Different fatty chain compositions of alkenylacyl,alkylacyl and diacyl phospholipids in rabbit alveolar macrophages: High amounts of arachidonic acid in ether phospholipids

High levels of ether phospholipids were found in rabbit alveolar macrophages. Choline phosphoglycerides (CPG) contained a significant amount of alkylacyl compound (32.5%). On the other hand, ethanolamine phosphoglyceride (EPG) included a very large amount of alkenylacyl compounds (61.2%). Small amounts of alkenylacyl CPG and alkylacyl EPG were also observed. The occurrence of a high amount of alkylacyl CPG may be related to the synthesis or release of platelet-activating factor (PAF) from macrophages. Fatty chains at the 1- and 2-positions in each lipid class of CPG or CPG or alkenylacyl EPG were several other. Particularly, the levels of 20∶4 (arachidonic acid) in alkylacyl CPG or alkenylacyl EPG were several times higher than those in corresponding diacyl phospholipids. Large portions of 20∶4-containing species have alkenyl or alkyl ether moieties at their 1-position in both CPG (73.6%) and EPG (85.9%). These results suggest the importance of ether-containing phospholipids in rabbit alveolar macrophages.     

Effects of parenteral nutrition with high doses of linoleate on the developing human liver and brain

The developmental changes in the fatty acid composition of ethanolamine phosphoglycerides (EPG) and choline phosphoglycerides (CPG) were studied in the liver and brain of 18 newborn infants with gestational ages ranging from 20 to 44 wk. A small group of five newborns receiving total parenteral nutrition (TPN) with high doses of linoleic acid (18∶2ω6) was also studied and compared to controls of the same gestational age to look for effects on the developmental fatty acid patterns of liver and brain EPG and CPG. TPN with Intralipid 20% was given for 4–12 days, the total fat intake being 14.7–90 g (mean ±S.D.=47.1±29.8 g). The main developmental changes in the liver and brain of the control group were an increase in 22∶6ω3 (docosahexaenoic acid) at the end of gestation and a linear decrease in 20∶4ω6 (arachidonic acid) and 18∶1ω9 (oleic acid) in EPG and CPG. A very good correlation in the percent values of these fatty acids in the brain and liver tissues was obtained. Very significant changes in the fatty acid composition of liver EPG and CPG could be found in the infants receiving TPN with Intralipidmainly an increase in 18∶2ω6, a decrease in the linoleate elongation/desaturation to longer members of the series and a decrease in the 22∶6ω3 levels of liver EPG and CPG. In the brain, only an increase in the 18∶2ω6 value of CPG, not accompanied by any increase in the longer ω6 fatty acids, could be detected. Possible adverse effects of high doses of 18∶2ω6 on the tissue levels of long chain polyunsaturated fatty acids (PUFA), especially of 22∶6ω3, are discussed.     

On the membrane phospholipids and their acyl group profiles of adrenal gland

The phospholipid composition and their acyl group profiles from subcellular fractions of guinea pig adrenal gland and the same fractions from the cortex and medulla of the bovine gland were compared. The phospholipids of guinea pig adrenal were enriched in diacyl-glycerophosphocholines (GPC) which comprised over 50% of the total phospholipids, but the proportions of ethanolamine and choline plasmalogens, sphingomyelin and diacyl-glycerophosphoserine (GPS) were lower in guinea pig adrenals as compared to the bovine adrenals. In the bovine adrenal, sphingomyelin and diacyl-GPS were enriched in the medulla, whereas diacyl-glycerophosphoinositol (GPI) were enriched in the cortex. Although lysolecithin was present (up to 4.5%) in the bovine adrenal, only trace amounts of this lipid were detected in the guinea pig adrenal. Characteristic acyl group profiles were found associated with each type of the phosphoglycerides in adrenal membranes. However, acyl group profiles of the phosphoglycerides were not greatly different either between the bovine and guinea pig adrenal or with respect to the type of subcellular membranes isolated. Diacyl-GPC were enriched in 16∶0 and 18∶1, but also contained considerable amounts of 18∶0, 18∶2 and 20∶4. Diacyl-GPE were enriched in 18∶0, 18∶1 and 20∶4, while diacyl-GPI, diacyl-GPS, as well as alkenylacyl-GPE, were enriched in 20∶4. The lysolecithin from bovine adrenal membranes contained mainly 16∶0, 18∶0 and 18∶1 with only trace amounts of the polyunsaturated fatty acids. Other polyunsaturated fatty acids, such as 22∶4 and 22∶6, are apparently not prominent in the phosphoglycerides from either the bovine or the guinea pig adrenal gland.     

Polyenoic acid metabolism in cultured human skin fibroblasts

The incorporation of [1-¹⁴C]linoleic acid, and [1-¹⁴C]linoleic acid into cellular lipids of cultured human skin fibroblasts was studied. Cultured cells took up both labeled fatty acids at nearly the same rate and incorporated them into a variety of lipid classes. At the end of 1 hr incubation with [1-¹⁴C]linoleic acid, radioactivity was found in the triacylglycerol (TG) and choline phosphoglyceride (CPG) pools preferentially. Incorporation into the TG fraction decreased rapidly, while the uptake into CPG, serine phosphoglyceride (SPG), and ethanolamine phosphoglyceride (EPG) fractions increased progressively with longer incubation times. Similar results were obtained with [1-¹⁴C]linoleic acid as precursor. At the end of 24 hr, desaturation and chain elongation of 18∶3 n−3 was more extensive than conversion of 18∶2 n−6 to higher polyenoic acids. During pulse-chase experiments with either fatty acid precursor, the incorporated radioactivity was progressively lost from cellular lipids, particularly from the TG and CPG fractions, but continued to increase in the SPG and EPG pools. The similar labeling pattern of cellular phospholipids with linoleic or linolenic acids, and data from pulse-chase studies suggest that a direct transfer of fatty acids from CPG to EPG is a likely pathway in fibroblast cultures. Incorporation into the EPG pool during the pulse-chase experiments paralleled extensive desaturation and elongation of linoleic acid into 20∶4 n−6, and 22∶4 n−6; and of linolenic acid into 22∶5 n−3 and 22∶6 n−3.     

Composition of lipids of bovine optic nerve

Lipids from bovine optic nerve were analyzed. The total content of 16.5% by weight included 27.2% nonpolar lipids, 26.1% glycolipids, and 46.7% phospholipids by weight. Free cholesterol was the major component of the nonpolar lipid fraction. The cerebrosides, 73.5% of total glycolipids, were separated by thin layer chromatography (TLC) into two bands (upper and lower) that were present in equal proportion. Cerebroside sulfates comprised about 27.5% of total glycolipids. Gangliosides were also detected in the glycolipid fraction. In order of predominance, choline glycerophospholipids, ethanolamine glycerophospholipids, ethanolamine plasmalogens, serine glycerophospholipids, sphingomyelins, and inositol glycerophospholipids were the major phospholipids. Palmitoyl (16∶0), stearoyl (18∶0), and oleoyl (18∶1) groups were the major acyl groups in all neutral and phospholipid classes. However, ethanolamine glycerophospholipids, serine glycerophospholipids, and inositol glycerophospholipids contained a large percentage of 22∶6 (docosahexaenoyl) group. The major alk-1-enyl groups of the plasmalogens were 16∶0, 18∶0, and 18∶1. Steroyl (18∶0), lignoceroyl (24∶0), and nervonoyl (24∶1) were the major acyl groups in all sphingolipids. Lower cerebroside band and cerebroside sulfates contained large amount of hydroxylignoceroyl (cerebronoyl) and hydroxynervonoyl groups. This investigation was supported by Grants DE-03191 and 2S06-RR-08037 from the National Institutes of Health, Bethesda, MD.     

Characterization of trans-monounsaturated alkenyl chains in total plasmalogens (1-O-alk-1′-enyl-2-acyl glycerophospholipids) from sheep heart

In the present study, we investigated the alkenyl chains from sheep heart plasmalogens (1-O-alk-1′-enyl-2-acyl glycerophospholipids) after their conversion into trimethylene dioxyalkanyl (TMDOA) derivatives. Particular attention was given to monounsaturated alkenyl chains (C₁₈ mainly). For this purpose, a combination of silver ion TLC and GLC on highly polar, very long capillary columns was applied to TMDOA derivatives. Approximately 30 different alkenyl chains could be separated, and the main observation was that the component previously reported as a cis-9 18∶1 alkenyl chain in plasmalogens embraces in fact a wide range of trans and cis isomers, in amounts equal to 7.9 and 5.6%, respectively, of total alkenyl chains. Concerning the trans-monoenoate fraction, isomers with their ethylenic bond spanning from Δ6–Δ8 to Δ16 were tentatively identified on the basis of their distribution profile, which was similar to that of trans-18∶1 acids prepared and isolated from sheep adipose tissue. The main trans-monoenoic C₁₈ alkenyl chain in sheep heart plasmalogens would thus have its double bond in position 11, which seems logical, as alkenyl chains are derived from the corresponding alcohols, themselves issued from the corresponding FA, and in this particular case, vaccenic (trans-11 18∶1) acid. cis-Monoenoic C₁₈ alkenyl chains also appear more complex than realized earlier, showing in particular isomers with their ethylenic bond farther than the Δ9 position, in addition to the main isomer derived from oleic acid. Several trans-16∶1 alkenyl chains could be observed (totaling ca. 1%), but cis-16∶1 isomers were present in trace amounts only.     

Composition of phospholipids of white muscle of six tuna species

A comparative study of the phospholipids of white muscle of six of the comercially utilized tuna species, including quantitative analyses of phospholipid classes and studies of the acyl composition of the major components. Plasmalogen compounds also were identified and quantified. Choline and ethanolamine glycerophospholipids were the most abundant classes in all the samples, as well as the only molecules containing plasmalogens (16∶0, 18∶0, and 18∶1 alkenyl ether chains). The patterns of fatty acid distribution within each of the phospholipid classes showed general similarities in the species analyzed. However, ratios between certain saturated and polyunsaturated fatty acids in different phospholipid classes showed remarkable diffences. The high content of n−3 polyunsaturated fatty acids in the principal phospholipids, such as the plasmalogens, and taking into account the fatty acids possible importance in human nutrition, indicates that the white muscle of tuna species may be a potentially important dietary item.     

The acyl and Alk-1-enyl groups of the major phosphoglycerides from ox brain myelin and mouse brain microsomal,mitochondrial and myelin fractions

The major phosphoglycerides from ox brain myelin and mouse brain microsomal, mitochondrial and myelin fractions were separated by preparative thin layer chromatography. Alk-1-enyl groups from the alk-1-enyl acyl glycerophosphorylethanolamines were reacted with 1,3-propanediol to form the 1,3-dioxolane derivatives. Acyl groups were converted to the methyl ester derivatives and the acyl groups from alk-1-enyl acyl glycerophosphorylethanolamines and diacyl glycerophosphorylethanolamines were also determined separately. The acyl and alk-1-enyl group compositions of the phosphoglycerides from microsomal and mitochondrial fractions were quite similar. The ethanolamine and serine phosphoglycerides contained large amounts of 18∶0, 18∶1, 20∶4 and 22∶6 acyl groups. The choline phosphoglycerides had small amounts of polyunsaturated acyl groups and large amounts of 16∶0, 18∶1 and 18∶0 acyl groups. The mitochondrial cardiolipins contained unusual amounts of several acyl groups including 18∶1, 52%; 18∶2, 6%; and 16.1, 4%. A large portion of the mouse brain 18∶2 is in that fraction. The myelin phosphoglycerides were deficient in saturated and 22∶6 groups and markedly enriched in 18∶1 and 20∶1 groups when compared with the corresponding microsomal or mitochondrial phosphoglycerides. Presented in part at the AOCS Meetings, New York, October 1968 and San Francisco, April 1969.     

Fatty acid and aldehyde composition of major phospholipids in salt gland of marine birds and spiny dogfish

The lipophilic components of choline phosphoglycerides and ethanolamine phosphoglycerides obtained from the salt gland of herring gull and eider duck and from the rectal gland of spiny dogfish were investigated by means of thin-layer chromatography, gas chromatography, and gas chromatography-mass spectrometry. All phospholipids analyzed were shown to contain small amounts of plasmalogens, and mainly C16, C18, and C18∶1 aldehyde was detected. The fatty acids were composed of saturated, unsaturated, straight chain, and branched chain types, ranging between 14–22 carbon atoms. The lipophilic composition of the rectal gland phospholipids showed a higher degree of unsaturation and the presence of more branched chain fatty acids than that of the birds, possibly related to body temperature.     

Occurrence of ethanolamine- and choline-containing plasmalogens in adipose tissue

Analysis of phospholipids in porcine, bovine and rat adipose tissue revealed a relatively high level of plasmalogens (O-alk-1-enyl lipids). About 50% of the ethanolamine phospholipids in the pig and beef samples consisted of alk-1-enylacylglycerophosphorylethanolamine, and the corresponding value for the rat sample was near 35%. In the ethanolamine and choline phospholipid fractions, theO-alk-1-enyl moieties were almost exclusively 16∶0, 18∶0 and 18∶1, whereas the acyl moieties had chain lengths ranging from 16 to 22 carbon atoms with a high degree of unsaturation.     

Ether lipid content and fatty acid distribution in rabbit polymorphonuclear neutrophil phospholipids

This study was undertaken to determine if rabbit neutrophils contain sufficient ether-linked precursor for the synthesis of 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine (platelet activatin factor) by a deacylation-reacylation pathway. The phospholipids from rabbit peritoneal polymorphonuclear neutrophils were purified and quantitated, and the choline-containing and ethanolamine-containing phosphoglycerides were analyzed for ether lipid content. Choline-containing phosphoglycerides (37%), ethanolamine-containing phosphoglycerides (30%), and sphingomyelin (28%) were the predominant phospholipid classes, with smaller amounts of phosphatidylserine (5%) and phosphatidylinositol (<1%). The choline-linked fraction contained high amounts of 1-O-alkyl-2-acyl-(46%) and 1,2-diacyl-sn-glycero-3-phosphocholine (54%), with a trace of the 1-O-alk-1′-enyl-2-acyl species. The ethanolamine-linked fraction contained high amounts of 1-O-alk-1′-enyl-2-acyl-(63%) and 1,2-diacyl-sn-glycero-3-phosphoethanolamine (34%), and a low quantity of the 1-O-alkyl-2-acyl species (3%). The predominant 1-O-alkyl ether chains found in thesn-1 position of the choline-linked fraction were 16∶0 (35%), 18∶0 (14%), 18∶1 (26%), 20∶0 (16%), and 22∶0 (9%). The major 1-O-alk-1′-enyl ether chains found in thesn-1 position of the ethanolamine-linked fraction were 14∶0 (13%), 16∶0 (44%), 18∶0 (27%), 18∶1 (12%) and 18∶2 (3%). The major acyl groups in thesn-1 position of 1,2-diacyl-sn-glycero-3-phosphocholine and 1,2-diacyl-sn-glycero-3-phosphoethanolamine were 16∶0, 18∶0 and 18∶1. The most abundant acyl group in thesn-2 position of all classes of choline- and ethanolamine-linked phosphoglycerides was 18⩺2. Although this work does not define the biosynthetic pathway for platelet activating factor, it does show that there is ample precursor present to support its synthesis by a deacylation-reacylation pathway.     

Changes in the acyl and alkenyl group composition of cardiac phospholipids in boars fed corn oil or rapeseed oil

Boars fed diets containing rapeseed oil for 8 weeks showed significantly higher levels of neutral lipids and similar levels of phospholipids, compared to those fed corn oil. Erucic and eicosenoic acids were found to be high in ethanolamine phosphoglycerides, and in particular alkenyl acyl-ethanolamine phosphoglyceride. Furthermore, both long chain monoenes were incorporated preferentially in position 2 of the choline and ethanolamine phosphoglycerides. The alkenyl group composition of the cardiac lipids of pigs was influenced by dietary fatty acids. When rapeseed oil was fed, small amounts of 20∶1 and 22∶1 alkenyl constituents were detected. Contribution No. 641 Animal Research Institute     

Lipid composition of yoshida ascites hepatoma and of livers and blood plasma from host and normal rats

The lipid composition of Yoshida ascites hepatoma cells was analyzed together with that of ascitic plasma and of livers and blood plasma from host and normal rats. In comparison to normal livers, host livers showed no significant differences in the content of the various lipid classes, but contained a higher percentage of palmitic acid and a lower proportion of arachidonic acid in the major phospholipid classes. In addition, tumor growth induced a marked hypertriglyceridemia in host animals; changes in the concentration of other plasma lipid classes were not statistically significant. The ascitic plasma contained small amounts of lipids mainly constituted by cholesteryl esters and phospholipids. Yoshida hepatoma cells contained less phospholipids in comparison to both host and normal liver, while the increased level of triglycerides and the decrease of free fatty acids were not statistically significant. Hepatoma cells showed appreciable amounts of ether-linked lipids associated in part to neutral lipids (as glyceryl ether diesters) and, in part, to ethanolamine and choline phosphoglycerides. The alkyl groups in GEDE as well as in ethanolamine and choline phosphoglycerides were mainly constituted by C_16∶0 and C_18∶0 followed by C_18∶1. The alk-1-enyl groups in ethanolamine and choline phosphoglycerides were C_16∶0 and C_18∶0 with only a minor proportion of C_18∶1. In comparison to both host and normal liver, Yoshida hepatoma cells showed significant changes in the fatty acid composition of neutral lipids and phospholipids. Some of the major changes consisted of an increase of monoenoic acids associated with a decrease of arachidonic and docosahexaenoic acids in phosphatidylethanolamine, phosphatidylcholine, and phosphatidylinositol.     

Hydrocarbon chain distribution of ether phospholipids of the ascidianHalocynthia roretzi and the sea urchinStrongylocentrotus intermedius

The contents and compositions of the 1-O-alk-1′-enyl-2-acyl, 1-O-alkyl-2-acyl, and 1,2-diacyl glycerophospholipids in the muscle and viscera of the ascidianHalocynthia roretzi, and of the gonad of the sea urchinStrongylocentrotus intermedius, which are eaten to some extent in Alaska and in Asia, were analyzed by gas-liquid chromatography. 1-O-Alk-1′-enyl-2-acyl glycerophospholipids were found in all of the samples, accounting for 64.4–69.0% of the ethanolamine glycerophospholipid (EPL). By contrast, the levels of the 1-O-Alk-1′-enyl-2-acyl choline glycerophospholipids (CPL) were low (3.1–5.7%). CPL was rich in the 1-O-alkyl-2-acyl subclass amounting to 12.5–23.9% in the ascidian sample. The level of CPL in the sea urchin gonad was extremely high, amounting to 46.1%. The most prominent alkyl chains in thesn-1 position of CPL from the ascidian muscle were 16∶0 (44.6%), 18∶1 (26.5%), and 18∶0 (10.7%), and of CPL from the sea urchin gonad were 18∶0 (36.2%), 16∶0 (33.0%), and 18∶1 (17.8%). Unusually high levels of odd-numbered alkyl chains, e.g., 19∶0 andanteiso 17∶0, were detected in the CPL of all samples. The prominent alkenyl chains of EPL were 18∶0 (69.4%), 16∶0 (10.0%), and 18∶1 (8.54%) (not counting the vinyl double bond) for the sea urchin gonad. Relatively high levels of 20∶1 alkenyl chains were also present. The glycerolsn-2 positions contained high proportions of polyunsaturated fatty acids. Thus, 20∶5n-3 (43.6%) and 22∶6n-3 (20.1%) were most abundant in the alkylacyl CPL from the ascidian muscle and 20∶5n-3 (54.9%) and 20∶4n-6 (30.1%) in alkylacyl CPL from the sea urchin gonad. Despite a possible interconversion of the alkyl and alkenyl chains of each class of the ether phospholipids, they showed few features in common.     

Positional specificity oftrans fatty acids in fetal lecithin

Differences in the positional incorporation of 9-trans[1-¹⁴C] octadecenoic (elaidic) and 9-trans,12-trans[1-¹⁴C] octadecadienoic (linoelaidic) acids in fetal lecithin of rats were demonstrated. On the 20th day of gestation, a¹⁴C-labeled albumin complex of elaidic or linoelaidic acid was injected into the jugular vein of pregnant rats. For comparative purposes, 9-cis[1-¹⁴C] octadecenoic (oleic) or 9-cis,12-cis[1-¹⁴C] octadecadienoic (linoleic acid) was injected into the maternal circulation of rats. Animals were killed 6 hr later. Distribution of label in total lipids and phospholipids (PL) of fetal tissue was measured by TLC. Irrespective of the label, the highest percentage of total radioactivity was associated with PL-59 to 67%. Within PL, the major portion of radioactivity was found in choline phosphoglycerides (CPG)-53 to 67%, and in ethanolamine phosphoglycerides (EPG)-18 to 33%. While linoelaidic acid was predominantly esterified in the 2-position of CPG, elaidic acid was nearly equally distributed between positions 1 and 2 of lecithin. Distribution of radioactivity within fatty acid methyl esters (FAME) of CPG measured by radio-GLC suggested that oleic and possibly linoleic acids may be converted to nervonic and arachidonic acid, respectively, in the rat by the 20th day of gestation. Following injection of elaidate, radioactivity of FAME was distributed between palmitate and elaidic acid indicating that rat fetal tissue may metabolize elaidic acid via β-oxidation. In contrast, following injection of linoelaidate, radioactivity of FAME was primarily associated withtt-18∶2, suggesting little biotransformation to other fatty acids by fetal tissues.     

Blood fatty acid composition of pregnant and nonpregnant Korean women: Red cells may act as a reservoir of arachidonic acid and docosahexaenoic acid for utilization by the developing fetus

Relative fatty acid composition of plasma and red blood cell (RBC) choline phosphoglycerides (CPG), and RBC ethanolamine phosphoglycerides (EPG) of pregnant (n=40) and nonpregnant, nonlactating (n=40), healthy Korean women was compared. The two groups were of the same ethnic origin and comparable in age and parity. Levels of arachidonic (AA) and docosahexaenoic (DHA) acids were lower (P<0.05) and palmitic and oleic acids higher (P<0.0001) in plasma CPG of the pregnant women. Similarly, the RBC CPG and EPG of the pregnant women had lower AA and DHA (P<0.05) and higher palmitic and oleic acids (P<0.01). The reduction in DHA and total n−3 fatty acids in plasma CPG of the pregnant women was paralleled by an increase in docosatetraenoic (DTA) and docosapentaenoic (DPA) acids of the n−6 series and in DPA/DTA ratio. In the RBC phospholipids (CPG and EPG) of the pregnant women, DTA and DPA acids of the n−6 series and DPA/DTA ratio did not increase with the decrease of the n−3 metabolites (eicosapentaenoic acid, DPA, and DHA) and total n−3. Since pregnancy was the main identifiable variable between the two groups, the lower levels of AA and DHA in RBC CPG and EPG of the pregnant women suggest that the mothers were mobilizing membrane AA and DHA to meet the high fetal requirement for these nutrients. It may also suggest that RBC play a role as a potential store of AA and DHA and as a vehicle for the transport of these fatty acids from maternal circulation to the placenta to be utilized by the developing fetus.     

Alterations in fatty acid composition of tissue phospholipids in the developing retinal dystrophic rat

Alterations in lipid composition occur in the retinal pigment epithelium and photoreceptor cells of the Royal College of Surgeons (RCS) dystrophic rat, a model for inherited retinal degeneration. With respect to lipid composition of nonretinal tissues, the developmental timing of lipid alterations and the incidence of dystrophy are unknown. We determined the fatty acid composition in choline phosphoglycerides (ChoGpl) and ethanolamine phosphoglycerides (EtnGpl) in the brain, liver, and retina from dystrophic RCS rats and from their nondystrophic congenics (controls) at the ages of 3 and 6 wk. At 3 wk, the fatty acid compositions were specific to individual phospholipid classes without any difference between dystrophic and nondystrophic tissues. In plasma phospholipids, there was an age-related increase in the relative contents of monounsaturated and n-3 polyunsaturated fatty acids, with only minor differences between dystrophic and nondystrophic rats. At 6 wk, the fatty acid compositions in ChoGpl and EtnGpl from dystrophic brain and retina were significantly different from those of nondystrophics. The effect of strain on developmental changes in brain fatty acid composition was significant for 18∶0 and 22∶6n−3 in EtnGpl and for 16∶0, 18∶0, 18∶1n−9, and 20∶4n−6 in ChoGpl. The brain ChoGpl fatty acid composition in nondystrophic rats was similar at 6 wk to that of normal rats, and there were almost no postweaning changes in the dystrophics. In retinal phospholipids, the effect of dystrophy was to increase the 20∶4n−6 content in EtnGpl and to decrease 22∶6n−3 in ChoGpl. The 18∶2n−6 and 22∶6n−3 contents in dystrophic liver ChoGpl were also significantly affected, while no difference was observed in the EtnGpl fraction. The dystrophy affected the phospholipid fatty acid developmental changes in a tissue- and class-specific manner. Fatty acid metabolism could be selectively altered in neural and nonneural tissues of developing dystrophic RCS rats.     

Neutral lipid and fatty acid composition of earthworms (Lumbricus terrestris)

Earthworms (Lumbricus terrestris) were extracted with chloroform-methanol (2∶1) and examined primarily for neutral lipids and fatty acids. TLC showed spots for sterols, hydrocarbons, free fatty acids, phospholipids and pigments but none for glycerides (tri-, di- or mono). Saponification of the crude lipid extract yielded 32% fatty acids, 25% unsaponifiables and 43% unidentified. The lipid contained 3% hydrocarbon and 16% sterols. GLC of the hydrocarbons showed at least 13 components. GLC of the sterol fraction showed peaks corresponding to cholesterol (the major component), γ-sitosterol, β-sitosterol, stigmasterol, campesterol, and ergosterol. GLC showed that at least 38 fatty acids were present, with 18∶1, 18∶2, 18∶0, 20∶1 and 17∶0 predominanting. Abstracted in part from the Ph.D. dissertation of J. Cerbulis, Rutgers, The State University, 1966.     

Molecular architecture and biophysical properties of phospholipids during thermal adaptation in fish: An experimental and model study

Phospholipids from livers of carps (Cyprinus carpio L.) adapted to winter (5°C) and summer (25°C) temperatures were isolated, and the fatty acid composition of total phospholipids, as well as molecular species composition of diacyl phosphatidylcholines and ethanolamines, were determined. Order parameter of 5-doxyl stearic acid and steady-state fluorescence anisotropy of different anthroyloxy fatty acids—[2-, 12(N-9-anthroyloxy)stearic acid and 16(N-9-anthroyloxy)palmitic acid—embedded in native and synthetic (16∶0/16∶0, 16∶0/22∶6, 18∶0/22∶6, 18∶1/22∶6, 20∶4/20∶4, 22∶6/22∶6 phosphatidylcholines and 16∶0/18∶1, 18∶1/22∶6 phosphatidylethanolamines) phospholipid vesicles was also determined between −30 and 30°C and 5 and 30°C, respectively. There is an accumulation of 1-monoenoic, 2-polyenoic diacyl phosphatidylcholine and ethanolamine with a concomitant reduction of 1-stearoyl,2-docosahexaenoyl species in the cold-adapted state. Despite a 30% accumulation of long-chain polyunsaturated fatty acids in phospholipids in cold, there is only a 5°C downshift in the solid-gel to liquid-crystalline phase transition temperature (−8 vs. −13°C). Vesicles from total phospholipids of cold-adapted fish proved to be more disordered in all segments than from the warmadapted ones when assayed using 2,12-(N-9-anthroyloxy)stearic and 16-(N-9-anthroyloxy)palmitic acid. Vesicles made from purified phosphatidylcholines showed the same pattern, but they were more disordered than the corresponding total phospholipids. This could be modelled using mixed phospholipid vesicles made of synthetic 16∶0/22∶6 phosphatidylcholine (75%) and either 18∶1/22∶6 phosphatidylethanolamine (25%) vs. 16∶0/18∶1 phosphatidylethanolamine (25%) and comparison of the anisotropy parameters of 100% 16∶0/22∶6 and 100% 18∶1/22∶6 phosphatidylcholine vesicles. Mixing either 16∶0/18∶1 (25%) or 18∶1/22∶6 (25%) phosphatidylethanolamines to 18∶0/22∶6 (75%) phosphatidylcholine shifted down or up, respectively, the transition temperature of vesicles compared to 100% 18∶0/22∶6 vesicles assayed by electron spin resonance spectroscopy using 5-doxylstearic acid. It is concluded that it is not the gross amount of long-chain polyunsaturated fatty acids in phospholipids, but rather their specific combination withcis Δ9 monounsaturated fatty acids in the positionsn-1, especially in phosphatidylethanolamines, that is important in determining the physical properties of biomembranes in relation to adaptational temperature.     

Fatty chain compositon of ether and ester glycerophospholipids in the Japanese oysterCrassostrea gigas (Thunberg)

The fatty chain compositions of 1-O-alk-1′-enyl-2-acyl, 1-0-alkyl-2-acyl, and 1,2-diacyl glycerophospholipids of the Japanese oysterCrassostrea gigas (Thunberg) were investigated. Major fatty chains in thesn-1 position of 1-alk-1′-enyl-2-acyl ethanolamine phospholipids (EPL) were 18∶0 (64.7%) and 20∶1 (11.1%). Majorsn-1 chains of alkenylacyl choline phospholipids (CPL) were 18∶0 (63.3%) and 16∶0 (22.2%). In the case of 1-alkyl-2-acyl EPL, the predominant fatty chains in thesn-1 position were 18∶0 (51.5%), 16∶0 (16.0%) and 20∶1 (12.5%); in the case of 1-alkyl-2-acyl CPL, the majorsn-1 chains were 16∶0 (44.0%) and 14∶0 (23.4%). Saturated fatty chains were predominant in both EPL and CPL. Prominent fatty acids in thesn-2 position of the alkenylacyl EPL were 22∶6n−3 (29.0%), 20∶5n−3 (19.0%) and 22∶2 NMID (non-methylene interrupted dienes, 16.6%) contributing to about 65% of the total fatty acids, while alkenylacyl CPL was rich in the saturated acids 16∶0 (32.0%) and 18∶0 (9.2%). In the alkylacyl EPL, 16∶0, 18∶1n−9, 18∶0 and 16∶1n−7 were prominentsn-2 fatty acids and accounted for 30.6%, 10.0%, 9.8%, and 8.3%, respectively. Polyunsaturated fatty acids were detected, but were present at extremely low percentages. Majorsn-2 fatty acids in alkylacyl CPL were 16∶0 (25.4%), 22∶6n−3 (16.0%) and 20∶5n−3 (8.4%). The major fatty acids of diacyl EPL were 20∶5n−3 (22.3%), 16∶0 (17.9%), and 18∶0 (16.1%), and those of diacyl CPL were 16∶0 (30.4%), 20∶5n−3 (17.6%) and 18∶1n−7 (7.4%).