The thrombin-dependent enrichment of alkenylacyl ethanolamine phosphoglyceride with [14C]eicosapentaenoic and [3H]arachidonic acids in prelabelled human platelets

1987 ◽  
Vol 65 (4) ◽  
pp. 405-408 ◽  
Author(s):  
B. J. Weaver ◽  
B.J. Holub
Keyword(s):  
Fatty Acids ◽  
Arachidonic Acid ◽  
Human Platelet ◽  
Platelet Reactivity ◽  
Human Subjects ◽  
Human Platelets ◽  
Arachidonic Acids ◽  
Layer Chromatography ◽  
Hydrolysis Of ◽  
Individual Human

The thrombin-dependent enrichment of alkenylacyl ethanolamine phosphoglyceride in [14C]eicosapentaenoic acid ([14C]EPA) was demonstrated and compared with [3H]arachidonic acid ([3H]AA) following the simultaneous prelabelling of individual human platelet phospholipids with these two fatty acids. The alkenylacyl, diacyl, and alkylacyl classes of ethanolamine phosphoglycerides (PE) were separated by thin-layer chromatography as their acetylated derivatives after hydrolysis of the parent phospholipid with phospholipase C. The ratios of [3H]/[14C] for the increased radioactivity appearing in alkenylacyl PE following 60 and 120 s of thrombin stimulation were the same as the corresponding ratio (2.0) found in the choline phosphoglycerides (PC) from control (unstimulated) platelets. These results suggest no significant selectivity between EPA and AA in the thrombin-stimulated transfer of these fatty acids from diacyl PC to alkenylacyl PE. The present findings may possibly bear some relevance to the altered platelet reactivity and (or) decreased thromboxane A2 formation observed in human subjects following the ingestion of marine lipid containing EPA.

The relative degradation of [14C]eicosapentaenoyl and [3H]arachidonoyl species of phosphatidylinositol and phosphatidylcholine in thrombin-stimulated human platelets

1986 ◽  
Vol 64 (12) ◽  
pp. 1256-1261 ◽  
Author(s):  
Bonnie J. Weaver ◽  
Bruce J. Holub
Keyword(s):  
Fatty Acids ◽  
Arachidonic Acid ◽  
Phosphatidic Acid ◽  
Platelet Rich Plasma ◽  
Human Platelets ◽  
The Other ◽  
Preferential Loss ◽  
Marked Selectivity ◽  
The Individual ◽  
Layer Chromatography

The platelet-rich plasma from volunteers who had consumed a supplement containing eicosapentaenoate (EPA) was incubated with [3H]arachidonic acid (AA) and [14C]EPA so as to provide for the labelling of these fatty acids in the individual platelet phospholipids. Washed dual-labelled platelet suspensions were prepared and incubated with and without thrombin in the presence of BW755C and in the presence and absence of trifluoperazine (TFP) or indomethacin. The platelet lipids were extracted and the individual phospholipids, as well as diacylglycerol and phosphatidic acid, were separated by thin-layer chromatography and the radioactivity in each fraction was determined. The [H]AA/[14C]EPA dpm ratio for the loss of radioactivity from phosphatidylcholine (PC) upon thrombin stimulation, as well as that in the residual PC remaining after stimulation, was similar to that in PC in the resting platelets. This suggests no marked selectivity in the degradation of EPA- versus AA-containing species of PC during platelet activation. The [3H]/[14C] ratios for the increased radioactivity appearing in diacylglycerol (DG) and phosphatidic acid (PA) upon thrombin stimulation were not significantly different from the corresponding ratio in phosphatidylinositol (PI) from resting platelets, suggesting little or no preference for 1-acyl-2-eicosapentaenoyl PI over 1-acyl-2-arachidonoyl PI in the pathway from PI to DG to PA. These results suggest that the relative formation of the 2- and 3-series prostaglandins, including thromboxane (Tx) A2 and A3, in stimulated platelets is not regulated by a preferential loss of one of the corresponding eicosanoid precursors over the other from membrane PC and PI.

Release of a 6-Oxoprostaglandin E1-like Substance from Human Platelets

1983 ◽  
Vol 64 (1) ◽  
pp. 63-68 ◽  
Author(s):  
F. J. Lofts ◽  
P. K. Moore
Keyword(s):  
Biological Activity ◽  
Smooth Muscle ◽  
Thin Layer ◽  
Human Platelet ◽  
Platelet Reactivity ◽  
Platelet Rich Plasma ◽  
Human Platelets ◽  
Prostaglandin I2 ◽  
Gastrointestinal Smooth Muscle ◽  
Layer Chromatography

1. Human platelet-rich plasma incubated at 37°C generates an antiaggregatory prostaglandin which is spasmogenic on gastrointestinal smooth muscle. 2. Platelet-rich plasma from female donors generated more biological activity and was more sensitive to the anti-aggregatory activity of added prostaglandin I2 (PGI2) compared with that from age-matched male controls. 3. After thin-layer chromatography of extracted platelet-rich plasma, biological activity was detected in a zone which co-chromatographed with 6-oxoprostaglandin E1. 4. Neither extracted platelet-rich plasma nor authentic 6-oxoprostaglandin E1 were inactivated following incubation with purified 15-hydroxyprostaglandin dehydrogenase. 5. The relevance of these findings for regulating platelet reactivity is discussed.

Lipids of the intestinal mucosa of normal and essential fatty acid deficient rats

1970 ◽  
Vol 48 (9) ◽  
pp. 631-639 ◽  
Author(s):  
M. Yurkowski ◽  
B. L. Walker
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Essential Fatty Acid ◽  
Corn Oil ◽  
Essential Fatty Acids ◽  
Coconut Oil ◽  
Fatty Acid Deficiency ◽  
Arachidonic Acids ◽  
Layer Chromatography

Mucosal lipids were isolated from the proximal, middle, and distal intestinal sections of rats fed diets containing either 10% corn oil or 10% hydrogenated coconut oil, the latter diet being deficient in essential fatty acids. By a combination of column and thin-layer chromatography, the lipids were fractionated and the major components found to consist of triglycerides, free fatty acids, cholesterol, phosphatidylcholine, and phosphatidylethanolamine. Several minor constituents were present. Triglycerides and free fatty acids were generally present in higher concentrations in animals fed corn oil, and the concentration of mucosal triglycerides decreased towards the distal end of the intestine whereas free fatty acids increased in this group. Essential fatty acid deficiency resulted in lower levels of linoleic and arachidonic acids and higher levels of palmitoleic, oleic, and eicosatrienoic acids in the mucosal lipids. Mono- and di-enoic fatty acids tended to decrease in concentration from the proximal to the distal end of the intestine; the polyunsaturated acids and, to some extent, the saturated acids, were lowest in the proximal section of the intestine.

Inhibition Of Platelet Aggregation, Malonyldialdehyde And Thromboxane Formation By Hydroperoxides Of Arachidonic Acid

1981 ◽  
Author(s):  
D Aharonv ◽  
J B Smith ◽  
M J Silver
Keyword(s):  
Arachidonic Acid ◽  
Platelet Aggregation ◽  
Platelet Rich Plasma ◽  
Human Platelets ◽  
Lipoxygenase Pathway ◽  
Dose Dependent Fashion ◽  
Induced Aggregation ◽  
Layer Chromatography ◽  
Dose Dependent ◽  
Thromboxane Formation

The arachidonate hydroperoxides 12-HPETE and 15-HPETE were biosynthesized from arachidonic acid using partially purified human platelet lipoxygenase or soybean lipoxidase respectively, and isolated by thin layer chromatography. Both compounds inhibited the arachidonic acid- induced aggregation of washed human platelets, suspended in calcium-free Krebs Henseleit solution, in a dose dependent fashion at concentrations between 1 and 50 uM. No inhibition was seen with up to 100 uM of these hydroperoxides when platelet -rich plasma was used. 12-HPETE (in micromolar concentrations) inhibited the formation of both thromboxane B2 (radioimmunoassay) and malonyldialdehyde (spectrophotometrie assay) when washed platelets were incubated with arachidonic acid. The 12-hydroxide, 12-HETE also inhibited platelet aggregation and thromboxane formation, but was less potent than 12-HPETE. We suggest that arachidonate hydroperoxide generated in platelets via the lipoxygenase pathway modulates platelet aggregation induced by arachidonic acid by inhibiting thromboxane formation.

scholarly journals Resistance of Biomphalaria alexandrina to Schistosoma mansoni and Bulinus truncatus to Schistosoma haematobium Correlates with Unsaturated Fatty Acid Levels in the Snail Soft Tissue

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Marian Elias ◽  
Rasha S. Hanafi ◽  
Samia El-Bardicy ◽  
Ebtisam A. Hafez ◽  
Rashika El Ridi
Keyword(s):  
Fatty Acids ◽  
Arachidonic Acid ◽  
Fatty Acid ◽  
Soft Tissue ◽  
Polyunsaturated Fatty Acids ◽  
Schistosoma Mansoni ◽  
Schistosome Infection ◽  
Bulinus Truncatus ◽  
Biomphalaria Alexandrina ◽  
Arachidonic Acids

Only a fraction of the Biomphalaria and Bulinus snail community shows patent infection with schistosomes despite continuous exposure to the parasite, indicating that a substantial proportion of snails may resist infection. Accordingly, exterminating the schistosome intermediate snail hosts in transmission foci in habitats that may extend to kilometres is cost-prohibitive and damaging to the ecological equilibrium and quality of water and may be superfluous. It may be more cost effective with risk less ecological damage to focus on discovering the parameters governing snail susceptibility and resistance to schistosome infection. Therefore, laboratory bred Biomphalaria alexandrina and Bulinus truncatus snails were exposed to miracidia of laboratory-maintained Schistosoma mansoni and S. haematobium, respectively. Snails were examined for presence or lack of infection association with soft tissue and hemolymph content of proteins, cholesterol, and triglycerides, evaluated using standard biochemical techniques and palmitic, oleic, linoleic, and arachidonic acid, assayed by ultraperformance liquid chromatography-tandem mass spectrometry. Successful schistosome infection of B. alexandrina and B. truncatus consistently and reproducibly correlated with snails showing highly significant (up to P < 0.0001 ) decrease in soft tissue and hemolymph content of the monounsaturated fatty acid, oleic acid, and the polyunsaturated fatty acids, linoleic, and arachidonic acids as compared to naïve snails. Snails that resisted twice infection had soft tissue content of oleic, linoleic, and arachidonic acid similar to naïve counterparts. High levels of soft tissue and hemolymph oleic, linoleic, and arachidonic acid content appear to interfere with schistosome development in snails. Diet manipulation directed to eliciting excessive increase of polyunsaturated fatty acids in snails may protect them from infection and interrupt disease transmission in a simple and effective manner.

EFFECT OF ESTRADIOL AND TESTOSTERONE ON THE FATTY ACIDS OF PLASMA CHOLESTERYL ESTERS AND PHOSPHOLIPIDS IN THE CASTRATED RAT

1964 ◽  
Vol 42 (3) ◽  
pp. 365-376 ◽  
Author(s):  
R. L. Lyman ◽  
Angela Shannon ◽  
Rosemarie Ostwald ◽  
P. Miljanich
Keyword(s):  
Fatty Acids ◽  
Arachidonic Acid ◽  
Palmitic Acid ◽  
Phospholipid Fatty Acid ◽  
Male Rats ◽  
Cholesteryl Esters ◽  
Phospholipid Fatty Acid Composition ◽  
Plasma Phospholipids ◽  
Plasma Cholesteryl Ester ◽  
Arachidonic Acids

The effects of physiological doses of estradiol and testosterone on plasma cholesteryl ester and phospholipid fatty acid composition were investigated in castrated male rats. The animals were killed after 3 weeks on experiment, and their plasma cholesteryl esters and phospholipids were analyzed and compared with those of intact female and male rats.Estradiol appeared to be responsible for the increased proportion of plasma cholesteryl arachidonate seen in the female or estrogen-injected rats since the proportion of cholesteryl arachidonate in castrated control rats was lower and similar to that of male or testosterone-treated rats. Plasma phospholipids of female and estradiol-injected rats had a higher percentage of stearic acid relative to palmitic acid. On the other hand, male, castrated control and testosterone-treated rats had higher proportions of palmitic acid. Fractionation of the plasma phospholipids into cephalins, lecithins, sphingomyelins, and lysolecithins, and analyses of their fatty acids, revealed that a principal effect of estradiol was to increase proportions and amounts of stearic and arachidonic acids in the lecithin fraction.The results suggest that estradiol may influence the synthesis of a lecithin rich in stearic and arachidonic acid. A possible relationship between the arachidonic-acid-rich lecithin and the higher percentage of cholesteryl arachidonate in estradiol-treated rats is discussed.

scholarly journals Thrombin induces a biphasic 1,2-diacylglycerol production in human platelets

1991 ◽  
Vol 275 (2) ◽  
pp. 355-361 ◽  
Author(s):  
S Nakashima ◽  
A Suganuma ◽  
A Matsui ◽  
Y Nozawa
Keyword(s):  
Fatty Acids ◽  
Arachidonic Acid ◽  
Phosphatidic Acid ◽  
Myristic Acid ◽  
Time Course ◽  
Human Platelets ◽  
Second Phase ◽  
Mass Content ◽  
Small Production ◽  
Later Phase

The 1,2-diacylglycerol (DAG) mass content was measured in thrombin-stimulated human platelets. Thrombin stimulates a biphasic accumulation of DAG, with an early phase reaching a peak at 10 s and a later phase reaching a peak at 2-3 min. The time course of first-phase DAG production corresponded well to that of Ins(1,4,5)P3 formation, which was rapid and transient. The second phase of DAG accumulation occurred after the level of Ins(1,4,5)P3 returned to nearly basal. Thrombin stimulated the decrease in PtdIns and phosphatidylcholine contents. The source of second-phase DAG was examined in platelets prelabelled with three radioactive fatty acids, i.e. arachidonic, palmitic and myristic. Thrombin stimulated the increase in radioactivity of DAG with decline of PtdIns in platelets labelled with [3H]arachidonic acid or [3H]palmitic acid, in which PtdIns was considerably labelled. In contrast, significant accumulation of [3H]DAG was not observed in [3H]myristic acid-labelled platelets, in which PtdIns was poorly labelled. In platelets prelabelled with [3H]inositol, an increase in InsP in response to thrombin was seen for more than 5 min. In contrast, upon stimulation, significant increases in [3H]phosphocholine and [3H]choline were not observed in [methyl-3H]choline-labelled platelets. Thrombin induced a small production of phosphatidylethanol, when ethanol was present during stimulation. However, the formation of DAG and phosphatidic acid was not significantly affected by ethanol. These results suggest that thrombin stimulates a biphasic accumulation of DAG, initially from PtdInsP2 and later from PtdIns in human platelets.

Mobilization of arachidonic acid in thrombin-stimulated human platelets

1990 ◽  
Vol 68 (2) ◽  
pp. 520-527 ◽  
Author(s):  
V. G. Mahadevappa ◽  
Frank Sicilia
Keyword(s):  
Arachidonic Acid ◽  
Phosphatidic Acid ◽  
Phospholipase C ◽  
Selective Inhibition ◽  
Human Platelets ◽  
Phospholipase A ◽  
Serine Esterase ◽  
Membrane Phospholipids ◽  
Esterase Inhibitors ◽  
Hydrolysis Of

In the present work we investigated the effect of serine esterase inhibitors such as 2-nitro-4-carboxyphenyl N,N-diphenylcarbamate (NCDC) and phenylmethylsulfonyl fluoride (PMSF), as well as the effect of mepacrine on thrombin-induced mobilization of arachidonic acid (AA) in human platelets. The inhibitor NCDC (0.6 mM) completely abolished the thrombin-induced activation of phospholipase C, phospholipase A2, and transacylase enzymes, whereas the pretreatment of platelets with PMSF (2 mM) resulted in a highly selective inhibition of phospholipase A2 and transacylase activities, with no marked effect on thrombin-induced activation of phospholipase C. The thrombin-induced release of [3H]AA from phosphatidylcholine and phosphatidylinositol was reduced by 90 and 56%, respectively, in the presence of PMSF. This inhibitor also caused a parallel inhibition in the accumulation of [3H]AA (85%) with little effect on thrombin-induced formation of [3H]phosphatidic acid (5%), whereas mepacrine (0.4 mM) caused a selective inhibition of phospholipase A2 and transacylase activities with concomitant stimulation of [3H]phosphatidic acid formation in intact human platelets. These results demonstrate that NCDC and PMSF (serine esterase inhibitors) do not affect agonist-induced activation of phospholipases that mobilize arachidonic acid through a common site. Our results further demonstrate that the inhibition of [3H]AA release observed in the presence of NCDC, PMSF, and mepacrine is primarily due to their direct effects on enzyme activities, rather than due to their indirect effects through formation of complexes between inhibitors and membrane phospholipids. Based upon these results, we also conclude that the combined hydrolysis of phosphatidylcholine and phosphatidylinositol by phospholipase A2 serves as a major source for eicosanoid biosynthesis in thrombin-stimulated human platelets.Key words: deacylation, phospholipids, thrombin, platelets, phospholipase A2.

Lumenal hydrolysis of menhaden and rapeseed oils and their fatty acid methyl and ethyl esters in the rat

1989 ◽  
Vol 67 (4-5) ◽  
pp. 192-204 ◽  
Author(s):  
L.-Y. Yang ◽  
A. Kuksis ◽  
J. J. Myher
Keyword(s):  
Fatty Acids ◽  
Rapeseed Oil ◽  
Monounsaturated Fatty Acids ◽  
Ethyl Esters ◽  
Intestinal Lumen ◽  
Glycerol Molecule ◽  
A Chain ◽  
Layer Chromatography ◽  
Hydrolysis Of ◽  
Long Chain

Simple alkyl (ethyl) esters of polyunsaturated fish oil fatty acids have been proposed as dietary supplements, but their relative efficiency of digestion and absorption have not been determined. Using stomach tubes, we gave rats menhaden or rapeseed oils, or the corresponding methyl and ethyl esters, and determined by chromatographic methods the lipid classes and molecular species recovered from the lumen of the jejunum during the first 1 to 2.5 h of digestion. Hydrolysis of menhaden oil resulted in a preferential retention of a high proportion of the polyunsaturated long chain acids in the sn-2-monoacylglycerols and in the residual triacylglycerols, while digestion of rapeseed oil led to a preferential release of free long chain monounsaturated fatty acids. In contrast, hydrolysis of the alkyl (methyl and ethyl) esters of the fatty acids of either menhaden or rapeseed oil resulted in a composition of free fatty acids which was much more representative of the original esters. It was therefore concluded that the differential lumenal liberation of the long chain and polyunsaturated (three or more double bonds) fatty acids from fish and rapeseed oil is largely due to their characteristic distribution between the primary and secondary positions in the glycerol molecule, and to a much lesser extent to a chain length discrimination by pancreatic lipase. This study also shows that the methyl and ethyl esters are hydrolyzed about 4 times more slowly than the corresponding triacylglycerols, which is sufficient to maintain a saturated micellar solution of fatty acids in the intestinal lumen during absorption.Key words: gas chromatography, thin-layer chromatography, total lipid profiles, micellar and oil phases.

Biosynthesis of diacylglycerols by rat intestinal mucosa in vivo

1976 ◽  
Vol 54 (2) ◽  
pp. 137-144 ◽  
Author(s):  
W. C. Breckenridge ◽  
S. K. F. Yeung ◽  
A. Kuksis ◽  
J. J. Myher ◽  
M. Chan
Keyword(s):  
Fatty Acids ◽  
Intestinal Mucosa ◽  
Weight Fraction ◽  
Gas Liquid Chromatography ◽  
Long Chain Fatty Acids ◽  
Butter Oil ◽  
Arachidonic Acids ◽  
Layer Chromatography

The biosynthesis of diacylglycerols was studied in rat intestinal mucosa during in vivo absorption of a low molecular weight fraction of butter oil and of the corresponding medium and long chain fatty acids. The experimental fat solutions were given by stomach tube to the animals after a 24-h fast and mucosal scrapings were collected 3 h later. The lipids were isolated and the acylglycerols determined by combined thin-layer chromatography gas–liquid chromatography techniques and stereospecific analyses. Free fatty acid feeding led mainly to, sn-1,2-diacylglycerols, which contained exogenous and endogenous fatty acids. During triacylglycerol feeding, both.sn-1,2- and sn-2,3-diacylglycerols were recovered in significant amounts from the intestinal mucosa. The composition of the sn-2,3-diacylglycerols corresponded to that with exogenous fatty acids but the sn-1,2-diacylglycerols clearly contained both exogenous and endogenous fatty acids. In all cases it was possible to isolate endogenous sn-1,2-diacylglycerols made up largely of species with linoleic and arachidonic acids in the 2 position and palmitic and stearic acids in the 1 position, which apparently were not converted to triacylglycerols. The in vivo reacylation of 2-monoacylglycerols via both sn-1,2- and sn-2,3-diacylglycerols is in agreement with similar findings in vitro with everted sacs of rat intestinal mucosa.

Sign in / Sign up

Export Citation Format

Share Document