Requirement For Polyunsaturated Fatty Acids Research Articles

Effects of terrestrial lipid blend on the growth performance, body composition, nonspecific immunity, antioxidant status and stress resistance when the dietary n‐3 long‐chain polyunsaturated fatty acids requirements are met in juvenile Japanese sea bass ( Lateolabrax japonicus )

This study was conducted to investigate the effects of replacing dietary lipid source FO with a terrestrial lipid blend (LB) on the growth performance, body composition and immunity of juvenile Japanese sea bass when the dietary n-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFAs) requirements are met (Lateolabrax japonicus). Two types of experimental diets were formulated with the total FO (the control) or the LB (linseed oil and lard = 1:1). A 56-day feeding trial was conducted in floating cages with three replicates for each treatment. The results indicated that a significantly higher specific growth rate (SGR) and feed efficiency ratio (FER) occurred in fish that were fed the LB diet compared with the control group (p < 0.05). There was no significant difference in the survival rate, body composition or body indicates between the groups (p > 0.05). The respiratory burst, alternative complement pathway activity, lysozyme activity, cytokine genes expression and air exposure test results indicated that the replacement of FO with LB did not significantly affect the nonspecific immunity or stress resistance (p > 0.05). The serum antioxidant enzyme activities and liver tissue antioxidant-related gene expression were significantly higher in the control group than in the other group (p < 0.05). Therefore, the terrestrial lipid blends from linseed and lard (1:1) could be used as an alternative for dietary fish oil without compromising the growth performance, nonspecific immunity and resistance to stress in juvenile Japanese sea bass.

Meeting the fetal requirement for polyunsaturated fatty acids in pregnancy

The aim of this review is to summarize recent evidence on the importance of individual long chain polyunsaturated fatty acid (LCPUFA) to the developing fetus and the maternal dietary requirement for these. Large-scale randomized controlled trials and innovative genetic and stable isotope studies are providing new insights in this field. Large randomized controlled trials of LCPUFA supplementation in pregnancy suggest that higher n-3 LCPUFA intake reduces the risk of preterm birth and increases the length of gestation, with secondary effects on birth weight. There is little evidence of an effect on postnatal visual function and cognition, but interpretation is complicated by maternal metabolic adaptations and adipose tissue status in the newborn. The links between polymorphisms in the FADS genes and tissue fatty acid composition suggest that LCPUFA synthesis influences overall availability. Stable isotope studies have also demonstrated the capacity for LCPUFA synthesis in pregnancy, the fact that n-6 synthesis is greater than n-3, metabolic channeling of individual fatty acids to different fates, and selective placental transfer. Studies linking FADS genotype to cognition imply that n-3 LCPUFA synthesis could have an effect on infant cognition, but more large-scale genetic studies are needed.

Hormone-stimulated modulation of endocytic trafficking in osteoclasts

A precise control of vesicular trafficking is crucial not only for osteoclastic bone resorption, but also for the crosstalk between osteoclasts and osteoblasts, which regulates bone homeostasis. In addition to the release of growth factors and modulators, such as glutamate, flux through the intracellular trafficking routes could also provide the osteoclast with a monitoring function of its resorption activity. To establish the signaling pathways regulating trafficking events in resorbing osteoclasts, we used the bone conserving hormone calcitonin, which has the unique property of inducing osteoclast quiescence. Calcitonin acts through the calcitonin receptor and activates multiple signaling pathways. By monitoring trafficking of a fluorescent low molecular weight probe in mature, bone resorbing osteoclasts we show for the first time that calcitonin blocks endocytosis from the ruffled border by phospholipase C (PLC) activation. Furthermore, we identify a requirement for polyunsaturated fatty acids in endocytic trafficking in osteoclasts. Inhibition of PLC prior to calcitonin treatment restores endocytosis to 75% of untreated rates. This effect is independent of protein kinase C activation and can be mimicked by an increase in intracellular calcium. We thus define an essential role for intracellular calcium levels in the maintenance of endocytosis in osteoclasts.

Effect of a supplement rich in linolenic acid, added to the diet of gestating and lactating goats, on the sensitivity to stress and learning ability of their offspring

The requirements for polyunsaturated fatty acids during brain development are high and in certain situations supply may be inadequate. Numerous studies in rodents have shown that a diet rich in linolenic acid improves learning ability and modifies emotional reactivity of offspring. Thirty-two goats received from 1.5 months before to 2 months after parturition either a control supplement (C, rapeseed supplement, n = 16), rich in oleic acid (C18:1 n − 9) or a test supplement (L, linseed supplement, n = 16), rich in linolenic acid (C18:3 n − 3). At birth the profile of fatty acids was measured in blood, mammary secretions and tissue samples from the goats and their kids. After birth the kids were fed a mixture of milk obtained from the same treatment group as their dam and their emotional reactivity and learning ability were studied. The profile of fatty acids was also measured in goat milk and kid plasma. Plasma proportions of linolenic acid, eicosapentaenoic acid (C20:5 n − 3) and docosahexaenoic acid (C22:6 n − 3) were increased ( P < 0.05) and arachidonic acid (C20:4 n − 6) decreased ( P < 0.01) by L compared to C in goats and kids at birth. At 11 days, L kids spent more time sniffing the environment ( P < 0.01) and less time immobile ( P < 0.05) in a novel environment and passed more frequently next to the novel object ( P < 0.05). The kids also tended to spend more time watching the object ( P = 0.079) and tended to delay the first vocalisation with mouth open ( P = 0.070) compared to C kids. Learning ability in a T-maze test at 46 days and the reaction to a startling stimulus at 48 days were unaffected by treatment. In conclusion, a diet rich in linseed given to gestating and lactating goats seems to increase the attention/exploration of their kids at 11 days without affecting their learning ability.

The predominance of polyunsaturated fatty acids in the butterfly Morpho peleides before and after metamorphosis

We hypothesized that the polyunsaturated fatty acids of the butterfly were probably derived from the diet and that there might be a great loss of body fat during metamorphosis. To substantiate these hypotheses, we analyzed the fatty acid composition and content of the diet, the larva, and the butterfly Morpho peleides. Both the diet and the tissues of the larva and butterfly had a high concentration of polyunsaturated fatty acids. In the diet, linolenic acid accounted for 19% and linoleic acid for 8% of total fatty acids. In the larva, almost 60% of the total fatty acids were polyunsaturated: linolenic acid predominated at 42% of total fatty acids, and linoleic acid was at 17%. In the butterfly, linolenic acid represented 36% and linoleic acid represented 11% of total fatty acids. The larva had a much higher total fatty acid content than the butterfly (20.2 vs. 6.9 mg). Our data indicate that the transformation from larva to butterfly during metamorphosis drastically decreased the total fatty acid content. There was bioenhancement of polyunsaturated fatty acids from the diet to the larva and butterfly. This polyunsaturation of membranes may have functional importance in providing membrane fluidity useful in flight.

Fatty acid desaturase activities and polyunsaturated fatty acid composition in human liver between the seventeenth and thirty-sixth gestational weeks

Objective: The aim of the study was to characterize n-3 and n-6 fatty acid Δ5- and Δ6-desaturase activities and their time course variations in human fetal liver between the 17th and 36th gestational week. Study Design: Twenty-one biologic samples were obtained after legally approved medical abortion, according to French law. The desaturase activities were measured in the 21 liver samples by a radiochemical method by means of reverse-phase high-performance liquid chromatography. The fatty acid composition (percentage by weight) of liver phospholipids was assessed in 16 samples by gas-liquid chromatographic analysis. Results: Both Δ5- and Δ6-desaturase activities were significantly expressed between the 17th and 36th gestational weeks. During the second trimester n-6 fatty acid Δ5- and Δ6-desaturase activities showed opposite patterns of variation; both then remained stable between the 25th and 36th weeks. Δ6-Desaturation was higher in n-3 than n-6 fatty acids and peaked at the 18th gestational week. The percentages of linoleic and docosahexaenoic acids in liver microsomes were positively correlated with the gestation age (P < .01), whereas arachidonic acid remained stable. Conclusion: Significant n-3 and n-6 Δ5- and Δ6-desaturase activities are expressed in human fetal liver as early as the 17th gestational week and are stable throughout the third trimester. Their theoretic capacity evaluated from in vitro measurements appears lower than polyunsaturated fatty acid requirements and is not directly related to liver microsomal membrane fatty acid composition. (Am J Obstet Gynecol 1998;179:1063-70.)

A Mutant of Arabidopsis Deficient in Desaturation of Palmitic Acid in Leaf Lipids

The overall fatty acid composition of leaf lipids in a mutant of Arabidopsis thaliana was characterized by elevated amounts of palmitic acid and a decreased amount of unsaturated 16-carbon fatty acids as a consequence of a single nuclear mutation. Quantitative analysis of the fatty acid composition of individual lipids suggested that the mutant is deficient in the activity of a chloroplast omega9 fatty acid desaturase which normally introduces a double bond in 16-carbon acyl chains esterified to monogalactosyldiacylglycerol (MGD). The mutant exhibited an increased ratio of 18- to 16-carbon fatty acids in MGD due to a change in the relative contribution of the prokaryotic and eukaryotic pathways of lipid biosynthesis. This appears to be a regulated response to the loss of chloroplast omega9 desaturase and presumably reflects a requirement for polyunsaturated fatty acids for the normal assembly of chloroplast membranes. The reduction in mass of prokaryotic MGD species involved both a reduction in synthesis of MGD by the prokaryotic pathway and increased turnover of MGD molecular species which contain 16:0.

The failure of the cat to desaturate linoleic acid; its nutritional implications.

In vivo administration of 1-14C-linoleic acid to domestic cats demonstrated that these animals are unable to convert this essential fatty acid to its physiologically active metabolities. This experiment confirms the absence of both the delta6 and delta8 desaturases in the cat, and suggests that this species has a dietary requirement for polyunsaturated fatty acids of animal origin.

Methyl Linolenate as an Essential Nutrient for the Cabbage Looper, Trichoplusia ni (Hübner)

A DIETARY requirement for polyunsaturated fatty acids has been demonstrated in several lepidopterous and orthopterous species. The most common expression of fatty acid deficiency was a slower larval growth-rate or faulty adult emergence with resulting wing deformity, or both1–5. In the lepidopterous species examined the requirement was fulfilled with either linoleic or linolenic acids2,3,5. In the genus Ephestia, the flour moths, linoleic or linolenic acids promoted larval growth and normal wing development3. Arachidonic acid improved the growth-rate of Ephestia, but had no positive effect on wing development6. Linoleic acid allowed normal wing development of the pink boll-worm, Pectinophora gossypiella (Saund.), but, because lower levels were active, linolenic acid was considered more effective5. Normal wing development of the greater wax moth, Galleria mellonella (L.), was promoted with linoleic or linolenic acids, but not with arachidonic acid2.

FATTY ACIDS IN SOME INSECT AND SPIDER FATS.

Chromatographic analysis of the fats of 30 species of Insecta and 2 species of Arachnida showed specific differences, and also two characteristics apparently related to existing taxa: a high concentration of myristic acid in fats of Aphidoidea, and a high concentration of palmitoleic acid in Diptera. A possible relationship between the high palmitoleic acid content of the fat of Agria affinis (Fallén) (Diptera: Sarcophagidae) and its lack of requirement for polyunsaturated fatty acids is suggested.

Factors Influencing the Requirement for Polyunsaturated Fatty Acids

Factors Influencing the Requirement for Polyunsaturated Fatty Acids