scholarly journals Studies on the positional integrity of glyceride fatty acids during digestion and absorption in rats

1969 ◽  
Vol 113 (1) ◽  
pp. 81-87 ◽  
Author(s):  
S. S. Raghavan ◽  
J. Ganguly
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Palmitic Acid ◽  
Free Fatty Acids ◽  
Neutral Lipid ◽  
Intestinal Mucosa ◽  
Sodium Taurocholate ◽  
Intestinal Lumen ◽  
Lipid Components

1. Rats previously starved for 24hr. were separately given by intraduodenal injections 0·5ml. of a dispersion containing 10mg. of sodium taurocholate, with 50mg. of glycerol 1,3-dioleate 2[1−14C]-palmitate, glycerol 1,2-dioleate 3[1−14C]-palmitate, a mixture of [1−14C]palmitic acid and triolein, or a mixture of [1−14C]-palmitic acid and oleic acid. 2. At the end of 30min., the net amounts, and the radioactivity, of the neutral-lipid components recovered from the intestinal lumen and mucosa, and the position of the labelled palmitic acid in the mucosal triglycerides, were determined. 3. When glycerol 1,3-dioleate 2[1−14C]-palmitate was administered, most of the labelled acid was retained in the di- and monoglycerides of the lumen; the triglycerides were the major components containing the radioactivity in the mucosa and 75–80% of the labelled acid was located at the β-position of these triglycerides. 4. When glycerol 1,2-dioleate 3[1−14C]-palmitate was administered, the labelled acid was readily split off in the lumen and virtually no radioactivity could be traced in the monoglyceride fraction; in the intestinal mucosa, triglycerides were again the chief components containing most of the radioactivity, and 80–85% of the labelled acid was esterified at the outer positions of the glycerol. 5. When [1−14C]palmitic acid mixed with triolein was administered, the concentrations of free fatty acids increased markedly in the intestinal lumen and mucosa, and 80–88% of the radioactivity of the mucosal triglycerides was located at the outer positions of the glycerol. 6. When [1−14C]palmitic acid mixed with oleic acid was administered, the labelled acid accumulated in the lumen as well as in the cell, and it was randomly incorporated into all three positions of the mucosal triglycerides.

scholarly journals High rates of [1-14C]acetate incorporation into the lipid of isolated spinach chloroplasts

1976 ◽  
Vol 158 (3) ◽  
pp. 593-601 ◽  
Author(s):  
P G Roughan ◽  
C R Slack ◽  
R Holland
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Palmitic Acid ◽  
Free Fatty Acids ◽  
Acid Synthesis ◽  
Polar Lipids ◽  
Acetate Incorporation ◽  
Spinach Chloroplasts ◽  
Triton X

Spinach chloroplasts, isolated by techniques yielding preparations with high O2- evolving activity, showed rates of light-dependent acetate incorporation into lipids 3-4 fold higher than any previously reported. Incorporation rates as high as 500 nmol of acetate/h per mg of chlorophyll were measured in buffered sorbitol solutions containing only NaHCO3 and [1-14C]acetate, and as high as 800 nmol/h per mg of chlorophyll when 0.13 mM-Triton X-100 was also included in the reaction media. The fatty acids synthesized were predominantly oleic (70-80% of the total fatty acid radioactivity) and palmitic (20-25%) with only minor amounts (1-5%) of linoleic acid. Linolenic acid synthesis was not detected in the system in vitro. Free fatty acids accounted for 70-90% of the radioactivity incorporated and the remainder was shared fairly evenly between 1,2-diacylglycerols and polar lipids. Oleic acid constituted 80-90% of the free fatty acids synthesized, but the diacylglycerols and polar lipids contained slightly more palmitic acid than oleic acid. Triton X-100 stimulated the synthesis of diacylglycerols 3-6 fold, but stimulated free fatty acid synthesis only 1-1.5-fold. Added glycerol 1-phosphate stimulated both the synthesis of diacylglycerols and palmitic acid relative to oleic acid, but did not increase acetate incorporation into total chloroplast lipids. CoA and ATP, when added separately, stimulated acetate incorporation into chloroplast lipids to variable extents and had no effect on the types of lipid synthesized, but when added together resulted in 34% of the incorporated acetate appearing in long-chain acyl-CoA. Pyruvate was a much less effective precursor of chloroplast fatty acids than was acetate.

Comparative effects of dietary fatty acids and triglycerides on lymph lipids in the rat

1959 ◽  
Vol 196 (4) ◽  
pp. 881-883 ◽  
Author(s):  
George V. Vahouny ◽  
C. R. Treadwell
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Linoleic Acid ◽  
Palmitic Acid ◽  
Free Fatty Acids ◽  
Bile Salt ◽  
Cholesterol Absorption ◽  
Dietary Fatty Acids ◽  
Total Lipids ◽  
Significant Elevation

The influence of fatty acids and corresponding triglycerides on the intestinal absorption of cholesterol has been studied in lymph-fistula rats. Butyric and lauric acids, given with bile salt and cholesterol as the free acids or the triglycerides, had little effect on total lymph lipids or on absorption of exogenous cholesterol. Palmitic acid gave a marked increase in lymph lipids which was due entirely to a rise in neutral fat, and a simultaneous depression of cholesterol absorption. The administration of stearic, oleic or linoleic acids produced large increases in the lymph levels of neutral fat and phospholipids. Oleic acid was most efficient, with linoleic and stearic acids somewhat less effective, in promoting cholesterol absorption. The increases in total lymph lipids after tristearin or triolein were less marked than with the free fatty acids, while in the case of trilinolein, total lipids, neutral fat, and phospholipid levels were comparable to the levels after linoleic acid. Of the triglycerides studied, only trilinolein caused a significant elevation of total lymph cholesterol.

Regulation of lysophosphatidylcholine-metabolizing enzymes in isolated myocardial cells from rat heart

1985 ◽  
Vol 63 (8) ◽  
pp. 944-951 ◽  
Author(s):  
David L. Severson ◽  
Thea Fletcher
Keyword(s):  
Fatty Acids ◽  
Palmitic Acid ◽  
Free Fatty Acids ◽  
Rat Heart ◽  
Marked Reduction ◽  
Myocardial Cells ◽  
Acyltransferase Activity ◽  
Metabolizing Enzymes ◽  
Enzymatic Pathways ◽  
Lysophospholipase Activity

Enzymatic pathways involved in the metabolism of lysophosphatidylcholine were investigated in rat heart myocardial cells. Acyl CoA-dependent acyltransferase activity was localized in microsomes, and was much greater than lysophospholipase activity in either cytosolic or microsomal fractions. The cytosolic lysophospholipase was more sensitive to inhibition by palmitylcarnitine in comparison to free fatty acids. In contrast, free fatty acids (oleate and palmitate) produced a greater inhibition of the microsomal acyltransferase and lysophospholipase than did palmitylcarnitine. A reduction in the assay pH to 6.5 resulted in an increase in microsomal acyltransferase and cytosolic lysophospholipase activities, but brought about a marked reduction in the microsomal lysophospholipase activity. At pH 6.5, the percentage inhibition of the microsomal acyltransferase by palmitylcarnitine was reduced, whereas the inhibition by palmitic acid was enhanced. The inhibition of the microsomal lysophospholipase by both palmitylcarnitine and palmitic acid was reduced at pH 6.5. With respect to myocardial ischemia, the inhibition of microsomal acyltransferase by free fatty acids and the reduction in microsomal lysophospholipase activity due to acidosis may contribute to the elevation of cellular lysophosphoglycerides which are arrhythmogenic.

Diacylglycerol Biosynthesis in Everted Sacs of Rat Intestinal Mucosa

1975 ◽  
Vol 53 (11) ◽  
pp. 1170-1183 ◽  
Author(s):  
W. C. Breckenridge ◽  
A. Kuksis
Keyword(s):  
Fatty Acids ◽  
Phosphatidic Acid ◽  
Thin Layer ◽  
Free Fatty Acids ◽  
Thin Layer Chromatography ◽  
Intestinal Mucosa ◽  
Gas Liquid Chromatography ◽  
Acid Pathway ◽  
Layer Chromatography ◽  
Everted Sacs

The molecular specificity in the biosynthesis of diacylglycerols by rat intestinal mucosa was examined by means of radioactive markers, thin-layer chromatography with silver nitrate and gas-liquid chromatography with radioactivity monitoring. Bile salt micelles of alternately labeled monoacylglycerols and free fatty acids were incubated with everted sacs of intestinal mucosa for various periods of time and the diacylglycerols were isolated by solvent extraction and thin-layer chromatography. Stereospecific analyses of the X-1,2-diacylglycerols labeled from 2-monoacylgiycerols showed that the sn-1,2-isomers (45–55%) were slightly in excess of the sn-2,3-isomers (34–45%) with the X-1,3-diacylglycerols accounting for the rest of the radioactivity (5–10%). This suggests that racemic diacylglycerols may be intermediates in the resynthesis of dietary fat in rat intestinal mucosa. Detailed analyses of the molecular species of the sn-1,2-diacylglycerols labeled from free fatty acids revealed that 10–45% of the total did not contain the acid present in the 2-monoacylglycerol supplied, and therefore had originated from the phosphatidic acid pathway. These findings are at variance with those obtained in isolated microsomes, which have suggested an inhibition of the phosphatidic acid pathway by monoacylglycerols as well as have given evidence of an exclusive synthesis of sn-1,2-diacylglycerols from 2-monoacylglycerols.

scholarly journals Effect of fatty acid chain length and saturation on the gastrointestinal handling and metabolic disposal of dietary fatty acids in women

1999 ◽  
Vol 81 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Amanda E. Jones ◽  
Michael Stolinski ◽  
Ruth D. Smith ◽  
Jane L. Murphy ◽  
Stephen A. Wootton
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Stearic Acid ◽  
Palmitic Acid ◽  
Chain Length ◽  
Time Course ◽  
Absorbed Dose ◽  
Dietary Fatty Acids ◽  
Fatty Acid Chain ◽  
Degree Of Unsaturation

The gastrointestinal handling and metabolic disposal of [1-13C]palmitic acid, [1-13C]stearic acid and [1-13C]oleic acid administered within a lipid–casein–glucose–sucrose emulsion were examined in normal healthy women by determining both the amount and nature of the13C label in stool and label excreted on breath as13CO2. The greatest excretion of13C label in stool was in the stearic acid trial (9.2 % of administered dose) whilst comparatively little label was observed in stool in either the palmitic acid (1.2 % of administered dose) or oleic acid (1.9 % of administered dose) trials. In both the palmitic acid and oleic acid trials, all of the label in stool was identified as being present in the form in which it was administered (i.e. [13C]palmitic acid in the palmitic acid trial and [13C]oleic acid in the oleic acid trial). In contrast, only 87 % of the label in the stool in the stearic acid trial was identified as [13C]stearic acid, the remainder was identified as [13C]palmitic acid which may reflect chain shortening of [1-13C]stearic acid within the gastrointestinal tract. Small, but statistically significant, differences were observed in the time course of recovery of13C label on breath over the initial 9 h of the study period (oleic acid = palmitic acid > stearic acid). However, when calculated over the 24 h study period, the recovery of the label as13CO2was similar in all three trials (approximately 25 % of absorbed dose). These results support the view that chain length and degree of unsaturation may influence the gastrointestinal handling and immediate metabolic disposal of these fatty acids even when presented within an emulsion.

scholarly journals Antagonism Between Saturated and Unsaturated Fatty Acids in ROS Mediated Lipotoxicity in Rat Insulin-Producing Cells

2015 ◽  
Vol 36 (3) ◽  
pp. 852-865 ◽  
Author(s):  
Wiebke Gehrmann ◽  
Wiebke Würdemann ◽  
Thomas Plötz ◽  
Anne Jörns ◽  
Sigurd Lenzen ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Palmitic Acid ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
H2o2 Production ◽  
Β Cell ◽  
Specific Expression ◽  
Insulin Producing Cells ◽  
H2o2 Formation

Background/Aims: Elevated levels of non-esterified fatty acids (NEFAs) are under suspicion to mediate β-cell dysfunction and β-cell loss in type 2 diabetes, a phenomenon known as lipotoxicity. Whereas saturated fatty acids show a strong cytotoxic effect upon insulin-producing cells, unsaturated fatty acids are not toxic and can even prevent toxicity. Experimental evidence suggests that oxidative stress mediates lipotoxicity and there is evidence that the subcellular site of ROS formation is the peroxisome. However, the interaction between unsaturated and saturated NEFAs in this process is unclear. Methods: Toxicity of rat insulin-producing cells after NEFA incubation was measured by MTT and caspase assays. NEFA induced H2O2 formation was quantified by organelle specific expression of the H2O2 specific fluorescence sensor protein HyPer. Results: The saturated NEFA palmitic acid had a significant toxic effect on the viability of rat insulin-producing cells. Unsaturated NEFAs with carbon chain lengths >14 showed, irrespective of the number of double bonds, a pronounced protection against palmitic acid induced toxicity. Palmitic acid induced H2O2 formation in the peroxisomes of insulin-producing cells. Oleic acid incubation led to lipid droplet formation, but in contrast to palmitic acid induced neither an ER stress response nor peroxisomal H2O2 generation. Furthermore, oleic acid prevented palmitic acid induced H2O2 production in the peroxisomes. Conclusion: Thus unsaturated NEFAs prevent deleterious hydrogen peroxide generation during peroxisomal β-oxidation of long-chain saturated NEFAs in rat insulin-producing cells.

Composition of Lipids of Piqui (Caryocar coriaceum Wittm.) Seed and Pulp Oil

1989 ◽  
Vol 44 (9-10) ◽  
pp. 739-742 ◽  
Author(s):  
Heidrun Dresen ◽  
R. B. N. Prasad ◽  
Paul-Gerhard Gülz
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Free Fatty Acids ◽  
Molecular Species ◽  
Lipid Composition ◽  
Seed Oil ◽  
Sterol Fraction

Abstract The lipid composition of Piqui (Caryocar coriaceum) seed oil and pulp oil was analyzed and found to contain triacylglycerols (95.1/95.3%) as major components followed by free fatty acids (1.7/1.6%), diacylglycerols (1.6/1.5%), squalene (0.3/0.3%) and monoacylglycerols (0.1/0.1%). Phospholipids were found only in seed oil (0.2%). They were identified as phosphatidylethanolamine and phosphatidylinositol. The sterol fraction (0.1/0.1%) contained stigmasterol and β-sito-sterol. In seed oil triacylglycerols the C-53 molecular species were dominated (52.8%) follow ed by C-55 (37.7%), C-57 (6.9%) and C-51 (2.6%) in minor quantities. In pulp oil triacylglycerols C-55 (51.7%) was predominant followed by C-53 (30.6%) and C-57 (17.7%). Palmitic (16:0) and oleic (18:1) acids were always the major fatty acids in both oils. In seed oil their quantities were nearly the same, whereas in pulp oil oleic acid was predominant. Composition of Lipids of Piqui (Caryocar coriaceum Wittm.)

Free fatty acid concentration and composition in arterial blood

1962 ◽  
Vol 203 (2) ◽  
pp. 306-310 ◽  
Author(s):  
Martin E. Rothlin ◽  
Christine B. Rothlin ◽  
Vernon E. Wendt
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Free Fatty Acids ◽  
Free Fatty Acid Concentration ◽  
Arterial Blood ◽  
Arterial Concentration ◽  
The Subject ◽  
Palmitic Acids

The effect of the administration of norepinephrine, glucose and insulin, pentobarbital, and Hypertensin on the arterial concentration and composition of plasma free fatty acids (FFA) has been studied in man and dog. With a rise of the FFA concentration as produced by norepinephrine, the contribution of oleic acid to the total FFA increased, while that of stearic and palmitic acids decreased. The reverse changes in the FFA composition were observed when their arterial level fell under the influence of other agents studied. The FFA composition was dependent on the FFA concentration in arterial blood, but not on the experimental condition of the subject or animal at the time of analysis. At high FFA levels, the FFA composition approached that of depot fat.

Lipid Absorption and Deposition in Rainbow Trout (Salmo gairdnerii)

1973 ◽  
Vol 51 (7) ◽  
pp. 1050-1058 ◽  
Author(s):  
J. Stephen Robinson ◽  
James F. Mead
Keyword(s):  
Fatty Acids ◽  
Rainbow Trout ◽  
Palmitic Acid ◽  
Free Fatty Acids ◽  
Intestinal Absorption ◽  
Lipid Absorption ◽  
Portal System ◽  
Absorption Mechanism ◽  
Dark Muscle ◽  
Muscle Lipids

Rainbow trout, fed or starved for 5 weeks, were force-fed 23 μCi 1-14C-palmitic acid and sacrificed at [Formula: see text], 1, 2, 4, 8, and 14 h after feeding. Analysis of the blood suggested that trout possess an intestinal absorption mechanism for lipid that is very different from that found in other animals. The fish, incapable of delivering triglyceride to its circulation in the usual way, receives most of its absorbed lipid as free fatty acids, probably via the portal system. It was also found that light muscle more easily yielded its triglyceride stores, in agreement with its role as the major lipid depot in trout. Nonetheless, dark muscle was metabolically more active in deposition of muscle lipids. Dark muscle appeared to function more as an organ than a kinetically responsible contractile body.

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