This Article Full Text Full Text (PDF) Data Supplement All Versions of this Article: 24/3/595    most recent 01.ATV.0000116219.09040.8cv1 Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Krötz, F. Articles by Pohl, U. Search for Related Content PubMed PubMed Citation Articles by Krötz, F. Articles by Pohl, U. Related Collections Secretion Aggregation Platelet function inhibitors Platelets Endothelium/vascular type/nitric oxide Other Vascular biology

(Arteriosclerosis, Thrombosis, and Vascular Biology. 2004;24:595.)
© 2004 American Heart Association, Inc.

Thrombosis

Membrane Potential-Dependent Inhibition of Platelet Adhesion to Endothelial Cells by Epoxyeicosatrienoic Acids

Florian Krötz; Tobias Riexinger; Martin A. Buerkle; Kasem Nithipatikom; Torsten Gloe; Hae-Young Sohn; William B. Campbell; Ulrich Pohl

From the Institute of Physiology (F.K., T.R., T.G., U.P.), Clinic of Anaesthesiology (M.A.B.), and Cardiology Division (H.-Y.S.), Medizinische Poliklinik–Innenstadt, Ludwig-Maximilians-University, Munich, Germany; and the Department of Pharmacology and Toxicology (K.N., W.B.C.), Medical College of Wisconsin, Milwaukee, Wisc.

Correspondence to Dr Florian Krötz, Institute of Physiology, Ludwig-Maximilians-Universität, Schillerstr. 44, 80336 München, Germany. E-mail fkroetz{at}lmu.de

Objective— Epoxyeicosatrienoic acids (EETs) are potent vasodilators produced by endothelial cells. In many vessels, they are an endothelium-derived hyperpolarizing factor (EDHF). However, it is unknown whether they act as an EDHF on platelets and whether this has functional consequences.

Methods and Results— Flow cytometric measurement of platelet membrane potential using the fluorescent dye DiBac₄ showed a resting potential of -58±9 mV. Different EET regioisomers hyperpolarized platelets down to -69±2 mV, which was prevented by the non-specific potassium channel inhibitor charybdotoxin and by use of a blocker of calcium-activated potassium channels of large conductance (BK_Ca channels), iberiotoxin. EETs inhibited platelet adhesion to endothelial cells under static and flow conditions. Exposure to EETs inhibited platelet P-selectin expression in response to ADP. Stable overexpression of cytochrome P450 2C9 in EA.hy926 cells (EA.hy2C9 cells) resulted in release of EETs and a factor that hyperpolarized platelets and inhibited their adhesion to endothelial cells. These effects were again inhibited by charybdotoxin and iberiotoxin.

Conclusions— EETs hyperpolarize platelets and inactivate them by inhibiting adhesion molecule expression and platelet adhesion to cultured endothelial cells in a membrane potential-dependent manner. They act as an EDHF on platelets and might be important mediators of the anti-adhesive properties of vascular endothelium.

Key Words: epoxyeicosatrienoic acids • platelet adhesion • membrane potential • potassium channels • EDHF

This article has been cited by other articles:

				F. Krotz, N. Hellwig, M. A. Burkle, S. Lehrer, T. Riexinger, H. Mannell, H.-Y. Sohn, V. Klauss, and U. Pohl A sulfaphenazole-sensitive EDHF opposes platelet-endothelium interactions in vitro and in the hamster microcirculation in vivo Cardiovasc Res, October 4, 2009; (2009) cvp301v2. [Abstract] [Full Text] [PDF]

				W. Zhang, T. Otsuka, N. Sugo, A. Ardeshiri, Y. K. Alhadid, J. J. Iliff, A. E. DeBarber, D. R. Koop, and N. J. Alkayed Soluble Epoxide Hydrolase Gene Deletion Is Protective Against Experimental Cerebral Ischemia Stroke, July 1, 2008; 39(7): 2073 - 2078. [Abstract] [Full Text] [PDF]

				I. C Villar, A. J Hobbs, and A. Ahluwalia Sex differences in vascular function: implication of endothelium-derived hyperpolarizing factor J. Endocrinol., June 1, 2008; 197(3): 447 - 462. [Abstract] [Full Text] [PDF]

				A. A. Spector and A. W. Norris Action of epoxyeicosatrienoic acids on cellular function Am J Physiol Cell Physiol, March 1, 2007; 292(3): C996 - C1012. [Abstract] [Full Text] [PDF]

				S. Chlopicki, R. Olszanecki, E. Marcinkiewicz, M. Lomnicka, and R. Motterlini Carbon monoxide released by CORM-3 inhibits human platelets by a mechanism independent of soluble guanylate cyclase Cardiovasc Res, July 15, 2006; 71(2): 393 - 401. [Abstract] [Full Text] [PDF]

				B. T. Larsen, H. Miura, O. A. Hatoum, W. B. Campbell, B. D. Hammock, D. C. Zeldin, J. R. Falck, and D. D. Gutterman Epoxyeicosatrienoic and dihydroxyeicosatrienoic acids dilate human coronary arterioles via BKCa channels: implications for soluble epoxide hydrolase inhibition Am J Physiol Heart Circ Physiol, February 1, 2006; 290(2): H491 - H499. [Abstract] [Full Text] [PDF]

				W. B. Campbell, B. B. Holmes, J. R. Falck, J. H. Capdevila, and K. M. Gauthier Regulation of potassium channels in coronary smooth muscle by adenoviral expression of cytochrome P-450 epoxygenase Am J Physiol Heart Circ Physiol, January 1, 2006; 290(1): H64 - H71. [Abstract] [Full Text] [PDF]

				Y. Wang, X. Wei, X. Xiao, R. Hui, J. W. Card, M. A. Carey, D. W. Wang, and D. C. Zeldin Arachidonic Acid Epoxygenase Metabolites Stimulate Endothelial Cell Growth and Angiogenesis via Mitogen-Activated Protein Kinase and Phosphatidylinositol 3-Kinase/Akt Signaling Pathways J. Pharmacol. Exp. Ther., August 1, 2005; 314(2): 522 - 532. [Abstract] [Full Text] [PDF]

				F. Krotz, H.-Y. Sohn, and U. Pohl Reactive Oxygen Species: Players in the Platelet Game Arterioscler Thromb Vasc Biol, November 1, 2004; 24(11): 1988 - 1996. [Abstract] [Full Text] [PDF]

				M. A. Buerkle, S. Lehrer, H.-Y. Sohn, P. Conzen, U. Pohl, and F. Krotz Selective Inhibition of Cyclooxygenase-2 Enhances Platelet Adhesion in Hamster Arterioles In Vivo Circulation, October 5, 2004; 110(14): 2053 - 2059. [Abstract] [Full Text] [PDF]