Ksiezak H J, Gibson G E
J Neurochem. 1981 Jul;37(1):88-94. doi: 10.1111/j.1471-4159.1981.tb05294.x.
The molecular basis of the close linkage between oxidative metabolism and acetylcholine (ACh) synthesis is still unclear. We studied this problem in slices and synaptosomes by measurement of ACh synthesis from [U-14C]glucose, and 14CO2 production from [3,4-14C]- and [2-14C]glucose, an index of glucose decarboxylation by the pyruvate dehydrogenase complex (PDH) and the enzymes of the Krebs cycle, respectively. We examined both under conditions that either inhibited (low O2 or antimycin) or stimulated (2,4-dinitrophenol [DNP] or 35 mM-K+) 14CO2 production from [2-14C]- or [3,4-14C]glucose. Incorporation of [U-14C]glucose into ACh was reduced under low O2 and by antimycin or DNP (by 51--93%) and stimulated by 35 mM-K+ (by 30--60%). Under all of these conditions, ACh synthesis and the decarboxylation of [3,4-14C]- and [2-14C]glucose were linearly related (r = 0.741 and 0.579, respectively). The difference in the rate of 14CO2 production from [3,4-14C]- and [2-14C]glucose was used as a measure of the amount of glucose that was not oxidatively decarboxylated (efflux). We found that efflux was reduced (low O2 and antimycin), unchanged (DNP in slices), or increased (DNP in synaptosomes and K+ stimulation in slices) compared with control values under 100% O2. ACh synthesis and efflux were more closely related (r = 0.860) than ACh synthesis and 14CO2 production from variously labeled glucoses.
氧化代谢与乙酰胆碱（ACh）合成之间紧密联系的分子基础仍不清楚。我们通过测量[U-14C]葡萄糖合成ACh以及[3,4-14C]-和[2-14C]葡萄糖产生14CO2的量（分别作为丙酮酸脱氢酶复合体（PDH）和三羧酸循环酶使葡萄糖脱羧的指标），在脑片和突触体中研究了这个问题。我们在抑制（低氧或抗霉素）或刺激（2,4-二硝基苯酚[DNP]或35 mM-K+）[2-14C]-或[3,4-14C]葡萄糖产生14CO2的条件下进行了检测。在低氧、抗霉素或DNP作用下，[U-14C]葡萄糖掺入ACh的量减少（减少51%-93%），而35 mM-K+可使其增加（增加30%-60%）。在所有这些条件下，ACh合成与[3,4-14C]-和[2-14C]葡萄糖的脱羧呈线性相关（r分别为0.741和0.579）。[3,4-14C]-和[2-14C]葡萄糖产生14CO2速率的差异被用作未氧化脱羧葡萄糖量（外流）的指标。我们发现，与100%氧气条件下的对照值相比，外流减少（低氧和抗霉素）、不变（脑片中的DNP）或增加（突触体中的DNP和脑片中的K+刺激）。ACh合成与外流的相关性（r = 0.860）比ACh合成与不同标记葡萄糖产生14CO2的相关性更密切。
