Johnstone R M
J Biol Chem. 1979 Dec 25;254(24):12479-83.
Trans-stimulation of glycine uptake by cellular glycine in Ehrlich cells is a Na+-dependent phenomenon. In contrast trans-stimulated methionine or leucine uptake is Na+-independent. Trans-stimulated uptake of glycine does not show any characteristics of an ex change process but rather appears to be due to changes in membrane potential which occur as a result of a net Na+-dependent loss of cellular amino acids. Trans-stimulated influx of glycine occurs during the time of net loss of cellular glycine and is absent when the cellular amino acid level is at steady or when the cell is depolarized. Exchange of leucine or methionine occurs when the amino acid level is at steady state and it is not directly affected by depolarizing agents such as gramicidin.
在艾氏腹水癌细胞中，细胞内甘氨酸对甘氨酸摄取的反式刺激是一种依赖钠离子的现象。相比之下，反式刺激的蛋氨酸或亮氨酸摄取则不依赖钠离子。甘氨酸的反式刺激摄取不表现出任何交换过程的特征，而似乎是由于细胞氨基酸净依赖钠离子的损失导致膜电位变化所致。甘氨酸的反式刺激内流发生在细胞内甘氨酸净损失期间，当细胞氨基酸水平稳定或细胞去极化时则不存在。亮氨酸或蛋氨酸的交换发生在氨基酸水平处于稳态时，并且不受诸如短杆菌肽等去极化剂的直接影响。
