Multiscale measurement of cardiac energetics

Clin Exp Pharmacol Physiol. 2013 Sep;40(9):671-81. doi: 10.1111/1440-1681.12139.

Abstract

Herein we describe our laboratories' experimental methods for interrogating cardiac energetics at the organ (whole heart), tissue (trabecula) and perforated fibre (mitochondrial) levels. In whole heart and trabecula experiments, we focus on measuring pressure-volume (force-length) work and oxygen consumption (heat production) from which mechanical efficiency is derived. In both preparations (i.e. across scales differing by three orders of magnitude) we find efficiency values of 10%-15%. Mitochondrial experiments invoke a trio of titration protocols to yield information on oxygen consumption, ATP flux, membrane potential, electron leak and reactive oxygen species production, the latter two of which index energy transfer inefficiencies.

Keywords: ATP flux; cardiac enthalpy production; cardiac heat production; mitochondrial membrane potential; mitochondrial proton leak; mitochondrial reactive oxygen species production.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Animals
  • Electrons
  • Energy Transfer / physiology*
  • Heart / physiology*
  • Membrane Potential, Mitochondrial / physiology
  • Mitochondria / physiology*
  • Oxygen Consumption / physiology
  • Rats
  • Reactive Oxygen Species / metabolism

Substances

  • Reactive Oxygen Species
  • Adenosine Triphosphate