Acids In Plasma Phospholipids Research Articles

AN ALTERED RATIO OF 18:2 (9,11) TO 18:2 (9,12) LINOLEIC ACID IN PLASMA PHOSPHOLIPIDS AS A POSSIBLE PREDICTOR OF PRE-ECLAMPSIA

As part of a larger study, 15 healthy primigravidas were studied from 28 weeks' gestation until 3 days after delivery. In 6 of these women pre-eclampsia (PET) developed; the remaining 9 subjects, who were age matched, had normal pregnancies. Plasma phospholipid-esterified 18:2 (9,11) and 18:2 (9,12) fatty acids were measured by high performance liquid chromatography (HPLC). The ratio of 18:2 (9,11): 18:2 (9,12) linoleic acid was significantly higher in the PET group than in the normotensive group at 28 weeks' gestation—that is before the onset of symptoms and signs of PET. The ratio remained significantly higher in the PET group than in the normotensive group until delivery, except at 30 weeks when the difference between the ratios just failed to reach statistical significance. It is suggested that measurement of the ratio of 18:2 (9,11) to 18:2 (9,12) linoleic acid in plasma phospholipids may be useful as a predictor of the likely development of PET.

Essential fatty acids in the plasma phospholipids of patients with atopic eczema

We have measured all the essential fatty acids (EFA) in plasma phospholipids in forty-one adults with atopic eczema and fifty normal controls. The major dietary n-6 EFA, linoleic acid, was significantly elevated, but all its metabolites, 18:3n-6, 20:3n-6, 20:4n-6, 22:4n-6, and 22:5n-6 were significantly reduced. The major dietary n-3 EFA, alpha-linolenic acid, was also elevated, though not significantly, while all its metabolites were also significantly reduced. These observations suggest that atopic eczema is associated not with any defect of EFA intake, but with abnormal metabolism, possibly involving the enzyme delta-6-desaturase. Treatment with oral evening primrose oil produced partial correction of the n-6 EFA abnormality, but had no effect on the n-3 EFAs.

INTRAVENOUS LIPID ADMINISTRATION IN THE PREMATURE INFANT. 1. EFFECT ON ESSENTIAL FATTY ACID STATUS (EFAS)

Rapid changes occur in essential fatty acid status (EFAS) during fat-free parenteral nutrition (Pediatr Res 4:309A, 1983). We therefore evaluated the effects of IV Liposyn 20% administration on EFAS and compared them to the control group (group 1). Infants received either 0.34 gm (group 2) or 0.68 gm (group 3)/kg of lipid daily for 5 days providing 2% or 4% of the estimated caloric requirement (120 cal/kg/day) in the form of linoleic acid. Mean birth weight (1410, 1400, and 1470 gm in groups 1, 2, and 3, respectively), gestation (31.2, 31.4, and 30.9), daily caloric intake during the study (51.2, 50.2, and 49.3 cal/kg) and clinical features were similar. EFAS was assessed at 4 ± 1 (#1, before starting PN), at 6 ± 1 (#2), and 8 ± 1 (#3) days of age. Triene/tetraene ratio (T/T; mean, SD) is expressed as weight % of fatty acid in plasma phospholipids. The results are outlined.Baseline (#1) T/T ratio is similar in all groups. T/T ratios in groups 2 and 3 do not change significantly and remain lower than in group 1 (P <.01, 2-way ANOVA). We conclude that 1) IV lipids prevent rapid changes occurring in EFAS during PN; 2) 2% is as effective as 4% linoleate in maintaining baseline T/T ratio.

Influence des huiles de colza et de canbra sur les lipides plasmatiques du rat&lt;sup&gt;1&lt;/sup&gt;

Rapeseed oil fed to male weanling rats as 15% by weight of the diet for 2 months does not influence the plasma content of triglycerides (TG), phospholipids (PL), nonesterified fatty acids (NEFA) and cholesterol esters (CE), as compared to peanut oil and canbra oil (‘zero erucic acid’ rapeseed oil). However, the fatty acid spectra are changed: erucic acid and eicosénoïque acid from dietary rapeseed oil are mainly incorporated in TG and NEFA, less in PL and practically not at all in CE. Feeding time has little effect. Therefore, the immediate but temporary cardiac steatosis which is obtained in weanling rats fed rapeseed oil cannot be explained by modifications of the plasma TG or NEFA concentration and/or their fatty acid composition. Rapeseed and canbra oil increase the percentages of ω3-polyunsaturated fatty acids and of nervonic acid in plasma PL.

Effect of sex and gonadal hormones on rat plasma lipids during the development of an essential fatty acid deficiency.

1. Male, female and castrated rats treated with oestradiol (30mug./week) or testosterone (2mg./week) were given an essential fatty acid-deficient diet containing 10% of hydrogenated coconut oil for 9 weeks. The concentrations and fatty acid composition of plasma phospholipids, cholesteryl esters and triglycerides were determined. 2. Between the second and third weeks of the deficiency, concentrations of plasma cholesteryl esters, phospholipids and triglycerides decreased, then remained relatively constant. There were no significant differences between males and females, but oestradiol caused a significant rise in plasma phospholipids and triglycerides as compared with testosterone-treated animals. 3. During the first 2 weeks of the deficiency, linoleic acid in the plasma lipids of all groups decreased to low concentrations and changed very little thereafter. 4. Female rats maintained higher percentages and concentrations of arachidonic acid and stearic acid in plasma phospholipids and arachidonic acid in cholesteryl esters than did males. Males had higher proportions of eicosatrienoic acid and oleic acid. There was no sex difference in the fatty acid composition of plasma triglycerides. 5. Oestradiol-treated rats had concentrations of cholesteryl and phospholipid arachidonate comparable with those of female rats and higher than the testosterone-treated group. Eicosatrienoic acid in the oestradiol-treated rats was high and resembled that of the male rats, apparently because of the higher concentration of plasma phospho lipids in this group. 6. Supplementation of the essential fatty acid-deficient rats with linoleate restored plasma cholesteryl and phospholipid linoleate and arachidonate nearly to normal concentrations in a single day. The increase in arachidonic acid in these fractions was accompanied by a similar quantitative decrease in eicosatrienoic acid. 7. These sex differences appear to be related to the smaller size of the female rat and to a more direct influence of oestradiol on the formation or maintenance of phospholipids rich in arachidonic acid.