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The effects of 5 c, 11 c, 14 c-eicosatrienoic acid (20∶3BSO) and 5 c, 11 c, 14 c, 17 c-eicosatetraenoic acid (20∶4BSO), polyunsaturated fatty acids (PUFA) contained in Biota orientalis seed oil (BSO), on lipid metabolism in rats were compared to the effects of fats rich in linoleic acid (LA) or α-linolenic acid (ALA) under similar conditions. The potential effect of ethyl 20∶4BSO as an essential fatty acid also was examined in comparison with the ethyl esters of LA. ALA and γ-linolenic acid (GLA). BSO- and ALA-rich fat decreased the concentration of plasma total cholesterol, high density lipoprotein cholesterol, triglyceride and phospholipid as compared to LA-rich fat. BSO was more effective in reducing plasma cholesterol concentrations than was the ALA-rich fat. Dietary BSO markedly decreased the hepatic triglyceride concentration as compared to the LA-rich or ALA-rich fats. Aortic production of prostaglandin I tended to decrease in rats fed BSO or ALA-rich fat compared to those fed the LA-rich fat. Adenosine diphosphate-induced platelet aggregation was similar in the three groups. The proportion of arachidonic acid (AA) in liver phosphatidylcholine (PC) of rats fed BSO was lowest compared to that of rats fed ALA-rich or LA-rich fats. Administration of 20∶4BSO, ALA or GLA to essential fatty acid-deficient rats decreased the ratio of 20∶3n−9 to AA in liver PC to the same extent; administration of LA was more effective. The results indicate that the effects of specific PUFA contained in BSO on lipid metabolism are different from those of LA and ALA. It is also suggested that 20∶4BSO may exhibit some essential fatty acid effects. [ABSTRACT FROM AUTHOR]

The effect of trans fat on the activities of liver mitochondrial and peroxisomal fatty acid oxidation enzymes was examined in various strains of rats. When Wistar and Sprague-Dawley rats were fed for 30 days diets containing either olive oil or partially hydrogenated corn oil as a source of cis-or trans-octadecenoate, respectively, the activities of various enzymes of mitochondrial and peroxisomal β-oxidation measured with cis- and trans-9-octadecenoic acid as substratese showed little dietary fatdependent change. In Fischer 344 rats, feeding trans fat for 15 mo increased only moderately various enzymes of β-oxidation except for carnitine acyltransferase. The rate of mitochondrial ketogenesis and the activity of carnitine acyltransferase measured with trans-9-octadecenoic acid as a substrate were about half those with the cis-counterpart. Peroxisomes oxidized trans-9-octadecenoyl-CoA at a rate comparable to the cis-counterpart. It was concluded from this study and previous ones that the difference in the geometry of dietary fatty acid had only a marginal effect in modulating the hepatic fatty acid oxidation system, in spite of marked differences in the metabolic behavior of cis-and trans fatty acid in cell-free preparations and perfused liver. [ABSTRACT FROM AUTHOR]

Rats were fed semipurified diets containing olive oil or partially hydrogenated corn oil at the 5 or 20% level for ca. 30 days. These fat diets contained the same amount of octadecenoate but differed in the geometry with respect to each fat level. Contents of t-18∶1 were 26% and 41% of total fatty acids, respectively. The linoleic acid content was also made equivalent (3.8 energy %). After feeding on cholesterol-free diets, rats on trans fat, compared to those on cis fat, showed: (a) no changes in serum cholesterol and apolipoprotein levels, (b) no effects on the bile flow and concentrations of biliary cholesterol or bile acids, (c) a trend toward increased fecal excretion of neutral and acidic steroids, (d) a lesser extent of transformation of cholesterol to coprostanol in the gut, and (e) no changes in the composition of biliary and fecal bile acids. Observations (c) and (d) were more marked with a high trans fat regimen. These observations, except for serum apolipoproteins and fecal steroid excretion, were practically reproducible even when rats were fed cholesterol-enriched diets. [ABSTRACT FROM AUTHOR]

Rats were fed cholesterol-free or cholesterol-enriched diets containing olive oil or partially hydrogenated corn oil at the 10% level for ca. 30 days ( c-18∶1, 77.0% in the former diet and c-18∶1, 24.7% and t-18∶1, 42.5% in the latter). The linoleic acid content of these fat diets was made equivalent (1.7 energy%). After feeding cholesterol-free diets, trans fat compared to cis fat showed(a) no untoward effects on growth parameters, (b) a reduction of serum cholesterol levels without influencing concentrations of serum apolipoproteins A-I, B and E, (c) no effects on the bile flow and the concentration of biliary cholesterol and bile acids, (d) an increasing trend of fecal excretion of neutral and acidic steroids, both in terms of mg/day and mg/g feces, and (e) rather equivocal change in the composition of fecal, but not biliary steroids. Similar response patterns were also observed when cholesterol-enriched diets were fed except for a decrease in serum apo B and an ineffectiveness to increase fecal acidic steroids. Together with the results obtained from experiments simultaneously performed with safflower oil and completely hydrogenated corn oil, it seems that the steroid metabolism can be specificallymodified by the geometry of dietary fats. [ABSTRACT FROM AUTHOR]

Rats were fed diets containing either camellia oil or partially hydrogenated corn oil, as a source of cis or trans octadecenoate, respectively, in the presence of adequate linoleic acid. After 35 days of feeding the diets, activities of several hepatic drug metabolizing enzymes as well as the content of hepatic microsomal cytochrome P-450 were determined. Geometrical difference in the dietary fat did not affect the amount of microsomal protein nor the content of cytochrome P-450. Also, activities of NADPH cytochrome C reductase, aminopyrine N-demethylase and biphenyl hydroxylase were approximately the same between two groups of rats. Aniline hydroxylase was slightly elevated in the rats fed trans fat. It was concluded that the difference in the geometry of dietary fatty acids had little effect in modulating the hepatic mixed function oxidase system. [ABSTRACT FROM AUTHOR]