Mitochondrial and peroxisomal beta-oxidation capacities in various tissuesfrom Atlantic salmon Salmo salar

In order to investigate the capacities of different tissues to oxidize fatt y acids, total beta-oxidation (mitochondrial and peroxisomal) of [1-C-14]pa lmitoyl-CoA was determined in liver and red- and white muscle from adult an d juvenile Atlantic salmon Salmo salar. By including potassium cyanide (KCN ) in the assay medium, it was possible to differentiate between mitochondri al and peroxisomal beta-oxidation capacities. Mitochondrial beta-oxidation dominated in all tissues except in livers from juvenile fish where the pero xisomal beta-oxidation dominated. In general, the red muscle possesses the highest fatty acid oxidation capacity, however, by taking into consideratio n the fact that white muscle occupies approximately 60% of the total body w eight, this study demonstrates that the white muscle is an important tissue in the overall fatty acid catabolism.