Erythrocyte Lipids in Infants with Low Birth Weights

Abstract

Extract: The lipid composition of erythrocytes, obtained from the cord blood of prematurely born, low birth weight infants, was compared with that obtained from term infants. Infants weighing less than 1,200 g at birth had increased total lipids, lipid phosphorus (P), and cholesterol per cell (total lipid = 7.60 ± 10-10 mg; lipid P = 1.80 ± 10-11 mg; cholesterol = 2.10 ± 10-10 mg) when compared with controls (total lipid = 6.45 ± 10-10 mg; lipid P = 1.54 ± 10-11 mg; cholesterol = 1.79 ± 10-10 mg). The lipid content per 100 ml packed cells and the percentageF of total lipid as phospholipid and cholesterol did not differ significantly over the range of birth weights studied. Phospholipid fractionation showed a higher percentage of phosphatidyl choline in infants under 1,200 g birth weight (30.0% of total lipid P) than that noted in term infants (27.7% of total lipid P). The higher levels of combined phosphatidyl serine and phosphatidyl inositol noted in term infant erythrocytes (compared with normal adult cells) were observed in the low birth weight infants. Fatty acids esterified to phos-pholipids showed an increasing percentage of oleic acid with decreasing birth weight (infants of less than 1,200 g had 16.0% total fatty acid; infants of more than 2,500 g had 11.9% total fatty acid). Speculation: These studies suggest that the earliest embryonic erythrocytes have the greatest membrane lipid content although the overall membrane lipid distribution does not vary greatly during fetal life.