Platelet aggregation is thought to be involved in renal pathology through induction of the intraglomerular coagulation that leads to subsequent glomerular damage. Thromboxane A2 (a potent pro- aggregatory substance) is the major cyclooxygenase product of arachidonic acid metabolism in the platelet. Thus, activation of this pathway results in stimulation of the aggregatory process. However, little is known about the consequences of the cytochrome P-450 route of arachidonic acid metabolism. A recent study has highlighted the possibility that the products of cytochrome P-450 mediated arachidonic acid metabolism can regulate platelet activation. The purpose of the proposed study is to assess the possible involvement of this pathway in human platelet activation. First, the profile of cytochrome P-450 metabolism in human platelets will be determined and the possibility that the arachidonic acid epoxides (EETs) are major endogenous products of the human platelet will be assessed. It is envisaged that this study will be carried out by the use of human platelets pre- labelled with 3H-arachidonic acid. Structural characterization will be made by the use of mass spectrometry. The profile of released products will be examined in response to three different agonists: thrombin, epinephrine and platelet activating factor. Second, a quantitative assessment of EET release by human platelets in response to the three agonists will be made. It is envisage that techniques we have developed recently based on stable isotope dilution gas chromagraphy/negative ion chemical ionization mass spectrometry will be used in these studies. Third, the localization of EET esterified in the various lipid pools will be determined. This letter aim will be accomplished by a strategy based on high performance liquid chromatography and mass spectrometry. This method was recently developed for the characterization of EETs esterified in rat liver. Fourth, the mechanism by which the EETs are synthesized and release will be explored. Finally, the mechanism by which the EETs themselves inhibit platelet aggregation will be explored. These studies will have relevance to understanding a novel mechanism by which platelet function can be modulated by endogenous lipids. It is envisaged that this will help designing interventions to protect function in disease states where platelet stimulated coagulation is thought to play an important role.

Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Vanderbilt University Medical Center
United States
Zip Code
Elijovich, Fernando; Milne, Ginger L; Brown, Nancy J et al. (2018) Two Pools of Epoxyeicosatrienoic Acids in Humans: Alterations in Salt-Sensitive Normotensive Subjects. Hypertension 71:346-355
Sausville, Lindsay N; Gangadhariah, Mahesha H; Chiusa, Manuel et al. (2018) The Cytochrome P450 Slow Metabolizers CYP2C9*2 and CYP2C9*3 Directly Regulate Tumorigenesis via Reduced Epoxyeicosatrienoic Acid Production. Cancer Res 78:4865-4877
Garcia, Victor; Gilani, Ankit; Shkolnik, Brian et al. (2017) 20-HETE Signals Through G-Protein-Coupled Receptor GPR75 (Gq) to Affect Vascular Function and Trigger Hypertension. Circ Res 120:1776-1788
Guo, Zhijun; Sevrioukova, Irina F; Denisov, Ilia G et al. (2017) Heme Binding Biguanides Target Cytochrome P450-Dependent Cancer Cell Mitochondria. Cell Chem Biol 24:1259-1275.e6
Zhang, Hui; Falck, John R; Roman, Richard J et al. (2017) Upregulation of 20-HETE Synthetic Cytochrome P450 Isoforms by Oxygen-Glucose Deprivation in Cortical Neurons. Cell Mol Neurobiol 37:1279-1286
Gangadhariah, Mahesha H; Dieckmann, Blake W; Lantier, Louise et al. (2017) Cytochrome P450 epoxygenase-derived epoxyeicosatrienoic acids contribute to insulin sensitivity in mice and in humans. Diabetologia 60:1066-1075
Shuey, Megan M; Billings 4th, Frederic T; Wei, Shouzou et al. (2017) Association of gain-of-function EPHX2 polymorphism Lys55Arg with acute kidney injury following cardiac surgery. PLoS One 12:e0175292
Fan, Fan; Pabbidi, Mallikarjuna R; Ge, Ying et al. (2017) Knockdown of Add3 impairs the myogenic response of renal afferent arterioles and middle cerebral arteries. Am J Physiol Renal Physiol 312:F971-F981
Imig, J D (2016) Epoxyeicosatrienoic Acids and 20-Hydroxyeicosatetraenoic Acid on Endothelial and Vascular Function. Adv Pharmacol 77:105-41
Savas, √úzen; Wei, Shouzou; Hsu, Mei-Hui et al. (2016) 20-Hydroxyeicosatetraenoic Acid (HETE)-dependent Hypertension in Human Cytochrome P450 (CYP) 4A11 Transgenic Mice: NORMALIZATION OF BLOOD PRESSURE BY SODIUM RESTRICTION, HYDROCHLOROTHIAZIDE, OR BLOCKADE OF THE TYPE 1 ANGIOTENSIN II RECEPTOR. J Biol Chem 291:16904-19

Showing the most recent 10 out of 376 publications