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Gilad D, Atiya S, Mozes-Autmazgin Z, Ben-Shushan RS, Ben-David R, Amram E, Tamir S, Chuyun D, Szuchman-Sapir A. Paraoxonase 1 in endothelial cells impairs vasodilation induced by arachidonic acid lactone metabolite. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1864:386-393. [PMID: 30572120 DOI: 10.1016/j.bbalip.2018.12.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 12/13/2018] [Accepted: 12/15/2018] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Paraoxonase 1 (PON1) is a high density lipoprotein (HDL)-associated lactonase, which is known for its antiatherogenic properties. Previous studies in PON1 knockout (PON1KO) mice revealed that PON1KO mice have low blood pressure, which is inversely correlated with the renal levels of the cytochrome P450 -derived arachidonic acid metabolite 5,6-epoxyeicosatrienoic acid (5,6-EET). Our previous studies revealed that 5,6-EET is unstable, transforming to the δ-lactone isomer 5,6-δ-DHTL, an endothelium-derived hyperpolarizing factor (EDHF) that mediates vasodilation, and it is a potential substrate for PON1. AIM To elucidate the role of PON1 in the modulation of vascular resistance via the regulation of the lactone-containing metabolite 5,6-δ-DHTL. RESULTS In mouse resistance arteries, PON1 was found to be present and active in the endothelial layer. Vascular reactivity experiments revealed that 5,6-δ-DHTL dose-dependently dilates PON1KO mouse mesenteric arteries significantly more than wild type (w.t.) resistance arteries. Pre-incubation with HDL or rePON1 reduced 5,6-δ-DHTL-dependent vasodilation. FACS analyses and confocal microscopy experiments revealed that fluorescence-tagged rePON1 penetrates into human endothelial cells' (ECs') in both dose- and time- dependent manner, accumulate in the perinuclear compartment, and retains its lactonase activity in the cells. The presence of rePON1, but not the presence of PON1 loss-of-lactonase-activity mutant, reduced the Ca2+ influx in the ECs mediated by 5,6-δ-DHTL. CONCLUSION PON1 lactonase activity in the endothelium affects vascular dilation by regulating Ca2+ influx mediated by the lactone-containing EDHF 5,6-δ-DHTL.
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Affiliation(s)
- Dan Gilad
- Laboratory of Vascular Signaling Research, MIGAL-Galilee Research Institute, Ltd., Kiryat Shmona, Israel; Tel-Hai College, Upper Galilee, Israel
| | - Shahar Atiya
- Laboratory of Vascular Signaling Research, MIGAL-Galilee Research Institute, Ltd., Kiryat Shmona, Israel; Tel-Hai College, Upper Galilee, Israel
| | - Ziv Mozes-Autmazgin
- Laboratory of Vascular Signaling Research, MIGAL-Galilee Research Institute, Ltd., Kiryat Shmona, Israel; Laboratory of Human Health and Nutrition Sciences, MIGAL-Galilee Research Institute, Ltd., Kiryat Shmona, Israel
| | - Rotem Shelly Ben-Shushan
- Laboratory of Vascular Signaling Research, MIGAL-Galilee Research Institute, Ltd., Kiryat Shmona, Israel
| | - Raz Ben-David
- Laboratory of Vascular Signaling Research, MIGAL-Galilee Research Institute, Ltd., Kiryat Shmona, Israel; Tel-Hai College, Upper Galilee, Israel
| | - Eytan Amram
- Laboratory of Vascular Signaling Research, MIGAL-Galilee Research Institute, Ltd., Kiryat Shmona, Israel; Tel-Hai College, Upper Galilee, Israel
| | - Snait Tamir
- Laboratory of Human Health and Nutrition Sciences, MIGAL-Galilee Research Institute, Ltd., Kiryat Shmona, Israel; Tel-Hai College, Upper Galilee, Israel
| | | | - Andrea Szuchman-Sapir
- Laboratory of Vascular Signaling Research, MIGAL-Galilee Research Institute, Ltd., Kiryat Shmona, Israel; Tel-Hai College, Upper Galilee, Israel.
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Levi-Rosenzvig R, Beyer AM, Hockenberry J, Ben-Shushan RS, Chuyun D, Atiya S, Tamir S, Gutterman DD, Szuchman-Sapir A. 5,6-δ-DHTL, a stable metabolite of arachidonic acid, is a potential EDHF that mediates microvascular dilation. Free Radic Biol Med 2017; 103:87-94. [PMID: 28007573 DOI: 10.1016/j.freeradbiomed.2016.12.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Revised: 11/25/2016] [Accepted: 12/18/2016] [Indexed: 10/20/2022]
Abstract
OBJECTIVE Prominent among the endothelium-derived hyperpolarizing factors (EDHFs) are the Cytochrome P450 (CYP) epoxygenase-derived arachidonic acid metabolites-the epoxyeicosatrienoic acids (EETs), that are known as vasodilators in the microcirculation. Among the EET isomers, 5,6-EET undergoes rapid lactonization in aqueous solution to the more stable 5,6-δ DHTL (5,6-dihydroxytrienoic lactone) isomer. It is unclear whether this metabolic transformation maintains its vasodilator potential and what is the mechanism of action. Thus, the aim of this study was to investigate the capacity of the lactone isomer, 5,6- δ DHTL, to induce dilation of arterioles and explore the endothelial Ca2+ response mechanism. APPROACH AND RESULTS In isolated human microvessels 5,6- δ DHTL induced a dose dependent vasodilation, that was inhibited by mechanical denudation of the endothelial layer. This 5,6- δ DHTL -dependent dilation was partially reduced in the presence of L-NAME (NOS inhibitor) or the NO-scavenger, cPTIO (by 19.7%, which was not statistically significantly). In human endothelial cells, 5,6- δ DHTL induced an increase in intracellular Ca2+([Ca2+]i) in a dose dependent manner. This increase in [Ca2+]i was similar to that induced by the 5,6-EET isomer, and significantly higher than observed by administering the hydrolytic dihydroxy isomer, 5,6-DHET. Further experiments aimed to investigate the mechanism of action revealed, that the 5,6-δ DHTL-mediated ([Ca2+]i elevation was reduced by IP3 and ryanodine antagonists, but not by antagonists to the TRPV4 membrane channel. Similar to their effect on the dilation response in the arteries, NO inhibitors reduced the 5,6-δ DHTL-mediated ([Ca2+]i elevation by 20%. Subsequent 5,6-δ DHTL -dependent K+ ion efflux from endothelial cells, was abolished by the inhibition of small and intermediate conductance KCa. CONCLUSIONS The present study shows that 5,6-δ DHTL is a potential EDHF, that dilates microvessels through a mechanism that involves endothelial dependent Ca2+ entry, requiring endothelial hyperpolarization. These results suggest the existence of additional lactone-containing metabolites that can be derived from the PUFA metabolism and which may function as novel EDHFs.
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Affiliation(s)
- Reut Levi-Rosenzvig
- Laboratory of Human Health and Nutrition Sciences, MIGAL-Galilee Research Institute, Ltd., Kiryat Shmona, Israel; Tel-Hai College, Upper Galilee, Israel
| | - Andreas M Beyer
- Department of Medicine and Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI, USA; Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Joseph Hockenberry
- Department of Medicine and Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Rotem Shelly Ben-Shushan
- Laboratory of Human Health and Nutrition Sciences, MIGAL-Galilee Research Institute, Ltd., Kiryat Shmona, Israel
| | | | - Shahar Atiya
- Laboratory of Human Health and Nutrition Sciences, MIGAL-Galilee Research Institute, Ltd., Kiryat Shmona, Israel; Tel-Hai College, Upper Galilee, Israel
| | - Snait Tamir
- Laboratory of Human Health and Nutrition Sciences, MIGAL-Galilee Research Institute, Ltd., Kiryat Shmona, Israel; Tel-Hai College, Upper Galilee, Israel
| | - David D Gutterman
- Department of Medicine and Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Andrea Szuchman-Sapir
- Laboratory of Human Health and Nutrition Sciences, MIGAL-Galilee Research Institute, Ltd., Kiryat Shmona, Israel; Tel-Hai College, Upper Galilee, Israel.
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Eryanni-Levin S, Khatib S, Levy-Rosenzvig R, Tamir S, Szuchman-Sapir A. 5,6-δ-DHTL, a stable metabolite of arachidonic acid, is a potential substrate for paraoxonase 1. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1851:1118-22. [PMID: 25958017 DOI: 10.1016/j.bbalip.2015.04.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Revised: 04/26/2015] [Accepted: 04/30/2015] [Indexed: 01/28/2023]
Abstract
Paraoxonase 1 (PON1) is an antiatherogenic high density lipoprotein-associated lactonase. Recent findings revealed that PON1 knockout mice have low blood pressure, which is negatively correlated with the level of 5,6-epoxyeicosatrienoic acid (5,6-EET), a cytochrome P450 -derived arachidonic acid metabolite. 5,6-EET is an endothelium-derived hyperpolarizing factor that causes arterial dilation. Under physiological conditions, 5,6-EET is unstable, transforming to its δ-lactone (5,6-δ-DHTL) that evades the degradation by soluble epoxide hydrolase (sEH), arguing for the existence of yet another enzyme that is responsible specifically for its hydrolysis. We therefore hypothesized that PON1 degrades the 5,6-δ-DHTL, and this specific PON1 lactonase activity thus decreases endothelial vasodilatation. The aim of the present study was to investigate the PON1-5,6-δ-DHTL relationship. A liquid chromatography mass spectrometry based method for 5,6-EET derivatives identification was developed. Tracking the lactonization of 5,6-EET in a physiological solution revealed that 5,6-EET was fully converted into 5,6-δ-DHTL. Incubation of 5,6-δ-DHTL with rePON1 resulted in 85.1±3.4% degradation of the substrate to 5,6 dihydroxytrienoic acid (5,6-DHET), while only 12.0±8.7% hydrolysis was detected in the absence of PON1. Accordingly, the levels of 5,6-DHTL were found to be significantly higher in the PON1KO mice than in the wild type mice. Kinetic analysis revealed values of Vmax=0.021±0.01μM/s and Km=150.99±62.1μM. Calculation of the docking energy suggested possible interaction of the 5,6-δ-DHTL in the catalytic region of PON1 with free energy of-5.57 Kcal/mol, preferentially for the (S) enantiomer. These findings demonstrate that 5,6-δ-DHTL is a PON1 substrate and imply that the 5,6-EET vasodilation effect may be impaired by PON1.
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Affiliation(s)
- Suzy Eryanni-Levin
- Laboratory of Human Health and Nutrition Sciences, MIGAL-Galilee Research Institute, Ltd., Kiryat Shmona, Israel; Tel-Hai College, Upper Galilee, Israel
| | - Soliman Khatib
- Laboratory of Oxidative Stress and Human Diseases, MIGAL-Galilee Research Institute, Ltd., Kiryat Shmona, Israel; Tel-Hai College, Upper Galilee, Israel
| | - Reut Levy-Rosenzvig
- Laboratory of Human Health and Nutrition Sciences, MIGAL-Galilee Research Institute, Ltd., Kiryat Shmona, Israel; Tel-Hai College, Upper Galilee, Israel
| | - Snait Tamir
- Laboratory of Human Health and Nutrition Sciences, MIGAL-Galilee Research Institute, Ltd., Kiryat Shmona, Israel; Tel-Hai College, Upper Galilee, Israel
| | - Andrea Szuchman-Sapir
- Laboratory of Human Health and Nutrition Sciences, MIGAL-Galilee Research Institute, Ltd., Kiryat Shmona, Israel; Tel-Hai College, Upper Galilee, Israel.
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Falck JR, Koduru SR, Mohapatra S, Manne R, Atcha KR, Atcha R, Manthati VL, Capdevila JH, Christian S, Imig JD, Campbell WB. 14,15-Epoxyeicosa-5,8,11-trienoic Acid (14,15-EET) surrogates: carboxylate modifications. J Med Chem 2014; 57:6965-72. [PMID: 25119815 PMCID: PMC4148164 DOI: 10.1021/jm500262m] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
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The cytochrome P450 eicosanoid 14,15-epoxyeicosa-5,8,11-trienoic
acid (14,15-EET) is a powerful endogenous autacoid that has been ascribed
an impressive array of physiologic functions including regulation
of blood pressure. Because 14,15-EET is chemically and metabolically
labile, structurally related surrogates containing epoxide bioisosteres
were introduced and have become useful in vitro pharmacologic tools
but are not suitable for in vivo applications. A new generation of
EET mimics incorporating modifications to the carboxylate were prepared
and evaluated for vasorelaxation and inhibition of soluble epoxide
hydrolase (sEH). Tetrazole 19 (ED50 0.18 μM)
and oxadiazole-5-thione 25 (ED50 0.36 μM)
were 12- and 6-fold more potent, respectively, than 14,15-EET as vasorelaxants;
on the other hand, their ability to block sEH differed substantially,
i.e., 11 vs >500 nM. These data will expedite the development of
potent
and specific in vivo drug candidates.
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Affiliation(s)
- John R Falck
- Departments of Biochemistry and Pharmacology, University of Texas Southwestern Medical Center , 5323 Harry Hines Boulevard, Dallas, Texas 75390, United States
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Imig JD. Epoxides and soluble epoxide hydrolase in cardiovascular physiology. Physiol Rev 2012; 92:101-30. [PMID: 22298653 DOI: 10.1152/physrev.00021.2011] [Citation(s) in RCA: 272] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Epoxyeicosatrienoic acids (EETs) are arachidonic acid metabolites that importantly contribute to vascular and cardiac physiology. The contribution of EETs to vascular and cardiac function is further influenced by soluble epoxide hydrolase (sEH) that degrades EETs to diols. Vascular actions of EETs include dilation and angiogenesis. EETs also decrease inflammation and platelet aggregation and in general act to maintain vascular homeostasis. Myocyte contraction and increased coronary blood flow are the two primary EET actions in the heart. EET cell signaling mechanisms are tissue and organ specific and provide significant evidence for the existence of EET receptors. Additionally, pharmacological and genetic manipulations of EETs and sEH have demonstrated a contribution for this metabolic pathway to cardiovascular diseases. Given the impact of EETs to cardiovascular physiology, there is emerging evidence that development of EET-based therapeutics will be beneficial for cardiovascular diseases.
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Affiliation(s)
- John D Imig
- Department of Pharmacology and Toxicology, Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.
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Félétou M. The Endothelium, Part I: Multiple Functions of the Endothelial Cells -- Focus on Endothelium-Derived Vasoactive Mediators. ACTA ACUST UNITED AC 2011. [DOI: 10.4199/c00031ed1v01y201105isp019] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Bukhari IA, Gauthier KM, Jagadeesh SG, Sangras B, Falck JR, Campbell WB. 14,15-Dihydroxy-eicosa-5(Z)-enoic acid selectively inhibits 14,15-epoxyeicosatrienoic acid-induced relaxations in bovine coronary arteries. J Pharmacol Exp Ther 2010; 336:47-55. [PMID: 20881018 DOI: 10.1124/jpet.110.169797] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Cytochrome P-450 epoxygenases metabolize arachidonic acid (AA) to epoxyeicosatrienoic acids (EETs). EETs relax vascular smooth muscle by membrane hyperpolarization. 14,15-Epoxyeicosa-5(Z)-enoic acid (14,15-EE5ZE) antagonizes many vascular actions of EETs. EETs are converted to the corresponding dihydroxyeicosatrienoic acids by soluble epoxide hydrolase (sEH). sEH activity in the bovine arterial endothelium and smooth muscle regulates endogenous EETs. This study examined sEH metabolism of 14,15-EE5ZE to 14,15-dihydroxy-eicosa-5(Z)-enoic acid (14,15-DHE5ZE) and the resultant consequences on EET relaxations of bovine coronary arteries (BCAs). BCAs converted 14,15-EE5ZE to 14,15-DHE5ZE. This conversion was blocked by the sEH inhibitor 12-(3-adamantan-1-yl-ureido)-dodecanoic acid (AUDA). 14,15-EET relaxations (maximal relaxation, 83.4 ± 4.5%) were inhibited by 14,15-DHE5ZE (10 μM; maximal relaxation, 36.1 ± 9.0%; p < 0.001). In sharp contrast with 14,15-EE5ZE, 14,15-DHE5ZE is a 14,15-EET-selective inhibitor and did not inhibit 5,6-, 8,9-, or 11,12-EET relaxations. 14,15-EET and 11,12-EET relaxations were similar in the presence and absence of AUDA (1 μM). 14,15-EE5ZE inhibited 14,15-EET relaxations to a similar extent with and without AUDA pretreatment. However, 14,15-EE5ZE inhibited 11,12-EET relaxations to a greater extent with than without AUDA pretreatment. These observations indicate that sEH converts 14,15-EE5ZE to 14,15-DHE5ZE, and this alteration influences antagonist selectivity against EET-regioisomers. 14,15-DHE5ZE inhibited endothelium-dependent relaxations to AA but not endothelium-independent relaxations to sodium nitroprusside. A series of sEH-resistant ether analogs of 14,15-EE5ZE was developed, and analogs with agonist and antagonist properties were identified. The present study indicates that conversion of 14,15-EE5ZE to 14,15-DHE5ZE produces a 14,15-EET-selective antagonist that will be a useful pharmacological tool to identify EET receptor(s) and EET function in the cardiovascular system.
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Affiliation(s)
- Ishfaq A Bukhari
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Rd., Milwaukee, WI 53226, USA
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Falck JR, Kodela R, Manne R, Atcha KR, Puli N, Dubasi N, Manthati VL, Capdevila JH, Yi XY, Goldman DH, Morisseau C, Hammock BD, Campbell WB. 14,15-Epoxyeicosa-5,8,11-trienoic acid (14,15-EET) surrogates containing epoxide bioisosteres: influence upon vascular relaxation and soluble epoxide hydrolase inhibition. J Med Chem 2010; 52:5069-75. [PMID: 19653681 DOI: 10.1021/jm900634w] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
All-cis-14,15-epoxyeicosa-5,8,11-trienoic acid (14,15-EET) is a labile, vasodilatory eicosanoid generated from arachidonic acid by cytochrome P450 epoxygenases. A series of robust, partially saturated analogues containing epoxide bioisosteres were synthesized and evaluated for relaxation of precontracted bovine coronary artery rings and for in vitro inhibition of soluble epoxide hydrolase (sEH). Depending upon the bioisostere and its position along the carbon chain, varying levels of vascular relaxation and/or sEH inhibition were observed. For example, oxamide 16 and N-iPr-amide 20 were comparable (ED(50) 1.7 microM) to 14,15-EET as vasorelaxants but were approximately 10-35 times less potent as sEH inhibitors (IC(50) 59 and 19 microM, respectively); unsubstituted urea 12 showed useful activity in both assays (ED(50) 3.5 microM, IC(50) 16 nM). These data reveal differential structural parameters for the two pharmacophores that could assist the development of potent and specific in vivo drug candidates.
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Affiliation(s)
- J R Falck
- Departments of Biochemistry and Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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Abstract
Neuronal activity is communicated to the cerebral vasculature so that adequate perfusion of brain tissue is maintained at all levels of neuronal metabolism. An increase in neuronal activity is accompanied by vasodilation and an increase in local cerebral blood flow. This process, known as neurovascular coupling (NVC) or functional hyperemia, is essential for cerebral homeostasis and survival. Neuronal activity is encoded in astrocytic Ca(2+) signals that travel to astrocytic processes (;endfeet') encasing parenchymal arterioles within the brain. Astrocytic Ca(2+) signals cause the release of vasoactive substances to cause relaxation, and in some circumstances contraction, of the smooth muscle cells (SMCs) of parenchymal arterioles to modulate local cerebral blood flow. Activation of potassium channels in the SMCs has been proposed to mediate NVC. Here, the current state of knowledge of NVC and potassium channels in parenchymal arterioles is reviewed.
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Affiliation(s)
- Kathryn M Dunn
- Department of Pharmacology, University of Vermont College of Medicine, Burlington, VT 05405, USA
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Sudhahar V, Shaw S, Imig JD. Epoxyeicosatrienoic acid analogs and vascular function. Curr Med Chem 2010; 17:1181-90. [PMID: 20158473 DOI: 10.2174/092986710790827843] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Accepted: 02/06/2010] [Indexed: 01/14/2023]
Abstract
Arachidonic acid metabolites, eicosanoids, are key contributors to vascular function and improper eicosanoid regulation contributes to the progression of cardiovascular diseases. Epoxyeicosatrienoic acids (EETs) are synthesized from arachidonic acid by epoxygenase enzymes to four regioisomers, 5,6-EET, 8,9-EET, 11,12-EET, and 14,15-EET. These EETs have interesting beneficial effects like vasodilation, anti-inflammation, and anti-platelet aggregation that could combat cardiovascular diseases. There is mounting evidence that each regioisomeric EET may have unique vascular effects and that the contribution of individual EETs to vascular function differs from organ to organ. Over the past decade EET analogs and antagonists have been synthesized to determine EET structure function relationships and define the contribution of each regioisomeric EET. A number of studies have demonstrated that EET analogs induce vasodilation, lower blood pressure and decrease inflammation. EET antagonists have also been used to demonstrate that endogenous EETs contribute importantly to cardiovascular function. This review will discuss EET synthesis, regulation and physiological roles in the cardiovascular system. Next we will focus on the development of EET analogs and what has been learned about their contribution to vascular function. Finally, the development of EET antagonists and how these have been utilized to determine the cardiovascular actions of endogenous epoxides will be discussed. Overall, this review will highlight the important knowledge garnered by the development of EET analogs and their possible value in the treatment of cardiovascular diseases.
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Affiliation(s)
- V Sudhahar
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, 53226, USA
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Miller TM, Donnelly MK, Crago EA, Roman DM, Sherwood PR, Horowitz MB, Poloyac SM. Rapid, simultaneous quantitation of mono and dioxygenated metabolites of arachidonic acid in human CSF and rat brain. J Chromatogr B Analyt Technol Biomed Life Sci 2009; 877:3991-4000. [PMID: 19892608 DOI: 10.1016/j.jchromb.2009.10.012] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2009] [Revised: 08/31/2009] [Accepted: 10/07/2009] [Indexed: 11/16/2022]
Abstract
Currently, there are few biomarkers to predict the risk of symptomatic cerebral vasospasm (SV) in subarachnoid hemorrhage (SAH) patients. Mono and dioxygenated arachidonic acid metabolites, involved in the pathogenesis of ischemic injury, may serve as indicators of SV. This study developed a quantitative UPLC-MS/MS method to simultaneously measure hydroxyeicosatetraenoic acid (HETE), dihydroxyeicosatrienoic acid (DiHETrE), and epoxyeicosatrienoic acid (EET) metabolites of arachidonic acid in cerebrospinal fluid (CSF) samples of SAH patients. Additionally, we determined the recovery of these metabolites from polyvinylchloride (PVC) bags used for CSF collection. Linear calibration curves ranging from 0.208 to 33.3 ng/ml were validated. The inter-day and intra-day variance was less than 15% at most concentrations with extraction efficiency greater than 73%. The matrix did not affect the reproducibility and reliability of the assay. In CSF samples, peak concentrations of 8,9-DiHETrE, 20-HETE, 15-HETE, and 12-HETE ranged from 0.293 to 24.9 ng/ml. In rat brain cortical tissue samples, concentrations of 20-, 15-, 12-HETE, 8,9-EET, and 14,15-, 11,12-DiHETrE ranged from 0.57 to 23.99 pmol/g wet tissue. In rat cortical microsomal incubates, all 10 metabolites were measured with formation rates ranging from 0.03 to 7.77 pmol/mg/min. Furthermore, 12-HETE and EET metabolites were significantly altered by contact with PVC bags at all time points evaluated. These data demonstrate that the simultaneous measurement of these compounds in human CSF and rat brain can be achieved with a UPLC-MS/MS system and that this method is necessary for evaluation of these metabolites as potential quantitative biomarkers in future clinical trials.
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Affiliation(s)
- Tricia M Miller
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261, USA
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Cui PH, Zhang WV, Hook J, Tattam BN, Duke CC, Murray M. Synthesis and NMR characterization of the methyl esters of eicosapentaenoic acid monoepoxides. Chem Phys Lipids 2009; 159:30-7. [PMID: 19428360 DOI: 10.1016/j.chemphyslip.2009.02.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2008] [Revised: 02/10/2009] [Accepted: 02/13/2009] [Indexed: 10/21/2022]
Abstract
The activities of cytochrome P450-derived epoxide metabolites of omega-6 polyunsaturated fatty acids (PUFAs) in cellular homeostasis have generated considerable topical interest, but there is less information on the effects of omega-3 PUFA epoxides. Mass spectroscopic data on the epoxides of the omega-3 PUFA eicosapentaenoic acid (EPA) have been reported but the absence of corresponding NMR data currently hinders their biological assessment. In the present study five monoepoxy derivatives of EPA methyl ester were synthesized by treating EPA methyl ester with m-chloroperbenzoic acid. The individual regioisomers were purified by normal-phase chromatography and characterized by LC-MS/MS and a combination of NMR approaches including (1)H-, (13)C-, (1)H-(1)H-COSY, (1)H-(13)C-HSQC, and (1)H-(13)C-HMBC. The chromatographic properties for these monoepoxides were studied in normal-phase and reversephase-HPLC systems and the MS/MS fragmentation patterns using electrospray ionization were established. This paper also focuses on the NMR characterization of epoxide, olefinic and methylenic moieties and the complete assignments of the isomers.
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Affiliation(s)
- Pei H Cui
- Faculty of Pharmacy, University of Sydney, NSW 2006, Australia
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Chiamvimonvat N, Ho CM, Tsai HJ, Hammock BD. The soluble epoxide hydrolase as a pharmaceutical target for hypertension. J Cardiovasc Pharmacol 2007; 50:225-37. [PMID: 17878749 DOI: 10.1097/fjc.0b013e3181506445] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The soluble epoxide hydrolase appears to be a promising target for the development of antihypertensive therapies based on a previously unexplored mechanism of action. Epoxide hydrolases are enzymes that add water to three membered cyclic ethers known as epoxides. The soluble epoxide hydrolase in mammalian systems (sEH) is a member of the alpha/beta-hydrolase fold family of enzymes and it shows a high degree of selectivity for epoxides of fatty acids. The regioisomeric epoxides of arachidonic acid or epoxyeicosanoids (EETs) are particularly good substrates. These EETs appear to be major components of the endothelium-derived hyperpolarizing factors (EDHFs). As such, EETs cause vasodilation and reduce blood pressure. The EETs also are strongly anti-inflammatory and analgesic. By inhibiting sEH, the increase in circulating EETs leads to a reduction in blood pressure in a number of animal models. Potent transition state mimic inhibitors have been developed for the sEH. Some of these sEH inhibitors (sEHIs) show nanomolar to picomolar potency and good pharmacokinetic properties. Because of their unique mode of action they show promise in treating hypertension while reducing problems with end organ failure, vascular inflammation and diabetes. Indeed, the anti-inflammatory properties of the sEHI may make them particularly suitable for treating hypertension in patients with other concomitant metabolic syndromes. They are more potent on a molar basis than most nonsteroidal anti-inflammatory drugs (NSAIDs) in reducing PGE2 in inflammation models, they strongly synergize with NSAIDs, and appear to ameliorate apparently unfavorable eicosanoid profiles associated with some cyclo-oxygenase-2 inhibitors.
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Affiliation(s)
- Nipavan Chiamvimonvat
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis, CA 95616, USA
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15
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Yang W, Holmes BB, Gopal VR, Kishore RVK, Sangras B, Yi XY, Falck JR, Campbell WB. Characterization of 14,15-Epoxyeicosatrienoyl-Sulfonamides as 14,15-Epoxyeicosatrienoic Acid Agonists: Use for Studies of Metabolism and Ligand Binding. J Pharmacol Exp Ther 2007; 321:1023-31. [PMID: 17327488 DOI: 10.1124/jpet.107.119651] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Epoxyeicosatrienoic acids (EETs) are cytochrome P450 epoxygenase metabolites of arachidonic acid. EETs mediate numerous biological functions. In coronary arteries, they regulate vascular tone by the activation of smooth muscle large-conductance, calcium-activated potassium (BK(Ca)) channels to cause hyperpolarization and relaxation. We developed a series of 14,15-EET agonists, 14,15-EET-phenyliodosulfonamide (14,15-EET-PISA), 14,15-EET-biotinsulfonamide (14,15-EET-BSA), and 14,15-EET-benzoyldihydrocinnamide-sulfonamide (14,15-EET-BZDC-SA) as tools to characterize 14,15-EET metabolism and binding. Agonist activities of these analogs were characterized in precontraced bovine coronary arterial rings. All three analogs induced concentration-dependent relaxation and were equipotent with 14,15-EET. Relaxations to these analogs were inhibited by the BK(Ca) channel blocker iberiotoxin (100 nM), the 14,15-EET antagonist 14,15-epoxyeicosa-5(Z)-enoylmethylsulfonamide (10 muM), and abolished by 20 mM extracellular K(+). 14,15-EET-PISA is metabolized to 14,15-dihydroxyeicosatrienoyl-PISA by soluble epoxide hydrolase in bovine coronary arteries and U937 cells but not U937 cell membrane fractions. 14,15-EET-P(125)ISA binding to human U937 cell membranes was time-dependent, concentration-dependent, and saturable. The specific binding reached equilibrium by 15 min at 4 degrees C and remained unchanged up to 30 min. The estimated K(d) and B(max) were 148.3 +/- 36.4 nM and 3.3 +/- 0.5 pmol/mg protein, respectively. These data suggest that 14,15-EET-PISA, 14,15-EET-BSA, and 14,15-EET-BZDC-SA are full 14,15-EET agonists. 14,15-EET-P(125)ISA is a new radiolabeled tool to study EET metabolism and binding. Our results also provide preliminary evidence that EETs exert their biological effect through a membrane binding site/receptor.
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Affiliation(s)
- Wenqi Yang
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
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16
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Larsen BT, Campbell WB, Gutterman DD. Beyond vasodilatation: non-vasomotor roles of epoxyeicosatrienoic acids in the cardiovascular system. Trends Pharmacol Sci 2007; 28:32-8. [PMID: 17150260 DOI: 10.1016/j.tips.2006.11.002] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2006] [Revised: 09/18/2006] [Accepted: 11/20/2006] [Indexed: 01/22/2023]
Abstract
Epoxyeicosatrienoic acids (EETs), derived from arachidonic acid by cytochrome P450 epoxygenases, are potent vasodilators that function as endothelium-derived hyperpolarizing factors in some vascular beds. EETs are rapidly metabolized by soluble epoxide hydrolase to form dihydroxyeicosatrienoic acids (DHETs). Recent reports indicate that EETs have several important non-vasomotor regulatory roles in the cardiovascular system. EETs are potent anti-inflammatory agents and might function as endogenous anti-atherogenic compounds. In addition, EETs and DHETs might stimulate lipid metabolism and regulate insulin sensitivity. Thus, pharmacological inhibition of soluble epoxide hydrolase might be useful not only for hypertension but also for abating atherosclerosis, diabetes mellitus and the metabolic syndrome. Finally, although usually protective in the systemic circulation, EETs might adversely affect the pulmonary circulation.
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Affiliation(s)
- Brandon T Larsen
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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17
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Rifkind AB. CYP1A in TCDD toxicity and in physiology-with particular reference to CYP dependent arachidonic acid metabolism and other endogenous substrates. Drug Metab Rev 2006; 38:291-335. [PMID: 16684662 DOI: 10.1080/03602530600570107] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Toxicologic and physiologic roles of CYP1A enzyme induction, the major biochemical effect of aryl hydrocarbon receptor activation by TCDD and other receptor ligands, are unknown. Evidence is presented that CYP1A exerts biologic effects via metabolism of endogenous substrates (i.e., arachidonic acid, other eicosanoids, estrogens, bilirubin, and melatonin), production of reactive oxygen, and effects on K(+) and Ca(2+) channels. These interrelated pathways may connect CYP1A induction to TCDD toxicities, including cardiotoxicity, vascular dysfunction, and wasting. They may also underlie homeostatic roles for CYP1A, especially when transiently induced by common chemical exposures and environmental conditions (i.e., tryptophan photoproducts, dietary indoles, and changes in oxygen tension).
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Affiliation(s)
- Arleen B Rifkind
- Department of Pharmacology, Weill Medical College of Cornell University, New York, NY 10021, USA.
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18
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Olearczyk JJ, Field MB, Kim IH, Morisseau C, Hammock BD, Imig JD. Substituted adamantyl-urea inhibitors of the soluble epoxide hydrolase dilate mesenteric resistance vessels. J Pharmacol Exp Ther 2006; 318:1307-14. [PMID: 16772540 DOI: 10.1124/jpet.106.103556] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The epoxyeicosatrienoic acids (EETs) have been identified as endothelium-derived hyperpolarizing factors. Metabolism of the EETs to the dihydroxyeicosatrienoic acids is catalyzed by soluble epoxide hydrolase (sEH). Administration of urea-based sEH inhibitors provides protection from hypertension-induced renal injury at least in part by lowering blood pressure. Here, we investigated the hypothesis that a mechanism by which sEH inhibitors elicit their cardiovascular protective effects is via their action on the vasculature. Mesenteric resistance arteries were isolated from Sprague-Dawley rats, pressurized, and constricted with the thromboxane A2 agonist U46619 (9,11-dideoxy-11,9-epoxymethano-prostaglandin F2alpha). Mesenteric arteries were then incubated with increasing concentrations of the sEH inhibitor 12-(3-adamantan-1-yl-ureido)dodecanoic acid (AUDA). AUDA resulted in a concentration-dependent relaxation of mesenteric arteries, with 10 microM resulting in a 48 +/- 7% relaxation. Chain-shortened analogs of AUDA had an attenuated vasodilatory response. Interestingly, at 10 microM, the sEH inhibitors 1-cyclohexyl-3-dodecylurea, 12-(3-cyclohexylureido)dodecanoic acid, and 950 [adamantan-1-yl-3-{5-[2-(2-ethoxyethoxy)ethoxy]pentyl}urea] were significantly less active, resulting in a 25 +/- 8%, 10 +/- 9%, and -8 +/- 3% relaxation, respectively. Treatment of mesenteric arteries with tetraethylammonium, iberiotoxin, ouabain, or glibenclamide did not alter AUDA-induced relaxation. The AUDA-induced relaxation was completely inhibited when constricted with KCl. In separate experiments, denuding mesenteric resistance vessels did not alter AUDA-induced relaxation. Taken together, these data demonstrate that adamantyl-urea inhibitors have unique dilator actions on vascular smooth muscle compared with other sEH inhibitors and that these dilator actions depend on the adamantyl group and carbon chain length.
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Affiliation(s)
- Jeffrey J Olearczyk
- The Medical College of Georgia, Vascular Biology Center, Augusta, GA 30912, USA.
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19
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Abstract
Epoxyeicosatrienoic acids (EETs) are epoxides of arachidonic acid generated by cytochrome P450 (CYP) epoxygenases. The activation of CYP epoxygenases in endothelial cells is an important step in the NO and prostacyclin-independent vasodilatation of several vascular beds, and EETs have been identified as an endothelium-derived hyperpolarizing factor. However, EETs also exert membrane potential-independent effects and modulate several signaling cascades that affect endothelial cell proliferation and angiogenesis. This review summarizes the role of CYP-derived EETs in endothelium-derived hyperpolarizing factor-mediated responses and highlights the evidence indicating that EETs are important second messengers involved in endothelial cell signaling pathways related to angiogenesis.
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Affiliation(s)
- Ingrid Fleming
- Institut für Kardiovaskuläre Physiologie, Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany.
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20
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Wei S, Brittin JJ, Falck JR, Anjaiah S, Nithipatikom K, Cui L, Campbell WB, Capdevila JH. Chiral resolution of the epoxyeicosatrienoic acids, arachidonic acid epoxygenase metabolites. Anal Biochem 2006; 352:129-34. [PMID: 16480681 DOI: 10.1016/j.ab.2006.01.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2005] [Revised: 12/21/2005] [Accepted: 01/04/2006] [Indexed: 11/19/2022]
Abstract
An HPLC method for the chiral analysis of the four regioisomeric epoxyeicosatrienoic acids (EETs) is described. The cytochrome P450 arachidonic acid epoxygenase metabolites are resolved, without the need for derivatization, by chiral-phase HPLC on a Chiralcel OJ column. Application of this methodology to the analysis of the liver endogenous EETs demonstrates stereospecific biosynthesis and corroborates the role of cytochrome P450 as the endogenous arachidonic acid epoxygenase.
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MESH Headings
- 8,11,14-Eicosatrienoic Acid/analogs & derivatives
- 8,11,14-Eicosatrienoic Acid/chemistry
- 8,11,14-Eicosatrienoic Acid/isolation & purification
- 8,11,14-Eicosatrienoic Acid/metabolism
- Animals
- Chromatography, High Pressure Liquid/methods
- Cytochrome P-450 CYP2J2
- Cytochrome P-450 Enzyme System/metabolism
- Liver/cytology
- Liver/metabolism
- Male
- Microsomes, Liver/metabolism
- Oxygenases/metabolism
- Rats
- Rats, Sprague-Dawley
- Stereoisomerism
- Vasodilator Agents/metabolism
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Affiliation(s)
- Shouzou Wei
- Department of Medicine, Vanderbilt Medical School, Nashville, TN 37232, USA
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21
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Larsen BT, Miura H, Hatoum OA, Campbell WB, Hammock BD, Zeldin DC, Falck JR, Gutterman DD. Epoxyeicosatrienoic and dihydroxyeicosatrienoic acids dilate human coronary arterioles via BK(Ca) channels: implications for soluble epoxide hydrolase inhibition. Am J Physiol Heart Circ Physiol 2005; 290:H491-9. [PMID: 16258029 PMCID: PMC1456013 DOI: 10.1152/ajpheart.00927.2005] [Citation(s) in RCA: 145] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Epoxyeicosatrienoic acids (EETs) are metabolized by soluble epoxide hydrolase (sEH) to form dihydroxyeicosatrienoic acids (DHETs) and are putative endothelium-derived hyperpolarizing factors (EDHFs). EDHFs modulate microvascular tone; however, the chemical identity of EDHF in the human coronary microcirculation is not known. We examined the capacity of EETs, DHETs, and sEH inhibition to affect vasomotor tone in isolated human coronary arterioles (HCAs). HCAs from right atrial appendages were prepared for videomicroscopy and immunohistochemistry. In vessels preconstricted with endothelin-1, three EET regioisomers (8,9-, 11,12-, and 14,15-EET) each induced a concentration-dependent dilation that was sensitive to blockade of large-conductance Ca2+-activated K+ (BK(Ca)) channels by iberiotoxin. EET-induced dilation was not altered by endothelial denudation. 8,9-, 11,12-, and 14,15-DHET also dilated HCA via activation of BK(Ca) channels. Dilation was less with 8,9- and 14,15-DHET but was similar with 11,12-DHET, compared with the corresponding EETs. Immunohistochemistry revealed prominent expression of cytochrome P-450 (CYP450) 2C8, 2C9, and 2J2, enzymes that may produce EETs, as well as sEH, in HCA. Inhibition of sEH by 1-cyclohexyl-3-dodecylurea (CDU) enhanced dilation caused by 14,15-EET but reduced dilation observed with 11,12-EET. DHET production from exogenous EETs was reduced in vessels pretreated with CDU compared with control, as measured by liquid chromatography electrospray-ionization mass spectrometry. In conclusion, EETs and DHETs dilate HCA by activating BK(Ca) channels, supporting a role for EETs/DHETs as EDHFs in the human heart. CYP450s and sEH may be endogenous sources of these compounds, and sEH inhibition has the potential to alter myocardial perfusion, depending on which EETs are produced endogenously.
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Affiliation(s)
- Brandon T. Larsen
- Departments of Pharmacology and Toxicology
- Cardiovascular Center, Medical College of Wisconsin and
| | - Hiroto Miura
- Medicine, and the
- Cardiovascular Center, Medical College of Wisconsin and
| | - Ossama A. Hatoum
- Medicine, and the
- Cardiovascular Center, Medical College of Wisconsin and
| | | | - Bruce D. Hammock
- Department of Entomology and Cancer Research Center, University of California, Davis, California
| | - Darryl C. Zeldin
- Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina; and
| | - John R. Falck
- Departments of Biochemistry and Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - David D. Gutterman
- Departments of Pharmacology and Toxicology
- Medicine, and the
- Cardiovascular Center, Medical College of Wisconsin and
- Veterans Affairs Medical Center, Milwaukee, Wisconsin
- Address for reprint requests and other correspondence: D. D. Gutterman, Northwestern Mutual Professor of Medicine, Senior Associate Dean for Research, Medical College of Wisconsin, 8701 Watertown Plank Rd., Milwaukee, WI 53226 (e-mail: )
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