Vind C, Grunnet N
Pharmacol Biochem Behav. 1983;18 Suppl 1:209-13. doi: 10.1016/0091-3057(83)90173-9.
The interaction between xylitol, alcohol and lactate dehydrogenase has been studied in hepatocytes from rats by applying specifically tritiated substrates. A simple model, describing the metabolic fate of tritium from [2-3H] xylitol and (1R) [1-3H]ethanol is presented. The model allows calculation of the specific radioactivity of free, cytosolic NADH, based on transfer of tritium to lactate, glucose and water. From the initial labelling rate of lactate and the specific radioactivity of cytosolic NADH, we have determined the reversible flow through the lactate dehydrogenase catalyzed reaction to 1-5 mumol/min . g wet wt. The results suggest that xylitol, alcohol and lactate dehydrogenase share the same pool of NAD(H) in the cytoplasma. This finding allows estimation of the ethanol oxidation rate by the non-alcohol dehydrogenase pathways from the relative yield of tritium in water and glucose. The calculations are based on a comparison of the fate of the 1-pro-R hydrogen of ethanol and the hydrogen bound to carbon 2 of xylitol or carbon 2 of lactate under identical conditions.
通过应用特定的氚标记底物，对大鼠肝细胞中木糖醇、乙醇与乳酸脱氢酶之间的相互作用进行了研究。本文提出了一个简单模型，用于描述[2-³H]木糖醇和(1R)[1-³H]乙醇中氚的代谢去向。该模型能够基于氚向乳酸、葡萄糖和水的转移来计算游离胞质NADH的比放射性。根据乳酸的初始标记速率和胞质NADH的比放射性，我们确定了通过乳酸脱氢酶催化反应的可逆通量为1-5微摩尔/分钟·克湿重。结果表明，木糖醇、乙醇和乳酸脱氢酶在细胞质中共享同一NAD(H)池。这一发现使得能够根据水和葡萄糖中氚的相对产率，通过非乙醇脱氢酶途径估算乙醇氧化速率。这些计算是基于在相同条件下对乙醇的1-前-R氢以及与木糖醇的碳2或乳酸的碳2结合的氢的去向进行比较得出的。
