Red cells, Phospholipids

Oliwiecki, S., Burton, J.L., Elies, K., and Horrobin, D.F., Level of essential and other fatty acids in plasma and red cell phospholipids from normal controls and patients with atopic eczema, Acta Derm. Venereol. (Stockh), 71, 224,1991. 

A number of reports indicate that at least a portion of schizophrenic patients have reduced levels of PUFA, particularly ArAc and DHA, in red cell phospholipids, with low levels particularly associated with negative symptoms (Horrobin, 2002). ArAc, DHA and EPA are important for monoaminergic neurotransmission, brain development, and synaptic functioning (Berger et al., 2006). This suggests that supplementation with essential fatty acids could alleviate symptoms of schizophrenia. In preliminary studies, however, DHA essentially had no effect and ArAc appeared to worsen symptoms in some... 

Phytanic acid of total red cell lipids may amount to 12% of total red cell fatty acids. Its concentration in the various lipid fractions of washed red cells varies the main portion is found in red cell phospholipids, although here cholesterol esters also contain phytanic acid. 

The narrowness of these signals from isolated erythrocyte membrane lipids (Chapman et al., 1968a) in contrast with their broadness observed with 1 1 mixtures of egg-yolk lecithin and cholesterol (Chapman and Penkett, 1966) is readily explained if an optimum cholesterol/phospholipid molecular ratio, 1 1, is required for maximum broadening effect. Red cell phospholipids and other membrane lipids in excess of the optimum ratio, i.e., lipids which could not form a complex with cholesterol (Vandenheuvel, 1963), would then be responsible for observed narrow signals. 

Woon, L.A., Holland, J.W., Kable, E.P. and Roufogahs, B.D., 1999, sensitivity of phospholipid scrambhng in human red cell ghosts. Cell Calcium, 25 313-320. 

Schroit, A.J., andZwaal, R.F., 1991, TransbUayer movement of phospholipids in red cell and platelet membranes. Biochim. Biophys. Acta 1071 313-329. 

Q Yang, M Wallsten, P Lundahl. Immobilization of phospholipid vesicles and protein-lipid vesicles containing red cell membrane proteins on octyl derivatives of large-pore gels. Biochim Biophys Acta 938 243-256, 1988. 

Zwaal RFA, Bevers EM, Comfurius P Rosing J, Tilly RHJ, Verhallen PFJ. Loss of membrane phospholipid asymmetry during activation of blood platelets and sickled red cells mechanisms and physiological significance, Mol Cell Biochem 1989 91 23-3 I. 

Verkleij, A.J., Zwaal, R.F., Roelofsen, B., Comfurius, P., Kastelijn, D. and van Deenen, L.L.M., 1973, The asymmetric distribution of phospholipids in the human red cell membrane. A combined study using phospholipases and freeze-etch electron microscopy. 

When mammalian red cell Hb is used as the raw material for production of a modified Hb, the requirement for the minimization of plasma proteins and red cell stroma is a rigorous and general one. Some manufacturers meet this requirement by extensive red cell washing to reduce contamination by residual plasma, controlled lysis, and careful filtration of the hemoly-sate, followed by ultrafiltration. Other manufacturers add a chromatographic purification step to this procedure. Published data indicate that the phospholipid content of the so-called stroma-free Hb resulting from either process is very low (<2pg/ml). ... 

In this paper, we examine the Interactions of pyran copolymer with model biomembranes of two kinds 1) the human red blood cell membrane (or red cell "ghost") and 11) multilamellar suspensions (liposomes) of dlpalmltoylphosphatldylchollne (DFPC), a pure synthetic phospholipid. Each of these systems offers advantages In studies of polymer-cell surface Interaction The red cell membrane, idille complex. Is still the most readily Isolated and best understood of the membranes of nonnal human cells, and Its molecular architecture Is, In a general way at least, typical of such membranes. The pure phospholipids provide a much simpler biomembrane model, with the prospect of yielding more complete Interpretation of experimental observations. 

The Importance of Ca2+ is also shown in experiments with pure phospholipids. In this work, we use "liposomes," or multilayer suspensions of a single lipid - dlpalmitoylphosphatldylchollne (DPPC) - to approximate the lipid bilayer of the natural membrane. DPPC was chosen because the bulk of the phospholipids in the outer monolayer of the red cell membrane are choline lipids. 

Carlson SE, Carver JD, House SG. High fat diets varying inratiosof polyunsaturated fatty acid and linoleic to linolenic acid a comparison of rat neural and red cell membrane phospholipids. J Nutr 1986 11 718-725. 

There is now substantial evidence from several groups that, although plasma levels of AA and other HUFAs are normal or near normal, red cell membrane phospholipid levels are reduced, particularly in patients with the negative syndrome (Peet, Laugharne, Horrobin, Reynolds, 1994 Yao, van Kammen, Welker, 1994 Glen etal., 1994). The abnormality may become more evident if red cells are not frozen immediately at very low temperatures, such as -70°C. Maintenance for a period at room temperature or for long periods at -20°C rather than -70°C is associated with loss of AA from membrane phospholipids in samples from schizophrenic patients but not from controls. This indicates increased loss of AA from membranes, a process that may continue in stored samples. 

There are clear abnormalities of fatty acid concentrations in depression that are distinct from those in schizophrenia (Adams, Lawson, Sanigorski, Sinclair, 1996 Maes et al., 1996 Maes et al., 1999 Peet, Murphy, Shay, Horrobin, 1998 Edwards, Peet, Shay, Horrobin, 1998). Eirst, the abnormalities are present in both plasma and in red cells, raising the possibility that the problem may be in fatty acid metabolism in general, rather than membrane phospholipid metabolism in particular. Second, the abnormalities are specifically deficits in the omega-3 fatty acids EPA, DHA, and docosapentaenoic acid (DPA), and particularly in EPA. In contrast to the situation in schizophrenia, AA levels are either normal or elevated. 

Lange, Y., Ye, J., and Steck, T. L. (2007). Scrambling of phospholipids activates red cell membrane cholesterol. Biochemistry 46,2233-2238. 

Maguire, P. A., and Sherman, I. W. (1990). Phospholipid composition, cholesterol content and cholesterol exchange in Plasmodium falciparum-infected red cells. Mol. Biochem. Parasitol. 38,105-112. 

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