In der vorliegenden Arbeit wurde der Einfluss mehrfach ungesättigter Fettsäuren (PUFA) auf das Phospho- und Sphingolipidmuster der Non-raft- und Lipid raft-Bereiche in Membranen von RAW264.7-Makrophagen massenspektrometrisch untersucht. Außerdem wurden mittels Fluoreszenzmikroskopie die Auswirkungen einer PUFA-Zugabe auf die Lokalisation des immunologisch bedeutsamen Mustererkennungs-Rezeptor TLR2 und seinen Ko-Rezeptoren TLR1 und TLR6 untersucht.

The diploma thesis is devided into two parts – theoretical and practical. The theoretical part deals with fatty acids, their nomenclature and chemical composition. Further the diploma thesis focuses on polyunsaturated fatty acids (PUFAs) – their analytical determination, metabolism, important representatives and influence on human nutrition. The practical part deals with the experiment, in which the fatty acids content was determined in mg/100 g using gas chromatography. Testing was carried out using model animals – rats Wistar Albino and pigs Landrace and Large White. By using statistical processing, the differences in the deposition of PUFAs in the livers of these animals, were compared.

The theoretical part of my thesis is based on the general classification and characterization of dietary lipids, especially fatty acids, cholesterol and lipoprotein particles. Also, their transport and absorption mechanisms are described, as well as medical complications that are closely linked to excessive lipid consumption. One part is used for the description of lipid extractions and determination of fatty acids. The experimental part is focused on the analysis of fatty acids in samples of liver, adipose and muscle tissues of laboratory rats after the addition of palm oil, safflower oil, fish oil and Schizochytrium microalgae oil into their diets. Lyophilized tissue samples were extracted and derivatized, followed by gas chromatography fatty acid determination. The results were then statistically evaluated.

Literar review of thesis is focused on clasification of lipids, fatty acids characteristics, particularly polyunsaturated acids n3 alpha linolenic, eicosapentaenoic and docosahexaenoic acid; and polyunsaturated acids n6. There is description of metabolic reactions. Degradation by beta oxidation, biosynthesis and conversion to eicosanoids. Function and effect of eicosanoids to organism and health, nutritional representation of this fatty acids, fortification of food sources, feed in interest of improvement health condition and functional foods producing. The practical part is focused on fatty acids analysis in muscular, liver and adipose tissue of pigs after feed fortification by 2,5 % fish oil and 2,5 % palm oil in the diet. Lyofilizated samples were derivatized and determinated by gas chromatography method. Results were evaluated by statistics program.

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1 Abstract In this thesis I have focused on the role of lipids in the pathogenesis of liver diseases, specifically on cholestasis and non-alcoholic fatty liver disease (NAFLD). The first major aim was to clarify the changes in liver ganglioside metabolism in various types of cholestasis and to elucidate the role of heme oxygenase-1 (HMOX1) and associated oxidative stress. The second objective was to determine the effects of n-3 polyunsaturated fatty acids (n-3 PUFA) administration on NAFLD development in a rodent dietary model of NAFLD and in patients with metabolic syndrome and NAFLD. Our results suggest that increased ganglioside biosynthesis and their re-distribution might represent a general protective mechanism of hepatocytes under cholestatic conditions (both estrogen-induced and obstructive aetiology). These changes are closely related to oxidative stress and might protect hepatocytes against deleterious effect of accumulated bile acids. The lack of HMOX1 activity and subsequent oxidative stress potentiate pathological changes in the liver and resulted in tissue-specific modulation of synthesis and re-distribution of gangliosides (in vivo and in vitro). Contrary to it, HMOX1 activation has an opposite effect and may represent a general hepatoprotective mechanism. We have proven that observed changes...

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Tilapia are freshwater fish that have become important in aquaculture and as a stable global source of seafood due to their ability to thrive in different environments. However, tilapia are sometimes considered nutritionally undesirable due to their high n-6 to n-3 fatty acid ratios. A market study was conducted first to determine fatty acid compositions in tilapia fillets in different US markets. Then a research was conducted to enhance nutritional value of tilapia by improving the n-3 and oleic acid contents in fish fillets without compromising fish growth or feed conversion ratios. Feeds were formulated with combinations of high and low n-6, n-3, and oleic acid levels using soybean oil, fish oil, algae oil, and high-oleic sunflower oil. Then 12 diets, including a commercial diet, were assigned to 24 tanks, each with 25 tilapia per tank. A Recirculating Aquaculture System (RAS) was used to grow the fish for 8 weeks. Fatty acid compositions of tilapia fillets were determined and samples were vacuum packed and stored at -10oC and -20oC to test oxidative degradation and fatty acid compositional changes. The market survey data showed that there were significant differences in fatty acid composition, lipid content, and n-6:n-3 fatty acid ratios depending on the country of origin. Samples from USA had ideal n-6:n-3 ratios (1.3 ±0.85) while samples from Southeast Asia had higher n-6:n-3 fatty acids ratio (6.6 ±0.54). Algae oil incorporation significantly increased DHA level while fish oil incorporation significantly increased both EPA and DPA. High-oleic sunflower oil based diets improved oleic acid levels and reduced linoleic acid compared to the soybean oil based diets. Sensory evaluation indicated that lipid source did not significantly impact preference or overall fillet quality, including texture. Interestingly, a survey showed people were interested in value-added tilapia, and would pay up to 30% more for nutritionally enhanced fish compared to the $5.00/lb fresh fillet price currently available in supermarkets. There was no observable oxidation during long term frozen storage. The oxidation study proved that value-addition would not be compromised during the long term storage conditions, even under temperature abuse. It is possible to improve tilapia nutritional quality through diet to provide consumers with value-added products that maintain quality during frozen storage. / Ph. D.