Oleic acid-13C is intended for use as an internal standard for the quantification of oleic acid by GC- or LC-MS. Oleic acid is a monounsaturated fatty acid and a major component of membrane phospholipids that has been found in human plasma, cell membranes, and adipose tissue.1,2 It contributes approximately 17% of the total fatty acids esterified to phosphatidylcholine, the major phospholipid class in porcine platelets.1 Oleic acid inhibits collagen-stimulated platelet aggregation by approximately 90% when used at a concentration of 10 μg/ml. It also inhibits fMLF-induced neutrophil aggregation and degranulation by 55 and 68%, respectively, when used at a concentration of 5 μM, similar to arachidonic acid .3 Oleic acid (60 μM) induces release of intracellular calcium in human platelets.4 In vivo, oleic acid increases TNF-α, IL-8, IL-6, and IL-1β production, neutrophil accumulation, and apoptotic and necrotic cell death in mouse lung and has been used to induce lung injury in a mouse model of acute respiratory distress syndrome (ARDS).2

References
1. Wahle, K.W., and Peacock, L.I. Effects of isomeric cis and trans eighteen carbon monounsaturated fatty acids on porcine platelet function. Biochim. Biophys. Acta 1301(1-2), 141-149 (1996).
2. Gon•alves-de-Albuquerque, C.F., Silva, A.R., Burth, P., et al. Acute respiratory distress syndrome: Role of oleic acid-triggered lung injury and inflammation. Mediators Inflamm. 260465, (2015).
3. Naccache, P.H., Moiski, T.F., Volpi, M., et al. Modulation of rabbit neutrophil aggregation and degranulation by free fatty acids. J. Leukoc. Biol. 36(3), 333-340 (1984).
4. Siafaka-Kapadai, A., Hanahan, D.J., and Javors, M.A. Oleic acid-induced Ca2+ mobilization in human platelets: Is oleic acid an intracellular messenger• J. Lipid Mediat. Cell Signal 15(3), 215-232 (1997).