Todhunter D A, Scholz R W
Am J Physiol. 1980 Dec;239(6):E407-11. doi: 10.1152/ajpendo.1980.239.6.E407.
In vivo fatty acid synthesis, as measured by tritium incorporation from 3H2O into fatty acids, was examined in the lungs of meal-fed and starved rats. In meal-fed animals, 74% of the radioactivity isolated from pulmonary lipids was found in the phospholipid fraction, with phospholipid fatty acids accounting for approximately 89% of total radioactivity in this fraction. Starving rats for 72 h markedly reduced in vivo 3H2O incorporation into pulmonary lipids. Intraperitoneal injection of (-)-hydroxycitrate prior to 3H2O administration also markedly reduced isotope incorporation into pulmonary lipid fractions of fed rats. These studies demonstrated net in vivo synthesis of fatty acids in pulmonary tissue of rats using a method that is not complicated by potential differences in metabolic pool sizes or peculiarities of specific carbon substrate sources. Synthesis of fatty acids in vivo was affected by the nutritional state of the animal and citrate appears to be a significant source of cytoplasmic acetyl-CoA for de novo pulmonary lipogenesis in the fed rat.
通过测量从3H2O掺入脂肪酸中的氚来检测进食和饥饿大鼠肺中的体内脂肪酸合成。在进食的动物中，从肺脂质中分离出的放射性物质有74%存在于磷脂部分，磷脂脂肪酸约占该部分总放射性的89%。饥饿72小时的大鼠显著降低了体内3H2O掺入肺脂质的量。在给予3H2O之前腹腔注射（-）-羟基柠檬酸也显著降低了进食大鼠肺脂质部分的同位素掺入量。这些研究表明，使用一种不会因代谢池大小的潜在差异或特定碳底物来源的特殊性而变得复杂的方法，可在大鼠肺组织中实现脂肪酸的体内净合成。体内脂肪酸的合成受动物营养状态的影响，柠檬酸似乎是进食大鼠肺从头脂肪生成中细胞质乙酰辅酶A的重要来源。
