The Binding of Luxol Fast Blue Arn by Various Biological Lipids

A determination of the selectivity and approximate stoichiometry of Luxol Fast Blue ARN by known chemical compounds showed that phosphatidyl ethanolamine, phosphatidyl serine, and phosphatidyl inositol bound the dye with an apparently stoichiometric ratio of 1 dye molecule to 2 molecules of lipid. Phosphatidyl choline, sphingomyelin, and palmitic acid showed a much weaker reaction. Of these, phosphatidyl choline bound the least amount of dye; about 1 dye molecule per 13-20 lipid molecules. Glycerides, methyl and cholesteryl esters of fatty acids, cholesterol, cerebrosides, and oleic acid gave negative results, as did a variety of low molecular weight substances, including ethanolamine, choline, inositol, and serine. Such negative results indicate that no isopropanol-insoluble complexes were formed with the dye. The behavior of the dye toward several phospholipids suggests that the phosphate groups are essential to the binding reaction and that the quaternary amine of phosphatidyl choline may interfere with it. The selectivity of the dye-binding reaction and the properties of the dye-phospholipid complexes suggest that this reaction will be useful for cytochemical studies of phospholipids, particularly those of the cell membrane     

THE SUBCELLULAR LOCALIZATION OF CARBAMYLCHOLINE-STIMULATED PHOSPHATIDYL INOSITOL TURNOVER IN RAT CEREBRAL CORTEX IN VIVO

Abstract— The intraventricular injection of 40 μCi of ³²P_i (carrier free) into adult rats resulted in maximum incorporation of ³²P_i into the phosphatidyl inositol of the whole cortex after 20 h. A further intraventricular injection of 2 nmol carbamylcholine plus 0.02 nmol eserine resulted in a 23% decrease in the specific activity of phosphatidyl inositol after 20 min. The specific radioactivities of phosphatidyl choline, phosphatidyl ethanolarmine and phosphatidyl serine were not changed. Cerebral cortex from rats treated in this way was subjected to an extensive subcellular fractionation. It was found that the specific radioactivity of the phosphatidyl inositol of the synaptic vesicle fraction showed a reduction of 60%. No other fractions showed effects of this magnitude.     

Lipids of ocular tissues: VII. Positional distribution of the fatty acids in the phospholipids of bovine retina rod outer segments

The positional distribution of the fatty acids in the major phospholipids of bovine retina rod outer segments was determined. Phosphatidyl ethanolamine and phosphatidyl serine have mostly saturated acids in the 1-position and docosahexaenoic acid in position 2. These phospholipids contain 94 and 79%, respectively, of polyun-saturated acids in the 2-position. Phosphatidyl choline contains mostly saturated acids in the 1-position, but has significant quantities of palmitic in the 2-position along with docosahexaenoic acid. The levels of docosahexaenoic acid in rod outer segment phospholipids are among the highest yet reported for membrane phospholipids, amounting to 23% in phosphatidyl choline, 39% in phosphatidyl ethanolamine, and 45% in phosphatidyl serine.     

Effect of Temperature and BASF 13 338 on the Lipid Composition and Respiration of Wheat Roots

The fatty acid composition of wheat seedling roots changed in response to temperature. As temperature declined, the level of linolenic acid increased and the level of linoleic acid decreased. The distribution of phospholipid classes was not influenced by temperature. Phosphatidyl choline and phosphatidyl ethanolamine were the predominant phospholipids isolated and comprised 85% of the total lipid phosphorus. Smaller quantities of phosphatidyl glycerol, phosphatidyl inositol, phosphatidic acid, and phosphatidyl serine were isolated. The fatty acid composition of phosphatidyl choline and phosphatidyl ethanolamine were the same and temperature affected the fatty acid composition of both phospholipids in the same manner.Growth in the presence of the substituted pyridazinone, BASF 13 338 (4-chloro-5-dimethylamino-2-phenyl-3(2H)pyridazinone), reduced the level of linolenic acid and increased the level of linoleic acid in the phosphatidyl choline, phosphatidyl ethanolamine, and total polar lipid fractions. BASF 13 338 did not affect the levels of palmitate, stearate, and oleate or the distribution of phospholipid classes.Respiration rates of wheat root tips were measured over a range of temperatures. The respiration rate declined as the temperature decreased. Neither the temperature at which the tissue was grown nor BASF 13 338 treatment influenced the ability of root tips to respire at any temperature from 4 to 30 C. The results indicated that the relative proportion of linolenic acid to linoleic acid did not influence the plants ability to grow and respire over the range of temperatures tested.     

In vivo incorporation of l-[14C]serine into phospholipids and proteins of the subcellular fractions of developing rat brain

A study was conducted on the in vivo incorporation of l -[¹⁴C]-serine into the lipids and proteins of the various subcellular fractions of the developing rat brain before and during the stage of active myelination. The total radioactivity in the various fractions at 12 days of age was higher than that at 3 days, while the radioactive specific activity was reversed. The specific activities of the proteins and lipids were higher at 3 days of age with the exception of the subcellular fraction containing myelin. At both ages the lipids of the various cellular fractions had similar specific activities, a finding that suggests a common source for lipid biosynthesis. Incorporation of radioactivity into the various phospholipids was in the following order: phosphatidyl serine > phosphatidyl ethanolamine > phosphatidal serine > sphingomyelin and phosphatidyl choline. Of all the phospholipids, the plasmalogens increased most in total radioactivity during the period when meylination was most active. Serine-containing phospholipids appear to be most tightly bound to proteins. The brain mitochrondrial fraction contained most of the phosphatidyl serine decarboxylase activity with some activity in the nuclei. Biosynthesis of phosphatdyil ethanolamine through decarboxylation of phosphatidyl serine could take place in rat brain. Four unidentified radioactive metabolites were found in the acid-soluble fraction in addition to l -[¹⁴C]serine.     

The utilisation of yolk phosphoglycerides by the alligator during embryonic development

Summary A study was made of the concentrations and fatty acid compositions of the major phosphoglycerides in the yolk of the alligator egg on the 8th and 75th days of incubation. The major phosphoglycerides were phosphatidyl choline and phosphatidyl ethanolamine which at the start of incubation accounted for 72 and 18%, respectively, of total phosphoglyceride. Phosphoglycerides were characterised by low levels of linoleic acid but extremely high levels of C20 and C22 polyunsaturates. The extensive absorption of phosphoglyceride over the incubation period was accompanied by a reduction in percentage of phosphoglyceride within the residual yolk lipid, a reduction in the proportion of phosphatidyl choline within the total phosphoglyceride, and increases in the proportions of phosphatidyl ethanolamine and lyso-phosphatidyl choline. There were small but wide-spread changes in the fatty acid composition of the phosphatidyl choline during incubation. Within the phosphatidyl ethanolamine and phosphatidyl serine fractions there were very large reductions in the C20 and C22 polyunsaturated fatty acid levels. The phosphoglyceride changes are discussed with respect to the unique role of yolk lipid absorption in the nutrition of the developing embryo.     

Effect of phospholipids on estrogen receptor of rat uterine cytosol

Phospholipids such as phosphatidyl inositol and phosphatidyl serine inhibit the binding of R5020 and progestin receptors. The effect of phospholipids on the binding of estrogen and estrogen receptors of rat uterine cytosol was studied. Phosphatidyl choline, sphingomyelin, phosphatidyl inositol, phosphatidyl ethanolamine, cardiolipin, and phosphatidic acid inhibited the binding of estradiol and estrogen receptors. This inhibitory effect of phosphatidyl inositol and cardiolipin was dose dependent.     

Phospholipids in the nuclei and chromatin of the rat thymus at long periods following gamma-irradiation

The phospholipid content of the homogenate, nuclei and chromatin of rat thymus was being studied during three months after fractionated gamma-irradiation (2 Gy X 3 at a week interval). The number of phospholipids in the total fraction of phosphatidyl choline + phosphatidyl serine and phosphatidyl ethanolamine in the nuclei and chromatin of rat thymus was shown to decrease 60 min following the last exposure. In a month the phospholipid content in the nuclei and chromatin increased up to the control level keeping it throughout the entire period of observation.     

Lipid and sterol composition of the pollen of the west african oilpalm, Elaeis guineensis

The lipid classes, fatty acid methyl esters and the sterols of oilpalm pollen were analysed. The neutral lipid fraction consisted of triglycerides, esterified and free sterols and trace amounts of hydrocarbons. Monogalactosyl and digalactosyl diglycerides, phosphatidyl choline, phosphatidyl inositol and phosphatidyl ethanolamine represented the polar lipids. The major fatty acids were linoleic, palmitic and linolenic acids together with small to trace amounts of oleic, stearic, arachidic, myristic, lauric, palmitoleic and margaric acids. Unsaturated fatty acids predominated over saturated ones in the ratio of 3:2. The 4-desmethyl sterols were the major phytosterols in the free form but they constituted a lower proportion of the sterols in the esterified state. 28-Isofucosterol was isolated and characterized as the principal sterol.     

Lipids from nerve tissues of the horseshoe crab, Limulus polyphemus.

1. The predominant lipids of nerve cords, ganglion and brain from horseshoe crabs were cholesterol (11% of lipid) and phospholipid (81% of lipid). 2. Major phospholipids were phosphatidyl ethanolamine and phosphatidyl choline with lesser amounts of phosphatidyl serine and phosphatidyl inositol and sphingomyelin. 3. The phospholipid fraction was characterized by a high content of plasmalogen, i.e. alk-1-enyl acyl phosphatides, so that 42% of the ethanolamine phosphatides were the plasmalogen, phosphatidal ethanolamine. 4. Phosphatidyl choline and phosphatidyl ethanolamine were high in polyunsaturation with 20:4 and 20:5 major fatty acids. Sphingomyelin had predominantly long chain saturated fatty acids. 5. Cerebrosides and gangliosides, which are associated with vertebrate nerve tissues, were absent from nerves of horseshoe crabs.     

Ischemia-reperfusion injury in the spinal cord of rabbits strongly enhances lipid peroxidation and modifies phospholipid profiles

The effect of spinal cord ischemia (10, 20, and 40 min) and post-ischemic reperfusion (10, 30, and 60 min) on lipid peroxidation and phospholipids was investigated. Spinal cord ischemia was accompanied by lipolytic processes with significant changes in concentration of lipid peroxidation products (LPP). Reestablishment of the blood supply after 10 min ischemia was accompanied by significantly increased levels of thiobarbituric acid reactive substances (TBA-RS) after 10 and 30 min of reperfusion. Following 20 and 40 min ischemia a significant increase was observed at all reperfusion periods. Ischemia itself significantly reduced the concentration of phosphatidyl inositol (IP), phosphatidyl ethanolamine (EP) and ethanolamine plasmalogens (Epls). Significant changes were observed in concentration of phosphatidyl serine (SP) too, but only after 20 and 40 min of ischemia. The concentration of phosphatidic acid (PA) was significantly reduced only after 10 min of ischemia. The onset of reperfusion after ischemia was accompanied by a diverse pattern of changes in PA, IP, Epls and SP, while the concentration of EP remained at the above mentioned ischemic intervals.     

EFFECTS OF DENERVATION ON THE INCORPORATION OF 32P INTO PHOSPHATIDYL INOSITOL AND OTHER PHOSPHOLIPIDS OF RAT DIAPHRAGM

Abstract— At 24 h after denervation of the rat hemidiaphragm, incorporation of ³²P into phosphatidyl inositol was depressed relative to incorporation of ³²P into phosphatidyl choline (measured 75 min after injection of the isotope intraperitoneally). The ratio of the specific radioactivity of phosphatidyl choline to the specific radioactivity of P_i was unaffected by denervation which implies that denervation had depressed incorporation of isotope into phospatidyl inositol. Denervation did not cause a measurable change in the pool size of phosphatidyl inositol relative to that of phosphatidyl choline. The effect of denervation on incorporation of ³²P into phosphatidyl inositol was not entirely a direct consequence of the cessation of ACh release at the motor end-plate since the effect was clearly manifest in strips of muscle not containing motor end-plates, but the magnitude of the denervation effect was slightly greater in the strips of denervated hemidiaphragm which contained motor end-plates.     

The effect of gamma irradiation at sub- and supralethal doses on the lipid composition of the mucosa and of the brush border membrane of the small intestine in rats]

A study was made of the amount of cholesterol and its ethers (phosphatidyl choline, phosphatidyl ethanolamine, sphingomyelin, phosphatidyl serine, and phosphatidyl inositol) in mucosa and membrane of the small intestine brush border 24 h after 4 Gy and 2 h after 20 Gy irradiation. No changes in the lipid content of mucosa and membrane of the brush border were noted after 4 Gy irradiation. Exposure to 20 Gy radiation doubled the number of cholesterol ethers and made the number of individual phospholipids and cholesterol increase by nearly 1.5 times. The amount of phosphatidyl serine in the brush border membrane increased by almost 3 times; the concentration of other lipids increased by nearly 1.5 times; cholesterol/phospholipid ratio was unchangeable.     

Phospholipids activate cathepsin D

Total lipids as well as phospholipids extracted from the mitochondrial-lysosomal fraction of porcine adrenal cortex activated the lysosomal cathepsin D of this tissue 30- and 40-fold, respectively, with bovine serum albumin as the substrate. Phosphatidic acid, phosphatidyl ethanolamine, phosphatidyl serine, phosphatidyl inositol, phosphatidyl glycerol and cardiolipin were found to activate greatly the cathepsin D. The degree of activation ranged from 6-fold by phosphatidyl ethanolamine to 40-fold by cardiolipin at 1 mM, respectively. These results strongly point to the importance of phospholipids in intracellular protein degradation by lysosomal cathepsin D.     

Phospholipid composition of oligodendroglial cells during normal development and in 18 day old hyperthyroid and malnourished rats.

The phospholipid composition of isolated oligodendroglial cell perikarya was studied in normal rats during development and in 18 day old malnourished and hyperthyroid rats. Phosphatidyl choline and phosphatidyl ethanolamine were found to be the major phospholipid constituents of oligodendroglial cells. Phospholipid content increased during development, mainly due to an increase of the above mentioned phospholipids. The major changes were observed in sphingomyelin, phosphatidyl serine, phosphatidyl inositol and phosphatidyl ethanolamine between 18 and 30 days of age. The phospholipid and protein content per cell was significantly decreased in the oligodendroglial cells isolated from malnourished rats as compared to controls. When data were expressed as a function of total proteins, the composition was similar to that of normal animals. In the hyperthyroid rats on the other hand, there were no changes in the amount of phospholipids per cell, while phospholipids per milligram of total oligodendroglial cell protein were markedly decreased. The changes in myelin composition produced by hyperthyroidism that we have previously described, do not follow closely those produced by this experimental condition in oligodendroglial cells, suggesting that the metabolism of myelin might be to a certain extent, independent of that in the parent cell.     

Serum of normal subjects contains IgG with antibody-like specificity for phospholipids

Using counterimmunoelectrophoresis, sera from normal subjects display precipitin activity against liposomes made by phosphatidic acid, phosphatidyl ethanolamine, phosphatidyl serine and cardiolipin. No activity is detected by using liposomes made with phosphatidyl choline, sphingomyelin and phosphatidyl inositol. The same pattern of precipitation is obtained when pure IgG from normal subjects is tested against phospholipids. No precipitin activity is found by using pure IgM. The precipitin reaction is prevented by preincubating liposomes with Fab obtained from normal IgG.     

Effects of prolactin and androgens on seminal vesicular lipids of castrated mature bonnet monkeys Macaca radiata

Effects of prolactin (PRL), bromocriptine (Br), testosterone propionate (TP), dihydrotestosterone (DHT) and the combination of these androgens with PRL/Br on the total lipid, total cholesterol, total glyceride glycerols, total phospholipid and their fractions in seminal vesicles of castrated mature monkeys were studied. Glyceride glycerols formed the major portion (50%) of total lipids in normal monkeys. Cholesterol and phospholipids were of equal share (25%). Esterified cholesterol formed major share (75%) of total cholesterol. Diacyl glycerol was the major (60%) glyceride glycerol and phosphatidyl choline and ethanolamine were the major phospholipid classes. Except triacyl glycerol castration markedly decreased all the lipid classes. PRL restored normal free and esterified cholesterol and phosphatidyl inositol but Br invariably decreased all the lipid classes. TP/DHT treatment stimulated the free and esterified cholesterol more than the control; it restored the normal glyceride glycerols. Phosphatidyl inositol, choline and ethanolamine were stimulated by androgens and other phospholipid classes were brought to normal. Addition of PRL + TP/DHT markedly increased esterified cholesterol, phosphatidyl inositol, choline, ethanolamine and phosphatidic acid. In all these aspects, Br counteracted the effects of androgens and PRL.     

Composition and fatty acid content of rat ventral prostate phospholipids

The major phospholipids of rat ventral prostate have been separated and examined using thin-layer chromatography, gas chromatography and mass spectrometry. The main phospholipid classes were choline and ethanolamine glycerophospholipids, accounting for 77.9% of total lipid phosphorus. The prostate also contained small amounts of serine glycerophospholipids and sphingomyelin. The relative proportions of fatty acids in the different phospholipid classes were also determined. Arachidonic acid in prostatic phospholipids is contributed primarily by ethanolamine glycerophospholipids. This fraction contained 65-69 mol% plasmalogens, whereas choline and serine glycerophospholipid fractions contained less than 5 mol% plasmalogens. Ethanolamine, choline and serine plasmalogens contained mainly vinyl ethers of palmitic and stearic aldehydes. Ethanolamine plasmalogens also contained the vinyl ether of oleic aldehyde.     

Changes in lipid peroxidation, superoxide dismutase activity, ascorbic acid and phospholipid content in liver of freshwater catfish Heteropneustes fossilis exposed to elevated temperature

1. 1. Lipid peroxidation, superoxide dismutase (SOD) activity, ascorbic acid (AsA) and individual phospholipid contents in liver of fresh water cat fish Heteropneustes fossilis were measured after exposure to different temperatures (25, 27, 32, 37°C) at various times (1–4 h).

2. 2. Lipid peroxidation and superoxide dismutase activity were significantly increased with increases in temperature at various times.

3. 3. Ascorbic acid content was depleted when temperature was increased.

4. 4. After temperature exposure, phosphatidyl inositol was increased while phosphatidyl choline, phosphatidyl serine and phosphatidyl ethanolamine were depleted. Phosphatidic acid level did not change.

5. 5. The findings indicated an increased oxidative stress in liver following increases in temperature at various times. Concurrent with the increase in lipid peroxidation, superoxide dismutase activity and ascorbic acid from the liver of fish varied. It is suggested that depletion of major individual phospholipids following temperature exposure could be due to superoxide created oxidative stress in the liver.

     

Effect of lipid composition changes on carbocyanine dye fluorescent response

Egg yolk phosphatidyl choline liposomes containing variable amounts of phosphatidyl ethanolamine, phosphatidyl inositol or phosphatidyl serine demonstrated important variations in the fluorescence of 3.3' dipropylthiodicarbocyanine. When the membrane contained no cholesterol, fluorescence was not correlated with membrane fluidity as measured by diphenyl hexatriene polarization. Increasing cholesterol concentration in valinomycin containing liposome membranes decreased the potassium induced apparent membrane potential and prevented sorption of dye to the membrane. Discontinuity in the apparent potential occurred at 30 mol% cholesterol but could not be correlated with changes in microviscosity. These results indicate that great care should be taken when correlating rapid variations of fluorescence to changes in membrane potential. We propose that changes in phospholipid metabolism could well explain fluorescent changes when monitoring the fluorescence of cyanine dye molecules sorbed to biological membranes.