Erythrocytes have a well-defined role in the gaseous exchange of oxygen and carbon dioxide in the mammalian body. The erythrocytes can contain more than half of the free amino acids present in whole blood. Based on measures showing that venous erythrocyte levels of amino acids are much less than arterial erythrocyte levels, it has previously been proposed that erythrocytes also play a role in the delivery of amino acids to tissues in the body. This role has been dismissed because it has been assumed that to act as an amino acid transport vehicle, the erythrocytes should release their entire amino acid content in the capillary beds at the target tissues with kinetic studies showing that this would take too long to achieve. This investigation set out to investigate whether the equine erythrocytes could rapidly take up and release smaller packages of amino acids when exposed to high or low external concentrations of amino acids, because it seemed very unlikely that cells would be able to release all of their amino acids without serious impacts on osmotic balance. Freshly prepared erythrocytes were placed in alternating solutions of high and low amino acid concentrations in PBS to assess the capacities of these cells to rapidly take up and release amino acids depending on the nature of the external environment. It was found that amino acids were rapidly taken up and released in small quantities in each cycle representing 15% of their total load in equine erythrocytes and 16% in human erythrocytes. The capacity for rapid uptake/release of amino acids by equine and human erythrocytes provided evidence to support the theory that mammalian erythrocytes have a significant role in transport of amino acids from the liver to tissues, muscles and organs.

中文翻译：

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有证据表明人和马的红细胞在氨基酸向器官和组织的运输和传递中可能起重要作用。

红细胞在哺乳动物体内的氧气和二氧化碳的气体交换中具有明确的作用。红细胞可以包含全血中存在的一半以上的游离氨基酸。基于显示出氨基酸的静脉血红细胞水平远低于动脉血红细胞水平的测量，先前已经提出了红血球在氨基酸向人体组织的递送中也起作用。该作用已被取消，因为已经假定红细胞作为氨基酸转运载体，应在靶组织的毛细血管床中释放其全部氨基酸含量，而动力学研究表明这将花费太长时间才能实现。这项研究旨在调查当暴露于高或低外部氨基酸浓度时，马红细胞是否能够迅速吸收并释放较小的氨基酸包装，因为看来细胞不太可能能够释放其所有氨基酸对渗透平衡没有严重影响。将新鲜制备的红细胞置于PBS中高低氨基酸浓度的交替溶液中，以评估这些细胞根据外部环境的性质快速摄取和释放氨基酸的能力。发现在每个循环中氨基酸被快速吸收和释放，占马红细胞总负载的15％和人红细胞总负载的16％。