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At least 19 recordsLinked to original sources
PubMed1986

Antihypertensive effect of dietary sunflowerseed oil and linseed oil in spontaneously hypertensive rats during a multigeneration feeding study.

Semisynthetic diets enriched with polyunsaturated fatty acids (30 en% sunflowerseed oil or linseed oil) reduced hypertension development in spontaneously hypertensive rats (SHR) compared with control SHR fed on a regular rat chow. The effect was most markedly expressed in the 3rd and 4th generations of a four generation feeding period. PGI2-like production from isolated, pulsatingly perfused aorta preparations was reduced in linseed oil but not in sunflowerseed oil fed rats. Effects on blood pressure and PGI2-like production were abolished when the semisynthetic diets were changed for regular chow (5th and 6th generations).

Animals↗
PubMed1976

Chromatographic column fractionation and fatty acid composition of different lipid classes of linseed oil.

Linseed oil is fractionated on silicic acid column, with subsequent identification of different lipid classes by thin layer chromatography. Sterol esters, triglycerides, free fatty acids, sterols and phospholipids represent 0.15, 92.25, 3.30, 1.15 and 1.16%, respectively of linseed lipids. The total saturated fatty acid content of the phospholipid fraction is higher than that of the oil, the triglyceride fraction and the free fatty acid fraction. Linolenic acid, which is the major fatty acid in linseed triglycerides (47.5%), makes 18.2% of the phospholipid fatty acids. Oleic acid is the major fatty acid in the phospholipid fraction (35.2%), while it constitutes 19.3% of the triglycerides fatty acids.

Chromatography, Gel↗
PubMed1976

[Influence of heated linseed oil on reproduction in the female rat and on the composition of hepatic lipids in young rats].

During gestation and lactation, six month old female Wistar rats were fed diets containing 10 p. 100 by weight of various vegetable oils; thermopolymerized linseed oil at 275 degrees C for 12 hours under nitrogen atmosphere (group T), oxidized linseed oil at 200 degrees C for 100 hours under air atmosphere (group O). The two oils contain respectively 11,5 and 1,1 p. 100 of cyclic monomers (18 C). Control groups were fed either fresh linseed oil or fresh peanut oil under the same conditions. In group T, most of the newborn rats die at birth or during the first three days of life; none of them survive 13 days after birth. In group O, mortality of youngs is not so high but is still significantly higher than in control groups. Moreover, dead young rats of group T have heavier livers and higher lipid content in the organ. Cyclic monomers were detected in liver fatty acids. In surviving young rats of group O,the body growth during lactation is significantly slower than in control animals. Young rats of group O were sacrificed at the age of 14 days. Liver weight and lipid content of the organ are increased and cyclic monomers were detected. The effects are however less pronounced than in group T. One can assume that among abnormal compounds formed during heating of linseed oil, cyclic monomers are responsible for the toxic effects observed in the present experiment since they have been transmitted to the litters either during gestation or lactation.

Animals↗
PubMed1975

Changes in the rumen metabolism of sheep given increasing amounts of linseed oil in their diet.

1. Linseed oil was incorporated gradually into the diet of four sheep until the animals received 90 g additional fat/d. Attempts were made to measure changes in concentration of substances and rates of synthesis in the rumen directly, and by incubation of rumen contents in vitro (zero-time technique). 2. The high-fat diet increased the dilution rate and the volume of rumen contents and decreased the synthesis of diaminopimelic acid in the rumen. The number of protozoa decreased and the number of bacteria increased in the rumen of animals receiving the high-fat diet. 3. The concentration of volatile fatty acids (VFA) in the rumen decreased for sheep given the high-fat diet, but the capacity of rumen contents to produce VFA in vitro increased. 4. The incorporation of radioactivity from [14C]acetate into lipids during incubation of rumen contents vitro increased with the amount of linseed oil in the diet. The greatest proportional increase was with the bacterial fraction of rumen contents. 5. In the group of four animals used, one animal showed consistent differences in the magnitude of the measured varibles. This animal appeared to have a smaller rumen, a lower dilution rate and larger concentrations of some substances in the rumen. A higher proportion of fatty acids appeared to be synthsized by the micro-organisms from this animal.

Animal Nutritional Physiological Phenomena↗
PubMed1991

Influence of dietary linseed oil and sunflower seed oil on some mechanical and metabolic parameters of isolated working rat hearts.

The role played by membrane lipid environment on cardiac function remains poorly defined. The polyunsaturated fatty acid profile of myocardial phospholipids could be of utmost importance in the regulation of key-enzyme activities. This study was undertaken to determine whether selective incorporation of n-6 or n-3 fatty acids in membrane phospholipids might influence cardiac mechanical performances and metabolism. For 8 wk, male weaning Wistar rats were fed a semi-purified diet containing either 10% sunflower seed oil (72% C18:2 n-6) or 10% linseed oil (54% C18:3 n-3) as the sole source of lipids. The hearts were then removed and perfused according to working mode with a Krebs-Henseleit buffer containing glucose (11 mM) and insulin (10 Ul/l). Cardiac rate, coronary and aortic flows and ejection fraction were monitored after 30 min of perfusion. Myocardial metabolism was estimated by evaluating the intracellular fate of 1-14C palmitate. Sunflower seed oil and linseed oil feeding did not modify either coronary or aortic flow, which suggests that cardiac mechanical work was not affected by the diets. Conversely, cardiac rate was significantly decreased (-18%; P less than 0.01) when rats were fed the n-3 polyunsaturated fatty acid rich diet. Radioanalysis of the myocardial metabolism suggested that replacing n-6 polyunsaturated fatty acids by n-3 polyunsaturated fatty acids: i) did not alter palmitate uptake; ii) prolonged palmitate incorporation into cardiac triglycerides; iii) reduced beta-oxidation of palmitic acid. These results support the assumption that dietary fatty acids, particularly n-6 and n-3 fatty acids, play an important role in the regulation of cardiac mechanical and metabolic activity.

Animals↗
PubMed1991

Effects of a linseed oil enriched diet on endotoxin-induced sequelae: differential in vitro and in vivo effects.

Endotoxin stimulates macrophages to synthesize membrane-associated inflammatory mediators including eicosanoids and procoagulant activity (PCA). Alpha linolenic acid, a component of linseed oil, is metabolized to eicosapentaenoic acid, which may replace arachidonic acid in membrane phospholipids. Thus, ingestion of linseed oil may alter the generation of eicosanoids, PCA and other membrane-dependent responses. This study compared the in vitro endotoxin-induced synthesis of eicosanoids and expression of PCA by peritoneal macrophages obtained from rats fed a control diet and rats fed a diet enriched with linseed oil. The effect of endotoxin on in vivo plasma eicosanoid concentrations, leukogram, and microvascular permeability were determined. Endotoxin (5 ug/ml) stimulated synthesis of iTxB2, i6-keto PGF1 alpha and expression of PCA by macrophages in vitro. These in vitro responses of macrophages from linseed oil fed rats were significantly less than those of macrophages from control rats. In contrast, there were no significant differences in in vivo responses to endotoxin. The fatty acid composition of total lipids and phospholipids in liver and plasma from linseed oil fed rats and control rats were not different. These composite data suggest several possibilities: (1) linseed oil may have effects independent of alpha-linolenic acid on macrophage function, (2) linseed oil may alter the fatty acid composition of macrophage phospholipids prior to changing that of other tissues, and (3) the reduced in vitro responses of peritoneal macrophages may not reflect the systemic responses to endotoxin.

6-Ketoprostaglandin F1 alpha↗
PubMed1979

Influence of linseed oil on cholesterol-induced atherosclerosis in rabbits.

Four groups of rabbits were studied to determine the effect of linseed oil on cholesterol-induced atherosclerosis. Group C received cholesterol alone; group CL received cholesterol and linseed oil, group L were given linseed oil alone, while group N were fed the normal stock diet for 18 weeks. Cholesterolemia was marked in groups C and CL but not in groups L or N. Cholesterolemia was significantly greater (P less than 0.001) in group CL (462 mg/dl) than in group C (318.6 mg/dl). Thus, the addition of linseed oil to cholesterol led to greater hypercholesterolemia than with the cholesterol diet alone. There was no significant change in the serum triglyceride level in either group. Atherosclerotic lesions (mostly fatty streaks but some fibrous plaques) were present only in groups C and CL and were absent in groups L and N. The percentage of atherosclerotic intimal involvement was significantly greater in group CL than C (P less than 0.001). The severity of atherosclerosis correlated with serum cholesterol levels (r = 0.79, P less than 0.001), but not with serum triglyceride levels.

Animals↗
PubMedDate not supplied

[Effect of linseed oil on fatty acid composition of low- and very low density lipoproteins, cholesterol and its fractions in the blood serum of albino rats].

The authors studied the influence of linseed oil, and mixtures of linseed and sunflower oils, in varying ratios, on the levels of cholesterol, low- and very low-density lipoproteins, high-density cholesterol, free and esterified cholesterol, and on the fatty-acid composition of low- and very low-density lipoproteins. In experiments on Wistar white rats linseed oil decreased cholesterol concentration, and the levels of low- and very low-density lipoproteins, as well as affected the fatty-acid composition of lipoproteins.

Animal Feed↗
PubMed1975

[Urinary excretion of glucuronic and hippuric acids in rats ingesting heated linseed oil].

Nutritionally harmful substances are formed when edible vegetable oils are heated (cyclization, polymerization of unsaturated fatty acids, ...). How are these substances metabolized in animals? This work is a first attempt to experiment if these altered fatty acids or their metabolites are excreted as conjugated compounds in the urine. Weaning rats (weighing 45 g) were divided into 3 groups of 9 animals each. They received balanced diets containing 10 p. 100 by weight of lipids. In the first group, the dietary of lipids was linseed oil which had been heated for 12 hours at 275 degrees C under nitrogen (group HC275); in the second group, the linseed oil had been heated 100 hours at 200 degrees C in presence of air (group HC200). These two groups of animals were fed ad libitum. The control group (group HF) was fed a diet containing fresh linseed oil and its food consumption was restricted to the quantity eated by the HC275 group (pair feeding). Urines were collected daily from the 8th to the 15th day of experiment and pooled for each rat. Hippuric acid and glucuronic acid contents were determined in these urines. During this period the hippuric acid excretion in HC275 and HC200 groups is twice as high as in HF group (32, 35 and 17 mumoles respectively). On the other hand urinary excretion of glucoronic acid is 8 times higher in HC275 and 3 times in HC200 than in HF (2214, 739 and 269 mumoles respectively). Hippuric acid excretion is very small as compared to that of glucuronic acid. Therefore it seems that most of the compounds formed during heating of the oil or their metabolites are excreted as glucoronic acid conjugates.

Air↗
PubMed1985

[Identification of an atypical polyunsaturated fatty acid present in the liver of rats after the ingestion of heated linseed oil].

A C20:5 fatty acid with a trans delta 17 ethylenic bond was identified in liver lipids of rats fed with heated linseed oil. This component was isolated using a combination of high performance liquid chromatography on a reverse phase column and AgNO3 thin layer chromatography (TLC). This fatty acid was identified after hydrazine reduction, methoxy-bromomercuric adducts fractionation, AgNO3-TLC and ozonolysis in BF3-MeOH. It could be a metabolite of one trans isomeric linolenic acid formed during the heat treatment of linseed oil.

Animals↗
PubMed1992

Effects of dietary linseed oil and marine oil on lipid peroxidation in monkey liver in vivo and in vitro.

Diets rich in linoleic acid (CO) from corn oil, or in linoleic acid and either alpha-linolenic acid (LO) based on linseed oil or n-3 fatty acids (MO) from menhaden oil were fed to male and female Cynomolgus monkeys for 15 wk. In the liver a 40% reduction of alpha-tocopherol occurred in the MO group relative to the CO and LO groups followed by increased formation of lipofuscin in vivo. A four-fold increase of alpha-tocopherol in the MO diet (MO + E) brought the level in the liver to that found with CO and LO. The increased peroxidation in the MO group in the liver phospholipids was associated with the replacement of 60% of the n-6 fatty acids by n-3 fatty acids from menhaden oil. Similar fatty acid profiles were found in groups fed MO and MO + E, respectively. Compared to the CO fed group, feeding alpha-linolenic acid only resulted in a slight incorporation of n-3 fatty acids in the liver membranes mainly due to a direct incorporation of alpha-linolenic acid. However, in monkeys fed menhaden oil more than 30% of the total fatty acids in the liver phospholipids were n-3 fatty acids. The various diets did not influence the activity of liver catalase (EC 1.11.1.6) nor superoxide dismutase (EC 1.15.1.1), but glutathione-peroxidase activity (EC 1.11.1.9) was higher in monkeys fed the MO diet. The catalase activity in females was 20% higher than in males.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Effect of a diet rich in linseed oil on complex viscosity and blood pressure in spontaneously hypertensive rats (SHR).

The influence of a diet rich in linseed oil (10% in weight) with a content of 61.2% of alpha-linolenic fatty acid on blood pressure and complex blood viscosity was investigated in spontaneously hypertensive rats. A decrease in blood pressure by 59 mm Hg was found compared to the age-matched, untreated control group. The viscous (eta') and elastic (eta") components of viscosity were also reduced at various shear rates (gamma). The same applies to the aggregation index, which is a measure of the aggregation tendency of red blood cells (RBC). Of course, the effects on blood viscosity cannot explain the observed degree of blood-pressure-lowering. Nevertheless, a decrease in the viscosity can improve the flow conditions in the microcirculation, which may lead to a better oxygen supply.

Animals↗
PubMed1989

Occurrence of geometrical isomers of eicosapentaenoic and docosahexaenoic acids in liver lipids of rats fed heated linseed oil.

Mono trans geometrical isomers of 20:5 n-3 and 22:6 n-3 were detected in liver lipids of rats fed heated linseed oil. The isomers were identified as being 20:5 delta 5c,8c,11c,14c,17t and 22:6 delta 4c,7c,10c,13c,16c,19t. These fatty acids were isolated as methyl esters by preparative high-performance liquid chromatography (HPLC) on reversed phase columns followed by silver nitrate thin layer chromatography (AgNO3-TLC). The structures were identified using partial hydrazine reduction, AgNO3-TLC of the resulting monoenes, oxidative ozonolysis of each monoene band, and gas-liquid chromatography (GLC) of the resulting dimethyl esters and monomethyl esters. Fourier-transform-infrared spectrometry confirmed the trans geometry in isolated 20:5 and 22:6 isomers. The isomers of eicosapentaenoic and docosahexaenoic acids in liver lipids probably resulted from desaturation and elongation of 18:3 delta 9c,12c,15t, a geometrical isomer of linolenic acid present in the heated dietary oil.

Animals↗
PubMed1976

[Transference of cyclic monomeric acids into the milk of female rats eating thermopolymerised linseed oil].

Six month old female Wistar rats were fed a commercial diet until littering. Then they received a diet containing 10 p. 100 by weight of thermopolymerized linseed oil at 275 degrees C for 12 hours under nitrogen atmosphere. No mortality has been found among young rats during lactation but body growth is slower. In rats sacrificed at the age of 14 days stomach content (milk) and liver were analyzed for lipids. In milk and liver fatty acids respectively 2,7 and 3,0 p. 100 cyclic monomers (18 C) were detected. Consequently, the present study shows that these abnormal compounds formed during hearing of the oil are transmitted to the youngs before weaning through mother's milk.

Animals↗
PubMedDate not supplied

Changes in prostanoid synthesis in response to diet and hypertension in one-kidney, one clip rats.

This study was designed to examine the effects of diets that alter prostaglandin biosynthesis on the blood pressure in one-kidney, one clip rats with established hypertension and to compare the prostanoid generating capacity of hypertensive animals with those that remained normotensive. Rats attaining blood pressures of at least 180 mm Hg within 8 weeks of nephrectomy and renal artery stenosis were paired by weight and blood pressure and then placed on either a safflower oil or a prostaglandin I2 inhibitory diet (cod liver oil-linseed oil mix) for 4 weeks. Animals with blood pressures of less than 150 mm Hg were also paired for the same two dietary regimens. Comparison between the two blood pressure groups revealed that on both dietary regimens hypertensive rats produced significantly more aortic 6-keto-prostaglandin F1 alpha and serum thromboxane B2. Rats on the cod liver oil-linseed oil diet incorporated eicosapentaenoic acid into tissue stores with a corresponding decrease in arachidonic acid and significantly impaired ability to generate serum thromboxane B2 (36%), aortic 6-keto-prostaglandin F1 alpha (65%), renal homogenate 6-keto-prostaglandin F1 alpha (64%) and prostaglandin E2 (58%), and urinary prostaglandin E2 (70%) and 6-keto-prostaglandin F1 alpha (52%). Despite these differences in prostanoid synthesizing capacity, no differences in blood pressure were observed between the safflower oil-fed rats and rats fed cod liver oil-linseed oil within either the hypertensive or normotensive groups. These results suggest that prostanoids do not play a major role in maintaining blood pressure in established one-kidney, one clip hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)

6-Ketoprostaglandin F1 alpha↗