Age-dependent fatty acid composition of erythrocyte membrane phospholipids in healthy children.

The fatty-acid composition of red-cell-membrane phospholipids (total phospholipids, phosphatidylcholine, and phosphatidylethanolamine fractions) was determined in 88 apparently healthy children aged 1 to 15 years, 10 cord blood samples, and 6 infants below 1 year of age. The major aim of the study was to determine the normal ranges of fatty-acid proportions, including trans- and odd-numbered fatty acids, for further studies of nutritional and metabolic disorders. The concentrations of most fatty acids of the phospholipids analyzed increased or decreased after birth and assumed adult levels before the second year of life, alpha-linolenic acid (C18:3n - 3) and trans fatty acids, however, continued to increase with age until late childhood.

Plasma tocopherol and tocopherol to lipid ratios in a normal population of infants and children.

The plasma tocopherol concentrations were measured by HPLC in 73 apparently healthy West German children aged from 1 to 14 years and in 7 cord blood samples and 5 infants below 1 year of age. Total tocopherols ranged from 584 to 2024 micrograms/dl in the children above 1 year of age (mean 1046 +/- 283 micrograms/dl) and from 511 to 1155 micrograms/dl in the infants below 1 year of age (mean 879 +/- 270 micrograms/dl). The total tocopherol/total lipid ratio-representing the reliable index for vitamin E status-was far above 0.6 mg/g lipid, a level which is regarded as the lower limit of normal (range 1.23 to 4.09 mg/g total lipid in the older children and 1.52 to 2.05 in the infants below 1 year). A positive correlation was found between plasma lipids and total tocopherol (r = 0.71). Our investigation demonstrated an excellent vitamin E status in the children investigated which is considered to reflect the high supply of West German food with PUFA and vitamin E.

Analysis of the fatty acid composition of erythrocyte phospholipids by a base catalysed transesterification method--prevention of formation of dimethylacetals.

A sensitive method for the analysis of the fatty acid composition of erythrocyte phospholipids with capillary column GLC is described. Under the assay conditions (base catalysed transesterification with sodium methoxide), only the fatty acids of the phospholipids are converted to their methylesters. The alkenyl ether chains of the plasmalogens are not transmethylated. This eliminates the need for thin layer chromatography for the separation of dimethylacetals and esterified fatty acids. The method is suitable for the measurement of the fatty acid patterns of erythrocyte phospholipids in small blood samples.