Dexamethasone treatment specifically increases the basal proton conductance of rat liver mitochondria

  • FEBS Lett. 2003 Apr 24;541(1-3):75-9. doi: 10.1016/s0014-5793(03)00307-7.
Damien Roussel  1 ,  Jean-François Dumas ,  Antoine Augeraud ,  Olivier Douay ,  Françoise Foussard ,  Yves Malthiéry ,  Gilles Simard ,  Patrick Ritz
Affiliations
  • 1. Laboratoire de biochimie et de biologie moléculaire, INSERM EMI-U 00.18, Angers, France.
PMID: 12706822 DOI: 10.1016/s0014-5793(03)00307-7
Abstract

We investigated the role that mitochondrial proton leak may play in the glucocorticoid-induced hypermetabolic state. Sprague-Dawley rats were injected with dexamethasone over a period of 5 days. Liver mitochondria and gastrocnemius subsarcolemmal and intermyofibrillar mitochondria were isolated from dexamethasone-treated, pair-fed and control rats. Respiration and membrane potential were measured simultaneously using electrodes sensitive to oxygen and to the potential-dependent probe triphenylmethylphosphonium, respectively. Five days of dexamethasone injection resulted in a marked increase in the basal proton conductance of liver mitochondria, but not in the muscle mitochondrial populations. This effect would have a modest impact on energy expenditure in rats.

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