|
Notas:
|
Previous studies have consistently shown
that 40% caloric restriction (CR) decreases the rate of
mitochondrial ROS production and steady-state levels
of markers of oxidative damage to macromolecules
including mitochondrial DNA. However, few
investigations have studied whether these changes
also occur in lower CR regimes. This is of potential
interest since moderate levels of dietary restriction
are more practicable for humans. In this investigation
male Wistar rats were subjected to 8.5% and 25%
caloric restriction. Neither 8.5% nor 25% CR
changed mitochondrial ROS production, oxygen
consumption or mtDNA oxidative damage in rat
liver mitochondria. However, both 8.5% and 25% CR
significantly decreased the five different markers of
protein oxidation, glycoxidation and lipoxidation
measured, aminoadipic and glutamic semialdehyde,
carboxyethyl-lysine, carboxymethyl-lysine, and malondialdehyde-lysine.
The fatty acid composition of
liver mitochondria was also affected and led to a
moderate decrease in the degree of membrane
unsaturation in both 8.5% and 25% CR. While
8.5% CR only affected complex I concentration
(which was decreased), 25% CR decreased complexes
I and IV and increased complexes II and III of
the respiratory chain. Apoptosis-inducing factor
(AIF) significantly decreased in 25% CR but not in
8.5% CR. The results show that moderate levels of
caloric restriction can have beneficial effects including
decreases in oxidative protein modification and a
lower sensitivity of membranes to lipid peroxidation,
in association with a reprogramming of the respiratory
chain complexes and AIF content.
This study was supported in part by I + D grants from the Spanish Ministry of Education and Science (BFU2006-14495/BFI), Spanish Ministry of Health (ISCIII, Red de Envejecimiento y Fragilidad, RD06/0013/ 0012), and the Generalitat of Catalunya (2005SGR00101) to R.P.; from the COST B35 Action, Spanish Ministry of Health (FIS 05-2241), Spanish Ministry of Education and Science (AGL2006-12433), and ‘‘La Caixa’’ Foundation to M.P.O.; and from the Spanish Ministry of Education and Science (BFU2005-02584) and from CAM/UCM groups (910521) to G.B.; A. Naudi received a predoctoral fellowship from ‘‘La Caixa’’ Foundation. P. Caro and J. Gómez received predoctoral fellowships from the Ministry of Education and Science. |
