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PubMed2001

Glucose suppresses the enhancement by free fatty acids on thrombin- stimulated production of prostacyclin in cultured aortic endothelial cells.

BACKGROUND: Prostacyclin (PGI2) is a potent vasodilator and inhibitor of platelet aggregation. It may reduce in diabetic patients to contribute to the platelet hyperaggregability and acceleration of atherosclerosis. While the major clinical manifestation of diabetes mellitus is increased blood levels of glucose, elevation of free fatty acids (FFA) levels in the circulation has also been reported. METHODS: Cultured rat aortic endothelial cells were treated with media containing high concentration of FFA (oleic acid 0.5 mM, palmitic acid 0.25 mM, linoleic acid 0.25 mM, stearic acid 0.06 mM, arachidonic acid 0.04 mM, total 1.1 mM, and the molar ratio of FFA/albumin < 2), glucose (22 mM) or both. Then the PGI2 release was studied by measuring 6-keto-PGF1alpha in the media. RESULTS: We found that high concentration of FFA increased the PGI2 production at basal (1.227 +/- 0.031 vs 0.762 +/- 0.028 ng/mg protein, n = 6, p = 0.002) and when stimulated by 0.5 unit/ml of thrombin (2.708 +/- 0.115 vs 1.337 +/- 0.225 ng/mg protein, n = 6, p = 0.002). Two-day treatment with high-glucose did not affect PGI2 production. However, in the presence of high-glucose, the enhancement by high FFA of thrombin stimulated PGI2 production disappeared (high-glucose 1.461 +/- 0.312 ng/mg, normal-glucose 2.708 +/- 0.115 ng/mg, n = 6, p = 0.002). CONCLUSIONS: The interaction between glucose and FFA can reduce PGI2 production in thrombin-stimulated state. Our findings further support their role in the pathogenesis of platelet hyperaggregability and acceleration of atherosclerosis in diabetes.

Animals↗
PubMed2001

[Effect of various substrate nutrient on the spore germination and infective germ tube inducing of Pandora delphacis].

The influence of nutrients on spore germmination of P. delphacis was investigated using amino acids, fatty acids, carbohydrates, vitamins, minerals, and extracts of aphids or planthoppers. It was found that the formation of germ tubes from primary conidia was significantly stimulated by cysteine, asparagine, behenic acid (C22:0), trehalose, fructose, glycerol, maltose, ascorbic acid, thiamine(VB1), Folic acid, ZnSO4, FeSO4 and extracts of aphids and planthoppers. Of these many could suppress the formation of secondary conidia from primary conidia, e.g., cysteine, behenic acid (C22:0), myristic acid (C14:0), palmitic acid (C16:0), stearic acid (C18:0), arachidic acid (C20:0), lignoceric acid (C24:0), ascorbic acid, thiamine (VB1), riboflavin (VB2), folic acid, nicotinic acid, ZnSO4, and FeSO4. However, the nutrients not conducive to the formation of germ tubes were stimulants to the formation of secondary conidia. These included tyrosine, alanine, glucose, galactose, sucrose, glycogen, inositol, pyridoxal (VB6), NaCl, and KCl. Moreover, nutrients including asparagine, trehalose, glycerol, maltose, fructose, thiamine (VB1), and folic acid stimulated the formation of both germ tubes and secondary conidia. The result above indicated that the substrate nutrients which can stimulate the formation of germ tubes were general in planthoppers and aphids, it means the formation of aggressive germ tubes was one of important factors of successful for infection to the hosts. Of which it confirmed that the host specificity for P. delphacis against N. lungus and M. persicae.

Amino Acids↗
PubMed1999

[Analysis of physicochemical property and composition of fatty acid of almond oil].

Almond oil was extracted from almond and saponified with saturated KOH-methanol. The mixed fatty acids methylated by methanol-H2SO4(4:1, V/V). Methyl esters were extracted by ether and detected by gas chromatography. The major fatty acids in Taiyuan almond oil were found to be about 68% oleic acid (C18:1), 25% linoleic acid(C18:2), 4.6%-4.8% palmitic acid(C16:0) and a little of palmitoleic acid(C16:1), stearic acid(C18:0). A trace of arachidic acid(C20:0) was also found.

Chromatography, Gas↗
PubMedDate not supplied

Polyunsaturated fatty acids induce cell death in YAC-1 lymphoma by a caspase-3-independent mechanism.

BACKGROUND: The involvement of certain fatty acids in the induction of apoptosis has been established recently. In fact, considerable attention has been given in the past few years to the participation of polyunsaturated fatty acids as substances capable of modulating tumor cell growth. MATERIALS AND METHODS: Fatty acids such as eicosapentaenoic acid (EPA), linolenic acid (LNA), arachidonic acid (AA), linoleic acid (LA), oleic acid (OA) or stearic acid (SA) were added to YAC-1 tumor cells. RESULTS: Incubation of cells with fatty acids revealed a loss of cell viability in a dose-dependent manner. Quantification of DNA fragmentation showed a significant increase particularly in cells treated in the presence of LA, whereas the accumulation of triacylglycerols in the form of cytoplasmic lipid droplets was significantly enhanced in cells cultured with EPA, LNA or AA. The production of reactive oxygen species (ROS) was substantially increased after cell incubation. Nevertheless, the analysis of caspase-3 activity indicated a relevant increase in cells cultured in the presence of LA, OA or SA, but not in cells cultured with EPA, LNA or AA. CONCLUSION: On the basis of these results, we can speculate that long-chain polyunsaturated fatty acids such as EPA and AA as well as LNA induce cell death in YAC-1 lymphoma by an independent mechanism of caspase-3 activation.

Animals↗
PubMed1989

Accumulation of ceramide in ischemic human brain of an acute case of cerebral occlusion.

An increase of ceramide, which is the major component of sphingolipids, was found in the ischemic human brain of an acute case of internal carotid artery occlusion. Amide-linked fatty acids in the ceramide isolated from the ischemic human brain were mostly non-hydroxy fatty acids, such as stearic acid (66.9%) and palmitic acid (20.2%). Other long-chain fatty acids, C24:0 and C21:1, were rare components in the ceramide. The ceramide contained C-20 sphingosine, and the ratio of C-20 to C-18 was 0.13. These findings indicate that an ischemic insult accelerates the degradation of gangliosides and causes an accumulation of ceramide in the ischemic human brain.

Aged↗
PubMed1988

[Effects of bifemelane on the free fatty acid levels during ischemia].

Using the four-vessel extracranial one staged occlusion model of adult Wistar rats, we analyzed quantitatively released free fatty acids during ischemia. Also have we analyzed the effect of bifemelane to reduce free fatty acid accumulation after the onset of ischemia. Bifemelane (15 mg/kg, 30 mg/kg) and saline as control were intraperitoneally administered to adult Wistar rat prior to 30 minutes of experimentally induced ischemia. The results obtained were analyzed by one or two way analysis of variance (ANOVA). Physiological variables (systemic arterial pressure, PaO2, PaCO2, pH) did not change significantly in all four experimental groups. Total free fatty acid levels (sum of 5 fatty acid) increased significantly after ischemia (30 minutes). Higher dose (30 mg/kg) of bifemelane administration significantly reduced total free fatty acid accumulation, though lower dose (15 mg/kg) did have no effect. Bifemelane (30 mg/kg) reduced significant accumulation in the amount of saturated and monounsaturated fatty acid (palmitic acid [16:0], stearic acid [18:0] and oleic acid [18:1]). Arachidonic (20:4) and docosahexaenoic (22:6) acid failed to show any effective reduction by bifemelane pre-treatment of lower nor higher dose. Bifemelane is supposed to have many pharmacological effects such as increase in cerebral blood flow, augmentation of glucose uptake, monoamine metabolism, cerebral vasodilatation and platelet antiaggregation. Free fatty acid accumulation is effectively suppressed by the higher dose of bifemelane administration. Although the exact mechanism are not clearly identified by the result obtained in this experiment, selective inhibition of accumulation in saturated and monounsaturated fatty acids by bifemelane pretreatment may be obtained by the improvement of energy metabolism, which may help to reacylation of fatty acid into phospholipid.

Animals↗
PubMedDate not supplied

The effect of C18 fatty acids on cancer cells in culture.

The influence of the 18 carbon chain length series of fatty acids on the growth of an SP210 mouse myeloma cell line were tested. The saturated fatty acid (C18:0, stearic acid) exhibited no cytotoxic or cytostatic effects, while the unsaturated fatty acids of the omega 9, omega 6, and omega 3 series proved effective in limiting cell growth. Although an overall concentration dependent cytotoxic effect was demonstrated with cis- and trans-mono- and dienoic fatty acids, within a narrow range of concentrations cell growth was stimulated. cis - C18:3 omega 6 and cis-C18:3 omega 3 showed the most dramatic effects, with ID50 values of 15 mg/ml for both, compared to ID50 values of 35 and 40 micrograms/ml with cis- and trans- C18:2 moeities, and ID50 values of 35 and 25 micrograms/ml with cis- and trans - C18:1 compounds, respectively.

Animals↗
PubMed1986

[Fatty acid content of the lipid fraction of the meat from deer and roe deer].

Investigations were carried out on musculus longissimus dorsi as sampled from 8 deer, weighing 90 to 120 kg, and from 10 fallow deer, weighing 25 to 35 kg, hunted in the autumn-winter season of 1983-1984. Fatty acid determination was performed via gas chromatograph Pye Unicam, model 104, supplied with a flame-ionization detector. It was found that the average content of fatty acids in the lipid fraction of m. longissimus dorsi from deer in percent to the total amount of fatty acids was 1.82% for myristic acid, 0.21% for tetradecenic acid, 30.17% for palmitic acid, 1.88% for palmitoleic acid, 19.42% for stearic acid, 43.18% for oleic acid, 3.32% for linoleic acid, while the ratio between saturated and unsaturated fatty acids had a numerical value of 1.06. With fallow deer the average amount of fatty acids in the lipid fraction of m. longissimus dorsi in percent to the total amount of fatty acids these figures were 3.46, 0.59, 30.48, 2.44, 20.15, 40.41, 2.47%, and 1.18, respectively. With both species of animals traces were also found of linolenic and arachidonic acids.

Animals↗
PubMed1986

Phospholipase C activity in palate mesenchyme cells: calcium and pH requirements, substrate specificity, and subcellular localization.

Primary cultures of mouse embryo palate mesenchyme cells were incubated with [3H]arachidonic acid and [14C]stearic acid in order to radiolabel their lipids. The cells were then washed, collected by centrifugation, and homogenized. Incubation of the homogenates under various conditions revealed that deoxycholate inhibited phospholipase A activity and stimulated a phospholipase C activity in these cells which preferentially degraded phosphatidylinositol (PI) compared to phosphatidylcholine (PC), -ethanolamine (PE), and -serine (PS). Expression of this phospholipase C (E.C. 3.1.4.10) activity was dependent on Ca2+ and had a pH optimum of no more than 7.0-7.5. Centrifugation of the homogenates at 105,000g for 30 min produced a membranous fraction that contained phospholipase C activity with characteristics similar to those of the enzyme found in the supernatant. Such a dual distribution of this enzyme may reflect that mouse embryo palate mesenchyme cells are neural crest in origin.

Animals↗
PubMed1985

[Fatty acid content in the lipid fraction of the meat of wild pigs].

The content of fatty acids was studied in the lipid fraction of m. longissimus dorsi of wild swine weighing 70 to 100 kg shot in the autumn-winter season of 1983-1984. A gas chromatography device of the Pye Unicam system, model 104 with a flame-ionization detector was used. It was found that the average content of fatty acids in the lipid fraction of m. longissimus dorsi in terms of percent of the total amount of the fatty acids was 1.57 for myristic acid, 25.78 for palmitic acid, 11.14 for stearic acid, 2.32 for palmitoleic acid, 50.90 for oleic acid, and 8.29 for linoleic acid. Linolenic acid and arachidonic acid were in trace amounts only.

Animals↗
PubMed1984

Cell-free fatty acid acylation of Semliki Forest viral polypeptides with microsomal membranes from eukaryotic cells.

Using [14C]palmitoyl-CoA as donor and deacylated (fatty acid-free) structural proteins of Semliki Forest virus as exogenous acceptors, palmitic acid was incorporated into polypeptide in a cell-free system with microsomes of baby hamster kidney cells, chicken embryo fibroblasts, and rat liver cells. Out of the four viral proteins (E1, E2, E3, and C) only E1 becomes acylated enzymatically. The protein bound fatty acids of the in vitro product are resistant to detergents and to organic extractions but can be released with hydroxylamine thus affording the typical features of acyl-proteins. Fatty acid transfer to E1 requires the presence of microsomes and is abolished when microsomal membranes are omitted or boiled prior to the incubation. Exogenous acceptor protein E1 had to be deacylated prior to the incubation in order to function during acylation in vitro since no fatty acid chains were transferred into untreated viral E1. Acylation of E1 is time- and temperature-dependent and can be stimulated by increasing the concentrations of acceptor protein, microsomal membranes, or of exogenous fatty acid donor. While Mg2+ does not influence the transfer reaction, Mn2+ leads to a dose-dependent inhibition commencing at a concentration of 1 mM. The cell-free acylation activity fails to show high specificity with regard to the chain length or degree of saturation of the acyl chain used as lipid substrate since palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1), and myristic acid (C14:0) are all transferred onto E1 as long as ATP is present in the incubation mixture. The type of detergent and its concentration were found to be critical for this acylation in vitro. Nonidet P-40 or Triton X-100 both up to a 0.2% concentration allowed the reaction while no enzymatic transfer of palmitic acid onto E1 was detected in the presence of octyl-beta-D-glucoside and Tween 20 at the conditions used for the in vitro incubation. However, when acyl transfer onto lipid acceptors was monitored, the incorporation of fatty acids into the neutral- and phospholipids functioned normally in octyl-beta-D-glucoside only, while Nonidet P-40 and Triton X-100 inhibited the acylation of all neutral lipids and of most of the phospholipids completely.(ABSTRACT TRUNCATED AT 400 WORDS)

Acylation↗
PubMed1982

The relative fatty acid composition of serum lecithin in preeclampsia.

Fasting vein blood samples were drawn from 12 women with an early, and from 14 women with a late, onset of preeclampsia and, in addition, from 21 normal pregnant women at comparable gestational length. The relative fatty acid composition of serum lecithin was an analyzed by gas-liquid chromatography. There seemed to be more pronounced fatty acid changes between early and late start of preeclampsia than between severe and mild preeclampsia as defined in terms of maternal symptoms. In the preeclamptic groups, palmitic acid increased and stearic acid decreased as among the normal pregnant women, suggesting a similar amount of lecithin synthesized along pathway. 1. Linoleic acid was reduced in preeclamptic patients as compared to normal pregnant women. This finding seems to be associated partly with the increased incorporation of longer polyunsaturated fatty acids and partly with the increased incorporation of nonessential monoenoic fatty acids. The increased content of longer polyunsaturated fatty acids in serum lecithin might indicate a further reinforcement of the deacylation-reacylation cycle in preeclampsia. Linoleic acid reduction may be associated with intrauterine growth retardation.

Fatty Acids↗
PubMed1980

Fatty acids in hepatic microsomal and mitochondrial phospholipids.

Hepatic microsomal phospholipids of rats showed a high incorporation rats of the precursor palmitic acid (1-[14C]-labelled), in comparison to U-[14C]-glucose and 1-[14C]-glycerol and in contrast to their corresponding mitochondrial fractions. This depends on a predominant occurrence of palmitic acid close to stearic acid in the 1- and 2-position of the glyceride skeleton of phosphatidylcholine and phosphatidylethanolamine, respectively. The reported results provide new approaches to the investigation of drug-induced interactions at the microsomal target on the molecular level, especially to establish sensitive criteria for drug-induced effects.

Animals↗
PubMed1978

An analysis of the fatty acid composition of total lipids from mycoplasmas.

The fatty acid composition of the total lipids obtained from 9 species (22 strains) of Mycoplasma and 3 species (7 strains) of Acholeplasma was determined by gas-liquid chromatography (GLC). The major fatty acids of the Mycoplasma species were palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1), and linoleic acid (C18:2). Lauric acid (C12:0) and myristic acid (C14:0) were present in small amounts in this genus. For the Mycoplasma species, the most prevalent fatty acid was C16:0 or C14:0, and other leading fatty acids were C12:0, C18:0, C18:1 and C18:2. A substantial amount of C12:0 and C14:0 was found in the Acholeplasma species. It was confirmed that C12:0 and C14:0 were synthesized de novo, based on the fact that 14C-acetate was incorporated into these acids. The total percentage of C16 fatty acid was less than that of C18 fatty acids in all the strains of Mycoplasma and Acholeplasma except 4 strains. This may be related to osmo-regulation of the L-forms of Streptococci as mentioned in other reports.

Acholeplasma↗
PubMedDate not supplied

In vitro effects of trapidil on fatty acid and prostaglandin metabolism in platelets.

The effects of trapidil, a coronary vasodilator and platelet aggregation inhibitor, on fatty acid metabolism and prostaglandin (PG) formation in platelets were studied using platelet suspensions from six normal subjects. The addition of trapidil to fatty acids in platelet phospholipids decreased palmitoleic acid and arachidonic acid, and increased an unidentified substance, X2 (palmitoleic acid, P < 0.05; arachidonic acid, P < 0.05; X2, P < 0.05). Thrombin stimulation following the addition of trapidil resulted in an increase in stearic acid and a decrease in arachidonic acid, compared with the trapidil-free control samples (stearic acid, P < 0.05; arachidonic acid, P < 0.02). The addition of trapidil tended to increase immunoreactive PGE (iPGE) and iPGF dose-dependently. On the other hand, thrombin stimulation following the addition of trapidil decreased the formation of thromboxane B2 (TXB2) significantly compared with the levels of TXB2 in the trapidil-free samples (10 micrograms/mL trapidil, P < 0.005, 100 micrograms/mL trapidil, P < 0.001). These results show that trapidil increased arachidonic acid mobilization in the platelets.

Blood Platelets↗
PubMedDate not supplied

[Changes in the fatty acid composition of the phospholipids in the internal organs of rats during the modelling of aconitine arrhythmia].

The changes of phospholipid fatty acid composition of the viscera were investigated in a model of aconitinic arrhythmia in rats by the GC method. Aconitinic arrhythmia leads to a reduction in a proportion of polyenic fatty acids (arachidonic, docosahexaenoic) and to an increase in that of saturated acids (palmitic and stearic acids) in visceral phospholipids as a result of developed respiratory and circulatory hypoxia and to activation of lipid peroxidation. The most hypoxia-sensitive are phospholipids of the heart and brain, the least are renal phospholipids. The ratio of saturated to polyunsaturated fatty acids is the most informative value of lipid peroxidation in aconitinic arrhythmia.

Aconitine↗
PubMedDate not supplied

Response of individual serum free fatty acids to oral and intravenous glucose: relation to adipose tissue composition.

The rate of oral glucose delivery determines whether serum total free fatty acids remain low (glucose sipping over 210 min) or rebound 120-180 min after initial suppression (via glucose bolus), but the response of individual serum free fatty acids to glucose ingestion is largely unknown. In this study, we measured the changes over 240 min in the levels of individual serum free and esterified fatty acids after bolus or sipped glucose ingestion and determined the extent to which the changes are related to abdominal subcutaneous adipose tissue composition. In eight healthy volunteers, 74% of the prolonged suppression of total serum free fatty acids resulting from sipping 50 g glucose over 210 min was caused by a decrease in free linoleic and oleic acids, whereas 92% of the rebound in total free fatty acids 240 min after consuming 50 g of glucose as a bolus was caused by increases in free oleic and linoleic acids. Two hundred forty minutes after the oral glucose, slower intravenous clearance of 5 g glucose was directly correlated to higher total serum free fatty acids and free stearic acid and higher oleic but lower linoleic acid in adipose tissue. We conclude that the net response of serum free fatty acids to an oral glucose load is mediated primarily by oleic and linoleic acids in a manner largely unrelated to adipose tissue composition.

Abdomen↗
PubMed1993

[The effect of oxytocin on production of free fatty acid in primary human uterine myometrial cell culture].

Oxytocin(OT) is considered to have several activities besides strongly inducing myometrial contraction by activating phosphatidilinositol-specific phospholipase C(PI-PLC). These include reconstructing the phospholipid constituents of the cell membrane and activating a variety of fatty acid producing systems. On the other hand, pregnancy-related steroid hormones which are produced by the fetus, placenta and mother are considered to be closely involved in the maintenance of pregnancy and the initiation of labor. In the present study with cultured myometrial cells, we examined what effect these steroid hormones might exert on the intramyometrial production of fatty acid by OT. Our results confirmed bi-phasic production of arachidonic acid(AA), linoleic acid(LA), palmitic acid(PA), and stearic acid(SA) by OT. Phase 1 was an increasing but transient phenomenon having its peak at 30 sec. It is considered to be derived from phosphatidylinositol bis-phosphate. Phase 2 was a persistent and increasing phenomenon which was initiated after 120 sec. It is considered to be mediated by Ca-dependent phospholipase. We also studied the effect of steroid hormones on the production of fatty acid. For AA, LA, and PA, we confirmed that dehydroepiandrosterone sulfate(DHAS) shortened the time taken in reaching the peak of Phase 1 to half of that of the control, and progesterone(P) extended the time 2-3 fold. These findings suggest that DHAS, P and F might modify the human myometrial construction mechanism as a factor which regulates the quantity and velocity of fatty acid production.

Arachidonic Acid↗