Erythrocyte phospholipids

Crinier S, Morrot G, Neumann J-M, Devaux PE. Lateral diffusion of erythrocyte phospholipids in model membranes-comparison between inner and outer leaflet components. Eur Biophys J 1990 18 33 1. 

Fig. 2. The time-course of mean fatty acid changes in erythrocyte phospholipids after tire feeding of fish oil. Note that reciprocal changes of the two major n-3 (EPA and DHA) and the two major n-6 (18 2 and 20 4) polyunsaturated fatty acids occuned as n-3 fatty acids increased and n-6 fatty acids decreased. The concentrations of these four fatty acids in the erythrocyte phospholipids of monkeys fed the control soybean-oil and the deficient safflower-oil diet from our previous study (Neuringer et al, 1986) are given for comparison. Expressed as percentage of total fatty acids, DHA in control monkeys was 1.7 0.9% EPA, 0.5 0.1% 20 4 n-6,15.4 0.5% 18 2 n-6,25.7 1.0%. In deficient monkeys,DHA was0.2 0% EPA was 0% 20 4n-6,18 2 1.3 18 2 n-6 was 25.2 0.4%.

In this study, the half-life of DHA of phosphatidylethanolamine in the cerebral cortex was similar to the half-lives of DHA in plasma and erythrocyte phospholipids, roughly 21 d. These data suggest that the blood-brain barrier present for cholesterol (Olendorf, 1975, Trapp and Bemson, 1977) and other substances may not exist for the fatty acids of the plasma phospholipids because of the relatively rapid uptake of plasma DHA into the brain. The mechanisms of transport of these fatty acids remain to be investigated. 

Wijendran, V., Bendel, R.B., Couch, S.C., Philipson, E.H., Cheruku, S., and Lammi-Keefe, C.J. (2000) Fetal Erythrocyte Phospholipid Polyunsaturated Fatty Acids Are Altered in Pregnancy Complicated with Gestational Diabetes Mellitus, Lipids 55,927-931. 

Takic M, Ristie-Medie D, Mandic Lj, et al. N-3 polyunsaturated acids in erythrocyte phospholipids are associated with insulin sensitivity in obese patients on a typical Serbian diet. Arch Biol Sci Belgrade. 2009, 61(1) 37-43. 

Ristic, V. Tepsic J, Ristic-Medic D, et al. Plasma and erythrocyte phospholipid fatty acids composition in Serbian hemodialyzed patients. Renal Eailure, 2006, 28 211-216. 

Arsic A, Vucic V, Tepsic J, Mazic S, Djelic M, Glibetic M. Altered plasma and erythrocyte phospholipid fatty acid profile in elite female water polo and football players. Appl PhysiolNutr Metab, 2012, 37(1) 40-47. 

It is known that cholesterol interacts with erythrocyte phospholipids reducing its molecular area (Demel et al., 1967) and, as a consequence, a decrease in the local fluidity of the lipid matrix of the erythrocyte membrane occurs, as it was determined by electron spin resonance studies (Kroes et al., 1972). The results obtained for the inhibition by F of the erythrocyte membrane acetylcholinesterase and (Na" ", KT ")-ATPase from rats fed corn oil and corn oil-plus-cholesterol supplemented diet, respectively, are presented in Table 5. In the case of acetylcholinesterase, the values of n change from 1.5 to 1.0 because of cholesterol dietary effect. Consequently, in the (Na , KT ")-ATPase the values of n vary in an inverse manner (from 2.0 to 3.6). (Bloj et al., 1973 ). 

The fact that thionins, although readily soluble in water, can be extracted from ground seeds with petroleum ether and other organic solvents to form proteolipids shows that the thionin peptides are amphipathic and do combine with membrane phospholipids. There is some information concerning the direct interaction of thionins with phospholipids. Binding studies have shown that I-PT binds readily to synthetic vesicles composed of PS, but not with PC (unpublished data). The experiments cited above (47) describe the effect of PT on phospholipid vesicles formed from extracted erythrocyte phospholipids to induce domain formation. 

FIGURE 9.10 Phospholipids are arranged asymmetrically in most membranes, including the human erythrocyte membrane, as shown here. Values are mole percentages. (After Rothman and Lenard, 1977. Science 194 1 744.)... 

Proteins that can flip phospholipids from one side of a bilayer to the other have also been identified in several tissues (Figure 9.11). Called flippases, these proteins reduce the half-time for phospholipid movement across a membrane from 10 days or more to a few minutes or less. Some of these systems may operate passively, with no required input of energy, but passive transport alone cannot establish or maintain asymmetric transverse lipid distributions. However, rapid phospholipid movement from one monolayer to the other occurs in an ATP-dependent manner in erythrocytes. Energy-dependent lipid flippase activity may be responsible for the creation and maintenance of transverse lipid asymmetries. 

Cholesterol is found in many biological membrane and is the main sterol of animal organisms. It is eqnimolar with phospholipids in membranes of liver cell, erythrocytes, and myelin, whereas in human stratum comeum it lies in the outermost layer of the epidermis... 

There is also inside-outside (transverse) asymmetry of the phospholipids. The choline-containing phospholipids (phosphatidylcholine and sphingomyelin) are located mainly in the outer molecular layer the aminophospholipids (phosphatidylserine and phos-phatidylethanolamine) are preferentially located in the inner leaflet. Obviously, if this asymmetry is to exist at all, there must be limited transverse mobility (flip-flop) of the membrane phospholipids. In fact, phospholipids in synthetic bilayers exhibit an extraordinarily slow rate of flip-flop the half-life of the asymmetry can be measured in several weeks. However, when certain membrane proteins such as the erythrocyte protein gly-cophorin are inserted artificially into synthetic bilayers, the frequency of phospholipid flip-flop may increase as much as 100-fold. 

The erythrocyte cell is surrounded by a membrane called the plasmalemma, which consists of equal weights of lipid (major components phospholipids,... 

Different tissues have different lipid compositions. The most common lipid components of membranes are PC and PE. Lipid extracts from brain and lung are also rich in PS heart tissue is rich in PG, and liver is rich in PI [567]. Human blood cells, as ghost erythrocytes (with cytoplasm contents removed), are often used as membrane models. These have different compositions between the inner and outer leaflets of the bilayer membrane. Phospholipids account for 46% of the outer leaflet membrane constituents, with PC and Sph about equal in amount. The inner leaflet is richer in phospholipids (55%), with the mix 19% PE, 12% PS, 7% PC and 5% Sph [567],... 

Chatelain, R Laruel, R., Amiodarone partitioning with phospholipid bilayers and erythrocyte membranes, J. Pharm. Sci. 74, 783-784 (1985). 

Marfey, S.P., and Tsai, K.H. (1975) Cross-linking of phospholipids in human erythrocyte membrane. Biochem. Biophys. Res. Comm. 65, 31-38. 

In 1977, Kellogg and Fridovich [28] showed that superoxide produced by the XO-acetaldehyde system initiated the oxidation of liposomes and hemolysis of erythrocytes. Lipid peroxidation was inhibited by SOD and catalase but not the hydroxyl radical scavenger mannitol. Gutteridge et al. [29] showed that the superoxide-generating system (aldehyde-XO) oxidized lipid micelles and decomposed deoxyribose. Superoxide and iron ions are apparently involved in the NADPH-dependent lipid peroxidation in human placental mitochondria [30], Ohyashiki and Nunomura [31] have found that the ferric ion-dependent lipid peroxidation of phospholipid liposomes was enhanced under acidic conditions (from pH 7.4 to 5.5). This reaction was inhibited by SOD, catalase, and hydroxyl radical scavengers. Ohyashiki and Nunomura suggested that superoxide, hydrogen peroxide, and hydroxyl radicals participate in the initiation of liposome oxidation. It has also been shown [32] that SOD inhibited the chain oxidation of methyl linoleate (but not methyl oleate) in phosphate buffer. 

Hydroxy-10,12-octadecadienoic acid, which is formed by the reduction of 9-HPODE, was identified in the erythrocyte membrane phospholipid of diabetic patients [83]. It was suggested that this compound was formed as a result of glucose-induced oxidative stress in the reaction of hydroxyl radicals with linoleic acid. 

The transport behavior of Li+ across membranes has been the focus of numerous studies, the bulk of which have concentrated upon the human erythrocyte for which the Li+ transport pathways have been elucidated and are summarized below. The movement of Li+ across cell membranes is mediated by transport systems which normally transport other ions, therefore the normal intracellular and subcellular electrolyte balance is likely to be disturbed by this extra cation. Additionally, Li+ has been shown to increase membrane phospholipid unsaturation in rat brain, leading to enhanced fluidity in the membrane, which could have repercussions for membrane-associated proteins and for membrane transport properties. 

Stangl, G.I. and M. Kirchgessner. 1997. Effect of nickel deficiency on fatty acid composition of total lipids and individual phospholipids in brain and erythrocytes of rats. Nutr. Res. 17 137-147. 

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