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A possible restriction of ferro- and ferricyanide oxidoreductase activities of rat liver mitochondria by the outer membrane

Authors :
Luis A. Gómez Ramírez
Victor V. Lemeshko
Source :
Archives of biochemistry and biophysics. 443(1-2)
Publication Year :
2005

Abstract

In this work, various ferro-ferricyanide oxidoreductase activities of rat liver mitochondria were studied to find conditions under which the outer membrane might restrict the flux of these highly charged non-biological anions. When the isotonic low ionic strength medium was supplemented with 25 mM KCl, a several-fold increase in the succinate-ferricyanide reductase activity of mitochondria and in the rate of external NADH oxidation in the presence of ferrocyanide was observed. Mitochondrial respiration with 5 mM ferrocyanide was almost completely inhibited after consumption of 3.8–18.5% of the dissolved oxygen, depending on the medium and the presence of 2,4-dinitrophenol. These and other experimental data together with mathematical modeling of the redox-state equilibrium suggest that the measured activities might be restricted by two factors: first, the permeability of the outer mitochondrial membrane and second, a strong influence of the ionic strength of incubation media on the intermembrane space redox reactions.

Details

ISSN :
00039861
Volume :
443
Issue :
1-2
Database :
OpenAIRE
Journal :
Archives of biochemistry and biophysics
Accession number :
edsair.doi.dedup.....94e8f0f74bb094938aa3437bfef3a753