Effects of Coenzyme A and Carnitine on Fatty Acid Oxidation by Rainbow Trout Mitochondria

Abstract

The effects of coenzyme A (CoA) and carnitine on the oxidation of 0.1 mM K-palmitate-1-¹⁴C and K-oleate-1-¹⁴C by mitochondrial fractions from lateral line muscle, white muscle, heart, liver, and kidney was studied in rainbow trout (Salmo gairdneri). CoA (0.01–0.10 mM) stimulated the oxidation of fatty acids by mitochondria from lateral line muscle and heart. With all the preparations of mitochondria, fatty acid oxidation was increased by addition of carnitine (1.0 mM) and in the presence of carnitine (1.0 mM), CoA (0.1–1.0 mM) gave a further increase in oxidative activity. Mitochondria from lateral line muscle and heart showed the same range of maximal activity (oxidized substrate at 15 C = 180–200 nmoles/mg N per hr), which was considerably above that found with mitochondria from other tissues. The results suggest similarities in the energy-supplying metabolism in lateral line muscle and heart of trout with respect to the utilization of fatty acids.