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Vliv PUFA n-3 na expresi genů kódujících proteiny řídící homeostázu cholesterolu
Hyblerová, Dagmar
The aim of this study was to confirm that the polyunsaturated fatty acids n-3 (n-3 PUFA) have a positive effect on plasma lipids. These acids can reduce cholesterol by increasing gene expression Insig-1 while decreasing the expression of genes encoding Hmgcr and Ldlr. We tested in experimental rats, which were added to the feed mixture of 6 % safflower oil , 6 % fish oil or 6 % of the oil from the algae Schizochytrium. Relative gene expression was Insig-1 in the test group with addition of fish oil to 120% of controls (P<0.05) and in the group with addition of oils from algae Schizochytrium the relative expression of 170 % of control (P<0.05). These results confirm our hypothesis, only a part, as the relative expression of the gene and Hmgcr and Ldlr was in the test group with addition of fish oil 103% (P>0.05) and 101 % of control (P>0.05) and in the group with addition of oils from algae Schizochytrium the relative expression of 117% (P>0.05) and 156 % (P>0.05) compared to control. Thus, to reduce the relative expression of these genes did not. However, we have shown that n-3 PUFA contribute to a reduction in plasma cholesterol and in this case up to 20 % of control. The concentration of cholesterol in the group with addition of safflower oil was 1.35 mmol.l-1, the group with the addition of fish oil 0.98 mmol.l-1.
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Vliv polynenasycených mastných kyselin na zastoupení mastných kyselin ve tkáních a hladinu cholesterolu u potkanů
Kácalová, Tereza
The aim of this work was demonstrate positive effect of n-3 polyunsaturated fatty acids EPA and DHA on the concentration of plasma triglycerides and cholesterol. According to the hypothesis, these polyunsaturated fatty acids are capable of reducing plasma cho-lesterol in mechanism, where is increased gene expression Insig-1 and simultaneously reduces the expression of genes encoding an enzyme for cholesterol synthesis (3-hydroxy-3-methylglutaryl-CoA reductase, a gene for HMG-CoA-R) and the gene for the LDL receptor, which is responsible for the entry of cholesterol from the plasma into the cells (low density lipoprotein receptor, the density, the LDL-R gene). LDL-R.The experiment was conducted on a model animal (Rattus norvegicus) fed with a standard feed mixture with the addition of 3% of salmon oil, fish oil 6% and 6% of oil from algae of the genus Schizochytrium. The control group was fed a feed mixture with the addition of 6% safflower oil, food with the addition of 3% palm oil was used as a negative control. Each group consisted of 10 animals. From the blood samples was determined levels of total cholesterol, HDL-cholesterol, LDL-cholesterol and triglycerides. The fatty acid content was determined in muscle, liver and adipose tissue. Food enriched with eicosapentaenoic acid and docosahexaenoic acid led to a reduction in total cholesterol and LDL-cholesterol levels. It was shown (P <0.05) after the addition of fish oil, salmon oil and algae of the genus Schizochytrium oil to feed mixtures of experimental rats, a decrease in total cholesterol (27%, 21%, 27% respectively) relative to controls. Our attempt partially confirmed the hypothesis. At the same time, we found that plasma lipid metabolism affects different mechanism than we thought.
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