Submitted on May 17, 2007
Accepted on July 19, 2007
GENDER DIMORPHISM IN LIVER MITOCHONDRIAL OXIDATIVE CAPACITY IS CONSERVED UNDER CALORIC RESTRICTION CONDITIONS
Adamo Valle1, Rocio Guevara2, Francisco J. Garcia-Palmer1, Pilar Roca1, and Jordi Oliver Oliver1*
1 Grup de Metabolisme Energetic i Nutricio, Departament de Biologia Fonamental i Ciencies de la Salut, Universitat de les Illes Balears, Palma de Mallorca, Illes Balears, Spain
2 Grup de Metabolisme Energetic i Nutricio, Departament de Biologia Fonamental i Ciencies de la Salut, Universitat de les Illes Balears, Palma de Mallorca, Illes Balears, Spain; Palma de Mallorca, Illes Balears, Spain
* To whom correspondence should be addressed. E-mail: jordi.oliver{at}uib.es.
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. Gender also has been shown to influence longevity and energy expenditure in many mammalian species. The aim of the present study was to determine the gender-related differences in rat liver mitochondrial machinery, bioenergetics and oxidative balance in response to short-term CR. Mitochondria were isolated from 6-month old male and female Wistar rats fed ad libitum or subjected to 40% CR for 3 months. Mitochondrial oxygen consumption, activities of the OXPHOS system (complex I, III, IV, V), antioxidative activities (MnSOD, GPx), mitochondrial DNA and protein content, mitochondrial H2O2 production, markers of oxidative damage, as well as COX II and mitochondrial transcription factor A (TFAM) levels were measured. Female rats showed a higher oxidative capacity and GPx activity than males. This gender 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 gender dimorphism in liver mitochondrial oxidative capacity was unaffected by CR, with females showing higher mitochondrial functionality and ROS protection than males.
