Enzymic mechanisms of superoxide production

Cross, Andrew R.; Jones, Owen

doi:10.1016/s0005-2728(05)80140-9

Cited by 465 publications

(256 citation statements)

References 289 publications

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“…These differences between the results with IgG and PMA seem to be due to differences in the activation process of NADPH oxidase and in the following regulatory process [1][2][3]. In the cases with IgG electrodes, single cells produced 02 only at the surface that contacted with the electrode, which was confirmed by no detection of current at other sites of the cell surface.…”

Section: Resultsmentioning

confidence: 87%

“…Large numbers of biochemical studies have been performed on mechanisms of the O~ generation and its regulation, and revealed that the reaction is catalyzed by an enzyme system 'NADPH oxidase', which consists of several cytosolic proteins and a membrane bound b-type cytochrome (cyt b55s). Cyt b558 catalyzes one electron reduction of 02 [5][6][7], and the cytosolic proteins are involved in the activation of cyt b558 [1][2][3].…”

Section: Introductionmentioning

confidence: 99%

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Direct measurement of oscillatory generation of superoxide anions by single phagocytes

et al. 1996

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Phagocytic cells such as neutrophils generate superoxide anions (O~) within phagocytic vacuoles for killing and digesting microorganisms. Here we report the simultaneous observation of morphological changes and O~ generation in single phagocytic cells during phagocytosis. Point stimulation of a cell by contact with an opsonized microelectrode at the cell surface induced significant deformation to engulf the electrode, and also induced the O~ generation which was measured by the electrode. Periodic fluctuations in the magnitude of the O~ generation were observed in the time course. These oscillations may be caused by metabolic regulation of the formation of NADPH, which is the substrate for the OF generation.

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Section: Resultsmentioning

confidence: 87%

Section: Introductionmentioning

confidence: 99%

Direct measurement of oscillatory generation of superoxide anions by single phagocytes

et al. 1996

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“…There are several mechanisms which, in conjunction, transform the mild reactive O 2 •− into more destructive radicals. First, superoxide can be protonized, to the more reactive and freely permeable HO 2 • radical; second, it can also be spontaneously dismutated to H 2 O 2 , also permeable into bacteria, which in turn can generate OH There was early evidence in the literature suggesting the presence of NAPDH oxidase activity in several cell types (Cross and Jones, 1991), but it was at the outset of this millennium that was shown that several NADPH oxidase isoforms do in fact exist. Today, the family of NADPH oxidases is known as the Nox family and has seven members: including Nox1, Nox2 (formerly known as gp91 phox , the phagocyte isoform), Nox3, Nox4, Nox5, Duox1 and Duox2.…”

Section: Napdh Oxidasementioning

confidence: 99%

Chemoreception in the context of the general biology of ROS

González

Agapito

Rocher

et al. 2007

Respiratory Physiology & Neurobiology

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Superoxide anion is the most important reactive oxygen species (ROS) primarily generated in cells. The main cellular constituents with capabilities to generate superoxide anion are NADPH oxidases and mitochondrial respiratory chain. The emphasis of our article is centered in critically examining hypotheses proposing that ROS generated by NADPH oxidase and mitochondria are key elements in O 2 -sensing and hypoxic responses generation in carotid body chemoreceptor cells. Available data indicate that chemoreceptor cells express a specific isoform of NADPH oxidase that is activated by hypoxia; generated ROS acting as negative modulators of the carotid body (CB) hypoxic responses. Literature is also consistent in supporting that poisoned respiratory chain can produce high amounts of ROS, making mitochondrial ROS potential triggers-modulators of the CB activation elicited by mitochondrial venoms. However, most data favour the notion that levels of hypoxia, capable of strongly activating chemoreceptor cells, would not increase the rate of ROS production in mitochondria, making mitochondrial ROS unlikely triggers of hypoxic responses in the CB. Finally, we review recent literature on heme oxygenases from two perspectives, as potential O 2 -sensors in chemoreceptor cells and as generators of bilirubin which is considered to be a ROS scavenger of major quantitative importance in mammalian cells.

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“…Células fagocíticas ativadas geram ERO intencionalmente como parte de sua ação bactericida. Em condições normais, entretanto, a principal fonte de ERO nas células é a perda de elétrons da cadeia de transporte na mitocôndria e no retículo citoplasmático (27,28) . A produção de ERO tem sido associada com o desenvolvimento de várias doenças, incluindo aterosclerose, doenças neurodegenerativas e câncer (26) .…”

Section: Introductionunclassified

Avaliação da produção de espécies reativas de oxigênio por granulócitos de sangue periférico de pacientes com fibromialgia primária

Souza¹,

Nogueira-Machado²,

Silva³

et al. 2003

Rev. Bras. Reumatol.

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RESUMOObjetivo: avaliar anormalidades bioquímicas que possam estar relacionadas à fibromialgia, mais especificamente o metabolismo oxidante de granulócitos de pacientes com fibromialgia primária (FMP). Métodos: foram selecionados 10 pacientes (9 mulheres e 1 homem) portadores de FMP, com idade entre 20 e 40 anos, de acordo com os critérios do Colégio Americano de Reumatologia, que não apresentavam qualquer outra doença de curso agudo ou crônico e estavam sem utilizar medicamentos no mínimo durante duas semanas. Controles normais (n = 19) pareados por sexo e idade foram selecionados. Os granulócitos de pacientes e controles foram separados do sangue periférico e utilizados como célula de trabalho. A produção de espécies reativas de oxigênio (ERO) foi determinada por meio de ensaio de quimioluminescência dependente de luminol. Resultados: demonstramos, pela primeira vez, uma produção significantemente elevada de ERO (3,2 vezes maior) em granulócitos de sangue periférico de pacientes com FMP (p < 0,05). Conclusões: estes resultados demonstraram um comportamento anormal dos granulócitos de pacientes com FMP, em que uma produção aumentada de espécies reativas do oxigênio foi observada. Estudos futuros serão necessários para melhor esclarecer estes resultados, delineando uma nova perspectiva na compreensão e abordagem destes pacientes.

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Enzymic mechanisms of superoxide production

Cited by 465 publications

References 289 publications

Direct measurement of oscillatory generation of superoxide anions by single phagocytes

Direct measurement of oscillatory generation of superoxide anions by single phagocytes

Chemoreception in the context of the general biology of ROS

Avaliação da produção de espécies reativas de oxigênio por granulócitos de sangue periférico de pacientes com fibromialgia primária

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