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PubMed2000

Effect of triiodothyronine on the content of phospholipids in the rat liver nuclei.

The aim of the present study was to examine the effect of triiodothyronine (T3) on the content of phospholipids and on the incorporation of blood-borne palmitic acid into the phospholipid moieties in the nuclei of the rat liver. T3 was administered daily for 7 days, 10 microg x 100 g(-1). The control rats were treated with saline. Each rat received 14C-palmitic acid, intravenously suspended in serum. 30 min after administration of the label, samples of the liver were taken. The nuclei were isolated in sucrose gradient. Phospholipids were extracted from the nuclei fraction and from the liver homogenate. They were separated into the following fractions: sphingomyelin, phosphatidylcholine, phosphatidylserine, phosphatidylinositol, phosphatidylethanolamine and cardiolipin. The content and radioactivity of each fraction was measured. It was found that treatment with T3 reduced the content of phosphatidylinositol and increased the content of cardiolipin in the nuclear fraction. In the liver homogenate, the content of phosphatidylinositol decreased and the content of phosphatidylethanolamine and cardiolipin increased after treatment with T3. The total content of phospholipids after treatment with T3 remained unchanged, both in the nuclear fraction and in the liver homogenate. T3 reduced the specific activity of phosphatidylcholine, phosphatidylserine, phosphatidylethanolamine and cardiolipin and had no effect on the specific activity of sphingomyelin and phosphatidylinositol both in the fraction of the nuclei and the liver homogenate. It is concluded that excess of triiodothyronine affects the content of phospholipids in the nuclei. The changes in the content of phospholipids in the nuclei largely reflect changes in their content in the liver.

Animals↗
PubMedDate not supplied

Sythesis and turnover of phospholipids in Escherichia coli cells with inhibited DNA synthesis.

The relative amounts of individual phospholipids are not greatly affected in E. coli B cells inhibited with mitomycin C, nalidixic acid or hydroxyurea. Turnover and synthesis of phospholipids continue in the first 40 minute period of treatment with nalidixic acid and then cease. Arrest of phospholipid synthesis is not coupled with protein synthesis since beta-galactosidase is still induced after cessation of phospholipid metabolism. The cells, washed free of drug, resume growth as well as synthesis and turnover of phospholipids. During the lag phase preceding the renewal of cell division, a decrease in phosphatidylglycerol content and an increase in cardiolipin content are observed. The ratio of these phospholipids is then comparable with that found in normal non-dividing cells. We suggest that the variation in the relative contents of cardiolipin and phosphatidylglycerol might be related to the cell division process.

Bacterial Proteins↗
PubMed2001

Efficacy and safety of phospholipid liposomes in the treatment of neuropsychological disorders associated with the menopause: a double-blind, randomised, placebo-controlled study.

A double-blind, randomised, placebo-controlled clinical trial was performed to evaluate the efficacy and safety of phospholipid liposomes (Liposom Forte) administered parenterally in the treatment of anxiety and depression linked to the menopause. A total of 64 females aged 40-60 years were randomised to receive the active drug or placebo intramuscularly; 58 patients completed the study. Treatment lasted 60 consecutive days. One i.m. administration of 2 ml active drug or placebo every other day was carried out. Efficacy was evaluated by the Hamilton Anxiety Scale (HAMA) and the Climacteric Index. An intention-to-treat analysis was performed, defined as all patients administered with at least one dose of the study medications with at least one return visit. A highly significant (p < 0.001) decrease in HAMA total score in both groups was noted. However, the decline in the HAMA score was significantly greater in patients administered phospholipid liposomes after 40 days (p = 0.006), 60 days of treatment (p < 0.001) and at the last follow-up visit (p < 0.001). Also, there were statistically significant differences between treatment groups after 60 days of therapy for individual items, such as anxious mood (p = 0.006), tension (p = 0.024) and fear (p = 0.009), with significantly less patients experiencing these symptoms in the phospholipid liposomes-treated group. When the Climacteric Index was evaluated, a highly significant (p < 0.001) decrease in the total score in both groups was noted. However, the decline was significantly greater in patients administered phospholipid liposomes after 40 days of treatment (p = 0.017), 60 days of treatment (p = 0.0013) and at the last follow-up visit (p = 0.0012). Significant differences between treatment groups were recorded after 60 days in asthenia (p = 0.05), dizziness (p = 0.024) and restlessness (p = 0.019) in favour of the active treatment. Twelve patients reported at least one adverse event, nine in the phospholipid liposomes group and three in the placebo group (p = 0.062). The most commonly reported event was drowsiness with two reports in each group. These findings further demonstrate that phospholipid liposomes administered intramuscularly are active against mild anxiety and depressive symptoms in menopausal women.

Adult↗
PubMed1975

[Phospholipids and thromboplastins in various sections of the brain normally and in excitation states].

The level of the neutral and acid phospholipids and thromboplastic activity of various portions of the rabbit brain were studied under normal conditions and following adrenaline stimulation. The level of total phospholipids, neutral phospholipids, and the ratio of neutral to acid phospholipids, thromboplastic activity and its increase following incubation of homogenates of the brain tissue of normal and adrenaline-treated animals were found to be distributed in the following descending order: the medulla oblongata, cerebellum, cerebral hemispheres. Adrenaline decreased the thromboplastic activity and induced changes in the neutral and acid phospholipid levels. The role of phospholipids in the biosynthesis of various components of the blood clotting and anticoagulant systems are discussed.

Animals↗
PubMedDate not supplied

Fromation and stoichiometry of a lysozyme-phospholipid-mitochondrial protein ternary complex.

Mitochondrial membranes reconstituted from lipid-depleted mitochondria and aqueous phospholipid dispersions still have the phospholipid negative charges available for ionic interaction with the basic protein, lysozyme. The stoichiometry of the binding is of about 6 nmoles of lysozyme per 100 nmoles of phospholipid in membranes reconstituted with Asolectin, and of 10 nmoles of phospholipid phosphorus in membranes reconstituted with cardiolipin. Unextracted submitochondrial particles ETP also bind lysozyme (about 3 nmoles per 100 nmoles of phospholipid). These observations indicate that the phospholipid anionic groups are not completely shielded by the mitochondrial proteins, which might occupy areas between the nonpolar groups of the lipid molecules.

Animals↗
PubMed1975

Effect of denervation on the phospholipid content in subcellular fractions of tonic and tetanic muscles.

Four weeks after denervation, various changes were observed in the phospholipid composition of the sarcolemmal and sarcoplasmic fractions of skeletal muscles with different functions. Neurotomy also affected the innervated contralateral muscles and produced opposite changes in the phospholipid content of subcellular fractions. The increase in the amount of phospholipids in the sarcolemmal fractions of the denervated muscles was only apparent. The difference between the denervated and contralateral muscles was also due to the decrease of phospholipids in the contralateral muscles. These changes were more pronounced in the tetanic (fast-twitch) than in the tonic (slow-twitch) muscles. In the sarcoplasmic fraction of the denervated tetanic muscle an increase, while in that of the tonic one a slight decrease of phospholipids appeared. In contrast, the phospholipid content in the sarcoplasmic fractions of contralateral muscles did not decrease, while it increased slightly in the tonic muscle. The amount of plasmalogens (fatty aldehyde: lipid phosphorus ratio) decreased only in the subcellular fractions of the denervated muscles while there was no change in those of the contralateral muscles.

Aldehydes↗
PubMed2002

Analysis of phospholipids from Coxiella burnetii by fast atom bombardment mass spectrometry. A rapid method for differentiation of virulent phase I and low virulent phase II cells.

Phospholipids extracted from the Coxiella burnetii strain Nine Mile virulent phase I and low-virulent phase II cells were directly analyzed by fast atom bombardment mass spectrometry (FAB-MS). Constant neutral loss (CNL) scanning mass spectra (MS) were acquired to identify various phospholipids within phospholipid classes. Phospholipids from the phase I C. burnetii cells were much more complex than those from the phase II cells. Moreover, in the latter, the absence of phospholipids of the phosphatidylinositol class could be noticed. The results indicate that CNL scanning of phospholipid samples provides a rapid and simple method for identification of the phase state of the bacterium.

Coxiella burnetii↗
PubMed2000

[Determination of residual acetone in soybean phospholipids by headspace gas chromatography].

Soybean phospholipids have many functions and alimentary actions. In our country, powder soybean phospholipids are generally got by extraction with acetone, followed by vacuum drying. There may be some residual acetone present in the soybean phospholipids, which is harmful to health. So, we must know residual acetone content in the soybean phospholipids. However we have not found a method to determine the residual acetone in the soybean phospholipids. In this paper, headspace GC was used to determine residual acetone in powder soybean phospholipids. The headspace bottle was glass with a volume of 15 milliliters. Certain amounts of water, ammonium sulfate, and sample were added into the bottle. The mixture was made into a brei as soon as possible. The bottle was put into a water bath at 40 degrees C for an hour. The GC column was a 2 m x 3 mm i.d. stainless steel tube packed with GDX-103 stationary phase. Temperatures of both injector and detector were kept at 120 degrees C. Column temperature was 160 degrees C. Injection volume was 1 mL. External standard method was used for quantitation. The RSD was 1.2%. The recoveries in the range of 25.0 micrograms/g-100 micrograms/g were 98.4%-104%.

Acetone↗
PubMed2003

NMDA receptor overactivation inhibits phospholipid synthesis by decreasing choline-ethanolamine phosphotransferase activity.

Overactivation of NMDA receptors is believed to induce neuronal death by increasing phospholipid hydrolysis and subsequent degradation. We showed previously that NMDA releases choline and inhibits incorporation of [3H]choline into phosphatidylcholine before excitotoxic neuronal death. On the basis of these results, we hypothesized that excitotoxicity results from inhibition of synthesis rather than from increased degradation of phospholipids. We now investigated the effect of NMDA receptor overactivation on synthesis and degradation of major membrane phospholipids in the early stages of the excitotoxic process. Exposure of cortical neurons to neurotoxic concentrations of NMDA increased extracellular choline and activated hydrolysis of phosphatidylcholine and phosphatidylinositol by phospholipase A2 but did not induce significant degradation of phosphatidylcholine, phosphatidylinositol, phosphatidylethanolamine, or phosphatidylserine. In contrast, NMDA strongly reduced the incorporation of [3H]choline and [3H]ethanolamine into their respective phospholipids. Metabolic labeling experiments in whole cells showed that NMDA receptor overactivation does not modify the activity of phosphocholine or phosphoethanolamine cytidylyltransferases but strongly inhibits choline-ethanolamine phosphotransferase activity. This effect was observed well before any significant membrane damage and cell death. Moreover, cholinephosphotransferase activity was lower in microsomes from NMDA-treated cells. These results show that membrane damage by NMDA is preceded by inhibition of phospholipid synthesis and not by phospholipid degradation in the early stages of the excitotoxic process, and that NMDA receptor overactivation decreases phosphatidylcholine and phosphatidylethanolamine synthesis by inhibiting choline-ethanolaminophosphotransferase activity.

Animals↗
PubMed2003

The influence of phytohormones on the properties of wheat phospholipid monolayers at the water-air interface.

The surface behaviour of monolayers of wheat phospholipids in the presence of phytohormones introduced into the water phase was studied using Langmuir's method. The phospholipids were extracted from the plasmalemma of non-embryogenic (NE) and embryogenic (E) calli initiated from two types of explant: immature inflorescences (inf) and embryos (emb). The surface properties were investigated in model systems of monolayers of mixed phospholipids with: 1) natural amphiphile composition (PL); 2) a determined hydrophobic part (16:0) and the natural percentage composition of the hydrophilic part (PPL); and 3) a determined hydrophilic part (PC) and the natural percentage composition of the hydrophobic part (HPL). The lower limit values of the molecular area (A(lim)) were observed for NE rather than for E monolayers in all the investigated systems (PL, PPL and HPL). The collapse pressure (pi(coll)) of the monolayer decreased in the order PPL>PL>HPL, indicating the high stability of monolayers containing saturated hydrocarbon chains. The injection of non-surface-active phytohormones into the water subphase and the subsequent formation of natural and also artificial phospholipid monolayers of E and NE causes a decrease in monolayer stability against collapse and molecular close packing. As a result of their amphipathic (hydrophilic-hydrophobic) structure, the surface properties of E phospholipids are probably optimal for these systems. The decreasing stability of the NE monolayer caused by the presence of the phytohormone seems to be advantageous in terms of membrane preparation for the differentiation process. All the investigated lipid monolayers (highly) stimulated the adsorption of indole-3-acetic acid (to the highest extent/degree) (among the examined phytohormones) from the subphase. Zearalenone had a significant influence on the surface properties of NE PPL and NE HPL monolayers. This may be connected with the ability of this phytohormone to affect the non-embryogenic structure of wheat. An anomalous temperature effect was observed in the presence of indole-3-acetic acid (IAA) in the bulk; phospholipid monolayers of embryogenic calli induced from embryos (E emb) when the temperature decreased from 25 to 15 degrees C. This phenomenon is ascribed to the dehydration of the polar groups in the monolayer

Cells, Cultured↗
PubMed2003

[Effects of soybean phospholipid on the content of malondialdehyde and lipofuscin in heart, liver and spleen in mice].

In order to observe the effects of soybean phospholipids on the SOD activity in liver and the content of malondialdehyde and lipofuscin in heart, liver and spleen in mice, forty male mice were divided into 4 groups. Experimental mice were fed with different doses of soybean phospholipids (2.5, 5 and 10 g/kg BW) and the control mice were fed with normal saline by tube feeding for 18 days. After that, the SOD activity in liver and the content of malondialdehyde and lipofuscin in heart, liver and spleen were measured. The results showed that the three doses of soybean phospholipid could significantly increased the SOD activity of liver (P < 0.05), and also could remarkably decrease the malondialdehyde content of in heart(P < 0.01) and in liver (P < 0.05). The soybean phospholipid at dose of 2.5 g/kg BW could significantly decrease the malondialdehyde content of in spleen(P < 0.05). But the three doses of soybean phospholipid did not obviously affect the content of lipofusin in liver, heart and spleen. The study indicated that the soybean phospholipid was effective on the inhibition of lipid peroxide.

Animals↗
PubMed2004

Abnormalities in the fatty-acid composition of the serum phospholipids of stroke patients.

The incidence of cardiovascular diseases, stroke, and myocardial infarction is increasing in sub-Saharan Africa. Since dietary polyunsaturated fatty acids (PUFA) are protective of the cardiovascular system in humans, we were interested in the question of the PUFA status of adults in northern Nigeria who had experienced a recent stroke. We collected blood from 21 consecutive admissions for stroke (15 male patients, mean age 39.3 years and six females, mean age 40.7 years) to the Federal Medical Centre in Gombe, Nigeria and analyzed the fatty-acid composition of the serum phospholipids. Blood was collected from 30 healthy controls for comparison. The contribution palmitic acid made to the fatty-acid total was greatly decreased in the phospholipids of the stroke patients (29.2% versus 37.2 %, p < 0.001). However, the phospholipids of the stroke patients had significantly higher percentages of 20-, 22-, and 24-carbon saturated fatty acids, as well as higher proportions of the omega-6 fatty-acid, arachidonic acid (11.4 versus 8.14%, p < 0.001), and the omega-3 fatty-acid, docosahexaenoic acid (3.21 versus 1.80%, p < 0.001). Using the percentages and melting points of the individual fatty acids, we estimated that the acyl chains of the serum phospholipids of the stroke patients had a lower mean melting point than the controls (27.8 versus 34.6 degrees C, p < 0.001). Assuming that serum phospholipids are surrogates for tissue phospholipids, we conclude that the tissue membranes of the stroke patients may be considerably more fluid than those of the controls.

Adult↗
PubMed2004

Secretion of gastric mucus phospholipids in response to beta-adrenergic G protein-coupled receptor activation is mediated by SRC kinase-dependent epidermal growth factor receptor transactivation.

Recent advances in understanding the nature of cellular responses mediated by G protein-coupled receptor (GPCR) activation indicate that integration of the converging regulatory signals into functional cellular pathways requires epidermal growth factor receptor (EGFR) transactivation. In this study, we report that G protein-coupled beta-adrenergic receptor activation leading to stimulation in gastric mucus phospholipid secretion occurs with the involvement of EGFR. Using [14C]choline-labeled gastric mucosal cells in culture, we show that stimulatory effect of beta-adrenergic agonist, isoproterenol, on phospholipid release was subject to a dose-dependent suppression by EGFR kinase inhibitor, PD153035, as well as wortmannin, a specific inhibitor of PI3K. Both inhibitors, moreover, caused the reduction in the gastric mucosal cell phospholipid secretory responses to beta-adrenergic agonist-generated second messenger, cAMP as well as adenyl cyclase activator, forskolin. The gastric mucosal phospholipid secretory responses to isoproterenol, furthermore, were inhibited by PP2, a selective inhibitor of tyrosine kinase Src responsible for ligand-independent EGFR phosphorylation, but not by ERK inhibitor, PD98059. The inhibition of ERK, moreover, did not cause attenuation in phospholipid secretory responses to cAMP and forskolin. The findings underline the central role of EGFR in mediation of gastric mucosal secretory processes, and demonstrate the requirement for Src kinase-dependent EGFR transactivation in regulation of gastric mucosal phospholipid secretion in response to beta-adrenergic GPCR activation.

Adrenergic beta-Agonists↗
PubMed2004

[Immunomodulating activity of polyunsaturated phospholipids and regulators of energy metabolism in toxic anemia].

Possible potentiation of the immunomodulating effects of carbohydrate and lipid metabolism regulators by their use in combination with polyunsaturated phospholipids was studied. The polyunsaturated phospholipids in toxic anemia icreased the immunomodulating effects of thiamine and inosine which activated glucose catabolism in erythrocytes. The combined use of the polyunsaturated phospholipids and thiamine normalized the oxidation--energy status and lowered manifestation of the immunosuppressing properties of light erythrocytes in laboratory rats exposed to hemolytic poison. The use of the combination of the polyunsaturated phospholipids and inosine normalized the oxidation--energy status and induced manifestation of the immunomodulating properties in heavy erythrocytes of the poisoned rats. The globulin fraction of the rat serum containing antibodies to erythrocytes of the poisoned rats exposed to the polyunsaturated phospholipids and inosine increased the immunity status of the poisoned rats treated with the above mentioned agents. Carnitine and biotin in combination with the polyunsatured phospholipids showed no effect on the phagocytic and metabolic activity of leukocytes and the immunity status of the rats exposed to hemolytic poison.

Anemia, Hemolytic↗
PubMedDate not supplied

[Biological effects of the soybean phospholipids].

Soyabean phospholipids, particularly commercial lecithin, are now widely used as biological active food additives. Mechanisms of their activities are based mainly on their similarity with ow phospholipids of biomembranes and blood lipoproteins. The similarity allows the inclusion of plant phospholipids into these structures and promotes prevention of number of pathological processes. Soybean phospholipids have a wide range of biochemical and physical effects. Lecithin complex is the source of easily accessible linoleic acid, choline and inositol. Lecithin plays a notable role as synergist for antioxidants also. The proven health benefits which can be achieved by taking soybean phospholipids include lipid-lowering; control of blood levels of cholesterol and triglyceride, stabilisation of the membrane functions, supporting the hepatic functions. Structure, some physico-chemical properties and metabolism of phospholipids, and molecular mechanisms of their prophylactic effects are briefly reviewed.

Cholesterol↗
PubMed1992

[Effect of vasopressin on phospholipid metabolism in cultured rat mesangial cells].

Aqueous solutions containing extracts of cultured rat mesangial cells treated with and without arginine vasopressin (AVP) were measured by phosphorus-31 nuclear magnetic resonance spectroscopy (31P-NMR). Ratios of the NMR signal intensities of phospholipids in the solutions were calculated with the areas of those resonance lines. Furthermore, prostaglandin E2 (PGE2) production and incorporation of 3H-methyl group into phospholipids in mesangial cells were observed in the presence and in the absence of AVP. We examined the role of AVP in the phospholipid metabolism of mesangial cells by the results from these three kinds of experiments. Ratios of (phosphorylcholine + glycerophosphorylcholine)/(phosphorylethanolamine + glycerophosphorylethanolamine), (PC + GPC)/(PE + GPE), and PC/PE increased significantly 5 min after AVP administration. Ratios of (GPE + GPC)/(PE + PC) and GPE/PE also increased significantly 30 min and 60 min after administration of AVP. The production of PGE2 increased with AVP treatment. This increment was inhibited with mepacrine and Adenosyl-S-isobutyl mercaptan (SIBA). Incorporation of 3H-methyl group into cellular phospholipids was accelerated with AVP, and then the resolution of methylated phospholipids and the release of PGE2 increased. These findings indicate that phospholipid methylation may be accelerated with AVP treatment and phosphatidylcholine, synthesized by transmethylation pathway, may be important as the substrate for PGE2 production in mesangial cells.

Animals↗
PubMed1991

Patterns of anti-phospholipid antibody specificities.

To determine the importance of assaying for anti-phospholipid (PL) antibodies other than anti-cardiolipin antibodies in patients with putative anti-phospholipid antibody syndrome (APA), 1,513 serum samples from over 399 patients with the potential for thromboembolic disease were tested for IgM, IgG or IgA class antibodies to the following phospholipids: cardiolipin, phosphatidylserine, phosphatidylinositol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidic acid. Non-specific binding was subtracted from total binding of antibodies to each PL to eliminate false positive ELISA results. Only patients whose sera contained antibody levels which were greater than three standard deviations above the means were considered positive. Patients who were positive for anti-PL antibody had antibodies to at least one of six phospholipids tested. Approximately 60% of the positive samples contained antibodies to a phospholipid other than cardiolipin. For IgG class, antibodies to phosphatidylserine were the most prevalent followed by antibodies to phosphatidylethanolamine and cardiolipin. These findings indicate that anti-phospholipid antibody analysis should be performed for more than anti-cardiolipin antibody to detect patients with APA.

Abortion, Habitual↗
PubMed1991

Human crystalline lens phospholipid analysis with age.

Paired human crystalline lenses (n = 21, patient ages 20-79 years) were extracted for lipids with chloroform-methanol 2:1, using the Folch method. The extracted crude lipids were analyzed at 202.4 MHz by phosphorus-31 magnetic resonance spectroscopy (31P NMR). Fourteen membrane phospholipids were detected including phosphatidylcholine (PC), lysophosphatidylcholine (LPC), phosphatidylcholine plasmalogen (PC plas), phosphatidylethanolamine (PE), phosphatidylethanolamine plasmalogen, lysophosphatidylethanolamine (PA), phosphatidylglycerol (PG), lysophosphatidylglycerol, phosphatidylserine (PS), phosphatidic acid, phosphatidylinositol, sphingomyelin (SPH), and two uncharacterized phospholipids. The uncharacterized phospholipid at 0.13 was the predominant phospholipid, comprising 43.20% of the lens phospholipid profile. A decrease in mole percent of phosphorus concentrations of PE, PC plas, and PC and an increase in SPH correlated with age. The following computed indices decreased with age: PC/PG and PE/PS; PC + PE; (PC + PC plas); and PC/PS. The following computed indices increased with age: (PC + SPH)/(PE + PS), SPH/PG, (PC + SPH)/(PE + PS), LPC/PC, LPE/PE, SPH/PE, and SPH/PC. Changes in membrane phospholipids of the crystalline lens with age as detected by 31P NMR can be used to fingerprint lens maturation.

Adult↗