Malloy C R, Sherry A D, Jeffrey F M
FEBS Lett. 1987 Feb 9;212(1):58-62. doi: 10.1016/0014-5793(87)81556-9.
Mathematical models of the TCA cycle derived previously for 14C tracer studies have been extended to 13C NMR to measure the 13C fractional enrichment of [2-13C]acetyl-CoA entering the cycle and the relative activities of the oxidative versus anaplerotic pathways. The analysis is based upon the steady-state enrichment of 13C into the glutamate carbons. Hearts perfused with [2-13C]acetate show low but significant activity of the anaplerotic pathways. Activation of two different anaplerotic pathways is demonstrated by addition of unlabeled propionate or pyruvate to hearts perfused with [2-13C]acetate. In each case, the amount of [2-13C]acetate being oxidized and the relative carbon flux through anaplerotic versus oxidative pathways are evaluated.
先前为14C示踪研究推导的三羧酸循环数学模型已扩展至13C核磁共振，以测量进入该循环的[2-13C]乙酰辅酶A的13C分数富集以及氧化途径与回补途径的相对活性。该分析基于13C在谷氨酸碳中的稳态富集。用[2-13C]乙酸灌注的心脏显示出回补途径的活性较低但显著。向用[2-13C]乙酸灌注的心脏中添加未标记的丙酸盐或丙酮酸盐，证明了两种不同回补途径的激活。在每种情况下，都会评估被氧化的[2-13C]乙酸的量以及通过回补途径与氧化途径的相对碳通量。
