Long term Incubation of Cardiac Myocytes with Oleic Acid and Very-low Density Lipoprotein Reduces Heparin-releasable Lipoprotein Lipase Activity
An exogenous [3H]triolein emulsion was hydrolyzed by intact cardiac myocytes with functional LPL located on the cell surface. This surface-bound LPL could be released into the medium when cardiac myocytes were incubated with heparin. Incubation of cardiac myocytes with VLDL, or the products of TG breakdown, oleic acid or 2-monoolein, did not increase LPL activity in the medium. However, incubation of cardiac myocytes with either VLDL or oleic acid for > 60 min did reduce heparin-releasable LPL activity. In the heart, this inhibitory effect of FF A could regulate the translocation of LPL from its site of synthesis in the cardiac myocyte to its functional site at the capillary endothelium. (Mol Cell Biochem 116: 33–37, 1992).
Keywordslipoprotein lipase cardiac myocytes free fatty acids
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- 1.Eckel RH: Lipoprotein lipase. A multifunctional enzyme relevant to common metabolic diseases. New Engl J Med 320: 1060–1068, 1989Google Scholar
- 2.Camp L, Reina M, Llobera M, Vilaro S, Olivecrona T: Lipoprotein lipase: cellular origin and functional distribution. Am J Physiol 258: C673–C681, 1990Google Scholar
- 10.Saxena U, Witte LD, Goldberg IJ: Tumor necrosis factor induced release of endothelial cell lipoprotein lipase. Arteriosclerosis 10: 470–476, 1990Google Scholar
- 16.Chajek T, Stein O, Stein Y: Lipoprotein lipase of cultured mesenchymal rat heart cells. Hydrolysis of labelled very low density lipoprotein triacylglycerol by membrane-supported enzyme. Biochim Biophys Acta 528: 466–474, 1978Google Scholar
- 19.Friedman G, Stein O, Stein Y: Lipoprotein lipase of cultured mesenchymal rat heart cells. Modulation of enzyme activity by VLDL added to the culture medium. Biochim Biophys Acta 573: 521–534, 1979Google Scholar