Changes In Phospholipid Composition Research Articles

Phospholipid composition and metabolism in the embryonic chick lens

This study compares the phospholipids of lens epithelial cells with those of lens fibers in 6-day-old embryonic chicks, in order to determine whether changes in phospholipid composition or metabolism are associated with lens fiber differentiation. Several differences are apparent. The total amount of phospholipid in an average lens fiber cell is three to four times greater than that in an average epithelial cell. The relative sphingomyelin concentration in the lens fibers (6%) is greater than that in the lens epithelial cells (less than 1%), although the phospholipid compositions are otherwise similar. In 32P incorporation studies, the proportion of radioactivity incorporated into phosphatidic acid is 10 times greater in the lens fibers than in lens epithelial cells; phosphatidylinositol displays a high rate of 32P incorporation in both lens cell populations. The observed differences in phospholipid composition and metabolism may be related to alterations in the plasma membrane associated with the early stages of lens fiber differentiation.

Erythrocyte Membrane Alterations in Lecithin: Cholesterol Acyltransferase Deficiency

Structural, compositional, and functional abnormalities were found in the erythrocyte membranes of homozygotes for LCAT deficiency. Similar but less pronounced abnormalities were also present in the heterozygotes for this disorder. Some of the membrane alterations, which included decreased osmotic fragility, changes in phospholipid composition, and membrane sulfydryl group latency, as well as changes in the activity of membrane p-nitrophenylphosphatases and acetylcholinesterase, may be secondary to the changes in plasma lipids. However, since plasma lipids (and LCAT activity) were normal in the hereozygotes, the existence in both the homo- and the heterozygotes of erythrocyte membrane abnormalities unrelated to plasma LCAT activity seems likely.

Influence of α- dl-tocopherol on fungal lipid composition

The addition of α- dl-tocopherol to growing cultures of the fungus Glomerella cingulata increased triacylglycerol content 50% or more but decreased the synthesis of triacylglycerols approximately 16-fold; moreover, α-tocopherol treated cultures had 10% to 85% less malonaldehyde than control cultures. These results suggest that α-tocopherol caused increased triacylglycerol content by decreasing triacylglycerol breakdown. In contrast, phosphoglyceride content and synthesis remained virtually unchanged by the addition of α-tocopherol. In both classes of glycerolipid, treatment with α-tocopherol led to increased ratios of unsaturated to saturated fatty acids; but, α-tocopherol treatment led to an increase in the number of double bonds per mole of fatty acid in the triacylglycerols and to a decrease in the number of double bonds per mole of fatty acid in the phosphoglycerides. We infer that, through deacylation-reacylation reactions, the triacylglycerols of treated cultures supplied the phosphoglycerides with relatively saturated fatty acids and that the triacylglycerols also were used for storage of relatively unsaturated fatty acids derived from the phosphoglycerides. Our results suggest that α-tocopherol can be used to produce predictable shifts in the fatty acid composition of fungal phosphoglycerides. Such shifts can be useful tools in attempting to understand how changes in the fatty acid composition of phospholipids influence the physical properties and functions of cellular membranes.

Changes in Phospholipid Composition of Escherichia coli Following γ- and uv-Irradiation

Cells of E. coli B/r and ${\rm B}_{{\rm s}-1}$ in exponential growth and labeled with14 C were analyzed for phospholipid composition after irradiation with either γ rays or uv radiation and reincubation for 0 to 180 min. Radiation doses ranged from 1 to 36 krad for ${\rm B}_{{\rm s}-1}$, and either 3 to 54 krad γ- or 500 to $4000 {\rm ergs}/{\rm mm}^{2}$ of uv-irradiation for B/r. Phospholipid composition was measured in terms of either14 C activity or phosphorus content. In unirradiated cells it was phosphatidylethanolamine (PE): 75-82%: phosphatidylglycerol (PG): 14-21%; cardiolipin (CL): 2-5%. The most significant change with time postirradiation was an increase in the total amount of CL and CL%, both of which were strain and dose dependent. In the γ-dose ranges studied, CL% at 180 min postirradiation increased continuously in B/r (14.2% at 54 krad), while it reached a plateau at 9 krad in ${\rm B}_{{\rm s}-1}$ (9.0%). The amounts of CL present showed a four- to fivefold increase over control levels. ...

Changes of phospholipid-composition induced by valinomycin in the maxillary gland of rat.

The effect of valinomycin on phospholipids (unidentified phospholipid (UI, possibly cardiolipin), phosphatidylcholine (PC), phosphatidylethanolamine (PE), sphingomyelin (Sph), lysophosphatidylcholine (Lyso-PC) and total phospholipid in the isolated rat submaxillary glant was examined and following results were obtained.1. In the presence of 1 μM, 10 μM and 100 μM valinomycin, no significant differences were observed in the content of UI, PE and total phospholipid, as compared with the experimental control.2. In the presence of 1 μM, 10 μM and 100 μM valinomycin, the content of PC was increased, and that of Lyso-PC was decreased.3. In 1 μM and 10 μM valinomycin, no significant changes were observed in the content of Sph, whereas in 100 μM valinomycin, the decreasing tendency was observed in the content.From the above mentioned results, it was suggested that these changes in the contents of PC, Lyso-PC and Sph might be due to the inhibition of phospholipase A activity and of the other enzymic activity, like that of phospholipase A and also the significance of the results obtained was discussed.

Changes in fatty acid composition of phospholipids and triglycerides of Musca domestica resulting from choline deficiency

The fatty acid composition of the phospholipids and triglycerides extracted from housefly larvae reared on diets containing no added fatty acids but containing differing concentrations of choline has been determined. Reducing the choline content of the diet resulted in a graded reduction of the percentage of phosphatidylcholine present in the phospholipids of the larvae. This was accompanied by changes in the fatty acid composition, choline deficiency causing an increased utilization of 16-C rather than 18-C acids by the phospholipids. Changes in the fatty acid composition of the triglyceride fraction were also observed but these were associated with insects containing very low levels of phosphatidylcholine. Examination of the fatty acids in the different classes of phospholipids showed that the major change resulting from choline deficiency was in the fatty acids of the phosphatidylethanolamine fraction—the phospholipid which increased as the phosphatidylcholine decreased. Although the fatty acid composition of the different classes of phospholipids was not completely fixed, some preferential utilization of certain fatty acids by certain classes was observed, in both larval and adult insects. The fatty acid composition of the phospholipids extracted from larval gut, muscle, fat body, cuticle, trachea, nervous tissue, and haemolymph was determined. Changes resulting from choline deficiency similar to those seen in the whole larva were observed in all tissues except the nervous tissue. The effect of rearing larvae at temperatures between 24 and 35°C resulted in only minor changes in the fatty acid composition of both phospholipid and triglyceride fractions but the difference due to choline deficiency was observed at all temperatures. The possibility that the observed changes in the fatty acids of the phospholipids are compensatory to the changes in the proportion of the choline to the ethanolamine phospholipids is discussed.

The inhibition of phospholipid synthesis in Escherichia coli by phenethyl alcohol

The kinetics of lipid metabolism during phenethyl alcohol treatment of Escherichia coli were examined. Phenethyl alcohol at a non-bacteriostatic concentration reduces the accumulation of [ 32P] phosphate into phospholipids and alters the phospholipid composition of the cell membrane. The changes in phospholipid composition are a result of the inhibitory effect of phenethyl alcohol on the rates of synthesis of the individual phospholipids. The inhibition in the rate of phosphatidylethanolamine synthesis by phenethyl alcohol was twice the inhibition in the rate of phosphatidylglycerol synthesis. The de novo rate of cardiolipin synthesis was only slightly inhibited. However, net cardiolipin accumulation increased during phenethyl alcohol treatment due to a more rapid turnover of phosphatidylglycerol to cardiolipin. Phenethyl alcohol also altered the fatty acid composition of the cell as a result of its inhibitory effect on the rate of individual fatty acid synthesis. However, the inhibition of phospholipid synthesis was not reversed by fatty acid supplementation of phenethyl alcohol treated cells. This result indicates that phenethyl alcohol does not inhibit phospholipid synthesis solely at the level of fatty acid synthesis.

Changes in phospholipid composition in hibernating ground squirrel, Citellis lateralis, and their relationships to membrane function at reduced temperatures.

AbstractThe hearts of hibernating mammals have the capacity to function at reduced temperatures of 1 C in contrast to hearts of nonhibernating mammals which undergo ventricular fibrillation during deep hypothermia. Thus, all vital membrane functions continue in hibernators. This suggests that there may be special features of their lipid and protein composition. Analysis of the hearts of the hibernating ground squirrel,Citellus lateralis, in the active (37 C) and hibernating state (1–4 C) reveals differences in the percent composition of the phospholipid classes. There is a decrease in the percentage of diacyl choline, ethanolamine, serine phosphoglycerides, and diphosphatidyl glycerol and an increase in the percentage of lysophosphatidyl choline, lysophosphatidyl ethanolamine, lysodiphosphatidyl glycerol, and phosphatidic acid in the hibernating state. There is also an increase in the molar amount of phosphorus/100 g fresh wt of tissue during hibernation. The most striking difference in phospholipid composition between active and hibernating heart tissue is the 3.5‐fold increase in lysoglycerophosphatides. These compounds are implicated as contributing factors controlling membrane fluidity during hibernation and upon which the physiological state of hibernation may be contingent.

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%.

Changes in the phospholipid composition in the differentiating cellular slime mold, Dictyostelium discoideum

1. 1. The phospholipid composition of Dictyostelium discoideum was determined at different stages of development by two-dimensional thin-layer chromatography, and both qualitative and quantitative changes in the composition of membrane phospholipids occurred during differentiation. 1,2-Diacylglycero- sn-3-phosphoryl-ethanolamine and its alkenyl-acyl derivative were the major phospholipids in all stages comprising 40–44 molar percent of the phospholipid phosphorous. The level of three phospholipids increased: 1,2-diacylglycero- sn-3-phosphorylcholine went from 7 to 24%; 1,2-diacylglycero- sn-3-phosphorylinositol from 6 to 13%; and 1,2-diacylglycero- sn-3-phosphate and its alkenyl-acyl derivative from 1 to 6%. The amount of 1-acylglycero- sn-3-phosphorylethanolamine and its 1-alkenyl form gradually decreased from 17% in amoebae to about 2% in mature fruiting bodies. 2. 2. Two unique unidentified plasmalogens comprising about 16% of amoebae phospholipids disappeared during aggregation, reappeared during culmination to 6%, and dropped to 2% in fruiting bodies. They were present in amoebae grown or produced in the absence of bacteria at relatively low levels, about 2–4%. 3. 3. The observed changes in phospholipid composition occurred during the time when cell membrane antigens were changing and when membrane-bounded prespore vesicles were forming. Since phospholipids are major components of membranes, these results suggest that D. discoideum membrane phospholipids change when the cells begin to adhere to each other and during spore formation.

Changes in Phospholipid Composition of a Winter Wheat Cultivar during Germination at 2 C and 24 C

Evaluation of various solvent systems for lipid extraction of wheat Triticum aestivum L. cv. Rideau seeds showed that boiling 2-propanol followed by the Bligh-Dyer procedure was the most efficient method, with respect to lipid yield and ability to inactivate lipolytic enzymes. Ten phospholipids were identified in dry seeds; the major components being phosphatidylcholine, lysophosphatidylcholine, N-acyl lysophosphatidyl-ethanolamine, N-acylphosphatidylethanolamine, and phosphatidylethanolamine. After growth for 1 week (2 C) or 31 hours (24 C), the proportions of phosphatidylethanolamine + lysophosphatidic acid and phosphatidic acid increased, lysophosphatidylcholine decreased, and the remaining phospholipids showed little change. At 5 weeks (2 C) or 72 hours (24 C), the seedlings showed 5-fold increases in the proportion of phosphatidic acid largely at the expense of phosphatidylcholine, small decreases in N-acyl lysophosphatidylethanolamine and N-acylphosphatidylethanolamine, and significant increases in lysophosphatidylcholine. The changes in phosphatidic acid and phosphatidylcholine are interpreted as being partially due to increasing phospholipase D activity during germination. In general, the phospholipid composition was similar in morphologically equivalent seedlings grown at 2 C or 24 C. The increased membrane content in seedlings grown at 2 C does not reflect any preferential synthesis of individual phospholipids.

Changes in phospholipid composition of Thiobacillus neapolitanus during growth.

During the stationary growth phase, the phospholipids of Thiobacillus neapolitanus consisted of phosphatidyl glycerol (PG), diphosphatidyl glycerol (DPG), phosphatidyl-N-monomethylethanolamine (PME) and phosphatidyl ethanolamine (PE) in increasing amounts. In general, the phospholipids increased to a maximum concentration during the stationary phase and then decreased in concentration. Individually, PG and PE increased to a maximum in late lag or early exponential phase and then decreased in concentration. DPG and PME increased during the transition between the exponential and the stationary phase and reached a maximum concentration in the stationary phase. In older cultures, a quantitative interconversion between PG and DPG and PE and PME was observed. A lyso-phospholipid compound also appeared in the late stationary phase.

Changes in acyl group composition of phospholipids from chicken embryonic fibroblasts after transformation by Rous sarcoma virus

The acyl group composition of individual phospholipids isolated from both normal and Rous sarcoma virus (RSV) transformed chicken embryo fibroblasts (CEF) was analyzed by Gas-Liquid Chromatography (GLC). Each of the phospholipids analyzed displayed a characteristic pattern of acyl groups. Significant differences between normal and transformed cells in the acyl group composition of the phospholipids was detected. In the transformed cells, the content of arachidonate decreased while oleate increased. These results indicate that a reduced content of certain polyunsaturated fatty acids accompanies malignant transformation by Rous sarcoma virus.

Zonal analysis of phospholipids in the epiphyseal cartilage and bone of normal and rachitic chickens and pigs.

The effect of various degrees of simple, vitamin D-deficient rickets on the levels, composition and extractability of phospholipids from calcifying and soft tissues was studied in chickens and pigs. A variety of effects of rickets on the phospholipid composition of the calcifying tissues were detected; there was little change in the soft tissues. The quantitative effects on the lipid concentration of rachitic hard tissues were variable from zone to zone and appeared to reflect variations in other tissue constituents. However, the qualitative differences indicated a direct effect on specific phospholipids. Acidic phospholipids displayed the greatest percentage change, although numerous statistically-significant changes were also seen in the neutral phospholipids. Tissue zones displaying the greatest change in phospholipid composition in rickets were proliferating and hypertrophic cartilage, and cancellous bone, with calcified cartilage showing the least effect. Rickets also reduced the extractability of certain acidic and neutral phospholipids from zones of early mineralization. These findings are interpreted as indicating the presence of elevated levels of phospholipid complexed with calcium phosphate in rachitic tissue, presumably due to the blockage of normal mineralization.

Structural and compositional changes in the red cell membrane during Clostridium welchii infection.

Summary. The RBC haemolysis resulting from Clostridium welchii septicaemia is generally thought to be caused by the lecithinase (α toxin) produced by that bacterium. A woman admitted to this hospital suffering from a Clostridium septicaemia presented us with the opportunity to study whether structural and compositional changes in her RBC membrane could account for the observed haemolysis. Previous studies showed that treatment of RBC membranes with phospholipase C (α toxin), obtained from Clostridium welchii, produces vast changes in both the phospholipid structure and composition, without any detectable alteration in the protein composition or structure. The RBC membranes, prepared from the patient's blood, exhibited little or no change in phospholipid composition and structure, when compared with normal cells; however, both the protein composition and structure appeared drastically altered. These results, therefore, suggest that the haemolysis observed during Clostridium welchii septicaemia is not the result of a lecithinase (α toxin), but may be due to the proteolytic action of one or more of the other toxins secreted by this bacterium.

Phospholipids in tissues of the eye: III. Composition and metabolism of phospholipids in human lens in relation to age and cataract formation

1. 1. In human lens a marked change in phospholipid composition occurs during life. This is mainly caused by a continuous net synthesis of sphingomyelin and by a decrease in concentrations of the other phospholipids at higher age. 2. 2. These changes are correlated with the process of cell differentiation and the formation of the lens nucleus, as appeared from investigations of cortex and nucleus. Some similarities with developing brain were observed. 3. 3. 32P i is rapidly incorporated into phosphatidic acid and phosphatidylinositol, while the ethanolamine and choline glycerophospholipids show a much lower phosphate turnover. These components contain, besides diacyl phospholipids, also vinylether analogues which have a low metabolic activity. 4. 4. The phospholipid composition of senile cataracts is similar to those of normal lenses of the same age. The amounts of bound lipids and of proteolipids decrease, which is an indication of membrane disintegration. The phosphate incorporation into phosphatidylinositol decreases while that into phosphatidic acid and phosphatidylglycerol increases.

The effect of antioxidant-deficiency on phospholipid composition in the chick brain.

Abstract— A significant increase in arachidonate was noted in the total phospholipids of brain of chicks with nutritional antioxidant‐deficiency and encephalomalacia. After thin‐layer chromatography of the brain lipids, this increase in arachidonate was found to be restricted to the phosphatidyl serine fraction. Significant decreases in docosahexaenoate and docosapentaenoate were noted in the phosphatidyl ethanolamine fraction. The changes in fatty acid composition of phospholipids in chick brain are comparable to those previously observed in phospholipids of skeletal muscle, liver and testes of the rat.

Atherosclerosis in nonhuman primates: sequences and possible mechanisms of change in phospholipid composition and metabolism.

Annals of the New York Academy of SciencesVolume 162, Issue 1 p. 120-136 ATHEROSCLEROSIS IN NONHUMAN PRIMATES: SEQUENCES AND POSSIBLE MECHANISMS OF CHANGE IN PHOSPHOLIPID COMPOSITION AND METABOLISM Oscar W. Portman, Oscar W. Portman Oregon Regional Primate Research Center Beaverton, Ore., and Department of Biochemistry University of Oregon Medical School, Portland, Ore.Search for more papers by this author Oscar W. Portman, Oscar W. Portman Oregon Regional Primate Research Center Beaverton, Ore., and Department of Biochemistry University of Oregon Medical School, Portland, Ore.Search for more papers by this author First published: July 1969 https://doi.org/10.1111/j.1749-6632.1969.tb56356.xCitations: 31AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume162, Issue1Experimental Medicine and Surgery in PrimatesJuly 1969Pages 120-136 RelatedInformation

Bacteria-shaped gymnoplasts (protoplasts) of Bacillus subtilis.

Addition of glucose to the medium in which Bacillus subtilis was grown lowered the pH and increased the amount of lysylphosphatidylglycerol relative to the phosphatidylglycerol content of the membrane fraction. This change in phospholipid composition was accompanied by changes in the shape and behavior of the gymnoplasts obtained by cell wall removal with lysozyme. These gymnoplasts appeared to retain most of their original cell shape and internal organization, often with preservation of the mesosomes. Cells harvested from neutral growth medium gave the usual spherical gymnoplasts. In a hypotonic medium, the spherical gymnoplasts lysed rapidly, whereas the rod-like gymnoplasts lost only part of their cell content while showing a tendency to preserve the original shape. This type of gymnoplast could not be produced from cells grown in neutral medium by simply raising the magnesium concentration. When this was done the gymnoplasts assumed bizarre shapes; they became compact and susceptible to the tonicity of the medium. Gymnoplasts or protoplasts, produced from bacilli exposed to low pH values, were found not to conform to the formulations on "protoplasts" given in 1958 by 13 authors. Cells exposed to a low environmental pH during growth seemed to possess a more rigid membrane structure than cells grown at neutral pH.

Changes in phospholipid composition of human aorta with age.

Changes in phospholipid composition of human aorta with age.