RELATIONSHIPS BETWEEN PROTEIN CARBONYLS, RETINOL AND TOCOPHEROLS LEVEL IN HUMAN PLASMA

Free radical oxidation has been claimed as one of the most important m echanism of damage in aging and in several diseases. Carbonyl content in tissue and circulating proteins is a stable marker of this attack. In 29 apparently healthy subjects (25-89 years old) carbonyl content o f plasma proteins and retinol and tocopherols (alpha- and gamma-) were studied. Carbonyls level did not show an increase with age. A good co rrelation between carbonyls content and gamma-tocopherol (r=0.44, P<0. 05) and a trend with retinol (r=0.34, P=0.07) was found, but not with cl-tocopherol. An inverse correlation was observed between carbonyls a nd plasma proteins (r=-0.63, P<0.01) and the natural antioxidant studi ed showed an increase with age and a good relationship with lipids. Th ese data suggest that retinol and tocopherols, well known scavengers o f free radicals, are involved, at least partially, in the prevention o f oxidative damage of circulating proteins.