Abstract
Holey electron transport chain: aging increases mitochondrial superoxide production in rat liver
The FASEB journal, Vol.20(5), pp.A1457-A1458
03/2006
DOI: 10.1096/fasebj.20.5.A1457-d
Abstract
Superoxide (O2·−) is produced by the one‐electron reduction of O2 mediated by mitochondrial electron transport chains (ETC) and has been proposed to play a key role in the increased oxidative damage associated with aging. Electron paramagnetic resonance spectroscopy (EPR) was used to test the hypothesis that rat liver mitochondria produce more O2·−as a function of age. Mitochondria were isolated from livers of young (6 mo) and old (24 mo) rats (n=4). Incubations of mitochondria for determinations of O2·− production were done with ETC substrates in the presence or absence of inhibitors of Complex I or Complex III [i.e., Rotenone (ROT) or Antimycin A (AA), for I and III, respectively], which are known to increase O2·− production in isolated mitochondria. Using the spin trap DMPO, EPR analysis indicated that DMPO‐OH signals were significantly greater (P<0.05) in freshly isolated mitochondria from old versus young rats when incubated with the Complex I substrate NADH alone, NADH + AA, and NADH + ROT. In contrast, the Complex II substrate succinate, succinate + AA, or succinate + ROT produced no apparent differences in DMPO‐OH signals between age groups. Inclusion of superoxide dismutase in the incubation eliminated virtually all DMPO‐OH signals from isolated mitochondria, confirming that the DMPO‐OH signals can be attributed to mitochondrial formation of O2·−. These data suggest that O2·− arises from Complex I of isolated rat liver mitochondria and increases as a function of aging. Alteration in O2·− from the ETC could provide insight into the contribution of mitochondria to aging‐associated increases in oxidative damage.
Supported by NIH AG12350
Details
- Title: Subtitle
- Holey electron transport chain: aging increases mitochondrial superoxide production in rat liver
- Creators
- J L Haak - The University of IowaH J Zhang - The University of IowaG R Buettner - The University of IowaD R Spitz - The University of IowaK C Kregel - The University of Iowa
- Resource Type
- Abstract
- Publication Details
- The FASEB journal, Vol.20(5), pp.A1457-A1458
- Publisher
- Federation of American Societies for Experimental Biology
- DOI
- 10.1096/fasebj.20.5.A1457-d
- ISSN
- 0892-6638
- eISSN
- 1530-6860
- Number of pages
- 2
- Grant note
- NIH (AG12350)
- Language
- English
- Date published
- 03/2006
- Academic Unit
- Fraternal Order of Eagles Diabetes Research Center; Radiation Oncology; Provost Office Administration; Health and Human Physiology; Pathology
- Record Identifier
- 9984213313602771
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