四岁以下健康儿童血浆游离氨基酸水平

A STUDY OF NORMAL PLASMA LEVELS OF FREE AMINO ACIDS IN CHILDEN

本文测定37例1～4岁健康儿童21种血浆游离氨基酸值(PFAA).其中丙氨酸(ALa)、谷氨酸(Glu)、谷氨酰胺(Glu-n)浓度较高,约占氨基酸总量的40%.本文结果显示4岁以下儿童血浆游离氨基酸值与性别、年龄无明显差别;提示儿童时期血浆游离氨基酸利用率相似.其中某些氨基酸比例值、如非必需氨基酸/必需氨基酸为1.5,丙氨酸/苏氨酸为2～3.0,丙氨酸/亮氨酸为2～2.5,丙氨酸/支链氨基酸为0.6～0.7,苯丙氨酸/酪氨酸与甘氨酸/缬氨酸均为1。

The plasma free amino acids (PFAA) were measured in 37 healthy children (27 boys, 14 girls) under 4 years of age. Blood samples were drawn after an overnight fast. All the analyses were performed by elution chromatograph with a Beckman 121 MB Amino Acid Analyser. Data of plasma concentrations of 21 free amino acids and of 9 essential ones were collected. Among them, the concentrations of Alamine, Glutamine and Glutamate were on the top accounting about 40% of the total. In this study there revealed noither sex nor age differences in infants and children under 4 years of age, suggesting that in younger children the pool of amino acids is so expansible to fit their growth and development. The ratios of different amino acids were calculated. For example, NEAA/EAA was 1.5, Ala/Thr 2-3.0, Ala/Leu 2-2.5,Ala/ BCAA 0.6-0.7, Phen/Tyr 1 and Gly/Val 1. It seemed possible using these ratios to evaluate the status of malnutrition of young children