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PubMed1999

Abnormal sterol metabolism in patients with Conradi-Hünermann-Happle syndrome and sporadic lethal chondrodysplasia punctata.

The term, "chondrodysplasia punctata" (CDP) denotes a pattern of abnormal punctate calcification of dystrophic epiphyseal cartilage and certain other cartilaginous structures, such as the larynx. CDP occurs in a variety of genetic disorders associated with skeletal dwarfism and can also be caused by prenatal exposure to warfarin. Although the most studied clinical syndrome with CDP, rhizomelic chondrodysplasia punctata (RCDP), is known to be caused by several different abnormalities of plasmalogen biosynthesis, there are many other genetic disorders with CDP for which the biochemical cause is unknown. Because patients with Smith-Lemli-Opitz syndrome, a primary disorder of sterol biosynthesis, often have rhizomesomelic limb shortness and, less commonly, CDP, we assessed sterol levels and metabolism in patients with different clinical forms of CDP. By quantitative sterol analysis of a variety of tissues, we identified 5 patients with similar radiological findings and abnormally increased levels of 8-dehydrocholesterol and cholest-8(9)-en-3beta-ol, suggesting a deficiency of 3beta-hydroxysteroid-delta8,delta7-isomerase, a principal enzyme of cholesterol biosynthesis. Cultured cells available from one patient showed increased levels of the same two sterols, decreased synthesis of cholesterol, and a pattern of inhibition by triparanol and AY-9944 consistent with a deficiency of 3beta-hydroxysteroid-delta8,delta7-isomerase. Clinical diagnoses among the 5 patients included X-linked dominant Conradi-Hünermann-Happle syndrome and nonspecific lethal CDP. We conclude that abnormal cholesterol biosynthesis is a characteristic of some clinical syndromes with rhizomesomelic dwarfing and CDP.

Abnormalities, Multiple↗
PubMed1999

Characterization of the molecular species of phosphatidylethanolamine from kidney of the fresh water snail Lymneae stagnalis by mass spectrometry.

The structural analysis of sixteen molecular species of diacyl glycerophosphoethanolamine from fresh water snail Lymneae stagnalis kidney using chromatography and mass spectrometry is described in this paper. 1-eicosadienoyl-2-eicosatetraenoyl-sn-glycero-3-phosphoethanolamine (PE 20:2-20:4), 1-eicosapentaenoyl-2-eicosadienoyl-sn-glycero-3-phosphoethanolamine (PE 20:5-20:2) and 1-eicosatrienoyl-2-eicosatetraenoyl-sn-glycero-3-phosphoethanolamine (PE 20:3-20:4) as well as 1-octadecanoyl-2-eicosatetraenoyl-sn-glycero-3-phosphoethanolamine (PE 18:0-20:4), 1-ocetadecenoyl-2-eicosatetraenoyl-sn-glycero-3-phosphoethanolamine (PE 18:1-20:4) and 1-octadecanoyl-2-eicosapentaneoyl-sn-glycero-3-phosphoethanolamine (PE 18:0-20:5) were found as the major molecular species, and the first three were tentatively identified as the novel species present in this biological material. The presence of a relatively high content of 1,2-dieicosenoyl-sn-glycero-3-phosphoethanolamine species (approximately 27% of total species) as well as the absence of 22-carbon fatty acid containing and plasmalogen PE molecular species are remarkable in healthy Lymneae stagnalis kidney. Copyright 1999 John Wiley & Sons, Ltd.

Journal Article↗
PubMed1999

Esophageal cancer phospholipids correlated with histopathologic findings: a 31P NMR study.

We analyzed 36 esophageal tumor specimens for phospholipid content using phosphorus nuclear magnetic resonance spectroscopy (31P NMR) and correlated the individual phospholipid profiles with specific clinical and histopathologic features. Among the 18 phospholipids identified in the esophageal tumor specimens, the mean mole percentage concentration of dimethylphosphatidylethanolamine, lysoalkylacylphosphatidylcholine, lysophosphatidic acid, lysophosphatidylcholine (deacylated at the glycerol-1 carbon), and lysoethanolamine plasmalogen correlated with pathologic T stage, nuclear grade, or the presence of lymphatic invasion. 31P NMR produces well-dispersed phospholipid spectra and a precise determination of phospholipid relative mole percentages. These data provide a statistical correlation between histopathologic features and molecules known to play an important role in cellular activities and processes unique to malignant tissues.

Esophageal Neoplasms↗
PubMed1978

The lipids of the erythrocyte in paroxysmal nocturnal hemoglobinuria.

Paroxysmal nocturnal hemoglobinuria (PNH) is a disorder characterized by the production of abnormal erythrocytes (PNH-E). The PNH-E undergoes early intravascular destruction which appears to be related to an intrinsic membrane defect that results in extreme sensitivity to lysis by complement. The lipids of the PNH-E have been evaluated because of the variable results reported in the past. This study shows a normal content of cholesterol and lipid phosphorus with a normal distribution of the phospholipids except for a slight increase in lysophosphatidyl choline (LPC) when measured using the complete lipid extract of the PNH-E. Fractionation of the lipid extract over a silicic acid column produced an alteration in the distribution of the phospholipids, with LPC and sphingomyelin increasing, and the other phospholipids decreasing. These alterations were seen only when the phospholipids were fractioned over a silicic acid column and were clearly an in vitro phenomenon. The levels of plasmalogen and malonaldehyde were normal, unlike those seen with oxidant stress. Fatty acid analysis of the phospholipids showed small but consistent changes: increased 16:0 and decreased 18:2. The total glycosphingolipids were slightly decreased in the patients with severe PNH. The results support and extend previous lipid data indicating abnormalities in the phospholipids of the PNH-E. The alterations of the phospholipids with fractionation correlate with previous whole cell data that suggest lipid instability in the PNH-E.

Animals↗
PubMed1986

Neonatal adrenoleukodystrophy: new cases, biochemical studies, and differentiation from Zellweger and related peroxisomal polydystrophy syndromes.

Eight new cases of autopsy-confirmed or suspected neonatal adrenoleukodystrophy (NALD) are presented together with new biochemical data on very-long-chain fatty acids (VLCFA) and plasmalogens and a review of all previously published cases. The clinical, biochemical, and histopathologic abnormalities characteristic of this newly recognized form of adrenoleukodystrophy are analyzed in detail and compared to the principal characteristics of the similar disorder, the cerebrohepatorenal syndrome of Zellweger (ZS). Using strict pathologic criteria for the diagnosis of NALD, we find that, despite many clinical resemblances, NALD and the ZS are distinguishable on the basis of histology and peroxisomal biochemistry. Patients with NALD demonstrate adrenal atrophy, systemic infiltration by abnormal lipid-laden macrophages, and elevations of saturated VLCFA. In contrast, patients with ZS have chondrodysplasia, glomerulocystic disease of the kidney, central nervous system dysmyelination, and elevations of unsaturated as well as saturated VLCFA, but they lack adrenal atrophy. We conclude that NALD and the ZS probably represent at least two different genetic defects.

Abnormalities, Multiple↗
PubMed2003

A new autosomal recessive syndrome with Zellweger-like manifestations.

A son and daughter of consanguineous Ashkenazi Jewish parents presented with phenotypic features that are typically seen in Zellweger syndrome: high forehead, broad nasal bridge, epicanthal fold, upslanting palpebral fissures, and micrognathia. In addition to the physical anomalies, they also have severe psychomotor retardation and hypotonia. However, results of peroxisomal studies including very long chain fatty acids and plasmalogen functions, were normal. There was partial deficiency of respiratory chain complexes. We suggest that this is a new autosomal recessive syndrome that could be due to a nuclear-encoded mitochondrial defect.

Abnormalities, Multiple↗
PubMed1995

Distinction between peroxisomal bifunctional enzyme and acyl-CoA oxidase deficiencies.

The clinical distinction between patients with a disorder of peroxisome assembly (e.g., Zellweger syndrome) and those with a defect in a peroxisomal fatty acid beta-oxidation enzyme can be difficult. We studied 29 patients suspected of belonging to the latter group. Using complementation analysis, 24 were found to be deficient in enoylcoenzyme A hydratase/3-hydroxyacylcoenzyme A dehydrogenase bifunctional enzyme and 5 were deficient in acyl-CoA oxidase. Elevated plasma very long-chain fatty acids (VLCFA), impaired fibroblast VLCFA beta-oxidation, decreased fibroblast phytanic acid oxidation, normal plasmalogen synthesis, normal plasma L-pipecolic acid level, and normal subcellular catalase distribution were characteristic findings in both disorders. The elevation in plasma VLCFA levels and impairment in fibroblast VLCFA beta-oxidation were more severe in bifunctional-deficient than in oxidase-deficient patients. The clinical course in bifunctional deficiency (profound hypotonia, neonatal seizures, dysmorphic features, age at death approximately 9 months) was more severe than in oxidase deficiency (moderate hypotonia without dysmorphic features, development of a leukodystrophy, age at death approximately 4 yr). Based on these findings, accurate early diagnosis of these deficiencies of peroxisomal beta-oxidation enzymes is possible.

Acyl-CoA Oxidase↗
PubMed1982

Studies on molecular species of choline and ethanolamine glycerophospholipids obtained from rat brain myelin and synaptosomes by gas-liquid chromatography mass spectrometry.

By converting to t-butyldimethylsilyl derivatives, molecular species of ethanolamine glycerophospholipid including both 1,2-diacyl and 1-alk-1'-enyl-2-acyl (plasmalogen) types were able to be analysed by a gas chromatography mass spectrometry selected ion monitoring technique. The samples analysed were ethanolamine glycerophospholipid and also choline glycerophospholipid obtained from myelin and synaptosomes of rat brain, both of which are characteristic subcellular organella of the nervous system. Main molecular species of ethanolamine glycerophospholipid were as follows: in myelin as 1,2-diacyl type, 36:1 (mainly 18:0/18:1), and as 1-alk-1'-enyl-2-acyl type, 34:2 (mainly vinyl 16:0/18:1), 36:2 (mainly vinyl 18:0/18:1) and 36:3 (mainly vinyl 18:1/18:1), whereas in synaptosomes as 1,2-diacyl type 36:1 (mainly 18:0/18:1), 38:4 (mainly 18:0/20:4) and 40:6 (18:0/22:6), and as 1-alk-1'-enyl-2-acyl type 34:2 (mainly vinyl 16:0/18:1), 36:2 (mainly vinyl 18:0/18:1), and 36:3 (mainly vinyl 18:1/18:1). The molecular species of choline glycerophospholipid consisted almost entirely of 1,2-diacyl type and they were in myelin 34:1 (mainly 16:0/18:1), 36:1 (mainly 18:0/18:1) and 36:2 (mainly 18:1/18:1), whereas in synaptosomes 32:0 (mainly 16:0/16:0), 34:0 (16:0/18:0), 34:1 (mainly 16:0/18:1) and 36:1 (mainly 18:0/18:1). In myelin as 1-alkyl-2-acyl type, 34:1 (1-hexadectl-2-octadecenoyl) was present at about 7%.

Animals↗
PubMedDate not supplied

Studies on the endogenous phospholipids of mammalian kidney and their in vitro hydrolysis by endogenous phospholipases: a thin layer chromatographic and densitometric study.

The phosphoglycerides profile of six species of mammalian kidney (guinea pig, pig, cat, dog, mouse and rat) and their in vitro response to the endogenous phospholipases were determined by TLC technology in conjunction with densitometric measurements. Changes in their phospholipids profile subsequent to in vitro incubation of whole tissue homogenate of these kidneys for 60 min, at pH 7.4, 38 degrees C, and prior to phospholipids extraction have shown that the deacylation of the endogenous cardiolipin (CL) is the most prevalent lipolytic event of all mammalian kidneys studied. Concurrent with the deacylation of CL, there was also formation of monolysocardiolipin (MLCL) and a reduction in CL level. To a much lesser extent, lyso alkenyl phosphatidyl ethanolamine (LPE) was also produced concomitant with a decrease of the endogenous alkenyl phosphatidyl ethanolamine (PE) level. The deacylation of PE plasmalogen to its lyso form confirms the action of endogenous PLA(2) releasing sn-2 fatty acids.

Animals↗
PubMedDate not supplied

Comparative studies of the endogenous phospholipids and their in vitro hydrolysis by endogenous phospholipases of various tissues from 7-day-old chicks: a thin layer chromatographic and densitometric analysis.

The phospholipid profiles of heart, kidney, and pectoral muscle of 7-day-old chicks and their in vitro response to the endogenous lipolytic enzymes (mainly in the phospholipase group) at pH 7.4 and 38 degrees C for 60 min were analysed by TLC technology and densitometry. The noticeable preferential deacylation of cardiolipin (CL) as detected by the formation of monolysocardiolipin (MLCL) and concurrent reduction of CL level were the most prevalent lipolytic events of chick cardiac muscle, but the least prevalent in chick pectoral muscle. Deacylation of ethanolamine plasmalogen (PE) as revealed by the formation of the corresponding lyso alkenyl derivative was also prominent in cardiac muscle, but much less so in kidney and none at all was detected in pectoral muscle. The level of sphingomyelin (SM) was much higher in kidney than heart and pectoral muscle. Following in vitro incubation, the reduction in the level of SM and the high level of ceramide (Cer) production were most conspicuous in kidney, less in cardiac muscle and least in pectoral muscle. The hydrolysis of PE and SM confirm the action of endogenous PLA(2) and endogenous sphingomyelinase on PE and SM respectively. These data clearly illustrate the differential response of the endogenous substrates (phospholipids) to the endogenous phospholipases of the tissues studied and are probably related to their physiological activities in vivo.

Animals↗
PubMedDate not supplied

On the differential lipolytic capabilities of rat spleen and cardiac muscle. An in vitro incubation in conjunction with chromatographic and densitometric analysis.

The phospholipid profiles of newborn, young adult and aged rat heart and spleen and their in vitro response to endogenous phospholipases at pH 7.4 and 38 degrees C for 60 min were analysed by thin layer chromatography (TLC) technology and densitometry measurement. The noticeable high level of cardiolipin (CL) and its preferential deacylation, as detected by the formation of monolysocardiolipin (MLCL) and concurrent reduction of CL level were the most prevalent lipolytic events of rat cardiac muscle (newborn, young adult and aged) but the least prevalent in rat spleen. The level of ethanolamine plasmalogen (PE) was high in both the rat spleen and cardiac muscle (newborn, young adult and aged). Following in vitro incubation, the reduction in the level of PE and the high level of lyso alkenyl PE produced were most conspicuous in rat spleen (newborn, young adult and aged) and noticeably less in rat cardiac muscle. These data clearly illustrate the differential response of the endogenous substrates (phospholipids) to the endogenous phospholipases of these two tissues, and probably are related to their physiological activities in vivo.

Aging↗
PubMed2003

TNFalpha downregulates PPARdelta expression in oligodendrocyte progenitor cells: implications for demyelinating diseases.

TNFalpha has been implicated in several demyelinating disorders, including multiple sclerosis (MS) and X-adrenoleukodystrophy (X-ALD). TNFalpha abundance is greatly increased in the areas surrounding damaged regions of the central nervous system of patients with MS and X-ALD, but its role in the observed demyelination remains to be elucidated. A class of nuclear receptors, the peroxisome proliferator-activated receptors (PPARs), has been implicated in several physiological and pathological processes. In particular, PPARdelta has been shown to promote oligodendrocyte (OL) survival and differentiation and PPARgamma has been implicated in inflammation. In the present study, we investigate on the effects of TNFalpha on OLs during differentiation in vitro. The results obtained show that TNFalpha treatment impairs PPARdelta expression with concomitant decrease of lignocerolyl-CoA synthase and very-long-chain fatty acid beta-oxidation as well as plasmalogen biosynthesis. We propose a hypothetical model possibly explaining the perturbation effects of proinflammatory cytokines on myelin synthesis, maturation, and turnover.

Animals↗
PubMed2004

Alternative approaches for the detection of various phospholipid classes by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

The detection of phospholipids (PLs) by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was demonstrated nearly a decade ago. However, its use as a conventional tool for PL analysis has been hindered by ambiguities in peak assignments caused by spectral overlaps and difficulties in the detection of some PL classes when analytes with positively charged head groups, such as sphingomyelins (SMs) and phosphatidylcholines (PCs) are present. In this work, either a strong cation-exchange resin or CsCl crystals were added directly to the PL samples to reduce spectral complexity and enhance sensitivity. The quantitative exchange resulted in virtually only protonated or Cs+ adducts. To alleviate difficulties in the detection and identification of PL classes with ionization efficiencies lower than those of SMs and PCs, improvements in the sensitivity of negative-ion mass spectra were sought. For this purpose, several neutral and basic matrices were tried. Among them, p-nitroaniline (PNA) proved to be an advantageous alternative to the use of 2,5-dihydroxybenzoic acid (DHB), the most commonly used matrix in PL analysis. Because of its lower acidity, PNA increased the relative amount of deprotonated species and improved the sensitivity of negative-ion mass spectra. It was possible to confirm peak assignments for PL classes that normally give weak signals when DHB is used. Noteworthy is the detection (in both positive and negative modes) and conclusive identification of species in natural mixtures of phosphatidylethanolamines (PEs) and PE plasmalogens (PEps). PNA allowed the identification of PEs and PEps even in mixtures containing SMs and PCs. Although some cations related to PCs and PEs overlapped in positive-ion spectra, these interferences were eliminated in the negative mode as only the deprotonated forms of PEs and PEps were detectable and those of SMs and PCs were absent owing to their neutrality.

Animals↗
PubMed2004

Regional phospholipid analysis of porcine lens membranes by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

The applicability of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) to the qualitative and quantitative analysis of most mammalian phospholipid (PL) classes was demonstrated in a crude extract of porcine lens membranes. When 2,5-dihydroxybenzoic acid (DHB) was used as the matrix, positive-ion spectra allowed the accurate quantification of phosphatidylcholines (PCs) and sphingomyelins (SMs). Other PLs such as phosphatidylethanolamines (PEs), phosphatidylethanolamine plasmalogens (PEps), phosphatidylethanolamine ethers (PEes) and phosphatidylserines (PSs), could also be detected, but their lower ionization efficiency led to negative errors in their quantification. Despite this limitation, it was possible to determine relative changes among PLs extracted from cortical and nuclear regions. Negative-ion spectra were acquired with the use of p-nitroaniline (PNA) as the matrix. Because neither PCs nor SMs produce negative ions, other PL classes can be analyzed selectively. The absolute quantification of the various PL classes detectable in negative-ion spectra was also affected by differences in ionization efficiencies. However, the trends in compositional changes between cortical and nuclear-fiber PLs were in agreement with those obtained by (31)P NMR spectroscopy. MALDI-TOFMS also offers the possibility of studying variations in the acyl-chain distribution of the various species comprising each PL class. For porcine lenses, PCs, PEs and phosphatidylinositols (PIs) exhibited the greatest depletions in going from cortical to nuclear membranes. Among their individual species, those with two or more sites of unsaturation suffered the most significant reduction.

Animals↗
PubMed2003

PPAR gamma activators induce growth arrest and process extension in B12 oligodendrocyte-like cells and terminal differentiation of cultured oligodendrocytes.

Peroxisome proliferator-activated receptors (PPARs) are key transcription factors in the control of lipid homeostasis and cell differentiation, but little is known about their function in oligodendrocytes, the major lipid-synthesizing cells in the central nervous system (CNS). Using the B12 oligodendrocyte-like cell line and rat spinal cord-derived oligodendrocytes, we evaluated the importance of PPARgamma in the maturation process of these cells. B12 cells express all PPAR isoforms (alpha, beta/delta, and gamma), as assessed by RT-PCR, Western-blot, and transactivation assays. B12 cells respond specifically to PPARgamma agonists by arresting cell proliferation and extending cell processes, events that are blocked by the PPARgamma antagonist GW9662. In addition, alkyl-dihydroxyacetone phosphate synthase (ADAPS), a key peroxisomal enzyme involved in the synthesis of myelin-rich lipid plasmalogens, is increased in PPARgamma agonist-treated B12 cells. In contrast with B12 cells, both immature and mature isolated spinal cord oligodendrocytes presented a high and similar expression level of ADAPS, as assessed by immunocytochemistry. However, as in B12 cells, isolated spinal cord oligodendrocytes were also found to respond specifically to PPARgamma agonists with a four-fold increase in the number of mature cells. Our data suggest a relevant role for PPARgamma in oligodendrocyte lipid metabolism and differentiation.

Alkyl and Aryl Transferases↗
PubMed1984

The effect of cytidine-diphosphate choline (CDP-choline) on brain lipid changes during aging.

Lipid synthesis has been tested in vivo in different brain areas of 12-month-old male rats. Cortex, striatum, brainstem, and subcortex of brain have been examined. The cerebellum was discarded. Mixtures of (2-3H)glycerol and (Me-14C)choline were injected into the lateral ventricle of the brain as lipid precursors, and their incorporation into total lipid, water-soluble intermediates and choline-containing phospholipids was examined 1 hr after isotope injection. In another series of experiments cytidine-5'-diphosphate choline (CDP-choline) was injected intraventricularly to the aged rats 10 min before sacrifice with a simultaneous injection, and radioactivity assays were performed as above. Distribution of radioactivity content of CDP-choline among brain areas 10 min after its administration showed a noticeable enrichment of the nucleotide and water-soluble-related compounds in the examined areas, but to a lesser degree in the cerebral cortex. The incorporation of labelled glycerol, which is severely depressed in aged rats in all four areas [Gaiti et al, 1982, 1983], was increased only in the cortex, and apparently decreased in the other areas. This last result is probably due to a dilution effect brought about by the administered cold CDP-choline upon the (14C)-containing water-soluble metabolites. As a consequence, the (3H)/(14C) ratio in total lipid and in isolated phosphatidylcholine and choline plasmalogen increased after CDP-choline treatment.

Aging↗
PubMed1995

Differential incorporation of fatty acids into and peroxidative loss of fatty acids from phospholipids of human spermatozoa.

Intact human sperm incorporated radiolabelled fatty acids into membrane phospholipids when incubated in medium containing bovine serum albumin as a fatty acid carrier. The polyunsaturated fatty acids were preferentially incorporated into the plasmalogen fraction of phospholipid. Uptake was linear with time over 2 hr; at this time sufficient label was available to determine the loss of fatty acids under conditions of spontaneous lipid peroxidation. Loss of the various phospholipid types, the loss of the various fatty acids from these phospholipids, and the overall loss of fatty acids were all first order. The loss of saturated fatty acids was slow with first order rate constant k1 = 0.003 hr-1; for the polyunsaturated fatty acids, arachidonic and docosahexaenoic acids, k1 = 0.145 and 0.162 hr-1, respectively. The rate of loss of fatty acids from the various phospholipid types was dependent on the type, with loss from phosphatidylethanolamine being the most rapid. Among the phospholipid types, phosphatidylethanolamine was lost at the greatest rate. Analysis of fatty acid loss through oxidation products was determined for radiolabelled arachidonic acid. Under conditions of spontaneous lipid peroxidation at 37 degrees C under air in the absence of albumin, free arachidonic acid was found in the medium, along with minor amounts of hydroxylated derivative. All the hydroperoxy fatty acid remained in the cells. In the presence of albumin, all the hydroperoxy fatty acid was found in the supernatant bound to albumin; none could be detected in the cells. Albumin is known as a very potent inhibitor of lipid peroxidation in sperm; its action may be explained, based on these results, as binding the damaging hydroperoxy fatty acids. These results also indicate that a phospholipase A2 may act in peroxidative defense by excising a hydroperoxy acyl group from phospholipid and providing the hydroperoxy fatty acid product as substrate to glutathione peroxidase. This formulation targets hydroperoxy fatty acid as a key intermediate in peroxidative degradation.

Adult↗
PubMed1994

Binding and metabolism of platelet-activating factor (PAF) by isolated rat type II pneumonocytes.

The specific binding of platelet-activating factor (PAF) to isolated type II pneumonocytes from rat lung has been investigated employing an intact cell preparation. The dissociation constant (Kd) for the autacoid has been determined to be 0.46 x 10(-9) M and approximately 3000 receptor sites per cell are present. In studies conducted on the metabolism of PAF in these cells, it was demonstrated that PAF is rapidly converted into 1-alkyl-2-acylglycerophosphocholine (alkyl-acyl GPC). After longer time intervals there was a substantial conversion of alkyl-acyl GPC into alkyl-acylglycerophosphoethanolamine (alkyl-acyl GPE). Both the alkyl-acyl GPC and alkyl-acyl GPE fractions were devoid of plasmalogens. The alkyl-acyl GPC fraction was further characterized and a distinct double peak could be visualized following thin-layer chromatography and the same lyso-compound was produced from both peaks following mild alkaline hydrolysis. By using appropriate standards it was concluded that the dual alkyl-acyl GPC peaks represent differences in the fatty acid present in the sn-2 position. One peak corresponds to the presence of saturated fatty acid in the sn-2 position and is probably due to the characteristic high capacity of the type II cells to produce disaturated glycerophospholipids.

Animals↗