Martens M E, Lee C P
Can J Biochem. 1980 Jul;58(7):549-58. doi: 10.1139/o80-075.
Several aspects of fatty acids metabolism have been examined in skeletal muscle mitochondria from both strain 129 dystrophic (dy/dy) and myodystrophic (myd/myd) mice. Skeletal muscle mitochondria from dy/dy mice showed significantly decreased state 3 respiratory rates with both palmityl- and acetyl-carnitine + malate as substrates when compared with their normal littermate controls. A similar, though less severe impairment in acylcarnitine oxidation by mitochondria from myd/myd skeletal muscle has also been shown by us in a previous study. In the present study, kinetic measurements revealed decreased activities of the reverse carnitine palmityltransferase (palmitylcarnitine + CoASH as substrates) in intact mitochondria from dy/dy muscle, and of citrate synthase in myd/myd muscle mitochondria. However, neither of these reactions appeared to be rate limiting for acylcarnitine oxidation in mouse skeletal muscle mitochondria. All other enzyme activities of cofactor contents measured were either comparable to those of controls or were higher. The results reported here indicate that neither of the impairments in acylcarnitine oxidation by skeletal muscle mitochondria from dy/dy or myd/myd mice is due to deficiencies in either carnitine palmityltransferase, carnitine acetyltransferase, citrate synthase, coenzyme A, or substrate-reducible flavoprotein.
已对129品系营养不良（dy/dy）和肌营养不良（myd/myd）小鼠的骨骼肌线粒体中脂肪酸代谢的几个方面进行了研究。与正常同窝对照相比，dy/dy小鼠的骨骼肌线粒体以棕榈酰肉碱和乙酰肉碱+苹果酸为底物时，状态3呼吸速率显著降低。我们在之前的一项研究中也表明，myd/myd骨骼肌线粒体对酰基肉碱氧化的损害类似，但程度较轻。在本研究中，动力学测量显示，dy/dy肌肉完整线粒体中反向肉碱棕榈酰转移酶（以棕榈酰肉碱+辅酶A为底物）的活性降低，myd/myd肌肉线粒体中柠檬酸合酶的活性降低。然而，这些反应似乎都不是小鼠骨骼肌线粒体中酰基肉碱氧化的限速反应。所测量的所有其他辅因子含量的酶活性要么与对照相当，要么更高。此处报告的结果表明，dy/dy或myd/myd小鼠骨骼肌线粒体中酰基肉碱氧化的损害均不是由于肉碱棕榈酰转移酶、肉碱乙酰转移酶、柠檬酸合酶、辅酶A或底物可还原黄素蛋白的缺乏所致。
