Leucine and tissue distribution of bulky and small neutral amino acids in rats: dissociation between transport and insulin-mediated effects.
Leucine and tissue distribution of bulky and small neutral amino acids in rats: dissociation between transport and insulin-mediated effects.
复制标题
大鼠中亮氨酸和大中性氨基酸和小中性氨基酸的组织分布：运输和胰岛素介导作用之间的分离。
DOI：
10.1007/bf01800357
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发表时间：
1992
影响因子：
4.2
通讯作者：
Christensen,HN
中科院分区：
文献类型：
--
作者：
deCéspedes,C;Thoene,JG;Lowler,K;Christensen,HN
在高水平Leu存在下观察到的几种氨基酸血浆浓度降低的机制仍然无法解释。在本研究中，观察到腹腔注射Leu后断奶大鼠血浆中的Ile、瓦尔、Phe、Tyr、Met、Ala、Pro和Gly浓度降低。肌肉中净细胞内浓度的减少伴随着血浆中除Pro和Gly外的所有这些氨基酸的减少。肌肉/血浆的分布比的增加，观察到专门为甘氨酸后，给药的亮氨酸或非胰岛素转运系统L类似物。二氮嗪抑制亮氨酸诱导的血浆和肌肉细胞内Ile和瓦尔以及血浆中Pro浓度的降低。在不存在但不存在二氮嗪的情况下，观察到Pro和Gly的肝脏/血浆分布比增加。上述变化均具有统计学意义。因此，胰岛素可能介导Leu效应，促进肌肉中Ile和瓦尔以及肝脏中Pro的利用增加。Leu的一个更直接的作用似乎与Phe、Tyr和Ala在同一组织中的利用率明显增加有关。血浆中的Gly耗尽可以通过Leu对Gly通过转运系统L的流出的抑制作用来解释。
The mechanism of the observed decrease in the plasma concentration of several amino acids in the presence of high levels of Leu has remained unexplained. In the present study a decrease in the plasma concentration of Ile, Val, Phe, Tyr, Met, Ala, Pro and Gly was observed after the intraperitoneal injection of Leu to weanling rats. Decreases in net intracellular concentrations in muscle accompanied the decrease in plasma of all of these amino acids except Pro and Gly. An increase in the distribution ratio muscle/plasma was observed exclusively for Gly after administration of Leu or of a non-insulinogenic transport system L analogue. Diazoxide suppressed the Leu-induced decreases in plasma and muscle intracellular concentrations of Ile and Val as well as of Pro in plasma. An increase in the distribution ratio liver/plasma was observed for Pro and Gly in the absence but not in the presence of diazoxide. All the above changes were statistically significant. Hence insulin probably mediates Leu effects, promoting an increased utilization of Ile and Val in muscle and of Pro in liver. A more direct effect of Leu appears to be involved in the apparent increased utilization of Phe, Tyr and Ala in the same tissue. Gly depletion in plasma can be explained by its trapping by inhibitory action of Leu on the exodus of Gly through transport system L.