Food restriction affects energy metabolism in rat liver mitochondria.
To examine the effect of 50% food restriction over a period of 3 days on mitochondrial energy metabolism, liver mitochondria were isolated from ad libitum and food-restricted rats. Mitochondrial enzyme activities and oxygen consumption were assessed spectrophotometrically and polarographically. With regard to body weight loss (-5%), food restriction decreased the liver to body mass ratio by 7%. Moreover, in food-restricted rats, liver mitochondria displayed diminished state 3 (-30%), state 4-oligomycin (-26%) and uncoupled state (-24%) respiration rates in the presence of succinate. Furthermore, "top-down" elasticity showed that these decreases were due to an inactivation of reactions involved in substrate oxidation. Therefore, it appears that rats not only adapt to food restriction through simple passive mechanisms, such as liver mass loss, but also through decreased mitochondrial energetic metabolism.
Dumas
Jean-François
JF
INSERM EMI-U 00.18, Laboratoire de Biochimie et de Biologie Moléculaire, Medecine B, CHU, F-49033 Angers Cedex 01, France.
Roussel
Damien
D
Simard
Gilles
G
Douay
Olivier
O
Foussard
Françoise
F
Malthiery
Yves
Y
Ritz
Patrick
P
D000818:Animals; D001835:Body Weight; D002950:Citrate (si)-Synthase / Q000378:metabolism; D003576:Electron Transport Complex IV / Q000378:metabolism; D004734:Energy Metabolism; D005508:Food Deprivation / Q000502:physiology*; D008564:Membrane Potentials; D008930:Mitochondria, Liver / Q000201:enzymology / Q000378:metabolism*; D009840:Oligomycins; D009929:Organ Size; D010089:Oxidoreductases, N-Demethylating / Q000378:metabolism; D010101:Oxygen Consumption; D051381:Rats; D017207:Rats, Sprague-Dawley; D019802:Succinic Acid / Q000378:metabolism; D013997:Time Factors
D009840:Oligomycins; D019802:Succinic Acid; D010089:Oxidoreductases, N-Demethylating; C022726:tetramethylphenylenediamine oxidase; D003576:Electron Transport Complex IV; D002950:Citrate (si)-Synthase