Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PLASMALOGEN”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 685 records · Page 38Linked to original sources

Isolated defect of peroxisomal beta-oxidation in a 16-year-old patient.

We describe a 16-year-old boy suffering from psychomotor retardation, sensorineuronal hearing impairment, peripheral neuropathy, hepatosplenomegaly, short stature and delayed puberty. Postnatally, muscular hypotonia, mild facial dysmorphism and delayed fontanelle closure had been noticed. At the time of our examination, adrenal cortical function was normal. Biochemical analysis revealed accumulation of very long (> C22) chain fatty acids in plasma and fibroblasts. Furthermore, elevated levels of intermediates of bile acid synthesis and phytanic acid were detectable. These findings are consistent with a defect in the peroxisomal beta-oxidation system. A generalised defect of peroxisomal function was excluded by normal plasmalogen levels in erythrocytes and normal plasmalogen de novo synthesis in fibroblasts. Immunoblotting of the peroxisomal beta-oxidation enzymes gave normal results suggesting retained immunoreactivity but catalytic inactivity of one of the enzymes involved, probably either the trifunctional protein or the peroxisomal ketothiolase. This case markedly differs clinically from the few published reports on isolated deficiencies of peroxisomal beta-oxidation. Among the patients with comparable biochemical findings, this is the first report of survival into adolescence.

3-Hydroxyacyl CoA Dehydrogenases↗

Marked enrichment of the alkenylacyl subclass of plasma ethanolamine glycerophospholipid with eicosapentaenoic acid in human subjects consuming a fish oil concentrate.

Alteration in human platelet fatty acid levels with the consumption of fish oils containing eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) have been well documented, but changes in the fatty acid composition of plasma plasmalogenic phospholipid under similar circumstances have not been delineated. In the present study, subjects consumed the fish oil concentrate (MaxEPA) for 6 wk followed immediately by a 6-wk recovery period with no fish oil ingestion. Plasma total choline glycerophospholipid (GPC) and ethanolamine glycerophospholipid (GPE) subclasses isolated from blood samples obtained at 0, 3, 6, 9 and 12 wk of the experimental period were analyzed for fatty acid composition via thin-layer and gas-liquid chromatographic techniques. Consumption of fish oil for 3 or 6 wk significantly elevated the content of n-3 fatty acids while concomitantly decreasing n-6 fatty acid levels in plasma total GPC and in diacyl and alkenylacyl (plasmalogen) GPE. Alkenylacyl GPE exhibited the greatest alteration of both n-3 and n-6 fatty acid levels. Following 6 wk of supplementation with fish oil, EPA rose by 24.6 mol% in alkenylacyl GPE compared to increases of 6.7 and 7.1 mol% in diacyl GPE and total GPC, respectively. The increase in EPA (from 5.0 to 29.6 mol%) in plasma alkenylacyl GPE represents amongst the highest enrichment of EPA in any lipid yet reported in human subjects. DHA also rose by 8.0, 4.8, and 3.1 mol% in alkenylacyl GPE, diacyl GPE, and total GPC, respectively. Alkenylacyl GPE exhibited the greatest mol% decline (by 18.7 mol%) in arachidonic acid (AA, 20:4n-6) following 6 wk of fish oil supplementation. The corresponding decreases of AA in diacyl GPE and total GPC were 8.7 and 1.8 mol%, respectively. Following the 6 wk recovery period, n-3 and n-6 fatty acid levels had returned to pre-supplementation values. The marked enrichment of alkenylacyl GPE in n-3 fatty acids, especially EPA, may be of significance with respect to a unique role for this plasma phospholipid subclass in attenuating certain lipoprotein-mediated cardiovascular effects as observed with fish/fish oil consumption.

Acylation↗

Lateral microheterogeneity of diphenylhexatriene-labeled choline phospholipids in the erythrocyte ghost membrane as determined by time-resolved fluorescence spectroscopy.

Choline phospholipids are the major constituents of the outer layer of the erythrocyte membrane. To investigate their lateral membrane organization we determined the fluorescence lifetime properties of diphenylhexatriene analogues of phosphatidylcholine, choline plasmalogen, (the respective enolether derivative), and sphingomyelin inserted into the outer layer of hemoglobin-free ghosts. Fluorescence lifetimes were recorded by time-resolved phase and modulation fluorometry and analyzed in terms of Continuous Lorentzian distributions. To assess the influence of membrane proteins on the fluorescence lifetime of the labeled lipids in the biomembrane, lipid vesicles were used as controls. In general, the lifetime distributions in the ghost membranes are broad compared to vesicles. Phosphatidylcholine and sphingomyelin exhibit very similar lifetime distributions in contrast to an increased plasmalogen lifetime heterogeneity in both systems. Orientational effects of side chain mobilities on the observed lifetimes can be excluded. Fluorescence anisotropies revealed identical values for all three labeled phospholipids in the biomembrane.

Choline↗

Phospholipid composition of the granular amebocyte from the horseshoe crab, Limulus polyphemus.

The phospholipid composition was determined for the amebocyte of the primitive arthropod Limulus polyphemus. The total fatty acid composition of the cells' lipids was analyzed by gas chromatography/mass spectrometry (GC/MS) of fatty acid methyl esters (FAME). The FAME analysis revealed high levels of 20-carbon polyunsaturated fatty acids (PUFA), especially arachidonic (20:4n-6) and eicosapentaenoic (20:5n-3) acids. Almost 20% of the total lipid profile was comprised of dimethyl acetals of 16- to 20-carbon chain lengths, indicative of plasmalogens in the phospholipid pool. Phospholipids, analyzed by high-pressure liquid chromatography, included phosphatidylethanolamine (PE), phosphatidylcholine (PC), phosphatidylserine (PS), phosphatidylinositol (PI), sphingomyelin (SPH), and cardiolipin (CL). PE and PC levels predominated at 42.2 and 36.3%, respectively. Smaller amounts of PS (9.0%) and PI (6.2%) were present, as well as low levels of SPH (4.6%), CL (1.6%), and trace amounts of lysophosphatidylcholine. The major phospholipid species, PE, PC, PS and PI, were collected and their molecular species were examined by electrospray-ionization mass spectrometry. The molecular species within the phospholipid classes reflected the high levels of PUFA seen in the total lipid profile. PI was mainly composed of 18:0a/20:4. Over half of the PS consisted of 18:0a/18:1 and 18:0a/20:4. The major PE species were 20:1p/20:5, 20:1p/20:4, 18:0p/20:5, and 18:0p/20:4. PC had the largest distribution of molecular species, and its most abundant species were 16:0e/20:5, 16:0e/20:4, and 16:0p/20:4. The presence of 16:0e/20:4 is the first documentation of a specific precursor to platelet-activating factor in an invertebrate hemocyte. Note: at the sn-1 position: [a=1=O-acyl, e = 1-O-alkylether, and p = 1-O-alk-1'-enyl (plasmalogen)].

Animals↗

Unsaturated aminophospholipids are preferentially retained by the fast skeletal muscle CaATPase during detergent solubilization. Evidence for a specific association between aminophospholipids and the calcium pump protein.

When fast twitch skeletal muscle vesicles (SR) and purified calcium pump protein are stripped with the nonionic detergent C12E8 (octaethylene glycol dodecyl ether), not all the membrane phospholipids are removed from the calcium pump protein. Maximal extraction produces a remnant of 6-8 mol of phospholipid/mole of calcium ATPase (CaATPase). In contrast to native SR and the prestripped purified CaATPase, the remaining phospholipid is markedly enriched in phosphatidylethanolamine (PE) and phosphatidylserine (PS) in both preparations; the remaining lipid is also enriched in phospholipid that is predominantly unsaturated. In addition, virtually all of the associated PE is plasmalogenic (96% as opposed to 63% in the native SR). The amino-specific cross-linking reagent DFDNB (1,5-difluoro-2,4-dinitrobenzene sulfonic acid) and the amino binding reagent TNBS (2,4,6-trinitrobenzene sulfonic acid) were utilized to identify the monolayer of the native preparation where these phospholipids reside, and to determine which phospholipids are closely associated with the calcium pump protein following detergent treatment. These studies demonstrate that PE and PS are closely associated with the pump protein, PE residing almost exclusively in the outer monolayer of SR, while PS resides in the inner monolayer. Nonspecific phospholipid exchange protein was shown to be capable of exchanging phospholipids from donor vesicles into those phospholipids associated with the CaATPase; stripping of lipid-exchanged vesicles with C12E8 exhibited the same specificity with regard to head-group species (i.e., PE is markedly enriched in the extracted protein associated fraction). The results suggest that specific protein-lipid interactions exist, favoring the association of plasmalogenic aminophospholipids with the calcium pump protein.

Animals↗

Temperature adaptation of biological membranes. The effects of acclimation temperature on the unsaturation of the main neutral and charged phospholipids in mitochondrial membranes of the carp (Cyprinus carpio L.).

The phospholipid composition, fatty acid pattern and cholesterol content are studied in mitochondria of red lateral muscle of carp acclimated to high and low environmental temperatures. The results of the experiments are: mitochondria from cold-acclimated carp contain higher proportions of ethanolamine phosphatides than mitochondria from warm-acclimated fish, the opposite is true for the choline phosphatides. Thus, at constant pH, the membrane phospholipids are slightly more negatively charged at low acclimation temperature. The total plasmalogen content is reduced in the cold; this reduction is caused by a decrease in the proportion of the choline plasmalogens. The ethanolamine phosphoglycerides contain approx. 20% of the alk-1-enyl acyl type, irrespective of the acclimation temperature. There is no temperature-dependent difference in the low proportion of cholesterol. The fatty acids of total mitochondrial phospholipids are characterized by large amounts of the n-3 and n-6 families. The ratio of unsaturated to saturated fatty acids and the unsaturation index are remarkably higher than those reported for comparable mammalian phospholipids. Cold acclimation of carp does not significantly increase the unsaturation of total phospholipids. A fatty acid analysis of the main isolated phospholipids, however, shows that cold acclimation considerably increases unsaturation of the neutral phosphatidylcholine, whereas it dramatically decreases unsaturation of the negatively charged cardiolipin. It is suggested that the observed fatty acid substitution in phosphatidylcholine indicates a temperature-induced fluidity adaptation within the mitochondrial lipid bilayer, whereas the inverse acclimation pattern of cardiolipin provides a suitable lipid to accommodate the temperature-dependent modifications in the dynamic surface shape of integral membrane proteins.

Acclimatization↗

Ether lipid content of phosphoglycerides from the retina and brain of chicken and calf.

Phospholipid contents and compositions were determined for chicken and calf retinas, chicken brain and calf gray matter. Retinal phospholipid compositions differ from brain phospholipid compositions by including a higher percentage of choline phosphoglycerides and lower percentages of ethanolamine and serine phosphoglycerides. The proportion of sphingomyelin is lower in calf retina than in calf brain. Among the ethanolamine phosphoglycerides, the proportions of the alk-1-enylacyl (plasmalogen) type are lower and the proportions of alkylacyl and diacyl types are higher in retina than in brain. The alkyacyl glycerophosphoethanolamines accounted for 7.6% and 8.9% of the ethanolamine phosphoglycerides from chicken and calf retinas respectively. Lower proportions of plasmalogens in the choline phosphoglycerides were found in retina as compared with brain. The alkylacyl glycerylphosphocholines comprised 4.0% of the retinal choline phosphoglycerides. Overall, a smaller proportion of retinal phosphilipids than of brain phospholipids contained alkyl or alk-1-enyl ether groups and the ratio of alkyl groups to alk-1-enyl groups was greater in retina than in brain.

Animals↗

A phospholipid serine base exchange enzyme.

A membrane bound L-serine exchange enzyme which catalyzes the exchange reaction between L-serine and phospholipid-base was solubilized and separated from the ethanolamine-exchange enzyme by Sepharose 4B and DEAE-cellulose column chromatography. The separated fraction was purified approximately 37-fold with a yield of 2--5%. This fraction did not possess ethanolamine or choline exchange activity. The optimal pH was approx. 8.0, the incorporation rate of L-serine into phospholipid was linear up to 20 min incubation time and the activity was maximum at 10 mM CaCl2. The calculated Km value for L-serine was 0.4 mM. Ethanolamine phospholipid was the most effective acceptor for L-serine incorporation, particularly ethanolamine plasmalogen. The Km values obtained were: 0.25 mM for ethanolamine plasmalogen, 0.25mM for pig liver phosphatidylethanolamine and 0.66 mM for egg yolk phosphatidylethanolamine. These observations suggest that the hydrophobic moiety in ethanolamine phospholipid, as well as the base moiety, is important for the affinity of the L-serine exchange enzyme. Neither ethanolamine nor choline inhibited the L-serine exchange activity. There was no detectable conversion of phosphatidylcholine or phosphatidylethanolamine to phosphatidic acid by the partially purified enzyme.

Animals↗

Choline and ethanolamine glycerophospholipid synthesis in isolated synaptosomes of rat brain.

Substantial activities of cholinephosphotransferase (EC 2.7.8.2) and ethanolaminephosphotransferase (EC 2.7.8.1) were found with lysed synaptosomes but not with intact synaptosomes isolated from adult rat brains. Synaptosomal and non-synaptosomal microsomal transferases were similar in kinetic properties. Substantial activities of synaptosomal transferases have not been described previously. Part of the glycerophospholipids in synaptosomal membranes may be synthesized in the nerve ending in addition to the glycerophospholipids supplied by axonal transport. The synthesis of the alkylacyl type of choline and ethanolamine glycerophospholipids was moderately inhibited by 1 mM ATP and 1 microM cyclic AMP. This synthesis was also inhibited by more than 50% by 1 mM norepinephrine and to a lesser extent by 5 mM hydroxytryptamine and 1 mM acetylcholine. Cyclic AMP may mediate the effects of biogenic amines. The relative synthesis of different glycerophospholipid classes and the relative proportion of alkylacyl type (plasmalogen precursors) and diacyl type of glycerophospholipids may be influenced by the levels of adenine nucleotides and/or biogenic amines. Elevated cyclic AMP levels will decrease the synthesis of plasmalogen precursors.

Adenine Nucleotides↗

Composition and incorporation of [3H]arachidonic acid into molecular species of phospholipid classes by cultured human endothelial cells.

Based on quantitative high-performance liquid chromatographic analyses of molecular species in selected phospholipid subclasses from culture human umbilical vein endothelial cells, the relative degree of unsaturation was ethanolamine plasmalogens greater than phosphatidylethanolamine greater than phosphatidylcholine. A total of 36 different molecular species were identified in the phosphatidylcholine fraction. Interestingly, the phosphatidylcholine contained a significant amount (11.7%) of the dipalmitoyl species, a lipid normally associated with lung surfactant. The arachidonoyl-containing molecular species of phosphatidylserine/inositol were labeled to the highest extent and the ethanolamine plasmalogens contained the lowest specific radioactivity after incubating [3H]arachidonic acid with human endothelial cells for 4 h. Within each phospholipid subclass the arachidonoyl species where both acyl groups of the phospholipid are unsaturated (20:4-20:4, 18:2-20:4 + 16:1-20:4, and 18:1-20:4) had higher specific radioactivities, after labeling with [3H]arachidonic acid, than those that contained saturated aliphatic chains (16:0-20:4 and 18:0-20:4). This indicates that the unsaturated species have higher turnover rates.

Arachidonic Acid↗

Coenzyme A-dependent and -independent acyl transfer between dog heart microsomal phospholipids.

We have recently shown that dog heart microsomes catalyze the transfer of acyl groups from the sn-2 position of exogenous phosphatidylcholine to lysophosphatidylethanolamine with strong preference for arachidonate over linoleate (Biochem. Biophys. Res. Commun. 129, 381-388 (1985)). We now report that the addition of 0.5 mM CoA enhances the acyl transfer activity 3-4-fold but reduces the selectivity for arachidonate. Acyl transfer in the absence of CoA exhibits a pH optimum of 7.5-8.5, whereas two pH optima (7.5 and 4.5) are observed in the presence of CoA with transfer activity at pH 4.5 exceeding that of pH 7.5 by 4-5-fold. The plasmalogen (alkenyl) analog of lysophosphatidylethanolamine is an equally effective acyl acceptor in the absence of CoA but less effective in its presence. The microsomal acyl-CoA/lysophosphatidylethanolamine acyltransferase does not favor arachidonate over linoleate. Therefore, transacylation from phosphatidylcholine may account for the high arachidonate content of dog heart microsomal phosphatidylethanolamine and its plasmalogen analog. In fact, acyl transfer from endogenous lipids to 1-[1'-14C]palmitoyl-2-lyso-sn-glycerophosphoethanolamine results in the generation of mostly (over 80%) tetraunsaturated phosphatidylethanolamine. This proportion is reduced by the addition of CoA and, even more, by CoA plus acyl-CoA-generating cofactors. We conclude that in dog heart microsomes, lysophosphatidylethanolamine can be acylated by different mechanisms, of which the CoA-independent transacylase exhibits the greatest acyl selectivity.

Acylation↗

Characterization and comparison of lipids in different squid nervous tissues.

We have studied the lipid composition of brain (optic and cerebral lobes), stellate ganglia and fin nerves of the squid. Cholesterol, phosphatidylethanolamine and phosphatidylcholine were the major lipids in these nervous tissues. Phosphatidylethanolamine contained about 3% of its amount in [corrected] plasmalogen form. Phosphatidylserine and -inositol, sphingomyelin and ceramide 2-aminoethylphosphonate were also present in significant amounts. In addition, cardiolipin and free fatty acids were detected in brain (each 2-3% of total lipids) and stellate ganglia (about 1% each), but not in fin nerves. Phosphatidylethanolamine, phosphatidylserine and phosphatidylinositol from brain contained large amounts of polyunsaturated fatty acids, namely 20:4, 20:5 and 22:6 in the n-3 family. On the other hand, phosphatidylcholine, cardiolipin, and sphingomyelin, and ceramide 2-aminoethylphosphonate contained only saturated or monounsaturated C16-C18 fatty acids. The aldehyde moieties of ethanolamine plasmalogen were also C16-C18 saturated or monounsaturated. These lipid compositions are compared with those in other invertebrate nervous systems.

Animals↗

Solubilization, purification and characterization of lysoplasmalogen alkenylhydrolase (lysoplasmalogenase) from rat liver microsomes.

Alkenylhydrolase (EC 3.3.2.2; EC 3.3.2.5) has been purified 200-fold to a specific activity of 8.0 mumol/min per mg from rat liver microsomes with 51% of the activity recovered. Purification was accomplished by solubilization of the membrane-associated enzyme with octylglucoside and chromatographic resolution on sequential DEAE cellulose and hydroxylapatite (HPLC) columns in the presence of octylglucoside. The partially purified enzyme, specific for the 2-deacylated plasmalogen, lysoplasmalogen (1-alk-1'-enyl-sn-glycero-3-phosphocholine or -ethanolamine), had no hydrolytic activity with intact plasmalogens or 1-acyl-sn-glycero-3-phosphoethanolamine. Kinetic analyses of enzymic activity demonstrated apparent Km values of 5.5 and 42 microM for 1-alk-1'-enyl-sn-glycero-3-phosphocholine and 1-alk-1'-enyl-sn-glycero-3-phosphoethanolamine, respectively. The Vmax values were 11.7 and 13.6 mumol/min per mg with the choline and ethanolamine substrates, respectively. The optimal pH range was between 6.6 and 7.1 with both substrates; the energy of activation for the purified enzyme was 15,200 cal. The enzyme required no cofactors and was unaffected by low millimolar concentrations of Ca2+, Mg2+, Mn2+ or EDTA. It was inhibited by the sulfhydryl-reacting reagent, p-chloromercuribenzoate. Mono- or diradylglycerophospholipids or sphingomyelin did not affect the enzymic activity at 37 degrees C. Activity of the purified enzyme, destroyed by freezing at -20 degrees C, was preserved if stored at this temperature in the presence of 300-600 microM diradylglycerophosphocholine or 50% glycerol. A continuous spectrophotometric assay, adapted in our laboratory for the assay of liver alkenylhydrolase, facilitated this purification. This is the first reported purification of alkenylhydrolase.

Animals↗

Fatty acid desaturation in an animal cell mutant defective in plasmanylethanolamine desaturase.

We have recently reported the isolation of three plasmalogen-deficient mutants in a murine, macrophage-like cell line, RAW 264.7 (Zoeller et al. (1992) J. Biol. Chem. 267, 8299-8306). One of these mutant strains, RAW.12, is deficient in delta 1'-desaturase (plasmanylethanolamine desaturase, EC 1.14.99.19), the activity responsible for introducing the vinyl-ether double bond found in plasmalogens. We have examined these mutant cells to determine whether any of the desaturase activities involved in the desaturation of fatty acyl-CoAs were affected and found no evidence to suggest this. Stearoyl-CoA desaturase (delta 9-desaturase) activity was normal when measured in microsomes from RAW.12 cells and the conversion of stearate to oleate (which requires the delta 9-desaturase system) by intact RAW.12 cells was unaltered compared to wild-type cells. The conversion of linoleate to arachidonate by intact cells (which requires the delta 5 and delta 6 desaturase activities) was also normal in the mutant cells. Fatty acid analyses showed no decreases in the relative levels of the unsaturated fatty acids that require the delta 9, delta 6 and delta 5 desaturase activities for biosyntheses of 18:1, 18:3, and 20:4 respectively. Analysis of the cytochrome b5/cytochrome b5 reductase electron transport system, which supports delta 1'-desaturase activity, showed only a modest (30%) decrease in activity. These data suggest that the delta 1'-desaturase system contains at least one component (possibly the terminal desaturase) that is not shared by the acyl-CoA desaturases examined and that RAW.12 is deficient in this component.

Acyl-CoA Dehydrogenases↗

Comparison of acceptor and donor substrates in the CoA-independent transacylase reaction in human neutrophils.

In human neutrophils (PMN) the ethanolamine-containing phosphoglyceride fraction (PE), principally plasmalogen-linked PE (1-O-alk-1'-enyl-2-acyl-sn-glycero-3-phosphoethanolamine), is the major store of arachidonic acid (AA). Exogenous AA is initially incorporated into 1-acyl-linked phosphoglycerides and is believed to be transferred into the 1-ether-linked phosphoglycerides via the action of a CoA-independent transacylase (CoA-IT). We have investigated the selectivity for both the "acceptor' lysophospholipids and "donor' AA-containing phospholipid substrates in the CoA-IT reaction. Evidence suggests CoA-IT may also participate in the synthesis of platelet activating factor. The transfer of [3H]AA from endogenously labeled choline-containing phosphoglycerides (PC) to exogenously added alkenyl-lyso-PE (0-50 microM) was examined in saponin-permeabilized PMN. In these "donor' studies, we observed that [3H]AA was transferred from both alkyl- and diacyl-linked PC in a proportional manner. More detailed molecular species analysis showed that [3H]AA was deacylated from all the major AA-containing molecular species in both the alkyl and diacyl subclasses with no selectivity for either subclass. To investigate the "acceptor' selectivity, membrane fractions prelabeled with either [3H]alkyl-arachidonoyl-PE or -PC were utilized as donor substrates. Various unlabeled lysophospholipids (10 microM) were added and the generation of [3H]lyso-PE or -PC was monitored as a measure of CoA-IT activity. Significant subclass preference was observed upon addition of lyso-PE species (1-alkenyl > 1-alkyl > 1-acyl) however, little selectivity was seen with the corresponding lyso-PC species. On the other hand, lysophosphatidylserine, lysophosphatidylinositol, and lysophosphatidic acid all served as poor acceptor substrates in the reaction. These data from PMN are consistent with other evidence that the CoA-IT plays a pivotal role in the enrichment of AA into plasmalogen-linked PE.

Acylation↗

Deficiency of acyl-CoA: dihydroxyacetone phosphate acyltransferase in patients with Zellweger (cerebro-hepato-renal) syndrome.

We have recently reported on plasmalogen deficiency in tissues and fibroblasts from patients with Zellweger syndrome. In this paper we have analyzed the activity of the first enzyme in the pathway leading to plasmalogen biosynthesis, i.e. acyl-CoA:dihydroxyacetone phosphate acyltransferase in liver, brain and cultured skin fibroblasts from Zellweger patients and controls. The results indicate a severe deficiency of this enzyme in Zellweger patients. Thus, the Zellweger syndrome constitutes the first inborn error of metabolism with a deficiency in an enzyme involved in phospholipid biosynthesis. Cultured amniotic fluid cells contained an enzymatic activity comparable to that of control fibroblasts. These findings suggest a method for prenatal diagnosis of this disease.

Acyltransferases↗

Altered phospholipid composition and changed fatty acid pattern of the various phospholipid fractions of red cell membranes of cystic fibrosis children with pancreatic insufficiency.

After two-dimensional thin-layer chromatography, it appears that the phospholipid composition of the erythrocyte membranes of cystic fibrosis children, compared with healthy ones, is changed by an increase of the phosphatidyl inositol content. The plasmalogen concentration of the membrane phospholipids is the same for both groups. The fatty acid pattern of the various red cell membrane phospholipid fractions was determined by gas chromatography (Tables II, III and IV), and significant changes were observed in the cystic fibrosis patients (Table V). Phosphatidyl choline and ethanolamine (non-plasmalogen forms) especially show strikingly abnormal fatty acid patterns similar to those in the various plasma lipid fractions.

Child↗

Studies on the extraction of phospholipids from erythrocyte membranes in the rat.

The effects of choice of solvent and period of extraction on recovery of phospholipid classes extracted from rat erythrocyte membranes were investigated. For extraction of phosphatidylserine (PS) the best recovery was achieved using chloroform-methanol (2:1, v/v), for diacyl phosphatidylethanolamine (PE) acetone-isopropanol (3:2, v/v), and for extraction of plasmalogen PE, phosphatidylcholine (PC) and sphingomyelin (SM) using hexane-isopropanol (3:2, v/v). Using hexane-isopropanol (3:2, v/v), boiling during the extraction increased the recovery of some of the individual phospholipid classes whereas mechanical treatment of the sample had only a slight effect. Furthermore, the fatty acid composition of PS and PE varied most with different extraction conditions and the phospholipid classes PC and SM were extracted more readily from rat erythrocyte membranes than PS, diacyl and plasmalogen PE.

Animals↗