Sexual dimorphism in liver mitochondrial oxidative capacity is conserved under caloric restriction conditions

Abstract

Valle A, Guevara R, García-Palmer FJ, Roca P, Oliver J. Sexual dimorphism in liver mitochondrial oxidative capacity is conserved under caloric restriction conditions. Am J Physiol Cell Physiol 293: C1302-C1308, 2007. First published July 25, 2007; doi:10.1152/ajpcell.00203.2007.-Caloric restriction (CR) without malnutrition has been shown to increase maximal life span and delay the rate of aging in a wide range of species. It has been proposed that reduction in energy expenditure and oxidative damage may explain the life-extending effect of CR. Sex-related differences also have been shown to influence longevity and energy expenditure in many mammalian species. The aim of the present study was to determine the sex-related differences in rat liver mitochondrial machinery, bioenergetics, and oxidative balance in response to short-term CR. Mitochondria were isolated from 6-mo-old male and female Wistar rats fed ad libitum or subjected to 40% CR for 3 mo. Mitochondrial O 2 consumption, activities of the oxidative phosphorylation system (complexes I, III, IV, and V), antioxidative activities [MnSOD, glutathione peroxidase (GPx)], mitochondrial DNA and protein content, mitochondrial H 2O2 production, and markers of oxidative damage, as well as cytochrome C oxidase and mitochondrial transcription factor A levels, were measured. Female rats showed a higher oxidative capacity and GPx activity than males. This sexual dimorphism was not modified by CR. Restricted rats showed slightly increased oxygen consumption, complex III activity, and GPx antioxidant activity together with lower levels of oxidative damage. In conclusion, the sexual dimorphism in liver mitochondrial oxidative capacity was unaffected by CR, with females showing higher mitochondrial functionality and ROS protection than males.

Combined Effect of Gender and Caloric Restriction on Liver Proteomic Expression Profile

“…[62][63][64] In agreement with this, here we report higher female levels of mitochondrial enzymes involved in lipid (ECHM, spot 26) and amino acid catabolism (IVD, spot 31), which, in turn, were regulated by CR in the same direction. This may explain the increased need for chaperone activity and antioxidant protection of mitochondria in females and restricted animals.…”

Tissue and sex specificities in Ca2+ handling by isolated mitochondria in conditions avoiding the permeability transition

“…Oestrogens are able to modulate mitochondrial biogenesis in some cells (Chen et al 2009), and rat liver mitochondrial respiration differs by sex (Valle et al 2007); thus, it was tempting to investigate whether such sexual dimorphism would occur in other tissues and whether this difference would also involve Ca 2+ handling by mitochondria. Likewise, previous studies showed lower levels of Peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC1α) and mitochondrial transcription factor A (TFAM) and lower activities of respiratory complexes III and IV in whole hearts of female rats compared with those of male rats (Colom et al 2007).…”

Skeletal Muscle and Liver Oxidative Metabolism in Response to a Voluntary Isocaloric Intake of a High Fat Diet in Male and Female Rats

“…We have previously reported a gender dimorphism in energy balance in both basal conditions [12,13] and in response to diet manipulations [14][15][16][17], with female rats showing greater total energy expenditure than males. The gender differences in energy efficiency can be linked to changes in the regulation of mechanisms to obtain this energy [13,18].…”