Free fatty acids brain

Triacylglycerols must be hydrolyzed by a lipase to their constiment fatty acids and glycerol before further catab-ohsm can proceed. Much of this hydrolysis (hpolysis) occurs in adipose tissue with release of free fatty acids into the plasma, where they are found combined with semm albumin. This is followed by free fatty acid uptake into tissues (including hver, heart, kidney, muscle, lung, testis, and adipose tissue, but not readily by brain), where they are oxidized or reesterified. The uti-hzation of glycerol depends upon whether such tissues... 

Chloroform-methanol extracts of Borrelia burgdorferi were used for the identification of lipids and other related components that could help in the diagnosis of Lyme disease [58]. The provitamin D fraction of skin lipids of rats was purified by PTLC and further analyzed by UV, HPLC, GLC, and GC-MS. MS results indicated that this fraction contained a small amount of cholesterol, lathosterol, and two other unknown sterols in addition to 7-dehydrocholesterol [12]. Two fluorescent lipids extracted from bovine brain white matter were isolated by two-step PTLC using silica gel G plates [59]. PTLC has been used for the separation of sterols, free fatty acids, triacylglycerols, and sterol esters in lipids extracted from the pathogenic fungus Fusarium culmorum [60]. 

Cortisol-induced lipolysis not only provides substrates for gluconeogenesis (formation of glucose from noncarbohydrate sources) but it also increases the amount of free fatty acids in the blood. As a result, the fatty acids are used by muscle as a source of energy and glucose is spared for the brain to use to form energy. 

The rate of free fatty acid production in the mammalian brain correlates to the extent of resistance to ischemia 586... 

Under physiologic conditions, the balance of membrane lipid metabolism, particularly that of arachidonoyl and docosahexaenoyl chains, favors a very small and tightly controlled cellular pool of free arachidonic acid (AA, 20 4n-3) and docosahexaenoic acid (DHA, 22 6n-3), but levels increase very rapidly upon cell activation, cerebral ischemia, seizures and other types of brain trauma [1, 2], Other free fatty acids (FFAs) in addition to AA, released during cell activation and the initial stages of focal and global cerebral ischemia, are stearic acid (18 0), palmitic acid (16 0) and oleic acid (18 1). 

The rate of free fatty acid production in the mammalian brain correlates to the extent of resistance to ischemia. FFA production rate is much lower in the brains of neonatal mammals and poikilothermic animals, organisms that display a greater resistance to cerebral ischemic insults than mature mammals [63]. In addition, within the mammalian brain, FFA release is higher in the gray matter compared with white matter, and there is a greater accumulation of AA in areas of the brain, such as the hippocampus, selectively vulnerable to cerebral ischemic damage. 

Panetta, T., MarcheselH, V. L., Braquet, P., Spinnewyn, B. and Bazan, N. G. Effects of a platelet-activating factor antagonist (BN52021) on free fatty acids, diacylglycerols, polyphosphoinositides and blood flow in the gerbil brain Inhibition of ischemia-reperfusion induced cerebral injury. Biochem. Biophys. Res. Commun. 149 580-587,1987. 

Aveldano, M. I. and Bazan, N. G. Differential lipid deacylation during brain ischemia in a homeotherm and a poikilo-therm. Content and composition of free fatty acids and triacylglycerol. Brain Res. 100 99-110,1975. 

Rodriguez de Turco EB, Droy-Lefaix MT, Bazan NG. (1993). Decreased electroconvulsive shock-induced diacylglycerols and free fatty acid accumulation in the rat brain by Ginkgo biloba extract (EGb 761) selective effect in hippocampus as compared with cerebral cortex. J Neurochem. 61(4) 1438-44. 

Fate of fatty acids The free (unesterified) fatty acids move through the cell membrane of the adipocyte, and immediately bind to albumin in the plasma. They are transported to the tis sues, where the fatty acids enter cells, get activated to their CtA derivatives, and are oxidized for energy. [Note Active transport of fatty acids across membranes is mediated by a membrane fatty acid binding protein.] Regardless of their blood levels, plasma free fatty acids cannot be used for fuel by erythrocytes, which have no mitochondria, or by the brain because of the imperme able blood-brain barrier. rr f-... 

Vahidy W. H., Ong W. Y., Farooqui A. A., and Yeo J. F. (2006). Effects of intracerebroventricular injections of free fatty acids, lysophospholipids, or platelet activating factor in a mouse model of orofacial pain. Exp. Brain Res. 174 781-785. 

Epileptic seizures also stimulate CPLA2 activity and expression with accumulation of arachidonic acid (Visioli et al., 1994 Kajiwara et al., 1996). Levels of free fatty acids and diacylglycerols in rat brain rise rapidly with the onset of epileptic... 

Dhillon H. S., Donaldson D., Dempsey R. J., and Prasad M. R. (1994). Regional levels of free fatty acids and Evans blue extravasation after experimental brain injury. J. Neurotrauma 11 405 415. 

Fig. 5 Discovery metabolite profiling of brain tissue, where mass ion intensity ratios (FAAH / / FAAH+/+) of metabolites are presented on three-dimensional surface plots. Global view of the relative levels of metabolites in FAAH / and FAAH+/+ brains, plotted over a mass range of 200-1,200 m/z and liquid chromatography retention times of 0-105 min (plot shown for negative ionization mode). FAAH / brains possessed highly elevated levels of A-acyl ethanolamines (NAEs) (lipid group 4) and an unknown class of lipids (group 5), identified as A-acyl taurines (NATs). Other lipids, e.g., free fatty acids (group 1), phospholipids (group 2), and ceramides (group 3) were unaltered in these samples...

Busto R., Globus M. Y., Dietrich W. D., Martinez E., Valdes I., and Ginsberg M. D. (1989) Effect of mild hypothermia on ischemia-induced release of neurotransmitters and free fatty acids in rat brain. Stroke 20, 904-910. 

Figure 32-3. Schematic representation of fuel mobilization during fasting. Catabolism of muscle proteins provides alanine for gluconeogenesis and glutamine for utilization by the gut and kidney, while branched chain amino acids are primarily oxidized within the muscle. Breakdown of adipocyte triacylglycerols provides glycerol and free fatty acids (not shown) the free fatty acids provide fuel for liver, muscle and most other peripheral tissues. The liver utilizes both alanine and glycerol to synthesize glucose which is required for the brain and for red blood cells (not shown). Adapted from Besser and Thirner (2002).

Even though water-soluble Se-GPx reduces a number of hydrophobic substrates [215,225], it does not directly reduce phospholipid hydroperoxides [226], Such a reduction would require the release of free fatty-acid hydroperoxides through activation of phospholipase A2 [227,228], More importantly, a membrane-bound Se-GPx has been found in a number of animal tissues, including liver, heart, brain and testis [229]. In vitro, this enzyme does reduce phospholipid hydroperoxides in micelles and exhibits kinetic features which, in the presence of detergent, are similar to those of the soluble enzyme (reviewed in ref. [230]). This enzyme which has been named PHGPx, also reduces hydroperoxide derivatives of cholesterol and that formed... 

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