[32P]orthophosphate incorporation into phospholipids in rat liver mitochondria and ageing

Phosphate incorporation into phospholipids was examined in rat liver mitochondria. About 67% of the total phosphate incorporated was observed in phosphatidylcholine (lecithin). It is suggested that an excess amount of phospholipids or peroxidation of phospholipids might accelerate ageing. It may be that catalase, superoxide dismutase, peroxidase, nitric oxide, glutathione and redoxin eliminate peroxides in the cells and protect against inactivation of cytochrome oxidase. In this way cells could be defended from oxygen stress and decreased efficiency of energy production, and ageing and cancer, might be prevented. It is likely that the promotion of ageing is caused by the inactivation of cytochrome oxidase and it is assumed that physiological function of catalase, superoxide dismutase and peroxidase might prevent the inactivation of cytochrome oxidase, slow ageing and furthermore protect cells from apoptosis. It is suggested that as the mitochondrial functions decline so ageing accelerates.