Oleic acid blood

Vitamin A. To overcome the difficulty of identification, vitamin A can be used as a label. The changes in the blood vitamin A curve following the administration of vitamin A in oil provide similar information to that given by the chylomicrograph. In malabsorption due to enteropathy the curve is depressed and delayed, and in pancreatic lipase deficiency it is markedly flattened. The use of vitamin A in oil and in aqueous dispersion is similar in principle to the use of labeled triolein and oleic acid (B4, G3, L4). 

Figure 11.15 The reaction catalysed by lecithin cholesterol acyltransferase (LCAT). LinoLeate is transferred from a phospholipid in the blood to cholesterol to form cholesteryl linoleate, catalysed by LCAT. The cholesterol ester forms the core of HDL, which transfers cholesterol to the liver. Discoidal HDL (i.e. HDL3) is secreted by the liver and collects cholesterol from the peripheral tissues, especially endothellial cells (see Figure 22.10). Cholesterol is then esterified with lin-oleic acid and HDL changes its structure (HDL2) to a more stable form as shown in the lower part of the figure. R is linoleate.

About 40 different fatty acids occur naturally. Palmitic acid (Ci6) and stearic acid (Cis) are the most abundant saturated acids oleic and linoleic acids (both G ) are the most abundant unsaturated ones. Oleic acid is monounsaturated because it has only one double bond, but linoleic and linolenic acids are polyunsaturated fatty acids (called PUFAs) because they have more than one carbon-carbon double bond. Although the reasons are not yet clear, it appears that a diet rich in saturated fats leads to a higher level of blood cholesterol and consequent higher risk of heart attack than a diet rich in unsaturated fats. 

Primary amides of unsaturated fatty acids have been characterized in humans and other mammals, and although their biological role is not fully understood, they may represent a group of important signalling molecules. Oleamide, the simple amide of oleic acid, has been shown to be a sleep-inducing lipid, and the amide of erucic acid, eru-camide, stimulates the growth of blood vessels. 

Avocado benefits circulation, lowers cholesterol, and dilates blood vessels. Its main fat, monounsaturated oleic acid (also concentrated in olive oil), acts as an antioxidant to block artery-destroying toxicity of bad-type-LDL cholesterol. It is one of the richest sources of glutathione, a powerful antioxidant shown to block 30 different carcinogens and to block proliferation of the AIDS virus (see Chapter 13). 

Three major families of unsaturated fatty acids are seen in warm-blooded animals, that is, the n-9, monounsaturated fatty acids (e.g. oleic acid, OA), and the n-6 and n-3, both polyunsaturated fatty acids (PUFAs). However, only the n-6 and n-3 families, derived from LA and ALA, respectively, are EFA. These must be obtained from the diet since mammals lack the desaturase enzymes necessary for the insertion of a double bond in the n-6 and n-3 positions of the fatty acid carbon chain. Fatty acid nomenclature is as follows The first number denotes the number of carbon atoms in the acyl chain and the second refers to the number of unsaturated (double) bonds. This is followed by a symbol n or co and a number that denotes the number of carbon atoms from the methyl terminal of the molecule to the first double bond. Hence, LA is 18 2(n-6), while the more unsaturated ALA is denoted as 18 3(n-3) (Figure 26.1). These fatty acids must be metabolized to their longer chain derivatives before carrying out many of their activities. 

Chan, J.K., Bruce, V.M., and McDonald, B.E. 1991. Dietary-linolenic acid is as effective as oleic acid and linoleic acid in lowering blood cholesterol in normolipidemic men. Am. J. Clin. Nutr. 53, 1230-1240. 

There, also, is interest in dietary monounsaturated fatty acids because of their possible protective effect against oxidation of LDL cholesterol (101). There is appreciable evidence that the uptake of LDL cholesterol and the formation of fatty streaks in the intima of large blood vessels, which is considered an early lesion of atherosclerosis, is enhanced by the oxidation of the LDL cholesterol (102, 103). LDL cholesterol was found to be appreciably more stable to oxidation when subjects were fed diets rich in oleic acid than when fed linoleic acid enriched diets (104-106). 

Canola oil is characterized by a low level of saturated fatty acids (less than 4% palmitic acid) and relatively high levels of oleic acid (60%) and a-linolenic acid (10%). It is second only to olive oil, among the common fats and oils, in oleic acid level and, except for soybean oil, the only common dietary fat that contains a significant amount of a-linolenic acid. Furthermore, there is a favorable balance in the levels of linolenic and linoleic acids (viz., 18 3/18 2 ratio of 1 2) in canola oil. Canola oil has been found equally as effective as soybean oil, safflower oil, and sunflower oil in reducing plasma total and LDL cholesterol levels in normolipi-demic subjects. It also was effective in reducing plasma total and LDL cholesterol levels in hyperlipidemic subjects when it replaced saturated fat in their diets. Canola oil diets also have been shown to affect the fatty acid composition of blood... 

A mix of 1,3- and 1,2-DAG (70% 30%, respectively, as diolein) was administered orally to rats followed by collection of blood from the portal vein at predetermined time periods. Oleic acid tended to be elevated from 0.5 hour to 1 hour after administration compared with triolein (8). 

In vitro tests have shown that oleic acid causes rupture of red blood cells (hemolysis), and intravenous injection or ingestion of a large quantity of oleic acid can therefore be harmful. The effects of oleic acid on alveolar and buccal epithelial cells in vitro have also been studied the in vitro and in vivo effects of oleic acid on rat skin have been reported. Oleic acid is a moderate skin irritant it should not be used in eye preparations. 

A. The 16-carbon, fully saturated fatty add, palmitate (16 0), is the product of the fatty acid synthase complex. It may be elongated by two carbons to form stearic add (18 0), or it may be oxidized to form palmitoleic acid (16 1,A9). Stearate can be oxidized to oleic acid (18 1,A ). Arachidonic acid (20 4,A5,8 11 14) can be synthesized from the essential fatty acid linoleate (18 2,A9 12). It cannot be produced from palmitate. Fatty acids synthesized in the liver are converted to triacylglycerols, packaged in VLDL, and secreted into the blood. 

The blood and tissues of animals typically contain not only unesterified cholesterol (UC), but also cholesterol esters (CE). Most of the CE are formed from long-chain fatty acids such as palmitic acid, oleic acid, linoleic acid, or arachidonic acid, but small amounts of cholesterol sulfate (CS) and cholesterol glucuronide also are present. The aim of this chapter is to provide a brief overview of the biochemistry, physiology, and pathology of these esters as an introduction to the field of CE research. The primary focus will be on long-chain fatty acid esters because much more is known about them than about other CE. However, current knowledge of the biochemistry of CS will be reviewed as well. 

Judd, J. D. Baer B. Clevidence et al. Blood lipid and lipoprotein modifying effects of trans mono-unsaturated fatty acids compared to carbohydrate, oleic acid, stearic acid, and C 12 0-16 0 saturated fatty acids in men fed controlled diets. FASEB J. 1998, 12, A229-A229.abstract. 

The enzymes in the pathways of fatty acid activation and p-oxidation (the synthetases, the carnitine acyltransferases, and the dehydrogenases of p-oxidation) are somewhat specific for the length of the fatty acid carbon chain. The chain length specificity is divided into enzymes for long-chain fatty acids (C20 to approximately C12), medium-chain (approximately C12 to C4), and short-chain (C4-C2). The major lipids oxidized in the liver as fuels are the long-chain fatty acids (palmitic, stearic, and oleic acids), because these are the lipids that are synthesized in the liver, are the major lipids ingested from meat or dairy sources, and are the major form of fatty acids present in adipose tissue triacylglycerols. The liver, as well as many other tissues, uses fatty acids as fuels when the concentration of the fatty acid-albumin complex is increased in the blood. 

Koyama, S., Kiyono, S., Kayaba, K., Kimura, M. and Nishizawa, M. (1985). Cardiovascular and blood gas responses to ketanserin canine pulmonary edema induced by oleic acid. Anesthesiology, 62, 457-461... 

Oba et al. used a W/O/W multiple emulsion composed of oleic acid as a carrier of carboxyfluorescein via the enteral route as a model for future drug transport. The W/O/W emulsion was considered to be superior to micelles because it maintained a higher blood level of carboxyfluorescetn over long periods and tran.sferred it to the lymphatic system (51). 

Olive oil is a good example of a lipid that provides numerous health benefits when included in the diet. The main type of lipid found in all types of olive oil is monounsaturated fatty acids, or MUFAs, with the 18-carbon oleic acid being the predominant component (see Table 8.1 for its formula). MUFAs are considered to be healthy lipids. There is evidence that dietary MUFAs help lower total cholesterol levels in the body, and especially the levels of undesirable low-density lipoproteins (LDLs). Some research results show that MUFAs may help maintain normal blood clotting and normal blood pressure and may aid in the control of blood sugar levels. 

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