In an effort to determine the metabolic changes that occur in fatty acid oxidation during the rapid growth period, the activity of carnitine palmitoyltransferase was measured in four groups of animals at 4, 8, 12 and 16 weeks of age.Muscle samples were taken from the soleus after animals were anesthesi2ed, and the samples were assayed for CPT activity. The CPT activity was significantly higher at 4 weeks than at 8, 12 and 16 weeks (p0.0001), and the fl week activity was significantly higher that the 16 week animals. It was found that there were two distinct phases of decline in CPT activity. The first occured from 4-8 weeks where a 74% drop in activity was recorded. The second phase was a more gradual decline that occured after 8 weeks. 21% decline in activity occured between 8 and 12 weeks, followed by a 23% decrease after 12 weeks. The first drastic drop in activity can be attributed to the residual heightened enzyme concentration carried over from the suckling period in which the rat was exposed to a high fat diet found in the mother's milk. The second phase of the decline in activity is due to a dietary change which caused a shift in metabolism from fat to glucose as the primary carbon source for fuel. / School of Physical Education

Penicillium chrysogenum was investigated to determine whether there are lipoproteins specifically associated with fatty acid synthesis and in what fraction of P. chrysogenum they are located. Radio-activity labeled free fatty acids and CoA thioester substrates were added to cell-free extracts and incubated. Samples of these incubation mixtures were analyzed for lipoprotein content with electrophoresis and for the presence of radioactivity with a radiochromatogram scanner and scintillation spectrometer.Label from fatty acyl thioester substrates migrated with protein fractions having alpha-2 or beta mobility showing the existence of lipoproteins associated with fatty acid metabolism in cell-free extracts of P. chryogenum. The percent distribution of radioactivity from the thioester incubations supported previous work in this laboratory on the desaturase system and suggested the presence of a long chain fatty acyl-CoA-ACP synthetase enzyme in Penicillium chrysogeum.

Thesis (Ph. D.)--University of Texas at Austin, 1998. / Vita. Includes bibliographical references. Available also in a digital version from Dissertation Abstracts.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1968. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

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The effect of vitamin B-6 (B-6) status on plasma fatty acids (FA) levels and lipid metabolism was investigated in this metabolic study. Eight female subjects were fed for 28 days. For the first 7 days, they were fed a constant diet containing 2.10 mg of B-6. For the rest of the period (21 days), they were differentiated in terms of B-6 intake; 4 of them were fed a low (0.93 mg/day) and 4 a high (2.60 mg/day) B-6 diet. B-6 status indices, plasma FA concentration and lipid profile were determined. Plasma pyridoxal 5'-phosphate and total B-6 concentration (P<0.01), urinary 4- pyridoxic acid and total B-6 concentration (P<0.001) showed a significant difference between the two groups at the end of the study. Erythrocyte PLP failed to show any significant difference between the two groups throughout the diet study. There was no significant difference in the plasma FA or lipid profile between the two groups. Plasma total cholesterol (TC) of the low B-6 group decreased slightly (7 %), but was not statistically significant. When comparing day 7 and day 28 values, plasma triglycerides increased (9 %) for the high and decreased for the low B-6 group. LDL-C decreased (5 %) for the high B-6 group but did not change in the low B-6 group. HDL-C decreased slightly in both groups (~8 %). There was no clear evidence that a low intake of vitamin B-6 affects the fatty acid and lipid metabolism. Further studies are required to identify the relationship between vitamin B-6 and fatty acid and lipid metabolism in humans. / Graduation date: 1997

Copies of 16 publications from the thesis, authored and co-authored by the author, included as appendix. / Includes bibliographical references (leaves 195-220). / 1 v. (various pagings) : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Examines 3 hypotheses: that the lipid levels and fatty acid composition of meat produced in Australia may vary between cattle genotypes, ages, sexes, seasons, and anatomical sites of sampling; that genetic variation may be sufficiently large to warrant selective crossbreeding of dams to different sire genotypes as an improvement strategy in the proportion of monounsaturated fatty acids in beef; and, that genotype differences in bovine tissue may exist when phospholipid and triacylglycerol fractions of total lipids are analysed separately, regardless of fatness of the cattle. Genetic variation in fatty acid composition of 7 different cattle breads were examined in experiments using non-lactating cows, yearling steers, yearling heifers and weaner calves. Breed differences were found in the muscle and adipose tissues when phospholipid and triacylglycerol fractions were analysed separately regardless of the fatness of the cattle. Differences in age, sex, season and anatomical site were also significant. The study concludes that breed differences in fatty acid composition are related to fatness and stage of maturity such that early-maturing cattle are fatter, contain higher proportions of unsaturates, and have softer fats with low melting points than lean, late-maturing cattle. It is recommended that total lipids be separated into triacylglycerol and phospholipid fractions and analysed separately. Desturation indexes could be used as a biochemical marker for beef breeding decisions, and genetic parameters presented used for future selection indices for fatty acids in carcass quality assessment. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Science, 1999

Includes bibliographical references (leaves 59-79) Examines the metabolism of volatile fatty acid and formic acid in fed sheep. Develops a method for analysing and qualifying volatile fatty acids with special reference to formic acid in biological fluids by High-Performance Liquid Chromatography.

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