14CO₂的生成并非[14C]脂肪酸氧化的充分衡量指标。

14CO2 production is no adequate measure of [14C]fatty acid oxidation.

作者信息

Veerkamp J H, van Moerkerk T B, Glatz J F, Zuurveld J G, Jacobs A E, Wagenmakers A J

出版信息

Biochem Med Metab Biol. 1986 Jun;35(3):248-59. doi: 10.1016/0885-4505(86)90080-0.

Abstract

Palmitate oxidation was comparatively assayed in various cell-free and cellular systems by 14CO2 production and by the sum of 14CO2 and 14C-labeled acid-soluble products. The 14CO2 production rate was dependent on incubation time and amount of tissue in contrast to the total oxidation rate. The 14CO2 contribution to the oxidation rate of [1-14C]palmitate varied with homogenates from 1% with rat liver to 28% with rat kidney and amounted to only 2-4% with human muscles. With cellular systems the 14CO2 contribution varied between 20% in human fibroblasts and 70% in rat muscles and myocytes. Addition of cofactors increased the oxidation rate, but decreased the 14CO2 contribution. Various conditions appeared also to influence to a different extent the 14CO2 production and the total oxidation rate with rat tissue homogenates and with rat muscle mitochondria. Incorporation of radioactivity from [1-14C]palmitate into protein was not detectable in cell-free systems and only 2-3% of the sum of 14CO2 and 14C-labeled acid-soluble products in cellular systems. Assay of 14CO2 and 14C-labeled acid-soluble products is a much more accurate and sensitive estimation of fatty acid oxidation than assay of only 14CO2.

摘要

通过检测14CO2的生成以及14CO2与14C标记的酸溶性产物的总和，在各种无细胞和细胞体系中对棕榈酸氧化进行了比较测定。与总氧化速率不同，14CO2的生成速率取决于孵育时间和组织量。14CO2对[1-14C]棕榈酸氧化速率的贡献因匀浆而异，从大鼠肝脏的1%到大鼠肾脏的28%，而在人类肌肉中仅为2-4%。在细胞体系中，14CO2的贡献在人类成纤维细胞中为20%，在大鼠肌肉和心肌细胞中为70%。添加辅因子可提高氧化速率，但会降低14CO2的贡献。各种条件似乎也在不同程度上影响大鼠组织匀浆和大鼠肌肉线粒体中14CO2的生成和总氧化速率。在无细胞体系中未检测到[1-14C]棕榈酸的放射性掺入蛋白质，在细胞体系中仅占14CO2和14C标记的酸溶性产物总和的2-3%。与仅检测14CO2相比，检测14CO2和14C标记的酸溶性产物对脂肪酸氧化的估计更为准确和灵敏。