Mitochondrial and peroxisomal beta-oxidations in pig coronary smooth muscle cells

1. The total subcellular membranes of pig coronary media were fractionated using a sucrose density gradient. 2. A fraction with high succinate dehydrogenase activity and a mean density of 1.165 was separated from a fraction with high catalase activity and a mean density of 1.145. 3. Acyl CoA beta-oxidation activity measured in the absence of BSA was present in both fractions with 47% of the total activity in the succinate dehydrogenase fraction and 47% in the catalase fraction. 4. In the succinate dehydrogenase fraction bovine serum albumin stimulated the acyl CoA beta-oxidation (maximal stimulation, 3.2 times at a concentration of 15 mg%) while in the catalase fraction it had no effect. 5. It is concluded that, in pig coronary media, the beta-oxidation system has two components, i.e. mitochondrial and peroxisomal beta-oxidation.