Age related bioenergetics profiles in isolated rat cardiomyocytes using extracellular flux analyses

Kennedy S. Mdaki, Tricia D. Larsen, Lucinda J. Weaver, Michelle L. Baack

Research output: Contribution to journalArticlepeer-review

24 Scopus citations


Mitochondrial dysfunction is increasingly recognized and studied as a mediator of heart disease. Extracellular flux analysis (XF) has emerged as a powerful tool to investigate cellular bioenergetics in the context of cardiac health and disease, however its use and interpretation requires improved understanding of the normal metabolic differences in cardiomyocytes (CM) at various stages of maturation. This study standardized XF analyses methods (mitochondrial stress test, glycolytic stress test and palmitate oxidation test) and established age related differences in bioenergetics profiles of healthy CMs at newborn (NB1), weaning (3WK), adult (10WK) and aged (12-18MO) time points. Findings show that immature CMs demonstrate a more robust and sustained glycolytic capacity and a relative inability to oxidize fatty acids when compared to older CMs. The study also highlights the need to recognize the contribution of CO2 from the Krebs cycle as well as lactate from anaerobic glycolysis to the proton production rate before interpreting glycolytic capacity in CMs. Overall, this study demonstrates that caution should be taken to assure that translatable developmental time points are used to investigate mitochondrial dysfunction as a cause of cardiac disease. Specifically, XF analysis of newborn CMs should be reserved to study fetal/neonatal disease and older CMs (≥10 weeks) should be used to investigate adult disease pathogenesis. Knowledge gained will aid in improved investigation of developmentally programmed heart disease and stress the importance of discerning maturational differences in bioenergetics when developing mitochondrial targeted preventative and therapeutic strategies for cardiac disease.

Original languageEnglish (US)
Article numbere0149002
JournalPloS one
Issue number2
StatePublished - Feb 2016
Externally publishedYes

ASJC Scopus subject areas

  • General Biochemistry, Genetics and Molecular Biology
  • General Agricultural and Biological Sciences
  • General


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