Open AccessThreshold effect in the H2O2 production of skeletal muscle mitochondria during fasting and refeeding
Author(s) -
Damien Roussel,
Mélanie Boël,
Mathieu Mortz,
Caroline Romestaing,
Claude Duchamp,
Yann Voituron
Publication year - 2019
Publication title -
journal of experimental biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.367
H-Index - 185
eISSN - 1477-9145
pISSN - 0022-0949
DOI - 10.1242/jeb.196188
Subject(s) - skeletal muscle , medicine , endocrinology , mitochondrion , production (economics) , biology , chemistry , biochemistry , economics , macroeconomics
Under nutritional deprivation, the energetic benefits of reducing mitochondrial metabolism are often associated with enhanced harmful pro-oxidant effects and a subsequent long-term negative impact on cellular integrity. However, the flexibility of mitochondrial functioning under stress has rarely been explored during the transition from basal non-phosphorylating to maximal phosphorylating oxygen consumption. Here, we experimentally tested whether ducklings (Cairina moschata) fasted for 6 days and thereafter refed for 3 days, exhibited modifications to their mitochondrial fluxes, i.e. oxygen consumption, ATP synthesis, reactive oxygen species generation (ROS) and associated ratios, such as the electron leak (% ROS/O) and the oxidative cost of ATP production (% ROS/ATP). This was done at different steady state rate of oxidative phosphorylation in both pectoralis (glycolytic) and gastrocnemius (oxidative) muscles. Fasting induced a decrease in the rates of oxidative phosphorylation and maximal ROS release. All these changes were completely reversed by 3 days of refeeding. Yet, the fundamental finding of the present study is the existence of a clear threshold in ROS release and associated ratios, which remained low until a low level of mitochondrial activity is reached (30-40% of maximal oxidative phosphorylation activity).