Age-Related Changes in Mitochondrial Membrane Composition of Nothobranchius rachovii

: Mitochondrial membrane composition may be a critical factor in the mechanisms of the aging process by influencing the propagation of reactions involved in mitochondrial function during periods of high stress. Changes affecting either lipid class or fatty acid compositions could affect phospholipid properties and alter mitochondrial function and cell viability. In the present study, mitochondrial membrane phospholipid compositions were analyzed throughout the life cycle of Nothobranchius rachovii. Mitochondrial phospholipids showed several changes with age. Proportions of cardiolipin decreased and those of sphingomyelin increased between 11- and 14-month-old fish. Fatty acid compositions of individual phospholipids in mitochondria were also significantly affected with age. These data suggest increasing damage to mitochondrial lipids during the life cycle of N. rachovii that could be one of the main factors related with and contributing to degraded mitochondrial function associated with the aging process.