Release of phospholipid fatty acid from human erythrocytes

Shohet, Stephen B.

doi:10.1172/jci106384

Cited by 69 publications

(25 citation statements)

References 29 publications

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“…It has .been shown [25] that choline phosphoglyceride is the major metabolically active component of the erythrocyte plasma membrane lipids, and that cycling between choline phosphoglyceride and lysocholine phosphoglyceride is a relatively common process [26]. This process presents the opportunity for the selective accumulation of preferred fatty acids within the phosphoglycerides, and the possibility of their subsequent release when required to perform a function within a target tissue [27]. Thus the erythrocyte plasma membrane longchain acyl : CoA synthetase may act as the first step in a fluid system for the selective supply of fatty acids required by other tissues.…”

Section: Resultsmentioning

confidence: 99%

Erythrocyte membrane acyl : CoA synthetase activity

Davidson

Cantrill

1985

FEBS Letters

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The presence of long-chain acyl:CoA synthetases in mammalian microsomes and mitochondria has been established previously [( 1971) Biochim. Biophys. Acta 23 1, 32471. The presence of a plasma membrane-associated enzyme was investigated in human erythrocyte ghost plasma membranes, where an enzyme exhibiting high activity, and with a preferred substrate of 18 carbon chain length, was discovered. The results are consistent with the presence of a single enzyme. The effect of the degree of unsaturation of the fatty acid substrates was not as pronounced as that arising from the length of the carbon chain. The pattern of substrate preference of the enzyme was 03 polyenoics > ~6 polyenoics > w9 monoenoics > saturated fatty acids. This may relate to the similar substrate preference pattern exhibited by the fatty acyl desaturase enzymes. However, the role played by long-chain acyl: CoA synthetase in erythrocyte metabolism is uncertain, but may relate to the transportation of polyenoic fatty acids in the circulation. Erythrocyte Plasma membraneAcyl: CoA synthetase

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Section: Resultsmentioning

confidence: 99%

Erythrocyte membrane acyl : CoA synthetase activity

Davidson

Cantrill

1985

FEBS Letters

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“…The well documented low turnover rate of phospholipids in the erythrocyte membrane will certainly attribute to this phenomenon [14,15].…”

Section: Discussionmentioning

confidence: 99%

“…During the whole 120 days lifespan of the human erythrocyte, the overall phospholipid composition remains rather similar [1,9] and the differences in fatty acid composition which can be observed upon extreme variations in dietary fats are less pronounced than the changes in lipid composition of the plasma [10][11][12][13]. Relevant in this respect is the slow turnover of the membrane phospholipids: renewal of PC occurs by deacylation-reacylation as well as by an exchange of complete molecules with the serum; both processes proceed with a rate of about 1% per hour [14] and a halftime of 100 h [15], respectively.…”

Section: Introductionmentioning

confidence: 99%

The membrane of intact human erythrocytes tolerates only limited changes in the fatty acid composition of its phosphatidylcholine

Kuypers

Roelofsen

Kamp

et al. 1984

Biochimica et Biophysica Acta (BBA) - Biomembranes

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(1) Using the phosphatidylcholine specific transfer protein from bovine liver, native phosphatidylcholine from intact human erythrocytes was replaced by a variety of different phosphatidylcholine species without altering the original phospholipid and cholesterol content. (2) The replacement of native phospharidylcholine by the disaturated species, 1,2-dipalmitoyl-and 1,2-distearoylphosphatidyicholine, proceeded at a low rate and extensive replacement could only be achieved by repeatedly adding fresh donor vesicles. The replacement by disaturated molecules was accompanied by a gradual increase in osmotic fragility of the cells, finally resulting in hemolysis when 40% of the native PC had been replaced. Up to this lyric concentration, the replacement did not affect the permeability of the membrane for potassium ions. (3) Essentially, all of the PC in the outer monolayer of the membrane could be replaced by 1-palmitoyl-2-oleoyl-and 1-palmitoyl-2-1ino-leoylphosphatidylcholine. These replacements did not alter the osmotic fragility of the cells, nor the K + permeability of the membrane. (4) Increasing the total degree of unsaturation of the phosphatidyicholine species modified the properties of the membrane considerably. Replacement by 1,2-dilinoleoylphosphatidylcholine resulted in a progressive increase in osmotic fragility and hemolysis started to occur after 30% of the native PC had been replaced by this species. K ÷ permeability was found to be slightly increased in this case. Cells became leaky for K ÷ upon the introduction of 1-palmitoyl-2-arachidonoylphosphatidyicholine in the membrane. The increased permeability was also reflected by an apparent increase in the resistance of the cells against osmotic shock. (5) The conclusions to be drawn are that (i) 1-palmitoyl-2-oleoyi-and l-paimitoyi-2-1inoleoylphosphatidyicholine are species which fit most optimally into the erythrocyte membrane; (ii) loss of membrane stability results from an increase in the degree of saturation of phosphatidyicholine (unsaturation index > 0.5) and (iii) the permeability is enhanced by increasing the content of highly unsaturated species (unsaturation index > 1.0).

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“…Shohet [8,9] proposed the existence of two compartments of lecithin in the erythrocyte membrane: one of these is thought to be in equilibrium with lecithin from…”

Section: Discussionmentioning

confidence: 99%

Preferential incorporation of fatty acids at the inside of human erythrocyte membranes

Renooij

Golde

Zwaal

et al. 1974

Biochimica et Biophysica Acta (BBA) - Biomembranes

100

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Summary1. Phospholipase A2 isolated from Naja naja venom was used as a tool to discriminate between the outer and inner lipid monolayer of the membranes of human erythrocytes.2. Incubation of human erythorcytes with radioactive fatty acids resulted in the formation of labelled lecithin in the membrane. The label was found predominantly in that pool of lecithin which is localized in the inner monolayer of the membrane.3. Lecithins isolated from the total erythrocyte membrane and from the inner monolayer of the membrane possess identical fatty acid patterns and identical positional distributions of their fatty acyl constituents.Circulating red blood cells should be capable of incorporating fatty acids into their phospholipids since variations in the diet can induce alterations in the fatty acid pattern of the phospholipids within a much shorter period than the average lifespan of the erythrocyte [1,2], Two mechanisms have been described to play a major role in the renewal of the phospholipids of the erythrocyte membrane: (1) an exchange of phospholipids between serum lipoproteins and the red cell membrane [3--5] and (2) the incorporation of fatty acids into lysophospholipids which are either formed in the membrane or supplied by the surrounding serum [6,7]. Shohet [8,9] proposed the existence of two compartments of lecithin in the erythrocyte membrane: one of these is thought to be in equilibrium with lecithin from

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Release of phospholipid fatty acid from human erythrocytes

Cited by 69 publications

References 29 publications

Erythrocyte membrane acyl : CoA synthetase activity

Erythrocyte membrane acyl : CoA synthetase activity

The membrane of intact human erythrocytes tolerates only limited changes in the fatty acid composition of its phosphatidylcholine

Preferential incorporation of fatty acids at the inside of human erythrocyte membranes

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