Glatz J F, Jacobs A E, Veerkamp J H
Biochim Biophys Acta. 1984 Jul 26;794(3):454-65. doi: 10.1016/0005-2760(84)90012-2.
Oxidation rates of palmitate and activities of the mitochondrial marker enzymes cytochrome c oxidase and citrate synthase have been determined in homogenates, isolated mitochondria and slices of human and rat heart and in calcium-tolerant rat cardiac myocytes. Homogenates and mitochondria from rat heart showed a 6- and 2.5-fold higher palmitate oxidation rate than the corresponding preparations from human heart. From the palmitate oxidation rates and cytochrome c oxidase and citrate synthase activities as parameters, the mitochondrial protein contents of human and rat heart were calculated to be about 18 and 45 mg/g wet weight, respectively. Based on citrate synthase activities, the fatty acid oxidation rates were about the same in homogenates and isolated mitochondria, much lower in myocytes and lowest in slices. In the cellular systems the palmitate molecule was more completely oxidized than in homogenates or isolated mitochondria. Fatty acid oxidation rates were concentration-dependent in slices, but not with myocytes. With the cellular systems, palmitate oxidation was synergistically stimulated by the addition of carnitine, coenzyme A and ATP to the incubation medium. This stimulation could be attributed only partly to an increased oxidation in damaged cells.
已在人及大鼠心脏的匀浆、分离的线粒体和切片以及耐钙大鼠心肌细胞中测定了棕榈酸的氧化速率以及线粒体标记酶细胞色素c氧化酶和柠檬酸合酶的活性。大鼠心脏的匀浆和线粒体的棕榈酸氧化速率比人心脏相应制剂高6倍和2.5倍。以棕榈酸氧化速率以及细胞色素c氧化酶和柠檬酸合酶活性为参数，计算出人及大鼠心脏的线粒体蛋白含量分别约为18和45mg/g湿重。基于柠檬酸合酶活性，匀浆和分离的线粒体中的脂肪酸氧化速率大致相同，心肌细胞中较低，切片中最低。在细胞系统中，棕榈酸分子比在匀浆或分离的线粒体中氧化得更完全。切片中脂肪酸氧化速率呈浓度依赖性，而心肌细胞中则不然。在细胞系统中，向孵育培养基中添加肉碱、辅酶A和ATP可协同刺激棕榈酸氧化。这种刺激仅部分归因于受损细胞中氧化增加。
