Inositol Phosphoglycerides Research Articles

Gangliosides and phospholipids from frog and duck retina

Phospholipids and gangliosides have been analysed in duck and frog retinas. Expressed per g wet weight frog retina is richer in phospholipids and poorer in gangliosides than are duck retina and retinas of other species investigated. The phospholipid and ganglioside patterns are very different in the two species. In frog retina, choline phosphoglycerides and cardiolipin are higher and ethanolamine phosphoglycerides, inositol phosphoglycerides, sphingomyelin and phosphatidic acid much lower than in duck retina. In the latter species, ethanolamine plasmalogen levels are nearly twice as high than in frog retina. In the bird retina there are higher amounts in monosialogangliosides (G M1 and G M3), different distributions in disialogangliosides (G D3, G D1a, G D1b and G D2) and a lower contribution of tri- and tetrasialogangliosides (G T1 and G Q1) than in frog retina. In duck retina we found a new ganglioside called G Y, characterized by an R F lower than that of G Q1. In general, from the lipid analysis of retinas of several species, phospholipid pattern is rather stable and the ganglioside distribution more variable.

The lipid composition of the salt (rectal) gland of spiny dogfish

1. 1. The lipids from the salt (rectal) gland of spiny dogfish have been isolated and characterized. 2. 2. The major lipids were cholesterol, ethanolamine phosphoglycerides and choline phosphoglycerides. Other phospholipids were sphingomyelins, diphosphatidylglycerols, inositol phosphoglycerides and serine phosphoglycerides. The major fatty acid of ethanolamine phosphoglycerides was 22:6 with smaller amounts of 20:4, 18:1, 18:0 and 16:0. The major acids of choline phosphoglycerides were 16:0, 18:1, 20:4 and 22:6. 3. 3. The major glycosphingolipids were sulphatides and N-acetylneuraminylgalactosylglucosylceramides, and in addition there were minor amounts of glucosylceramides and galactosylceramides. 4. 4. The polar part of the sulphatides was galactose 3-sulphate. The fatty acids were mainly saturated and monounsaturated d-2-hydroxy C 22–C 24 acids. The longchain bases contained equal amounts of 1,3-dihydroxy-2-amino compounds and 1,3,4-trihydroxy-2-amino compounds with 16–20 carbon atoms. Bases with a methyl branch in Position 2, 3 or 4 from the methyl end were relatively abundant. The methyl branch was preferentially on carbon atom 16 as indicated from the polar end. 5. 5. The polar part of the choline phospholipids was phosphorylcholine exclusively. The sphingomyelin fatty acids were mainly normal C 14–C 24 acids with an unusually large amount of 22:1. A branched-chain 15:0 acid was identified, earlier unknown in sphingolipids of higher animals. All long-chain bases were dihydroxy bases with 15–19 carbon atoms. 6. 6. The unsaturation of paraffin chains was considerably higher among sphingolipids as well as glycerolipids of rectal gland of spiny dogfish (cold-blooded) than of salt gland of marine birds. Also, there was an unusually high amount of branched-chain components of sphingolipids of the rectal gland. These differences may be a prerequisite for an optimal liquid-crystalline state of the membrane. 7. 7. A role for sulphatides in Na + transport is indicated by a similar ratio of (Na +-K +)-ATPase and sulphatides in several tissues with increased transport capacity.

Skeletal muscle lipids. III. Changes in fatty acid composition of individual phosphoglycerides in man from fetal to middle age

The fatty acids in cardiolipin, choline phosphoglyc- MATERIALS AND METHODS eride, ethanolamine phosphoglyceride, inositol phosphoglycer- ide, and serine phosphoglyceride in the human gastrocnemius Material muscle were studied for changes between early fetal age to mid- The of the material and the procedure used for dle age. In cardiolipin, choline phosphoglyceride, and ethanol- amine phosphoglyceride, the relative total amount of the linoleic collection have been described earlier (1). The material in acid series increased considerably during the prenatal period and this study consisted of muscle samples from 10 fetuses, 10 reached maximum values during the first year of life. In inositol aged to lo yr, aged lo to 20~ phosphoglyceride and serine phosphoglyceride, only slight adults between 2O and 3o Yr Of age, and adults be- changes in the sum of fatty acids of the linoleic acid series were tween 50 and 60 yr of age. Most of the samples were ob- found. An increase in the concentration of fatty acids of the lino- lenic acid series was found in ethanolamine phosphoglyceride and serine phosphoglyceride, while only minor amounts of these fatty acids were present in choline phosphoglyceride and inositol phosphoglyceride and not at all in cardiolipin. During the peri- od studied, the amount of plasmalogen in ethanolamine phos- phoglyceride decreased slightly during the first year of life and then remained at 40%. The amount of plasmalogen increased in choline phosphoglyceride from 8% at the middle of the gesta- tional period to 15% 1 yr after birth. The individual phospho- lipids were found to have characteristic fatty acid patterns.

Skeletal muscle lipids. II. Changes in phospholipid composition in man from fetal to middle age

Phospholipid compositions were determined in samples of gastrocnemius muscles of individuals from fetal stage to the age of 55 yr. The lipids were separated by thin-layer chromatography. In order to enable characterization of the individual phospholipids, a lipid extract was prepared from pooled samples of gastrocnemius muscles from adult males and separated by ion-exchange chromatography on TEAE-cellulose. The individual phosphoglycerides were purified by thin-layer chromatography and then characterized according to their content of fatty acids, aldehydes, phosphorus, and the identity of the bases. The relative amounts of the major phospholipids, choline and ethanolamine phosphoglycerides, changed little with age, and in adult males they constituted 47% and 24%, respectively. Cardiolipin increased from 3% in the fetal stage to 9% by the end of the first year of life. Sphingomyelin and serine phosphoglyceride decreased with increasing age, while inositol phosphoglyceride increased. In adult males, cardiolipin constituted 10% of total lipid phosphorus, inositol phosphoglyceride constituted 9%, serine phosphoglyceride 3%, and sphingomyelin 7%.

Incorporation of (1-14c)-oleic acid into neutral glycerides and phosphoglycerides of mouse brain.

AbstractThe incorporation of [1‐14C]‐oleic acid into the neutral glycerides and phosphoglycerides of adult mouse brain was examined between 1 and 80 min after intracerebral injection. Radioactivity of the free oleic acid in brain decreased rapidly with a half‐life of ca. 5 min. The specific radioactivity of the phosphatidic acids was highest at 1 min after injection. This was followed by the diacylglycerols and triacylglycerols which attained a maximum specific radioactivity at 3 and 20 min after injection, respectively. Specific radioactivities of the neutral glycerides were higher than the phosphoglycerides. A larger proportion of the radioactivity in the diacylglycerols was transferred to the phosphoglycerides than to the triacylglycerols. Among the phosphoglycerides, radioactivity was actively incorporated into the inositol phosphoglycerides. The specific radioactivity of the inositol phosphoglycerides was higher than the diacylsn‐glycero‐3‐phosphorylcholines, and the kinetics of incorporation of radioactivity into these lipids was also different. A water soluble material was found which showed maximum specific radioactivity at 6–10 min after injection. The properties of this water soluble material suggested that it may be an intermediate involved in the acyl group metabolism of phosphoglycerides in brain.

The distribution of lipids in the human nervous system. III. Fatty acid composition of phosphoglycerides of human foetal and infant brain

The fatty acid compositions of choline (CPG), ethanolamine (EPG), serine (SPG) and inositol (IPG) phosphoglycerides were determined in the cerebrum of 11 foetuses, and in the cerebral cortex and the white matter of frontal lobe of 21 infants. The phosphogylcerides were separated by thin-layer chromatography and their fatty acid compositions determined by gas-liquid chromatography. In cerebral cortex, the largest changes occurred during prenatal development The concentration of 16:0 and 16:1 diminished in all the 4 phosphoglycerides, while 18:0 increased and 18:1 diminished or remained constant. The fatty acids of the linoleic acid series showed an increase in chain length and desaturation with maturation. 22:6 (n-3) increased during the whole period, while the concentration of the other fatty acids of the linolenic acid series was too small to permit accurate determination. After term, the changes were confined to the polyenoic acids. In all the phosphoglycerides the concentration of the fatty acids of the linoleic acid series showed a slight maximum between the 4th and 12th postnatal months. In the white matter, there was a very strong increase of monoenes, particularly of 18:1, but also of 20:1 in EPG, with a concomitant diminution of saturated fatty acids in CPG, EPG and IPG. In SPG, the saturated fatty acids remained constant, but the polyunsaturated fatty acids, particularly of the linolenic acid series, diminished drastically. The fatty acids of the linolenic acid series also diminished in the other 3 phosphoglycerides, while the fatty acids of the linoleic acid series showed a maximal plateau between the 6th and 18th postnatal months. The most striking feature was the very small individual differences of the fatty acids patterns brains of the same age.

The in vivo synthesis of acyl- and ether-bonded phospholipids in Heliothis virescens

Fatty acids and fatty alcohols serve as precursors in the formation of alkyl, and alk-1-enyl bonds in the phospholipids of the tobacco budworm [ Heliothis virescens (F)]. The insects are capable of interconverting the two precursors. Fatty acids of 16 or 18 carbons are preferred in acyl-bond formation, and fatty alcohols of 18 carbons are preferred in ether-bond synthesis. Alk-1-enyl glyceryl ethers appear to be derived from the saturated alkyl glyceryl ethers by dehydrogenation. The ether-bonded components are associated principally with the ethanolamine phosphoglycerids. Very little or no ether synthesis occurs in the choline, serine, or inositol phosphoglycerides.

Ether-bonded lipids of insects: a quantitative comparison of the glyceryl ethers associated with ethanolamine and choline phosphoglycerides

1. 1. Alkyl and alk-1-enyl glyceryl ethers occur almost exclusively in the ethanolamine phosphoglycerides of the tobacco budworm. Only traces of ether-bonded material can be found in the choline phosphoglycerides, and very little in the serine and inositol phosphoglycerides. 2. 2. In the mature larvae, 20·6 per cent of the PE fraction is ether-bonded, and four-fifths of this is the alk-1-enyl glyceryl ether (plasmalogen) form. The glyceryl ethers, therefore, cannot be considered as minor phospholipid constituents, because they make up a significant fraction of the ethanolamine phosphoglycerides.

Lipid metabolism of brain tissue in culture.

AbstractTissue explants from frontal lobes of rat brain were used for the study of cerebral fatty acid metabolism. After tissues had been maintained in serum‐supplemented medium, a lipid free medium was substituted and metabolic studies were carried out. Under these conditions explants continued to take up lipid precursors for at least 48 hr. Stearic acid 1‐C14, palmitic acid 1‐C14 and lignoceric acid 1‐C14 were bound to cells as the free fatty acids or incorporafed into neutral lipids (particularly triglycerides), glycolipids and phospholipids. In the galactolipid fraction, cerebrosides were the principal radioactive lipids. Choline phosphoglycerides, ethanolamine phosphoglycerides, inositol phosphoglycerides and serine phosphoglycerides were the principal radioactive phospholipids. Fatty acids were incorporated into cellular lipids either unchanged or after desaturation, chain elongation, or both. In a patient with a demyelinating disease, precursor uptake was reduced and chain elongation and desaturation of the fatty acid was diminished. In a patient with generalized GM2 gangliosidosis, glycolipids other than cerebrosides were labeled to a greater extent than normal. These studies exemplify the usefulness of tissue explants for prolonged metabolic studies in normal and pathological specimens of brain.

Lipid metabolism in brain tissue explants.

Abstract— Tissue explants from frontal lobes of rat brain were used for the study of cerebral fatty acid metabolism. After tissues had been maintained in serum‐supplemented medium, a lipid‐free medium was substituted and metabolic studies were carried out. Under these conditions explants continued to take up lipid precursors for at least 48 h, as judged by incorporation of dl‐[2‐14C]mevalonic acid into cellular lipids. [l‐14C]Stearic acid and [l‐14C]palmitic acid were bound to cells as the free fatty acids, or incorporated into neutral lipids (particularly triglycerides), glycolipids and phospholipids. In the galactolipid fraction, cerebrosides were the principal radioactive lipids. Choline phosphoglycerides, ethanolamine phosphoglycerides, inositol phosphoglycerides and serine phosphoglycerides were the principal radioactive phospholipids. Fatty acids were incorporated into cellular lipids either unchanged or after desaturation, chain elongation, or both. Maximum incorporation of stearate occurred in tissues derived from 3‐day‐old animals. With increasing age the uptake of fatty acid dropped sharply.When the labelling of lipids as a function of time was followed in 3‐day‐old animals, triglycerides and choline phosphoglycerides were the first fractions to take up labelled stearate. Labelling of cerebrosides occurred slowly, only becoming evident after 24 h. These studies exemplify the usefulness of tissue explants for prolonged metabolic studies in normal and pathological specimens of brain.

Distribution and fatty acid composition of phosphoglycerides in normal human brain

A thin-layer chromatographic procedure for the isolation of tissue phospholipids and their subsequent analysis is described. The method has been applied to the determination of the fatty acids of phosphoglycerides in human brain from the early fetal stage to old age. The study shows changes in the distribution and fatty acid composition of each phosphoglyceride in normal brain, although they are quite small after early childhood. A lipid-specific fatty acid pattern for each of the four major phosphoglycerides was found. Besides this, the pronounced differences between fatty acids of the lipids from the cerebral cortex and from the adjacent white matter justify speaking of a tissue-specific fatty acid pattern for brain phosphoglycerides. The phospholipids of cerebral white matter contained more monoenoic acid but much less polyunsaturated fatty acid than those of cerebral cortex. The brain phosphoglycerides also showed an age-dependent fatty acid pattern. With increasing age the concentration of the fatty acids of the linoleate family diminished while that of the linolenate family increased. Brain inositol phosphoglycerides, the fatty acid composition of which has not been studied systematically before, were characterized by a large concentration of arachidonate which was nearly as high for white as for gray matter and showed only small changes with age.

Composition of mouse brain myelin during development.

Abstract—Myelin was isolated from the brains of mice at ages of 14, 24, 41, 44, 47, and 182 days and the contents of lipid phosphorus, cholesterol, lipid galactose, alkenyl groups, ethanolamine phosphoglycerides, choline phosphoglycerides, sphingomyelin, and serine and inositol phosphoglycerides were determined. Significant differences in the composition relative to total lipid phosphorus were found in the myelin. At 14 days of age, the myelin had lower relative amounts of cholesterol, galactolipids, alkenyl groups, and ethanolamine phosphoglycerides and a higher relative amount of choline phosphoglycerides.