The erythrocyte membrane in kwashiorkor.

Abnormalities of lipid metabolism in kwashiorkor are well documented. In Uganda, as elsewhere, frequent findings are fatty infiltration of the liver and a reduction in the quantity of serum lipids (Schwarz & Dean, 1957). The concentrations of both the aand /I-lipoproteins are also reduced, the /3-lipoproteins possibly more so (Cravioto, De la Pena & Burgos, 1959; Monckeberg, 1968). Lipids, in particular phospholipids, are also essential components of membrane systems, and although there has been speculation about possible changes in these structures as a result of severe protein-calorie malnutrition, this has not yet been investigated. Membrane changes have, however, been described in other conditions where there are defects in lipid metabolism. The phospholipid composition of erythrocyte membranes is abnormal in a number of liver diseases (Nye & Marinetti, 1967; Boon, Broekhuyse, van Munster & Schretlen, 1969), in Niemann-Pick disease (Balint, Nyhan, Lietman & Turner, 1961), in Tay-Sachs disease (Balint, Spitzer & Kyriakides, 1963), in various other lipidoses (Hooghwinkel, van Gelderen & Staal, 1969) and in acanthocytosis (Ways, Reed & Hanahan, 1963). This study was carried out in order to investigate the possibility that malnutrition, leading to kwashiorkor, might result in structural and functional changes in cell membranes. Because they were readily available, erythrocytes were used to provide the membrane material for phospholipid analysis. Although erythrocytes must be regarded as somewhat specialized structures, the importance of phospholipids is common to all biological membranes; changes in erythrocyte phospholipids may indicate changes in other cells. Since the relative amounts of the different phospholipid components in erythrocyte membranes are thought to be associated with their passive permeability properties (van Deenen, 1965), measurements were also made of the velocity of penetration of glycerol and thiourea into the erythrocytes. The chemical analyses and permeability studies were made on the children when they were admitted to hospital with kwashiorkor and then at subsequent stages during treatment.