management of PD. In the present study, LD administration to rats resulted in a significant dose-dependent increase in Hsp70 synthesis which was specific for the SN. The amount of 70 kDa protein increased after 6 h treatment reaching the maximal induction after 24-48 h. Induction of Hsp70 in the SN was associated with a significant increase in constitutive Hsc70 and mitochondrial Hsp60 stress proteins, and with increased expression of mitochondrial complex I whereas no significant changes were found in the activity of complex IV. In the same experimental conditions, a significant decrease in reduced glutathione was observed, which was associated with an increased content of oxidized glutathione content as well as nitric oxide (NO) synthase activity, NO metabolites and nitrotyrosine immunoreactivity. Interestingly, Hsp70 induction, iNOS up-regulation and nitrotyrosine formation have been confirmed also in SN and striatum of rats treated with LD and carbidopa, this latter being an inhibitor of the peripheral DOPA decarboxylase. Our data are in favor of the importance of the heat shock signal pathway as a basic mechanism of defense against neurotoxicity elicited by free radical oxygen and nitrogen species produced in aging and neurodegenerative disorders.
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PMID:In vivo induction of heat shock proteins in the substantia nigra following L-DOPA administration is associated with increased activity of mitochondrial complex I and nitrosative stress in rats: regulation by glutathione redox state. 1724 Nov 15

The long-duration response (LDR) is a sustained improvement in parkinsonism due to chronic levodopa therapy and lasts after discontinuation of treatment. We have investigated the molecular changes that underlie the LDR in rats with a unilateral 6-hydroxydopamine (6-OHDA) lesion. Animals were treated for 22 days with levodopa or saline. Forelimb akinesia was evaluated prior and following a test dose of levodopa. Rotational behaviour was weekly evaluated. Levodopa induced an improvement in the parkinsonian limb akinesia that lasted for 48 h after withdrawal. A shortening in the duration of rotational behaviour was observed. After 3 days of washout, levodopa treatment maintained elevated striatal preproenkephalin mRNA expression, also inducing an increase in preprodynorphin (PDyn) and dopamine D-3 receptor mRNAs, but without any modification of the adenosine A(2A) mRNA expression induced by 6-OHDA. Levodopa reversed the lesion-induced increase in the expression of cytochrome oxidase mRNA in the subthalamic nucleus and glutamate decarboxylase mRNA in the pars reticulata of the substantia nigra. After 7 days of levodopa washout, the molecular markers show a decline in the basal ganglia evolving towards the parkinsonian state, being statistically significant for the striatal PDyn mRNA. This study characterizes the concomitant presence of the short-duration response and LDR to levodopa in the 6-OHDA model of parkinsonism and shows that the molecular changes induced by levodopa in the basal ganglia are not permanent and that this reversal after levodopa washout may be responsible for the gradual motor deterioration that characterize the LDR.
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PMID:Concomitant short- and long-duration response to levodopa in the 6-OHDA-lesioned rat: a behavioural and molecular study. 1724 Dec 87