Zelinski T A, Choy P C
Biochim Biophys Acta. 1984 Jul 6;794(2):326-32. doi: 10.1016/0005-2760(84)90163-2.
The effect of exogenous ethanolamine on phosphatidylcholine biosynthesis in the isolated hamster heart was investigated. Hamster hearts were perfused with [Me-3H]choline in the presence of 0.05-0.5 mM ethanolamine. Incorporation of label into phosphatidylcholine was decreased 26-63% at 0.1-0.5 mM ethanolamine. Similar decreases in the labelling of the metabolites of the CDP-choline pathway were observed at these ethanolamine concentrations. The observed decrease in phosphatidylcholine labelling at 0.1-0.5 mM ethanolamine was attributed to an inhibition of labelled choline uptake by ethanolamine. The inhibitory role of ethanolamine to choline uptake was examined by comparison to hemicholinium-3. Both compounds inhibited choline uptake in a competitive manner. Intracellular choline, phosphocholine and CDP-choline concentrations were not altered under all experimental conditions. It can be concluded that exogenous ethanolamine has no immediate effect on the rate of phosphatidylcholine biosynthesis in the isolated hamster heart. The reduced labelling of phosphatidylcholine in the presence of ethanolamine is a direct result of the reduction of labelled choline taken up by the heart.
研究了外源性乙醇胺对离体仓鼠心脏中磷脂酰胆碱生物合成的影响。在存在0.05 - 0.5 mM乙醇胺的情况下，用[甲基-³H]胆碱灌注仓鼠心脏。在0.1 - 0.5 mM乙醇胺浓度下，标记物掺入磷脂酰胆碱的量减少了26 - 63%。在这些乙醇胺浓度下，观察到CDP - 胆碱途径代谢物的标记也有类似程度的减少。在0.1 - 0.5 mM乙醇胺浓度下观察到的磷脂酰胆碱标记减少归因于乙醇胺对标记胆碱摄取的抑制作用。通过与半胱氨酸-3比较，研究了乙醇胺对胆碱摄取的抑制作用。两种化合物均以竞争性方式抑制胆碱摄取。在所有实验条件下，细胞内胆碱、磷酸胆碱和CDP - 胆碱的浓度均未改变。可以得出结论，外源性乙醇胺对离体仓鼠心脏中磷脂酰胆碱的生物合成速率没有直接影响。在乙醇胺存在下磷脂酰胆碱标记减少是心脏摄取的标记胆碱减少的直接结果。
