Effects of fatty acids on phosphatidylcholine biosynthesis in isolated hamster heart

The effects of stearic, oleic, and arachidonic acids on phosphatidylcholine biosynthesis in the hamster heart were investigated. When hamster hearts were perfused with labelled choline in the presence of fatty acids, biosynthesis of phosphatidylcholine was stimulated only by stearic acid. Stearic acid was found to accumulate in unesterified (free) form in the hamster heart after perfusion. The stimulation by stearic acid was mediated in vivo by an enhancement of CTP:phosphocholine cytidylyltransferase activity in the microsomal fraction of the hamster heart and the enzyme activity in the cytosolic fraction was not affected. In contrast with the observations in rat hepatocytes, cytidylyltransferase from the hamster heart was not stimulated directly by stearic acid. The selective activation of the microsomal enzyme when the heart was perfused with stearic acid suggests that activation of the enzyme was mediated via the modification of the membrane by stearic acid.

Download Full-text

Nutritional components of the sea cucumber Holothuria scabra

Functional Foods in Health and Disease ◽

10.31989/ffhd.v7i3.303 ◽

2017 ◽

Vol 7 (3) ◽

pp. 168 ◽

Cited By ~ 3

Author(s):

Morakot Sroyraya ◽

Peter J. Hanna ◽

Tanapan Siangcham ◽

Ruchanok Tinikul ◽

Prapaporn Jattujan ◽

...

Keyword(s):

Amino Acids ◽

Fatty Acids ◽

Stearic Acid ◽

Sea Cucumber ◽

Body Wall ◽

Essential Fatty Acids ◽

Essential Amino Acids ◽

Whole Body ◽

Holothuria Scabra ◽

Arachidonic Acids

Background: Holothuria scabra is one of the most commercially important species found in the Pacific region. The sea cucumber extracts have been widely reported to have beneficial health effects. The aim of this study was to determine the nutritional compositions of H. scabra, and compare its important nutritional contents with that of other species.Methods: The sea cucumbers were dissected, sliced into small pieces, and then freeze-dried. The nutritional compositions, including proximate composition, amino acids, fatty acids, collagen, GABA, Vitamin A, C, and E of the whole body and body wall of H. scabra, were analyzed.Results: H. scabra contained a high quantity of protein (22.50% in whole body and 55.18% in body wall) and very low lipids (1.55% in whole body and 1.02% in body wall). The three most abundant amino acids found in both the whole body and body wall were glycine, glutamic acid, and proline. The main fatty acids found in the whole body were stearic acid and nervonic acid, and in the body wall were arachidonic acid and stearic acid. The whole body and body wall also contained high levels of essential amino acids, essential fatty acids, and collagen, in addition to moderate amounts of vitamin E and low amounts of GABA and vitamin C.Conclusions: The sea cucumber, H. scabra, contained high quantity of protein and very low lipid. It contained high essential amino acids, essential fatty acids, nervonic and arachidonic acids, and collagen, which also contained GABA, vitamin C, and vitamin E.Keywords: sea cucumber; Holothuria scabra; nutrition components; functional food

Download Full-text

Oleic acid promotes the activation and translocation of phosphatidate phosphohydrolase from the cytosol to particulate fractions of isolated rat hepatocytes

Biochemical Journal ◽

10.1042/bj2190911 ◽

1984 ◽

Vol 219 (3) ◽

pp. 911-916 ◽

Cited By ~ 104

Author(s):

C Cascales ◽

E H Mangiapane ◽

D N Brindley

Keyword(s):

Fatty Acids ◽

Endoplasmic Reticulum ◽

Oleic Acid ◽

Microsomal Fraction ◽

Rat Hepatocytes ◽

Total Activity ◽

Cell Fractionation ◽

Isolated Rat Hepatocytes ◽

Phosphatidate Phosphohydrolase ◽

Isolated Rat

The incubation of hepatocytes with 1-4mM-oleate increased the total activity of phosphatidate phosphohydrolase that was measured in the presence of Mg2+ to about 2-fold. This was accompanied by an increase in the proportion of the enzyme that was isolated with the particulate fractions. Conversely, the addition of up to 4mM-oleate decreased the recovery of phosphatidate phosphohydrolase in the cytosolic fraction from about 70% to 3% when hepatocytes were lysed with digitonin. Most of the increase in the membrane-associated phosphohydrolase activity was isolated after cell fractionation in the microsomal fraction that was enriched with the endoplasmic-reticulum marker arylesterase. It is proposed that the translocation of phosphatidate phosphohydrolase facilitates the increased synthesis of triacylglycerols in the liver when it is presented with an increased supply of fatty acids.

Download Full-text

In vitro and in vivo inhibition of renin by fatty acids.

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1978.234.6.e593 ◽

1978 ◽

Vol 234 (6) ◽

pp. E593 ◽

Cited By ~ 1

Author(s):

T A Kotchen ◽

W J Welch ◽

R T Talwalkar

Keyword(s):

Blood Pressure ◽

Fatty Acids ◽

Linoleic Acid ◽

Angiotensin Ii ◽

Neutral Lipids ◽

Pressor Response ◽

Arterial Blood ◽

Arachidonic Acids

Circulating neutral lipids inhibit the in vitro renin reaction. To identify the inhibitor(s), free fatty acids were added to human renin and homologous substrate. Capric, lauric, palmitoleic, linoleic, and arachidonic acids each inhibited the rate of angiotensin I production in vitro (P less than 0.01). Inhibition by polysaturated fatty acids (linoleic and arachidonic) was less (P less than 0.01) after catalytic hydrogenation of the double bonds. To evaluate an in vivo effect of renin inhibition intra-arterial blood pressure responses to infusions of renin and angiotensin II (5.0 microgram) were measured in anephric rats (n = 6) before and after infusion of linoleic acid (10 mg iv). Mean increase of blood pressure to angiotensin II before (75 mmHg +/- 9) and after (90 +/- 12) linoleic acid did not differ (P greater than 0.05). However, the pressor response to renin after linoleic acid (18 +/- 3) was less (P less than 0.00)) than that before (102 +/- 13). In summary, several fatty acids inhibit the in vitro renin reaction, and in part inhibition is dependent on unsaturation. Linoleic acid also inhibits the in vivo pressor response to renin. These results suggest that fatty acids may modify the measurement of plasma renin activity and may also affect angiotensin production in vivo.

Download Full-text

The heart ofCiona intestinalis: eicosanoid-generating capacity and the effects of precursor fatty acids and eicosanoids on heart rate

Journal of Experimental Biology ◽

10.1242/jeb.205.11.1577 ◽

2002 ◽

Vol 205 (11) ◽

pp. 1577-1583

Author(s):

Edward C. Pope ◽

Andrew F. Rowley

Keyword(s):

Fatty Acids ◽

Heart Rate ◽

Fatty Acid ◽

Vascular System ◽

Prostaglandin E ◽

Isolated Hearts ◽

Sea Squirt ◽

Generating Capacity ◽

Arachidonic Acids

SUMMARYEicosanoids are a group of oxygenated fatty-acid derivatives formed from C20 polyunsaturated fatty acids including arachidonic and eicosapentaenoic acids. In mammals, these compounds have been shown to be key molecules in several physiological processes including regulation of the vascular system. This study determined whether eicosanoids or their precursors are involved in the regulation of heart rate in the sea squirt Ciona intestinalis. Eicosanoid generation by both heart and blood cells was measured. The major lipoxygenase products formed were both derivatives of eicosapentaenoic acid,namely 8- and 12-hydroxyeicosapentaenoic acids (8-HEPE and 12-HEPE). Smaller amounts of 8,15-dihydroxyeicosapentaenoic acid (8,15-diHEPE) were also formed. The cyclo-oxygenase product prostaglandin E was also found in small amounts in the heart. Isolated hearts were exposed either to these fatty acid precursors or to 8-HEPE, 12-HEPE or prostaglandin E3, and the effect on heart rate was recorded. Both eicosapentaenoic and arachidonic acids stimulated the heart rate at concentrations between 50 and 200 μmoll-1. 12-HEPE(5 μmoll-1) and prostaglandin E3 (50μmoll-1) caused a modest increase in heart rate, while 8-HEPE had no significant effects at any of the time periods studied (≤180 min). Overall, the results show that arachidonic and eicosapentaenoic acids have limited effects on heart rate and only at concentrations unlikely to be routinely liberated in vivo. Similarly, the eicosanoids tested had a minor stimulatory activity on heart rate. The potential mechanisms for this stimulation are discussed. Overall, these results suggest that such compounds are of limited importance in regulating the heart and vascular system of sea squirts.

Download Full-text

Increased oxidation of uroporphyrinogen by an inducible liver microsomal system. Possible relevance to drug-induced uroporphyria

Biochemical Journal ◽

10.1042/bj2500161 ◽

1988 ◽

Vol 250 (1) ◽

pp. 161-169 ◽

Cited By ~ 46

Author(s):

F De Matteis ◽

C Harvey ◽

C Reed ◽

R Hempenius

Keyword(s):

Chick Embryo ◽

Drug Metabolism ◽

Microsomal Fraction ◽

Marked Decrease ◽

Rat Hepatocytes ◽

Drug Induced ◽

Dependent Mechanism ◽

Stimulation Of

1. The hypothesis that uroporphyria-inducing drugs stimulate the oxidation of uroporphyrinogen by a microsomal NADPH-dependent mechanism was tested. 2. 3,4,3′,4′-Tetrachlorobiphenyl, a very effective inducer of uroporphyria in chick-embryo hepatocyte cultures, stimulates the NADPH-dependent oxidation of uroporphyrinogen by chick-embryo microsomal fraction in vitro. 3. Two different actions of 3,4,3′,4′-tetrachlorobiphenyl are apparently required for this effect: (a) induction of a microsomal system by treatment in vivo and (b) interaction with the induced microsomal fraction in vitro, producing an oxidizing species. 4. The analogue 2,4,2′,4′-tetrachlorobiphenyl is relatively ineffective in both the production of porphyria in culture and the stimulation of porphyrinogen oxidation in vitro. 5. Rat hepatocytes do not develop uroporphyria when treated with polychlorinated biphenyls in culture, yet they respond to these drugs with typical induction of cytochrome P-448-dependent drug metabolism. 6. These data provide support for the hypothesis of an increased oxidation of uroporphyrinogen in drug-induced uroporphyria, but also suggest that induction of cytochrome P-448 is not the only factor involved. 7. Both I and III isomers of uroporphyrin and heptacarboxylate porphyrin accumulate when chicken hepatocytes are made uroporphyric by drugs; treatment with desferrioxamine causes a marked decrease in both isomers, suggesting that iron may be involved in the accumulation of both.

Download Full-text

2.P.371 In vivo thromboxane/prostacyclin balance unfavourable affected in humans after diets rich in stearic acid or trans fatty acids

Atherosclerosis ◽

10.1016/s0021-9150(97)89008-9 ◽

1997 ◽

Vol 134 (1-2) ◽

pp. 194

Author(s):

Marja Mutanen ◽

Anu M. Turpeinen ◽

Joachim Wübert ◽

Reinhard Lorenz ◽

Antti Aro

Keyword(s):

Fatty Acids ◽

Stearic Acid ◽

Trans Fatty Acids

Download Full-text

Stearic acid unlike shorter-chain saturated fatty acids is poorly utilized for triacylglycerol synthesis and β-oxidation in cultured rat hepatocytes

Lipids ◽

10.1007/bf02522615 ◽

1996 ◽

Vol 31 (2) ◽

pp. 159-164 ◽

Cited By ~ 10

Author(s):

Tonkun Pai ◽

Yu-Yan Yeh

Keyword(s):

Fatty Acids ◽

Stearic Acid ◽

Saturated Fatty Acids ◽

Rat Hepatocytes ◽

Triacylglycerol Synthesis ◽

Cultured Rat Hepatocytes

Download Full-text

Effect of hypoxia on phosphatidylcholine biosynthesis in the isolated hamster heart

Biochemical Journal ◽

10.1042/bj2680047 ◽

1990 ◽

Vol 268 (1) ◽

pp. 47-54 ◽

Cited By ~ 18

Author(s):

G M Hatch ◽

P C Choy

Keyword(s):

Active Form ◽

Compensatory Mechanism ◽

Ctp:Phosphocholine Cytidylyltransferase ◽

Hypoxic Conditions ◽

Rate Limiting Step ◽

Phosphatidylcholine Biosynthesis ◽

Hamster Heart ◽

Rate Limiting ◽

Hypoxic Treatment

In hamster heart, the majority of the phosphatidylcholine is synthesized via the CDP-choline pathway, and the rate-limiting step of this pathway is catalysed by CTP:phosphocholine cytidylyltransferase (EC 2.7.7.15). We have shown previously [Choy (1982) J. Biol. Chem. 257, 10928-10933] that, in the myopathic heart, the level of cardiac CTP was diminished during the development of the disease. In order to maintain the level of CDP-choline, and consequently the rate of phosphatidylcholine biosynthesis, cardiac cytidylyltransferase activity was increased. However, it was not clear if the same compensatory mechanism would occur when the cardiac CTP level was decreased rapidly. In this study, hypoxia of the hamster heart was produced by perfusion with buffer saturated with 95% N2. The heart was pulse-labelled with radioactive choline and then chased with non-radioactive choline for various periods under hypoxic conditions. There was a severe decrease in ATP and CTP levels within 60 min of hypoxic perfusion, with a corresponding fall in the rate of phosphatidylcholine biosynthesis. Analysis of the choline-containing metabolites revealed that the lowered ATP level did not affect the phosphorylation of choline to phosphocholine, but the lower CTP level resulted in the decreased conversion of phosphocholine to CDP-choline. Determination of enzyme activities revealed that hypoxic treatment resulted in the enhanced translocation of cytidylyltransferase from the cytosolic to the microsomal form. This enhanced translocation was probably caused by the accumulation of fatty acids in the heart during hypoxia. We postulate that the enhancement of translocation of the cytidylyltransferase to the microsomal form (a more active form) is a mechanism by which the heart can compensate for the decrease in CTP level during hypoxia in order to maintain phosphatidylcholine biosynthesis.

Download Full-text

Biosynthesis of diacylglycerols by rat intestinal mucosa in vivo

Canadian Journal of Biochemistry ◽

10.1139/o76-021 ◽

1976 ◽

Vol 54 (2) ◽

pp. 137-144 ◽

Cited By ~ 17

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.

Download Full-text