CARNITINE PALMITOL TRANSFERASE. The carnitine palmitoyl transferase (CPT) system for transport of fatty acylnto mitochondria consists of CPT. 1 and CPT 2 [25, 26, 35](Figure:. 51). CPT. 1 catalyzes formation of fatty acyl càrnitine, which moves across the inner mitochondrial membrane. There, fatty acyl-CoA is regenerated: and carnitine is released and catalyzed by CPT 2 Once inside the lumen: of the mitochondrion, the fatty acyl-CoA can undergo B-oxidation, thus: generating NADH, FADH2, and acetyl-CoA for oxidation in the citric acid:: cycle. Over 25 years ago, Mole et al.[28] demonstrated some of the impor-, tant factors that determine the rate of fatty acid oxidation using mitochon-dria isolated from hindlimb muscle of trained and non-trained rats. They: showed that the oxidation of palmitate increased as a function offatty acid:. concentration, Both coenzyme A and carnitine were required to produce: optimal rates of palmitate oxidation, thus demonstrating the importance:. of the GPT fatty acyl-CoA transport system. In the absence of carnitine (and. with other substrates and cofactors non-limiting), the mitochondrial oxygen uptake was 69 il oxygen/hr/g With the addition of 1 mM carnitine, the:: rate increased to 543 pil oxygen/hr/g. Mitochondria isolated from the sanne:: amount of skeletal muscle of endurance-trained rats (2 hr/d for 3 mon): oxidized fatty acids at about twice the rate as mitochondria from sedentary rats. The requirement for carnitine clearly demonstrates the rate-limiting geSeSeeSeSeeeeSS nature of the CPT-system for governing the rate of fatty acid oxidation at.