n-6 and n-3 Long-chain polyunsaturated fatty acids in the erythrocyte membrane of Brazilian preterm and term neonates and their mothers at delivery

Placental transfer of the long-chain polyunsaturated fatty acids (LCPUFA) arachidonic (AA) and docosahexaenoic (DHA) acids is selectively high to maintain accretion to fetal tissues, especially the brain. The objectives of the present study were to investigate the essential fatty acid (EFA) and LCPUFA status at birth of preterm and term Brazilian infants and their mothers, from a population of characteristically low intake of n-3 LCPUFA, and to evaluate the association between fetal and maternal status, by the determination of the fatty acid composition of the erythrocyte membrane. Blood samples from umbilical cord of preterm (26-36 weeks of gestation; n = 30) and term (37-42 weeks of gestation; n = 30) infants and the corresponding maternal venous blood were collected at delivery. The LCPUFA composition of the erythrocyte membrane and DHA status were similar for mothers of preterm and term infants. Neonatal AA was higher (P < 0.01) whereas its precursor 18:2n-6 was lower (P < 0.01) than maternal levels, as expected. There was no difference in LCPUFA erythrocyte composition between preterm and term infants, except for DHA. Term infants presented a worse DHA status than preterm infants (P < 0.01) and than their mothers (P < 0.01) at delivery. There was a negative correlation of neonatal DHA with maternal AA and a positive correlation between neonatal AA and maternal AA and 18:2n-6 only at term. These results suggest that the persistent low DHA maternal status, together with the comparatively better AA and 18:2n-6 status, might have affected maternal-fetal transfer of DHA when gestation was completed up to term, and possibly contributed to the worse DHA status of term neonates compared with the preterm neonates.     

Essential fatty acid status of neonates born to Inuit mothers: comparison with Caucasian neonates and effect of diet.

Fatty acid compositions were determined of phospholipids isolated from venous cord plasma and from the walls of umbilical arteries and veins, collected from healthy, a terme, Inuit and Caucasian (Dutch) neonates. The Inuit fatty acid profiles were characterized by a lower essential fatty acid (EFA) status, with higher levels of monounsaturated fatty acids, of Mead acid [20:3(n-9)] and its direct elongation product, and with lower amounts of the longer chain (greater than or equal to 20 carbon atoms), highly unsaturated (greater than or equal to 4 double bonds) fatty acids of both the (n-3) and (n-6) families. Levels of linoleic- and dihomo-gamma-linolenic acids were higher in Inuit as compared to Caucasian neonates, which suggests a low activity of the delta-5-desaturase in the Inuit. Within the Inuit group, a higher intake of marine food was associated with a better neonatal (n-3) status. Although the differences between Inuit and Caucasian neonates may be of genetic rather than of dietary origin, the results imply that dietary long-chain (n-3) or (n-6) fatty acids may be particularly important during pregnancy in Inuit mothers. Further studies are indicated with respect to the EFA content of the habitual Inuit diet and levels of delta-5-desaturase activity in the Inuit.     

Plasma fatty acids of neonates born to mothers with and without gestational diabetes

Women with gestational diabetes mellitus (GDM) and their neonates have lower levels of arachidonic (AA) and docosahexaenoic (DHA) acids in red cell membranes. It is not clear if this abnormality is restricted to red cells or is a generalised problem. We have investigated plasma fatty acids of neonates (venous cord) of GDM (n=37), and non-diabetic (n=31) women. The GDMs had lower levels of dihomogamma-linolenic (20:3n-6, DHGLA) acid, summation operator n-6 metabolites, DHA and summation operator n-3 metabolites (p<0.05) in choline phosphoglycerides (CPG). They also had lower levels of AA (-4.5%), adrenic acid (22:4n-6, -13%), osbond acid (22:5n-6, -7%) and summation operator n-6 (-2.5%). There was a similar pattern in triglycerides (TG) and cholesterol esters (CE). Mead acid, a marker of generalised shortage of derived and parent essential fatty acids, was higher in CPG and TG of the GDM group by 73% and 76%. The adrenic/osbond acid (22:4n-6/22:5n-6) ratio, a biochemical marker of DHA insufficiency, was reduced in CPG (-4.5%), TG (-63%) and CE (-75%) of the GDM group. These findings, which are consistent with the previous red cell data, suggest that the neuro-visual and vascular development and function of the offspring of GDM women may be adversely affected if the levels of AA and DHA are compromised further by other factors, pre- or post-natally. Studies are required to elucidate the underlying mechanism for the reduction of the two fatty acids and to evaluate the developmental and health implications.     

Essential fatty acids in tissue phospholipids and triglycerides of the zinc-deficient rat

This study addressed the possibility that zinc deficiency has different effects on the fatty acid composition of triglyceride compared to total phospholipid. Male weanling Sprague-Dawley rats were maintained for 6 weeks on a semisynthetic diet deficient in zinc (3 mg/kg zinc). Control rats (40 mg/kg zinc) were pair-fed. Lipid fractionation and fatty acid analysis were by thin-layer and gas chromatography, respectively. In zinc-deficient rats, the percentage of linoleic acid was increased or that of arachidonic acid was decreased in total phospholipids of plasma, liver, and testis, and in skin total lipids. Saturated and monounsaturated fatty acids were increased in the triglyceride of liver but decreased in the triglyceride of epididymal fat of zinc deficient rats. Essential fatty acids, as a proportion of total fatty acids, were decreased in triglyceride of liver but increased in triglyceride of epididymal fat of zinc-deficient rats. Our fatty acid data from tissue total phospholipids therefore support the concept that linoleic acid desaturation is impaired in zinc deficiency.     

Free fatty acids, diacyl- and triacylglycerols and total phospholipids in vertebrate retina: comparison with brain, choroid and plasma

Abstract— A comparative study of the concentration and fatty acid distribution in diacyl- and triacylgly-cerols. free fatty acids and total phospholipids from rabbit, cattle and toad retina is presented. With respect to the toad, a comparison is made with brain, choroid and plasma lipids. Marked differences in diacylglycerol composition and levels between mammalian and toad retina are found: in the mammal arachidonate predominates (25 per cent), in the toad docosahexaenoate is the main fatty acid (42 per cent). The total phospholipid composition parallels that of the diacylglycerols only in the toad, whereas in the mammalian retina the phospholipids are richer in docosahexaenoate than are the diacylglycerols. It is suggested that there is a relationship between diacylglycerols and phosphoglyceride metabolism in the toad; in the retinas of other species the diacylglycerols may be related to specific phosphatides. In the three species, triacylglycerols show high levels of unsaturation; however, marked differences are found in the distribution of polyunsaturated acyl groups: in the cattle and toad retina docosahexaenoate predominates. whereas in the rabbit a higher proportion of 22:4 is found. Retina free fatty acid pools also show different features in the three species: the cattle retina contains the highest proportion of free 20:4 and 22:6. The triacylglycerol concentration is much higher in the toad choroid than in the retina, although the fatty acid compositions are similar. A possible relationship between these choroid lipids and those of the retina is suggested.     

Essential fatty acids and their metabolites in signal transduction.

The above examples argue that the diversity of eicosanoid structures is reflected in distinct actions, that the membrane-permeable nature of these molecules provides a system for interactive cellular signalling that may be particularly important in the nervous system, and that convincing evidence exists for direct actions of eicosanoids on both ion channels and kinases, as well as G-protein-coupled receptors.     

Composition of phospholipids and of phospholipid fatty acids of human plasma

The composition of the phospholipids and of the total phospholipid fatty acids was determined in the plasma of 10 normal subjects. In addition the fatty acid composition of the plasma phosphatidyl ethanolamine, phosphatidyl serine, lecithin, sphingomyelin, and lysolecithin of 6 of the subjects was measured. A wide array of fatty acids was found in the plasma total phospholipid similar to that found previously in red cell total phospholipid. The fatty acid composition in the plasma phospholipids of a given subject reflected that in his red cell phospholipids. Each individual phospholipid displayed a distinctive fatty acid pattern, which was generally similar to that of the corresponding phospholipid of red cells, although some marked differences in individual fatty acid levels between the corresponding phospholipids of plasma and red cells were evident. The high percentage of unsaturated fatty acids found in plasma lysolecithin suggests that this phospholipid did not arise entirely through the enzymatic cleavage of the -fatty acid of lecithin.     

Polyunsaturated fatty acids in plasma and erythrocyte membrane lipids of diabetic children

While insulin is a potent activator of essential fatty acid metabolism, portal hypoinsulinemia is common in Type 1 diabetes. Fatty acids were determined by high-resolution capillary gas-liquid chromatography in plasma and erythrocyte membrane lipids in diabetic children (n = 40) and in age-matched healthy controls (n = 40). In plasma phospholipids, values of linoleic acid (23.00 [2.35] vs. 18.13 [2.54], % by wt, median [range from the first to the third quartile], P<0.000l) and alpha-linolenic acid (0.12 [0.06] vs. 0.07 [0.07], P<0.05) were significantly higher in diabetic children than in controls. In contrast, values of arachidonic acid (10.73 [2.34] vs. 11.53 [2.50], P<0.05) and docosahexaenoic acid (2.23 [0.63] vs. 2.77 [0.98], P<0.01) were significantly lower in diabetic children than in controls. Reduced availability of long-chain polyunsaturates in diabetic children suggests that an enhanced dietary supply of long-chain polyunsaturates may be beneficial.     

Essential fatty acids and their role in the treatment of impulsivity disorders

Essential fatty acids (EFAs) have been shown to benefit patients with depression, schizophrenia and dementia. More recently, their role in disorders characterised by impulsivity has attracted some attention. The psychiatric conditions of attention-deficit hyperactivity disorder and borderline personality disorder as well as the phenomena of deliberate self-harm and violence have been ameliorated by the supplementation of EFAs in a number of recent clinical trials. This paper summarises the burgeoning clinical and basic research indicating the existence of significant deficits of EFAs in impulsivity disorders and the supplementation studies of EFAs in these diverse conditions, all of which remain a major therapeutic challenge.     

Placental fatty acids in the guinea pig during pregnancy

Prostaglandins are involved in different stages of reproduction. In respect to the placental metabolism of prostaglandins in the Guinea pig, we have studied the composition of Guinea pig placenta in free and total fatty acids. The arachidonic and dihomo-gamma-linolenic acids, precursors of prostaglandins of series 2 and 1, and the linoleic acid were quantified at different gestational ages using a gas-chromatography capillary column technique. Only the linoleic acid shows a significant increase at the end of gestation.     

Long-chain polyunsaturated fatty acids profile in plasma phospholipids of hyperphenylalaninemic children on unrestricted diet

IntroductionThe aim of the present study was to examine whether hyperphenylalaninemic children on unrestricted diet (MHP) may exhibit a different LCPUFA profile from PKU or healthy children in plasma phospholipids.Patients and methodsForty-five MHP children (age 9–14 years) were age and sex matched with 45 PKU and 45 healthy children. Fatty acids were determined and expressed as % of total fatty acids.ResultsMHP children showed docosahexaenoic acid (DHA) levels higher than PKU children (mean difference, 0.2%; 95% confidence interval, 0.02%–0.38%), although difference was not significant after correction for multiple comparisons, and lower levels than healthy children (?0.8%; ?1.01% to ?0.59%). Concentration of n-3 PUFA was higher in MHP than PKU children (0.6%; 0.4% to 0.8%),ConclusionsThe results suggest that low DHA levels in plasma phospholipids not only are evident in PKU but also may occur in MHP children, who are on unrestricted diet, as compared to healthy children.     

Markers of oxidative stress in diabetic mothers and their infants during delivery

Oxidative stress is probably a pathophysiological process leading to disadvantageous outcomes in diabetic pregnancies. We aimed to map a complex of potential markers of oxidative stress in this condition. Diabetic mothers had significantly higher concentrations of thiobarbituric acid reactive substances in the plasma [TBARS] both before (p<0.0001) and after (p<0.001) delivery and also their newborns showed higher values of TBARS (p<0.0001) in comparison with the control group. Diabetic mothers also showed lower concentrations of reduced glutathione in erythrocytes [GSH] both before (p<0.05) and after (p<0.01) delivery and their infants also had lower levels of GSH (p<0.0001). We found a lower total antioxidative capacity of plasma [AOC] before delivery (p<0.05) in the diabetic group in comparison with the control group. Newborns of diabetic mothers had higher plasmatic concentrations of apolipoproteine B [apo B] (p<0.05), higher erythrocyte glutathione peroxidase [GPx] activity (p<0.05) and lower pH (p<0.001) in the umbilical cord blood, when compared with infants of control non-diabetic mothers. We conclude that pregestational and gestational diabetes mellitus represent increased oxidative stress for both mother and her infant. TBARS in plasma are a valuable marker of oxidative stress in this condition. Disruption of glutathione peroxidase/glutathione pattern can be involved in pathophysiology of enhanced oxidative stress in diabetic pregnancies.     

Essential fatty acids: biochemistry, physiology and pathology

Essential fatty acids (EFAs), linoleic acid (LA), and alpha-linolenic acid (ALA) are essential for humans, and are freely available in the diet. Hence, EFA deficiency is extremely rare in humans. To derive the full benefits of EFAs, they need to be metabolized to their respective long-chain metabolites, i.e., dihomo-gamma-linolenic acid (DGLA), and arachidonic acid (AA) from LA; and eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from ALA. Some of these long-chain metabolites not only form precursors to respective prostaglandins (PGs), thromboxanes (TXs), and leukotrienes (LTs), but also give rise to lipoxins (LXs) and resolvins that have potent anti-inflammatory actions. Furthermore, EFAs and their metabolites may function as endogenous angiotensin-converting enzyme and 3-hdroxy-3-methylglutaryl coenzyme A reductase inhibitors, nitric oxide (NO) enhancers, anti-hypertensives, and anti-atherosclerotic molecules. Recent studies revealed that EFAs react with NO to yield respective nitroalkene derivatives that exert cell-signaling actions via ligation and activation of peroxisome proliferator-activated receptors. The metabolism of EFAs is altered in several diseases such as obesity, hypertension, diabetes mellitus, coronary heart disease, schizophrenia, Alzheimer's disease, atherosclerosis, and cancer. Thus, EFAs and their derivatives have varied biological actions and seem to be involved in several physiological and pathological processes.     

High dietary intake of medium-chain fatty acids during pregnancy in rats prevents later-life obesity in their offspring

We investigated the effects of dietary fatty acids of different chain lengths during pregnancy in the rat on the susceptibility of offspring to later-life obesity and the underlying mechanisms. Pregnant rats were fed three different diets: standard (STD), high medium-chain fatty acids (MCFA); and high long-chain fatty acids (LCFA). The male offspring were assigned to three groups: STD control, MCFA and LCFA according to the maternal diets and suckled by dams fed with STD during pregnancy and lactation. After weaning, the offspring were fed with STD from 3 to 8 weeks of age. At the age of 8 weeks, rats in three groups: high-fat diet (HFD) control, MCFA and LCFA were fed with HFD until 14 weeks of age in an attempt to induce obesity, and rats in the HFD control group were selected randomly from the STD control group. Body weight and body fat content were decreased in the MCFA group accompanied by down-regulated mRNA expression of fatty acid synthase and acetyl-coA carboxylase 1, and increased mRNA and protein expression of adenosine monophosphate (AMP)-activated protein kinase (AMPK), carnitine palmitoyltransferase 1 and uncoupling protein 3 compared with the corresponding controls at 3, 8 and 14 weeks of age. The results suggested that the MCFA diet during pregnancy prevented later-life obesity in the offspring when they were exposed to HFD in later life, which might be related to programming of the expression of genes involved in fatty acid metabolism.