Age-Associated Mitochondrial Oxidative Decay: Improvement of Carnitine Acetyltransferase Substrate-Binding Affinity and Activity in Brain by Feeding Old Rats Acetyl-L- Carnitine and/or R- -Lipoic Acid

Abstract

We test whether the dysfunction with age of carnitine acetyltransferase (CAT), a key mitochondrial enzyme for fuel utilization, is due to decreased binding affinity for substrate and whether this substrate, fed to old rats, restores CAT activity. The kinetics of CAT were analyzed by using the brains of young and old rats and of old rats supplemented for 7 weeks with the CAT substrate acetyl-Lcarnitine (ALCAR) and͞or the mitochondrial antioxidant precursor R-␣-lipoic acid (LA). Old rats, compared with young ra…