Data/hora: 05/06/2024 11:26:02

Provedor de dados: 	56	
País: 	Brazil	
Título: 	Arachidonic acid triggers an oxidative burst in leukocytes	
Autores: 	Pompeia,C.; Cury-Boaventura,M.F.; Curi,R.	
Data: 	2003-11-01	
Ano: 	2003	
Palavras-chave: 	Arachidonic acid; NADPH oxidase; Nitroblue tetrazolium; Leukocytes; Reactive oxygen species.	
Resumo: 	The change in cellular reducing potential, most likely reflecting an oxidative burst, was investigated in arachidonic acid- (AA) stimulated leukocytes. The cells studied included the human leukemia cell lines HL-60 (undifferentiated and differentiated into macrophage-like and polymorphonuclear-like cells), Jurkat and Raji, and thymocytes and macrophages from rat primary cultures. The oxidative burst was assessed by nitroblue tetrazolium reduction. AA increased the oxidative burst until an optimum AA concentration was reached and the burst decreased thereafter. In the leukemia cell lines, optimum concentration ranged from 200 to 400 µM (up to 16-fold), whereas in rat cells it varied from 10 to 20 µM. Initial rates of superoxide generation were high, decreasing steadily and ceasing about 2 h post-treatment. The continuous presence of AA was not needed to stimulate superoxide generation. It seems that the NADPH oxidase system participates in AA-stimulated superoxide production in these cells since the oxidative burst was stimulated by NADPH and inhibited by N-ethylmaleimide, diphenyleneiodonium and superoxide dismutase. Some of the effects of AA on the oxidative burst may be due to its detergent action. There apparently was no contribution of other superoxide-generating systems such as xanthine-xanthine oxidase, cytochromes P-450 and mitochondrial electron transport chain, as assessed by the use of inhibitors. Eicosanoids and nitric oxide also do not seem to interfere with the AA-stimulated oxidative burst since there was no systematic effect of cyclooxygenase, lipoxygenase or nitric oxide synthase inhibitors, but lipid peroxides may play a role, as indicated by the inhibition of nitroblue tetrazolium reduction promoted by tocopherol.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003001100013	
Editor: 	Associação Brasileira de Divulgação Científica	
Relação: 	10.1590/S0100-879X2003001100013	
Formato: 	text/html	
Fonte: 	Brazilian Journal of Medical and Biological Research  v.36 n.11 2003	
Fonte: 	info:eu-repo/semantics/openAccess