Adipose tissue lipids

Distribution. Generally the highest concentration of PCB residues in fish are in tissues of high lipid content. In Table V juvenile coho salmon were fed equal amounts of three chlorobi-phenyls for 117 days. Fish were then killed and lipid content and PCB concentration of various tissues determined (33). Tissues are arranged from top to bottom in order of increasing PCB concentration. For most tissues, but not all, as lipid content increases so does PCB concentration. Lipid content and PCB concentration are low in liver and white muscle, intermediate in spinal column and lateral line muscle, and high in adipose tissue. Lipid content cannot be the sole determinant of PCB concentration in fish tissues because a discrepancy exists between lipid content of brain, heart and spleen and PCB concentration. 

Alterations in the composition of the plasma lipids caused by estrogens are characterized by an increase in the high-density lipoproteins (HDL), a slight reduction in the low-density lipoproteins (LDL), and a reduction in total plasma cholesterol levels. Plasma triglyceride levels are increased. Estrogens decrease hepatic oxidation of adipose tissue lipid to ketones and increase synthesis of triglycerides. 

Yurawecz, M.P., Roach, J.A.G., Sehat, N., Mossoba, M.M., Kramer, J.K.G., Fritsche, J., Steinhart, H., Ku, Y. 1998. A new conjugated linoleic acid isomer, 7 trans, 9 m-octadcca-dienoic acid, in cow milk, cheese, beef and human milk and adipose tissue. Lipids. 33, 803-809. 

Z. Yasruel, K. Cianflone, A.D. Sniderman, M. Rosenbloom, M. Walsh, and M.A. Rodriguez, Effect of acylation stimulating protein on the triacylglycerol synthetic pathway of human adipose tissue, Lipids, 1991, 26, 495-499,... 

Another family of nuclear hormone receptors intimately involved in adipose tissue lipid metabolism is the liver X receptors (LXR), which also heterodimerize with RXRa. Within... 

The fatty acid profile can be modified substantially by feeding encapsulated (protected) polyunsaturated oils to cows. The oil is encapsulated in a film of polymerized protein or in crushed oil-rich seeds. The encapsulating protein is digested in the abomasum, resulting in the release of the unsaturated lipid, a high proportion of the fatty acids of which are then incorporated into the milk (and adipose tissue) lipids. The technical... 

PPARy activation in adipose tissue would be expected to result in an activation of adipocyte differentiation, as has been demonstrated in vitro. - Thrrs, htrmarts treated with pioglitazone worrld be expected to demonstrate an increase in adipocyte differentiation, which worrld lead to a potential increase in adipose tissue hpid. The mechanism of this increase in differentiation may be a direct effect of stimrrlation of adipogenesis from preadipocytes, or it may be due to a thiazolidinedione-induced decrease in inflammatory cytokine expression by macrophages. As a result of a thiazohdinedione-mediated increase in lipid accumttlation in adipose tissue, there may be a diversion of dietary lipid into adipose tissue and away from other organs that are more susceptible to lipotoxicity, such as muscle, islets, and liver. Thus, the increase in adipose tissue lipid may, in effect, steal lipid from other organs, such as islets and muscle, which are crucial comptonents of glucose homeostasis. 

The present study demonstrated that CLA accumulates in the liver lipids of rats (Tables 4 and 5) and liver or adipose tissue lipids of mice (Tables 6 and 7) fed CLN diets. The CLA detected in these tissue lipids was identified as c9,fll-CLA for PGO and BGO diets, the t9,rl 1-CLA isomer for the CTO diet, and f8,fl0-CLA for the PMO diet. The main CLN isomers contained in the PGO, BGO, CTO, and PMO diets were c9,tll,cl3-CLN, c9,tlI,rl3-CLN, t9,tll,cl3-CLN, and t8,tlO,cl2-CLN, respectively. Therefore, the formation of the CLA isomer in the tissue lipids of the animals fed the CLN diets may be explained by the enzymatic conversion of CLN to CLA, namely, the biohydrogenation at carbon 13 or carbon 12 double bonds. This metabolic pathway was confirmed by the result that no CLN was detected in the... 

Chief Fatty Acids of Adipose Tissue Lipids... 

Patel, M. S., Jomain-Baum, M., Ballard, F. J., and Hanson, R. W., 1971, Pathways of carbon flow during fatty acid synthesis from lactate and pyruvate in rat adipose tissue, /. Lipid Res. 12 179. 

It is fortunate that the development of adipose tissue lipids in man can be studied with relatively simple biopsy techniques. Detailed temporal studies of human brain lipids are more problematical and highlight the need for a good animal model. The pig, which is inadequate as a model for the temporal aspects of adipose tissue development, is useful as a model for... 

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