Hatch G M, Stevens W K, Choy P C
Department of Biochemistry, Faculty of Medicine, University of Manitoba, Winnipeg, Canada.
Biochem Cell Biol. 1988 May;66(5):418-24. doi: 10.1139/o88-050.
Choline uptake by the hamster heart has been shown to be enhanced by exogenous glycine. In this study, the effect of neutral, basic, and acidic amino acids on choline uptake was assessed. Hamster hearts were perfused with labelled choline, and in the presence of L-alanine, L-serine, or L-phenylalanine (greater than or equal to 0.1 mM), choline uptake was enhanced 20-38%. L-Arginine, L-lysine, L-aspartate, and L-glutamate did not influence choline uptake. The rate of phosphatidylcholine biosynthesis was unaffected by all amino acids tested. Enhancement of choline uptake by neutral amino acids was not additive or dose dependent but required a concentration threshold. The enhancement of choline uptake by neutral amino acids was not influenced by preperfusion with the same amino acid. Exogenous choline had no effect on the uptake of amino acids. We postulate that choline and the neutral amino acids are not cotransported and modulation of choline uptake is facilitated by direct interaction of the neutral amino acids with the choline transport system.
已证明外源性甘氨酸可增强仓鼠心脏对胆碱的摄取。在本研究中，评估了中性、碱性和酸性氨基酸对胆碱摄取的影响。用标记的胆碱灌注仓鼠心脏，在存在L-丙氨酸、L-丝氨酸或L-苯丙氨酸（大于或等于0.1 mM）的情况下，胆碱摄取增强了20%-38%。L-精氨酸、L-赖氨酸、L-天冬氨酸和L-谷氨酸不影响胆碱摄取。所测试的所有氨基酸均未影响磷脂酰胆碱的生物合成速率。中性氨基酸对胆碱摄取的增强作用既不是相加性的也不是剂量依赖性的，但需要一个浓度阈值。预先用相同氨基酸灌注并不影响中性氨基酸对胆碱摄取的增强作用。外源性胆碱对氨基酸的摄取没有影响。我们推测胆碱和中性氨基酸不是协同转运的，中性氨基酸与胆碱转运系统的直接相互作用促进了胆碱摄取的调节。
