Polyunsaturated fatty acid, <0-3-, fish

A prominent fish polyunsaturated fatty acid is docosahexaenoic acid (DHA), and when this is added to thrombocyte preparations in the presence of trout fibrinogen, it produces no aggregatory response (D.J. Hill and A.F. Rowley, unpublished work). However, DHA added to thrombocyte preparations immediately before the addition of U-46619 in the presence of trout fibrinogen causes a marked decrease in the amount of aggregation induced (D.J. Hill and A.F. Rowley, unpublished work). This inhibition of U-46619-induced thrombocyte aggregation by DHA is dose dependent and saturable at concentrations above 0.3 pM. Preliminary studies with EPA indicate a similar inhibition of U-46619-induced thrombocyte aggregation to that seen with DHA. These findings correlate... 

As mentioned earlier, both MCTs and LCTs are used in tube feeding products. Corn, soy, and safflower oils have been the mainstay sources of fat in these products, providing mainly co-6 polyunsaturated fatty acids (PUFAs). On the other hand, some newer EN products contain higher quantities of co-3 PUFAs from sources such as fish oil [i.e., docosahexenoic acid (DHA) and eicosapentenoic acid or (EPA)]. Still other formulas contain higher quantities of monounsaturated fatty acids from canola oil and high-oleic safflower or sunflower oils. The essential fatty acid (EFA) content (mainly linoleic acid) of EN... 

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are omega-3 polyunsaturated fatty acids that are most abundant in fatty fish such as sardines, salmon, and mackerel. A diet high in EPA plus DHA or supplementation with these fish oils reduces the risk of cardiovascular mortality, reinfarction, and stroke in patients who have experienced an MI. 

Diets high in omega-3 polyunsaturated fatty acids (from fish oil), most commonly eicosapentaenoic acid (EPA), reduce cholesterol, triglycerides, LDL, and VLDL and may elevate HDL cholesterol. 

Dietary polyunsaturated fatty acids (PUFAs), especially the n-3 series that are found in marine fish oils, modulate a variety of normal and disease processes, and consequently affect human health. PUFAs are classified based on the position of double bonds in their lipid structure and include the n-3 and n-6 series. Dietary n-3 PUFAs include a-linolenic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) whereas the most common n-6 PUFAs are linoleic acid, y-linolenic acid, and arachidonic acid (AA). AA is the primary precursor of eicosanoids, which includes the prostaglandins, leukotrienes, and thromboxanes. Collectively, these AA-derived mediators can exert profound effects on immune and inflammatory processes. Mammals can neither synthesize n-3 and n-6 PUFAs nor convert one variety to the other as they do not possess the appropriate enzymes. PUFAs are required for membrane formation and function... 

This disorder is characterised by inappropriate levels of activity, a high frequency of periods of frustration and distraction and hence inability to sustain attention and to concentrate on one activity for a prolonged period of time. A surprising finding is that amphetamine administration, which normally increases or facilitates activity, rapidly and markedly improves behaviour. Patients become calm and their alertness is enhanced. A drug that has been used is methylphenidate (Ritalin). One interesting and recent development is the improvement in the condition by supplementation of the diet with polyunsaturated fatty acids, particularly the omega-3 acids in fish oils (See Chapter 11). 

Fish Oil Supplements (Omega-3 Polyunsaturated Fatty Acid) Garlic Allium sativum) Gentian Genliana luiea) GingCT Zingiber officinale)... 

Fish Oil Supplements (Omega 3 Polyunsaturated Fatty Acid)... 

Marine fishes are rich sources of structurally diverse bioactive compounds including polyunsaturated fatty acids, polysaccharides, minerals, vitamins, antioxidants, enzymes, and bioactive peptides (Kim et ah, 2008). Marine fish-derived ACE inhibitory peptides have been purified from enzymatic digestion of various fish materials from Alaska pollack (Nakajima et ah, 2009), bonito (Fujita et ah, 2000 Hideaki et ah, 1993 Yokoyama et ah,... 

Fish oils that contain high amounts of the n-3 polyunsaturated fatty acids eiocosapentaenoic acid (EPA, 20 5, n-3) and docosahexaenoic acid (DHA, 22 6, n-3) have been suggested to decrease the risk of development of cardiovascular disease. Freshwater fish oil carp oil are not rich in n-3 polyunsaturated fatty acids, but tuna oil is rich in n-3 polyunsaturated fatty acids such as EPA and DHA Table (1) . 

Normally, the method of choice for the analysis of complex mixtures of polyenoic fatty acids such as those derived from fish oils is capillary gas chromatography with prechromato-graphic derivatization and mass spectrometric detection. However, GC is impractical for the purification of the large amounts of polyenoic fatty acids required for biological and clinical studies. Moreover, the temperatures required in GC may cause degradation of oxidized long-chain polyunsaturated fatty acids that are present as minor components of the mixture. 

More recent work emphasizes the synthesis by the fish of polyunsaturated fatty acids in the marine environment. Borlongan and Benitez (1992) maintained groups of milkfish (which can tolerate salinities from 0 to 100%o) in fresh water or sea water on the same diet, and while the two groups showed no differences in their total lipid contents, the proportion of phospholipids in the lipids of various organs was the greater in fish from sea water. The organs of fish in fresh water contained lipids with higher proportions of neutral lipids. 

There were marked differences in the fatty acid patterns of the lipids of gills and kidneys, those from seawater fish possessing more w-3 in proportion to w-6 fatty acids and a higher proportion of total polyunsaturated fatty acids. They suggested that the role of polyunsaturates in membrane permeability and plasticity might account for the observation, and pointed out that the w-3 structure allows a greater degree of unsaturation than do the <0-6 or w-9 series. 

On the other hand, some fish are able to synthesize long-chain polyenoic fatty acids (Kayama et al., 1963) from shorter carbon chains. Docosohexaenoic acid is laid down in coho salmon in quantities related to the size of the fish, rather than to its availability in the diet (Tinsley et al., 1973). Rainbow trout fed on 18 2 and 18 3 fatty acids can produce 20 3, 22 5 and 22 6 fatty acids in substantial quantities (Owen et al., 1975), but these workers noticed that the capacity of marine flatfish to elongate or desaturate the carbon chains was more limited. They found that 70% of the radioactivity of labelled 18 3 appeared later in the 22 6 fatty acid of rainbow trout, but that turbot converted only 3-15% of labelled precursors into polyunsaturated fatty acids of longer chain length. It was suggested that turbot in the wild probably received adequate polyunsaturated acids in their diet, which the fish therefore did not need to modify. The elongation of the carbon chains and the creation of more double bonds is also only slight in Atlantic cod, another marine teleost, presumably for the same reason (Ross, 1977). 

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