Palmer T N, Caldecourt M A, Sugden M C
Biochem J. 1984 Oct 1;223(1):113-7. doi: 10.1042/bj2230113.
Dichloroacetate (an activator of pyruvate dehydrogenase) stimulates 14CO2 production from [U-14C]glucose, but not from [U-14C]glutamate, [U-14C]aspartate, [U-14C]- and [1-14C]-valine and [U-14C]- and [1-14C]-leucine. It is concluded (1) that pyruvate dehydrogenase is not rate-limiting in the oxidation to CO2 of amino acids that are metabolized to tricarboxylic acid-cycle intermediates, and (2) that carbohydrate (and not amino acids) is the main carbon precursor in alanine formation in muscle.
二氯乙酸(丙酮酸脱氢酶激活剂)可刺激[U-¹⁴C]葡萄糖生成¹⁴CO₂,但对[U-¹⁴C]谷氨酸、[U-¹⁴C]天冬氨酸、[U-¹⁴C]-和[1-¹⁴C]-缬氨酸以及[U-¹⁴C]-和[1-¹⁴C]-亮氨酸生成¹⁴CO₂无刺激作用。由此得出结论:(1)对于代谢为三羧酸循环中间产物的氨基酸,丙酮酸脱氢酶在其氧化为CO₂的过程中并非限速酶;(2)在肌肉中丙氨酸形成过程中,碳水化合物(而非氨基酸)是主要的碳前体。