Erythrocyte Lipids in the Neonate

Abstract

The lipid composition has been characterized in erythrocytes obtained from the cord blood of fullterm normal infants. There is an increase in total lipid, lipid phosphorous and cholesterol per cell (total lipid = 6.45 X 10" 10 mg; Lipid P = 1.54 X 10" 11 mg; cholesterol = 1.79 X 10" 10 mg) when compared with adult controls (total lipid = 5.07 X 10" 10 mg; Lipid P = 1.22 X 10" 11 mg; cholesterol = 1.33 X 10~1 0 mg). Despite the increased lipid content, the percentages of total lipid comprised by lipid phosphorous and cholesterol are similar to those found in the adult (P = 2.40 % of total lipid in infants, 2.41 % in adults: cholesterol = 27.1 % of total lipid in infants, 26.0 % in adults). Phospholipid fractionation shows minor variations between the two groups. Cord blood erythrocyte phospholipid has 1.0% lysolecithin, 26.0% sphingomyelin, 27.7% phosphatidylcholine, 15.2% combined phosphatidylserine and phosphatidylinositol, and 29.1 % phosphatidylethanolamine. Adult erythrocyte phospholipid has 1.2% lysolecithin, 24.1% sphingomyelin, 29.5% phosphatidylcholine, 13.1% combined phosphatidylserine and phosphatidylinositol and 31.2% phosphatidylethanolamine. Phospholipid fatty acid patterns in cord blood erythrocytes show an increased percentage of palmitic acid (cord = 21.3%, adult = 17.0%), stearic acid (cord = 16.3%, adult = 15.3%) arachidonic acid (cord = 19.6%, adult = 17.4%) and combined 22 and 24 carbon fatty acids (cord = 17.6%, adult = 16.3%) associated with decreased percentages of oleic acid (cord = 11.9%, adult = 14.6%) and linoleic acid (cord = 3.4%, adult = 10.9%). SpeculationThe erythrocyte lipids of the newborn show deviations from the adult pattern which may have adaptive value for intrauterine life. These same adaptations may render the cell more vulnerable to oxidative damage in postnatal life. Introductionproportion of phosphatidylcholine and phosphatidylethanolamine and the presence of phosphatidylserine The lipid composition of erythrocytes has recently be-imprint a pattern of erythrocyte lipid in the adult come a matter of great interest. Studies have shown clearly different from that of the plasma-environment, that the red cell lipid is composed almost entirely of Adult plasma has two-thirds of the cholesterol in the free cholesterol and phospholipid [32,40]. The minute esterified form, a proportion of phosphatidylcholine amounts of cholesterol esters, the roughly equivalent ten times that of phosphatidylethanolamine and lacks

Alteration of Adult Erythrocyte Lipids during In Vivo Fetal Circulation

“…Despite the low level of plasma lipid noted in the study infants, the transfused erythrocytes tended to increase the lipid content, particularly cholesterol, with increasing duration of circulation in vivo. The changes noted in lipid composition of the adult erythrocytes are in the direction of that normally found in erythrocytes of normal newborns [22]. The one patient, IUT patient 8, in whom adult cells circulated for a minimum of 30 days, attained levels of total lipid and cholesterol in the erythrocytes comparable to those in the neonate.…”

“…The percentage of phosphatidyl choline in cells from IUT patients 1-7 did not differ significantly from that found in the donor group or those with EB. The level of phosphatidyl choline in cells of both IUT patients 1-7 and controls with EB was significantly increased over the relatively low levels previously emphasized as characteristic of normal newborn cells (P < 0.01) [22]. Two of the samples from IUT patients 1-7 had phosphatidyl choline values in excess of 2 SD above the mean for the donor cells (patient 1: 34.2%; patient 7: 33.4%).…”

“…The lipid composition of erythrocytes from normal neonates differs from that of adult erythrocytes primarily by having an increased amount of total lipid, phospholipid, and cholesterol per cell [22]. When compared with adult erythrocytes, phospholipid distribution in neonatal erythrocytes shows lower percentages of phosphatidyl choline and phosphatidyl ethanolamine coupled with increased percentages of sphingomyelin and combined phosphatidyl serine + phosphatidyl inositol [22].…”

“…Infants were selected in whom, at birth, essentially all circulating erythrocytes were transfused adult cells (based on cell ABO and Rh type, direct Coombs' test and acid elution staining characteristics). The clinical and laboratory course of these infants is shown in Table I; on samples of cord blood from a control group of 10 Rh infants with erythroblastosis (EB) who did not receive intrauterine transfusions to characterize the anticipated lipid patterns from residual fetal cells (group E)\ on samples from 15 freshly drawn type O, Rh-negative blood donor units to characterize the transfused adult donor cells (group D); and on samples of cord blood from a group of 42 full term normal newborn infants previously reported [22] (group N).…”

“…Despite this, the erythrocyte seems capable of maintaining relatively normal lipid composition in several pathologic states associated with severe plasma hyperlipemia [21]. Conversely, total lipid content of erythrocytes in cord blood is 27% higher than that found in adult erythrocytes despite circulation in a comparatively low plasma environment [8,22].…”