Unbound free fatty acid

Given the understanding that release of cardiac troponin into the circulation reflects myocardial cell death, it is understandable why, clinically, therapies are oriented toward inhibiting the pathophysiologic processes of thrombosis, fibrinolysis, platelet aggregation, and inflammation leading to ischemia and, ultimately, myocardial cell death. Several markers of ischemia have been proposed [2], and research and development studies are underway to adequately validate their clinical usefulness or lack of evidence. These include the topic of this chapter (ischemia-modified albumin [IMA]), as well as choline, unbound free fatty acids, and nourin. 

Unbound free fatty acid (uFFA) has also been touted as a marker of ischemia. Most fatty acid is bound and ischemia is thought to increase the small unbound fraction. Initial studies have reported mixed results." At present, there is no standardized assay and no reference interval studies or consistent assay validations. 

Adams JE, Kleinfeld A, Roe M, et al. Measurement of levels of unbound free fatty acid allows the early identification of patients with acute coronary syndromes. (abstract) Circulation 2002. 

Richieri, G. V., and Kleinfeld, A. M., 1995, Unbound free fatty acid levels in human serum, J. Lipid Res. 36 229-240. 

Kleirdeld, A. M., Prothro, D., Brown, D. L., Davis, R. C.. Richieri, Q. V, and DeMaria, A., 1996, Increases in serum unbound free fatty acid levels following coronary angioplasty. Am. J. Cardiol. 78 1350-1354. 

For AAG-bound drugs, a 35-80%i increase of the unbound fraction in the third trimester is reported for propranolol,f lidocaine, and bupivicaine. ° After pregnancy, whereas albumin takes 1 month to return to normal levels, AAG and free fatty acid levels return to normal within as few days of delivery.f ° ... 

A decrease in concentration of proteins and an increase in concentration of free fatty acids in plasma are observed in hyperthyroidism. For propranolol and warfarin, an increase of up to 20-30 % in the unbound plasma fractions has been reported. ... 

Short-chain fatty acids (butyrate, propionate, acetate) free (unbound) microorganisms in colon colonocytes, liver... 

Dry coating is extensively used with fatty acid treatment of natural calcium carbonates. The challenge is to convert as much as possible of the coating to a bound surface layer, with as little unbound salt and remaining free acid as possible. There is little scientific literature on this procedure but some useful studies have been made[51,64]. A number of different methods are employed. In most cases, unless a small amount of solvent is used, it is necessary for the procedure to be carried out at a temperature where the fatty acid blend is molten. With stearate mixtures this is about 80 °C. Some fatty acids such as iso-stearic acid have the advantage of being liquid at room temperature, but are not widely used as they are more expensive. 

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