NAD(P)H- and superoxide-dependent nitric oxide degradation by rat liver mitochondria.
Mitochondria consume nitric oxide (NO) mainly through reaction with superoxide anion (O(2)(-)). Here, we analyzed the O(2)(-) sources for NO degradation by isolated rat liver mitochondria. Electron leakage from complex III and reverse electron transport to complex I accounted for O(2)(-)-dependent NO degradation by mitochondria in the presence of a protonmotive force. Mitochondria incubated with NAD(P)H also presented intense O(2)(-) generation and NO degradation rates that were insensitive to respiratory inhibitors and abolished after proteinase treatment. These results suggest that an outer membrane-localized NAD(P)H oxidase activity, in addition to the electron leakage from the respiratory chain, promotes O(2)(-)-dependent NO degradation in rat liver mitochondria.
Oliveira
Halley Caixeta
HC
Departamento de Biologia Vegetal, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil.
Saviani
Elzira Elisabeth
EE
Salgado
Ione
I
D000818:Animals; D008297:Male; D008930:Mitochondria, Liver / Q000378:metabolism*; D009243:NAD / Q000378:metabolism*; D019255:NADPH Oxidases / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013481:Superoxides / Q000378:metabolism*
D009243:NAD; D013481:Superoxides; D009569:Nitric Oxide; D019255:NADPH Oxidases