Influence of mitochondrial membrane fatty acid composition on proton leak and H 2O 2 production in liver

Jon J Ramsey, Mary Ellen Harper, Stephen J. Humble, Edward K. Koomson, Jesmon J. Ram, Lisa Bevilacqua, Kevork Hagopian

Research output: Contribution to journalArticle

36 Scopus citations

Abstract

Mitochondrial membrane fatty acid composition has been proposed to play a role in determining mitochondrial proton leak rate. The purpose of this study was to determine if feeding rats diets with different fatty acid sources produces changes in liver proton leak and H 2O 2 production. Six-month-old male FBNF 1 rats were fed diets with a primary fat source of either corn or fish oil for a 6-month period. As expected, diet manipulations produced substantial differences in mitochondrial fatty acid composition. These changes were most striking for 20:4n6 and 22:6n3. However, proton leak and phosphorylation kinetics as well as lipid and protein oxidative damage were not different (P>0.10) between fish and corn oil groups. Metabolic control analysis, however, did show that control of both substrate oxidation and phosphorylation was shifted away from substrate oxidation reactions to increased control by phosphorylation reactions in fish versus corn oil groups. Increased mitochondrial H 2O 2 production was observed in corn versus fish oil-fed rats when mitochondria were respiring on succinate alone or on either succinate or pyruvate/malate in the presence of antimycin A. These results show that mitochondrial H 2O 2 production and the regulation of oxidative phosphorylation are altered in liver mitochondria from rats consuming diets with either fish or corn oil as the primary lipid source.

Original languageEnglish (US)
Pages (from-to)99-108
Number of pages10
JournalComparative Biochemistry and Physiology - B Biochemistry and Molecular Biology
Volume140
Issue number1
DOIs
StatePublished - Jan 2005

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Keywords

  • Aging
  • Calorie restriction
  • Corn oil
  • Fish oil
  • Lipid peroxidation
  • Metabolic control analysis
  • Protein carbonyls
  • Reactive oxygen species

ASJC Scopus subject areas

  • Biochemistry
  • Physiology

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