Lipid breakdown

JR Williamson, SK Joseph, KE Coll, AP Thomas, A Verhoeven, M Prentki. (1986). Hormone-induced inositol lipid breakdown and calcium-mediated cellular responses in liver. In G Poste, ST Crooke, eds. New Insights into Cell and Membrane Transport Processes. New York Plenum Press, pp 217-247. 

Free arachidonic acid, along with diacylglycerols and free docosahexaenoic acid, is a product of membrane lipid breakdown at the onset of cerebral ischemia, seizures and other forms of brain trauma 585... 

Free arachidonic acid, along with diacylglycerols and free docosahexaenoic acid, is a product of membrane lipid breakdown at the onset of cerebral ischemia, seizures and other forms of brain trauma. Because polyunsaturated fatty acids are the predominant FFA pool components that accumulate under these conditions, this further supports the notion that fatty acids released from the C2 position of membrane phospholipids are major contributors to the FFA pool, implicating PLA2 activation as the critical step in FFA release [1,2] (Fig. 33-6). 

Raise of blood pressure, contraction of smooth muscles, glycogen breakdown in liver, lipid breakdown in adipose tissue... 

Lipids or lipid breakdown products may also be Involved In the formation of 2-alkyl substituted heterocyclic compounds with roast and/or fried flavor notes (19.35 >. Therefore, llpld-derlved volatiles may have a special role In the development of flavor of roasted and or barbecued meats. 

Insulin inhibits lipid breakdown by a number of mechanisms and increases synthesis of glycogen, fetty acids, triglycerides, and proteins. Insulin reduces the level of cyclic AMP. It also promotes the transport of glucose into cells, especially fet cells, where glucose can be converted and stored as triglyceride. 

Lipoprotein disorders may also result from a variety of intestinal disorders that impede lipid absorption (such as certain inflammatory bowel diseases). Lipid disorders may also occur when there is triglyceride breakdown and shifting of triglyceride stores, as in the lipidemia that may accompany excess lipid breakdown in diabetes. 

Further details on oxidative damage to LDLs, and the possible role of hypochlorite and lipid breakdown products, are revealed in the Vitamin E section. 

Several methods can be performed after the above protocol to obtain a certain size of liposomes for complexation with siRNA probe sonication can be used to reduce the size of liposomes by introducing a mechanical rupture of membranes however, probe sonication can create lipid breakdown or introduce pieces of titanium from the sonicator itself into the sample. 

Before we leave our brief survey of intracellular Ca -binding proteins, we must write a few lines about an important Ca " -regulated kinase (a phospho-rylating enzyme), i.e., protein kinase C (PKC). The activity of this enzyme, or rather family of enzymes,appears to be regulated by three factors phospholipids, in particular phosphatidylserine diacyl-glycerols, one of the products of inositol lipid breakdown and Ca " ions. The high-activity form of PKC, which appears responsible for much of the phosphorylation activity of many cells, is presumably membrane-bound, whereas the low-activity form may be partly cytosolic (Figure 3.27). The schematic structure of rabbit PKC (Mr 11 kDa)... 

Exposure of cells to anthracyclines leads to apoptosis mediators of this process include the p53 DNA-damage sensor and activated caspases (proteases), although ceramide, a lipid breakdown product, and the fas receptor-ligand... 

The major components, except for phenylacetaldehyde and possibly 2-hexyl-3-methylmalelc anhydride, seem to be derived from oxidative lipid breakdown In common with the volatiles of many other foods and plant materials. 

Lipid oxidation is a major pathway for the formation of volatile compounds in roasted tree nuts. After the enzymes in the nuts (e.g., lipoxygenase) are inactivated by the high temperatures used for roasting, autoxidation becomes the principal source of lipid breakdown [66]. Lipid degradation reactions are not necessarily deleterious to flavor [67], and some aldehydes and ketones (e.g., n-aldehydes and 2-aIkanones) produced during roasting may impart desirable sweet, fruity, and pungent aroma notes to roasted tree nuts. 

Short-chain mono-, di-, and polycarboxylic acids are of significance to scientists studying amino acid degradation, metabolites of carbohydrate oxidation, and lipid breakdown. They can be indicators of human metabolic disorders and of importance in the biotechnology of food. LC is now the preferred method of analysis for these analytes irrespective of the sample origin - biological fluid, fermentation broth, or food. 

Lipases are primarily produced in the pancreas, but these hydrolytic enzymes are also secreted into the mouth and stomach [23], Pancreatic lipase hydrolyzes fatty acids from the C-1 and C-3 positions of triacylglyceiols. In humans and rodents, Von Ebner s glands in the oral cavity secrete salivary lipase for fat digestion. This soluble enzyme catalyzes lipid breakdown in the absence of bile salts. Salivary lipase is also important for fat digestion in newborn humans since their pancreatic lipase output is minimal [24]. 

However, generalization to include other oil seeds is not indicated, because lipases in other organelles must be involved in gluconeogenesis (see below). Involvement of the acid lipase in gluconeogenesis of castor bean has not been proven, and Muto and Bee vers (1974) have pointed out that the enzyme activity decreases before the peak of lipid breakdown in germinating castor beans. 

De Bock, K. Dresselaers, T. Kiens, B. Richter, E. A. Van Hecke, R Hespel, P. Evaluation of intramyocellular lipid breakdown during exercise by biochemical assay, NMR spectroscopy, and Oil Red O staining. Am. J. Physiol. 2007, 293, E428-E434. 

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