Waterhouse C, Clarke E F, Heinig R E, Lewis A M, Jeanpretre N
Am J Clin Nutr. 1979 Dec;32(12):2423-9. doi: 10.1093/ajcn/32.12.2423.
Free amino acid levels were determined in the blood of patients undergoing parenteral alimentation. During amino acid infusions, alanine, valine, glycine, isoleucine, leucine, proline, threonine, serine, methionine, phenylalanine, and lysine levels increased. Bivariate regression analysis was then done to determine the average rise in each amino acid when 1 mmole/hr of that amino acid was infused and when 1 mmole/hr of glucose was infused. This analysis was done on both arterial plasma and arterial wh-le blood increments. The average rise in the amino acid level with 1 mmole of infusion per hour varied from 32 to 133 mumole/liter. Only alanine levels were positively correlated with glucose infusion, while the branched chain levels were all negatively correlated. In no instance could a significant positive arteriovenous difference across the forearm be correlated with the infusion of an amino acid, despite amino acid levels as much as five times normal. Methionine, proline, valine, threonine, and lysine showed the greatest rise in blood concentration per millimole of amino acid infused per hour suggesting that their degradation or use in protein synthesis was limited. While the blood concentration rise in glycine was only about half as much per millimole per hour infused as was found in the previously mentioned group of amino acids, high rates of infusion of this amino acid resulted in large increments inglycine levels. It may be desirable to reduce the amounts of these amino acids in parenteral amino acid formulations.
对接受胃肠外营养的患者血液中的游离氨基酸水平进行了测定。在输注氨基酸期间，丙氨酸、缬氨酸、甘氨酸、异亮氨酸、亮氨酸、脯氨酸、苏氨酸、丝氨酸、蛋氨酸、苯丙氨酸和赖氨酸水平升高。然后进行双变量回归分析，以确定每小时输注1毫摩尔该氨基酸以及每小时输注1毫摩尔葡萄糖时每种氨基酸的平均升高幅度。该分析针对动脉血浆和动脉全血的增量进行。每小时输注1毫摩尔时氨基酸水平的平均升高幅度在32至133微摩尔/升之间。只有丙氨酸水平与葡萄糖输注呈正相关，而支链氨基酸水平均呈负相关。尽管氨基酸水平高达正常水平的五倍，但在前臂上没有任何情况下能将显著的正动静脉差异与氨基酸输注相关联。蛋氨酸、脯氨酸、缬氨酸、苏氨酸和赖氨酸每小时每输注1毫摩尔氨基酸时血液浓度升高幅度最大，这表明它们的降解或用于蛋白质合成受到限制。虽然每小时每输注1毫摩尔甘氨酸时血液浓度升高幅度仅为上述氨基酸组的一半左右，但高输注速率会导致甘氨酸水平大幅升高。可能需要减少胃肠外氨基酸制剂中这些氨基酸的含量。
