14 research outputs found
Rapeseed oil‑rich diet alters hepatic mitochondrial membrane lipid composition and disrupts bioenergetics
Diet is directly related with physiological alterations
occurring at a cell and subcellular level. However,
the role of diet manipulation on mitochondrial physiology
is still largely unexplored. Aiming at correlating diet with
alterations of mitochondrial membrane composition and
bioenergetics, Wistar-Han male rats were fed for 11, 22 and
33 days with a rapeseed oil-based diet and mitochondrial
bioenergetics, and membrane composition were compared
at each time point with a standard diet group. Considerable
differences were noticed in mitochondrial membrane lipid composition, namely in terms of fatty acyl chains and relative
proportions of phospholipid classes, the modified diet
inducing a decrease in the saturated to unsaturated molar
ratio and an increase in the phosphatidylcholine to phosphatidylethanolamine
molar ratio. Mass spectrometry lipid
analysis showed significant differences in the major species
of cardiolipin, with an apparent increased incorporation
of oleic acid as a result of exposure to the modified
diet. Rats fed the modified diet during 22 days showed
decreased hepatic mitochondrial state 3 respiration and
were more susceptible to Ca2+-induced transition pore
opening. Rapeseed oil-enriched diet also appeared to promote
a decrease in hydroperoxide production by the respiratory
chain, although a simultaneous decrease in vitamin E
content was detected. In conclusion, our data indicate that
the rapeseed oil diet causes negative alterations on hepatic
mitochondrial bioenergetics, which may result from membrane
remodeling. Such alterations may have an impact not
only on energy supply to the cell, but also on drug-induced
hepatic mitochondrial liabilities.The project was supported by the Foundation
for Science and Technology with FEDER/COMPETE/National
Budget funds (research grants PTDC/QUI–QUI/101409/2008 to P. J.
O., PTDC/QUI-BIQ/103001/2008 to A. S. J. and strategic grant PEst-
C/SAU/LA0001/2011to the CNC). J. P. M. and A. M. S. acknowledge
FCT for Ph.D. grants SFRH/BD/37626/2007 and PTDC/AGRALI/
108326/2008, respectively
Explaining longevity of different animals: is membrane fatty acid composition the missing link?
Saturated and monounsaturated fatty acids are very resistant to peroxidative damage, while the more polyunsaturated a fatty acid, the more susceptible it is to peroxidation. Furthermore, the products of lipid peroxidation can oxidatively damage other important molecules. Membrane fatty acid composition is correlated with the maximum lifespans of mammals and birds. Exceptionally long-living mammal species and birds have a more peroxidation-resistant membrane composition compared to shorter-living similar-sized mammals. Within species, there are also situations in which extended longevity is associated with peroxidation-resistant membrane composition. For example, caloric restriction is associated more peroxidation-resistant membrane composition; long-living queens have more peroxidation-resistant membranes than shorter-living worker honeybees. In humans, the offspring of nonagenarians have peroxidation-resistant erythrocyte membrane composition compared to controls. Membrane fatty acid composition is a little appreciated but important correlate of the rate of aging of animals and the determination of their longevity