Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2014 Feb;46(1):83-91.
doi: 10.1007/s10863-013-9534-8. Epub 2013 Nov 27.

Role of enzymatic and non-enzymatic processes in H2O2 removal by rat liver and heart mitochondria

Affiliations

Role of enzymatic and non-enzymatic processes in H2O2 removal by rat liver and heart mitochondria

Paola Venditti et al. J Bioenerg Biomembr. 2014 Feb.

Abstract

We compared the capacity of rat liver and heart mitochondria to remove exogenously produced H2O2, determining their ability to decrease fluorescence generated by H2O2 detector system. In the absence of substrates, liver and heart mitochondria removed H2O2 at similar rates. Respiratory substrate addition increased removal rates, indicating a respiration-dependent process. Moreover, the rates were higher with pyruvate/malate than with succinate and in heart than in liver mitochondria. Generally, the changes in H2O2 removal rates mirrored those of H2O2 release rates excluding the possibility that endogenous and exogenous H2O2 competed for the removing system. This idea was supported by the observation that the heaviest of three liver mitochondrial fractions exhibited the highest rates of both H2O2 release and removal. Pharmacological inhibition showed tissue-linked differences in antioxidant enzyme contribution to H2O2 removal which were consistent with the differences in antioxidant system activities. The enzymatic processes accounted only in part for net H2O2 removal and the non-enzymatic ones participated to H2O2 scavenging to a degree that was higher for heart than for liver mitochondria. The idea that non-enzymatic scavenging was due in great part to hemoproteins action was consistent with observation that the concentration of cytochromes, in particular cytochrome c, was higher in heart mitochondria. Indirect support was also obtained by a technique of enhanced luminescence, utilizing the capacity of cytochrome c/H2O2 to catalyze the luminol oxidation, which showed that luminescence response to an oxidative challenge was higher in heart mitochondria.

PubMed Disclaimer

References

    1. Nat Chem Biol. 2005 Sep;1(4):223-32 - PubMed
    1. Anal Biochem. 1984 Aug 15;141(1):280-6 - PubMed
    1. J Biophys Biochem Cytol. 1961 Jan;9:19-28 - PubMed
    1. J Biol Chem. 2003 Aug 8;278(32):29410-9 - PubMed
    1. J Biol Chem. 2004 Feb 6;279(6):4166-74 - PubMed

Publication types

LinkOut - more resources