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van der Sterren S, Villamor E. Contractile effects of 15-E2t-isoprostane and 15-F2t-isoprostane on chicken embryo ductus arteriosus. Comp Biochem Physiol A Mol Integr Physiol 2011; 159:436-44. [PMID: 21565280 DOI: 10.1016/j.cbpa.2011.04.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Revised: 04/24/2011] [Accepted: 04/26/2011] [Indexed: 01/15/2023]
Abstract
Isoprostanes (IsoPs) are prostaglandin (PG)-like compounds produced nonenzymatically by free radical-catalyzed peroxidation of arachidonate. Cyclooxygenase-derived PGs play a major role in ductus arteriosus (DA) homeostasis but the putative role of IsoPs has not been studied so far. We investigated, using wire myography, the vasoactive effects of 15-E(2t)-IsoP and 15-F(2t)-IsoP in the chicken embryo DA, pulmonary artery (PA) and femoral artery (FA). 15-E(2t)-IsoP and 15-F(2t)-IsoP contracted DA, PA, and FA rings in a concentration-dependent manner. 15-E(2t)-IsoP was equally efficacious (mean±SE E(max)=1.25±0.06 mN/mm) as and more potent (-log of molar concentration producing 50% of E(max)=pEC(50)=7.00±0.04) than the thromboxane-prostanoid (TP) receptor agonist U46619 (E(max)=1.49±0.11 mN/mm; pEC(50)=6.48±0.05) in contracting chicken DA (pulmonary side). 15-F(2t)-IsoP was less potent (pEC(50)=5.74±0.11) and less efficacious (E(max)=0.96±0.11) than U46619. Concentration-dependent contractions to 15-E(2t)-IsoP and U46619 in DA rings were competitively inhibited by the TP receptor antagonist SQ29548 (0.1 μM to 10 μM) with no decrease in the E(max) values. SQ29548 also inhibited concentration-dependent contraction to 15-F(2t)-IsoP but this inhibition was associated with a decrease in E(max). Pre-incubation of DA rings with 15-F(2t)-IsoP inhibited responses to U46619 and, in vessels contracted with U46619 (1 μM), 15-F(2t)-IsoP (>1 μM) evoked a relaxant response. Enzyme immunoassay did not show a measurable release of 15-F(2t)-IsoP by DA rings. In conclusion, 15-E(2t)-IsoP is a potent and efficacious constrictor of chicken DA, acting through TP receptors. In contrast, 15-F(2t)-IsoP is probably acting as a partial agonist at TP receptors. We speculate that IsoPs play a role in the control of chicken DA tone and could participate in its closure.
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Affiliation(s)
- Saskia van der Sterren
- Department of Pediatrics, Maastricht University Medical Center (MUMC+), School for Oncology and Developmental Biology (GROW), Maastricht, The Netherlands
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Mueed I, Tazzeo T, Liu C, Pertens E, Zhang Y, Cybulski I, Semelhago L, Noora J, Lamy A, Teoh K, Chu V, Janssen LJ. Isoprostanes constrict human radial artery by stimulation of thromboxane receptors, Ca2+ release, and RhoA activation. J Thorac Cardiovasc Surg 2008; 135:131-8. [PMID: 18179929 DOI: 10.1016/j.jtcvs.2007.06.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2007] [Revised: 04/27/2007] [Accepted: 06/11/2007] [Indexed: 11/30/2022]
Abstract
OBJECTIVES Radial artery vasospasm remains a potential cause of early graft failure after coronary bypass graft surgery, despite pretreatment with alpha-adrenergic or calcium channel blockers. We examined the roles of isoprostanes and prostanoid receptors selective for thromboxane A2 in the vasoconstriction of human radial arteries. METHODS Human radial arterial segments were pretreated intraoperatively with verapamil/papaverine or nitroglycerine/phenoxybenzamine, or not treated. In the laboratory, we measured isometric contractions in ring segments, vasoconstriction in pressurized segments, and changes in [Ca2+] and K+ currents in single cells. RESULTS Although phenoxybenzamine eliminated adrenergic responses, the isoprostane 15-F(2t)-IsoP and 2 closely related E-ring molecules (15-E(1t)-IsoP and 15-E(2t)-IsoP) still evoked powerful contractions; 15-E(2t)-IsoP was approximately 10-fold more potent than the other 2 agents. Responses were mediated through thromboxane receptors because they were sensitive to ICI-192605. Furthermore, they were sensitive to the Rho-kinase inhibitors Y-27632 or H-1152 (both 10(-5) mol/L) or to cyclopiazonic acid (which depletes the internal Ca2+ pool), but not to nifedipine. In single cells, 15-E(2t)-IsoP elevated [Ca2+]i and suppressed K+ current. CONCLUSIONS Isoprostanes accumulate after coronary artery bypass graft surgery, yet none of the currently available antispasm treatments for radial artery grafts is effective against isoprostane-induced vasoconstriction. It is imperative that more specific treatment strategies be developed. We found that isoprostane responses in radial arteries are mediated by prostanoid receptors selective for thromboxane A2 with activation of Rho-kinase and release of Ca2+. Pretreatment of radial artery grafts with Rho-associated kinase inhibitors may potentially reduce postoperative graft spasm. Clinical studies to test this are indicated.
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Affiliation(s)
- Irem Mueed
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
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3
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Seto V, Hirota C, Hirota S, Janssen LJ. E-Ring Isoprostanes Stimulate a Cl Conductance in Airway Epithelium via Prostaglandin E2-Selective Prostanoid Receptors. Am J Respir Cell Mol Biol 2007; 38:88-94. [PMID: 17673688 DOI: 10.1165/rcmb.2007-0117oc] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Isoprostanes comprise a class of membrane lipid metabolites produced during oxidative stress, including asthma, chronic obstructive pulmonary disease, and cystic fibrosis. They are widely recognized to evoke a variety of biological responses in airway and pulmonary vascular smooth muscle, lymphatics, and innervation. However, their effects on airway epithelium are largely unstudied. We examined the electrophysiological responses evoked by several different isoprostane species in bovine airway epithelium using the Ussing chamber technique. The E-ring isoprostanes 15-E(1t)-IsoP and 15-E(2t)-IsoP evoked a substantial increase in short-circuit current (I(SC)), whereas four different F-ring isomers were ineffective. 15-E(2t)-IsoP-evoked I(SC) was mimicked by the prostaglandin E(2)-selective prostanoid receptor (EP)-agonist prostaglandin E(2) but not by agonists of EP(1)/EP(3)-, FP-, or TP receptors (sulprostone, fluprostenol, and U46619, respectively). This response was significantly reduced by the EP(4)-receptor blocker GW627386 but not by blockers of other prostanoid receptors (ICI 192,605 [TP-selective], SC19220 [EP(1)-selective], AH6809 [DP/EP(1)/EP(2)-selective], and AL8810 [FP-selective]). 15-E(2t)-IsoP-evoked I(SC) was reduced by blockers of Cl(-) channels (niflumic acid and 5-nitro-2-(3-phenylpropylamino)-benzoic acid), of Na(+)/K(+)/2Cl(-) co-transport (furosemide and bumetanide), of adenylate cyclase (MDL 12,330A), or of guanylate cyclase (1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one) but not by blockers of Na(+) conductances (amiloride). We conclude that 15-E(2t)-IsoP activates a transepithelial Cl(-) conductance in bovine airway epithelium through an EP(4) receptor coupled to adenylate cyclase and soluble guanylate cyclase.
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MESH Headings
- Animals
- Cattle
- Chloride Channel Agonists
- Chloride Channels/metabolism
- Electric Conductivity
- Evoked Potentials/drug effects
- Ion Transport/drug effects
- Isoprostanes/chemical synthesis
- Isoprostanes/chemistry
- Isoprostanes/pharmacology
- Membrane Lipids/metabolism
- Muscle, Smooth, Vascular/innervation
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Oxidative Stress/drug effects
- Pulmonary Disease, Chronic Obstructive/drug therapy
- Pulmonary Disease, Chronic Obstructive/metabolism
- Pulmonary Disease, Chronic Obstructive/pathology
- Receptors, Prostaglandin E/agonists
- Receptors, Prostaglandin E/metabolism
- Receptors, Prostaglandin E, EP4 Subtype
- Respiratory Mucosa/innervation
- Respiratory Mucosa/metabolism
- Respiratory Mucosa/pathology
- Tissue Culture Techniques
- Trachea/innervation
- Trachea/metabolism
- Trachea/pathology
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Affiliation(s)
- Victoria Seto
- Firestone Institute for Respiratory Health, St. Joseph's Healthcare, and Department of Medicine, McMaster University, Hamilton, Ontario, Canada
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Paredes C, Tazzeo T, Janssen LJ. E-ring isoprostane augments cholinergic neurotransmission in bovine trachealis via FP prostanoid receptors. Am J Respir Cell Mol Biol 2007; 37:739-47. [PMID: 17630320 DOI: 10.1165/rcmb.2007-0022oc] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Isoprostanes are prostaglandin-like molecules that accumulate in oxidative stress and also exert powerful biological effects on a wide variety of tissues. We investigated the effects of several different isoprostanes on contractions evoked by electrical field stimulation (EFS) in bovine trachealis, finding only 15-E2t-IsoP to augment those responses. Many others have shown that isoprostanes act on prostanoid receptors, usually those of the thromboxane-selective prostanoid receptor (TP) subtype, although some describe actions through prostaglandin E2-selective prostanoid receptor (EP) or less frequently through prostaglandin F2alpha-selective prostanoid receptors (FP). We used an extensive panel of highly selective agonists and antagonists of prostanoid receptors to characterize the ones through which 15-E2t-IsoP was acting here. Pretreatment with the FP-selective AL-8810 significantly inhibited the augmentation, whereas TP- and EP-selective blockers did not. On the other hand, the augmentation exerted by 15-E2t-IsoP was mimicked by submicromolar concentrations of the FP-selective agonists PGF2alpha and fluprostenol, as well as by micromolar concentrations of the TP-selective agonist U46619. The concentration-response relationship for exogenously added acetylcholine was not significantly affected by 15-E2t-IsoP, confirming that the effect of the latter on EFS-evoked responses was exerted prejunctionally (i.e., to enhance release of Ach from nerve endings), rather than a direct postjunctional effect via a receptor on the smooth muscle. Finally, we investigated whether the inhibitory (adrenergic) innervation was also modulated by 15-E2t-IsoP, finding EFS-evoked relaxations to be unaffected by the isoprostane. We conclude that 15-E2t-IsoP acts upon an FP receptor on the cholinergic nerve endings, leading to enhanced neurotransmission.
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Affiliation(s)
- Christine Paredes
- Firestone Institute for Respiratory Health, St. Joseph's Healthcare, and Department of Medicine, McMaster University, Hamilton, Ontario, Canada
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Qi W, Wei JX, Dorairaj I, Mahajan RP, Wilson VG. Evidence that a prostanoid produced by cyclo-oxygenase-2 enhances contractile responses of the porcine isolated coronary artery following exposure to lipopolysaccharide. Br J Anaesth 2007; 98:323-30. [PMID: 17272385 DOI: 10.1093/bja/ael378] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Prolonged incubation of porcine isolated coronary artery (PCA) to lipopolysaccharide (LPS) causes a moderate reduction in vessel constrictive responsiveness. This has been attributed mainly to the induction of nitric oxide synthase (NOS). We aimed to investigate the role of induction of cyclo-oxygenase (COX) and expression of endothelin receptor 1-A (ET1(A)) in modulating the vascular responses of PCA in vitro. METHODS Segments of PCA were exposed to 100 microg ml(-1) LPS overnight. L-Arginine 0.4 mM was included in the medium in some preparations to examine the influence of intracellular nitric oxide, and the influence of extracellular donor sodium nitroprusside (SNP) was also examined in separate experiments. After overnight incubation, the contractile function of the artery was evaluated by the isometric tension recording test. The non-selective NOS inhibitor (L-NAME), non-selective COX inhibitor (indomethacin), COX-1 inhibitor (FR 122047), COX-2 inhibitor (NS 398), and ET1(A) receptor antagonist (FR 139317) were added into the organ bath 30 min before eliciting contractile responses to KCl or U46619 separately or in combinations. Vascular relaxations to 10 nM Substance P (SP) were also assessed. RESULTS L-Arginine did not potentiate the effects of LPS. SNP caused a quantitatively larger reduction in the responsiveness to KCl and U46619 compared with 100 microg ml(-1) LPS. Post exposure to a combination of indomethacin and FR 139317, indomethacin or NS 398 alone enhanced the inhibitory effects of LPS, but FR 122047 or FR 139317 alone failed to modify the responses to LPS. L-NAME fully reversed the changes induced by LPS combined with indomethacin and NS398. In terms of the relaxation by SP, LPS failed to change the magnitude; none of the agents used affected the response except L-NAME which abolished it. CONCLUSION NOS and COX-2 are both activated by overnight exposure to LPS in vascular smooth muscle from PCA in vitro. The prostanoid produced by COX-2 functionally antagonizes the effects of induction of NOS.
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Affiliation(s)
- W Qi
- Department of Anaesthesia and Intensive Care Medicine, School of Biomedical Sciences, Centre for Integrated Systems Biology and Medicine, Queens Medical Centre, University of Nottingham, Nottingham, UK
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Liu C, Tazzeo T, Guy A, Durand T, Janssen LJ. Pharmacological actions of isoprostane metabolites and phytoprostanes in human and bovine pulmonary smooth muscles. Prostaglandins Leukot Essent Fatty Acids 2007; 76:57-64. [PMID: 17049219 DOI: 10.1016/j.plefa.2006.08.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2006] [Accepted: 08/15/2006] [Indexed: 10/24/2022]
Abstract
We examined the responses to various isoprostane derivatives in bovine/human airway and pulmonary arteries. All biological activity of 15-F(2t)-IsoP was lost in its two major metabolites (15-keto-15-F(2t)-IsoP and 13,14-dihydro-15-keto-15-F(2t)-IsoP). We also examined the effects of several metabolites of 15-F(2t)-IsoP synthesized within our own laboratory-both epimers of 2,3-dinor-15-F(2t)-IsoP and of 2,3-dinor-5,6-dihydro-15-F(2t)-IsoP, as well as 20-carboxy-2,3,4,5-tetranor-15 oxo-5,6,13,14-tetrahydro-15-F(2t)-isoP)-finding none of these to have any substantial excitatory effect. Finally, several plant-derived isoprostanes ("phytoprostanes") synthesized within our laboratory elicited little or no excitatory response in these three pulmonary smooth muscle preparations. We conclude that, although isoprostane exhibit powerful constrictor effects on airway and pulmonary vascular smooth muscles, metabolic processing of those isoprostanes essentially abolishes those biological actions; also, the phytoprostanes lack any appreciable pharmacological activity on those smooth muscle preparations.
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Affiliation(s)
- Caiqiong Liu
- Firestone Institute for Respiratory Health, St. Joseph's Hospital and the Department of Medicine, McMaster University, L-314, St. Joseph's Hospital, 40 Charlton Avenue East, Hamilton, Ontario, Canada L8N 3Z5
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Zhang Y, Pertens E, Janssen LJ. 8-isoprostaglandin E(2) activates Ca(2+)-dependent K(+) current via cyclic AMP signaling pathway in murine renal artery. Eur J Pharmacol 2006; 520:22-8. [PMID: 16153635 DOI: 10.1016/j.ejphar.2005.08.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2005] [Revised: 08/02/2005] [Accepted: 08/05/2005] [Indexed: 10/25/2022]
Abstract
The inhibitory pathway of 8-isoprostaglandin E(2) was investigated in murine renal arterial smooth muscle. K(+) current was augmented in a concentration-dependent fashion, with an average increase of 123+/-28% (n=6) following application of 10(-5) M 8-iso PGE(2). This augmentation was observed in the presence of 4-aminopyridine (4-AP, 10(-3) M) but not that of charybdotoxin (Ch Tx, 10(-7) M). Fluorimetric recordings showed marked concentration-dependent increase of cytosolic Ca(2+) levels by 8-iso PGE(2), while an enzyme-linked immunosorbent assay (ELISA)-based cyclic AMP assay showed increased cAMP levels by 10(-7) M 8-iso PGE(2) challenge. The isoprostane-induced augmentation was prevented by the ryanodine receptor blocker ruthenium red (10(-5) M) or the adenylate cyclase blocker SQ 22536 (10(-4) M). The protein kinase A (PKA) inhibitor H 89 (10(-5) M) inhibited resting K(+) currents (78+/-5%, n=5) but did not prevent 8-iso PGE(2) from augmenting the remaining K(+) current. We conclude that 8-iso PGE(2) enhances Ca(2+)-dependent K(+) currents in murine renal artery through a cAMP-dependent pathway which may involve internally sequestered Ca(2+).
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MESH Headings
- Adenine/analogs & derivatives
- Adenine/pharmacology
- Adenylyl Cyclase Inhibitors
- Animals
- Biological Factors
- Calcium/metabolism
- Cyclic AMP/metabolism
- Dinoprostone/analogs & derivatives
- Dinoprostone/pharmacology
- Dose-Response Relationship, Drug
- In Vitro Techniques
- Isoprostanes/pharmacology
- Membrane Potentials
- Mice
- Mice, Inbred BALB C
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Potassium/metabolism
- Potassium Channel Blockers/pharmacology
- Potassium Channels, Calcium-Activated/drug effects
- Potassium Channels, Calcium-Activated/metabolism
- Protein Kinase Inhibitors/pharmacology
- Renal Artery/drug effects
- Renal Artery/metabolism
- Signal Transduction
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Affiliation(s)
- Yongde Zhang
- Department of Medicine, McMaster University, Firestone Institute of Respiratory Health, St. Joseph's Healthcare, 50 Charlton Avenue East, Hamilton, Ontario, Canada, L8N 4A6
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8
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Abstract
Isoprostanes were first recognized as convenient markers of oxidative stress, but their powerful effects on a variety of cell functions are now also being increasingly appreciated. This is particularly true of the lung, which is comprised of a wide variety of different cell types (smooth muscle, innervation, epithelium, lymphatics, etc.), all of which have been shown to respond to exogenously applied isoprostanes. In this review, we summarize these biological responses in the lung, and also consider the roles that isoprostanes might play in a range of pulmonary clinical disorders.
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Affiliation(s)
- Luke J Janssen
- Asthma Research Group, Father Sean O'Sullivan Research Center, Firestone Institute for Respiratory Health, St. Joseph's Hospital, Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
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Tazzeo T, Miller J, Janssen LJ. Vasoconstrictor responses, and underlying mechanisms, to isoprostanes in human and porcine bronchial arterial smooth muscle. Br J Pharmacol 2003; 140:759-63. [PMID: 14504139 PMCID: PMC1574071 DOI: 10.1038/sj.bjp.0705482] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
We investigated the effects of five different isoprostanes (8-iso PGE1, 8-iso PGE2, 8-iso PGF1alpha, 8-iso PGF2alpha and 8-iso PGF2beta) on vasomotor tone in human and porcine bronchial arterial tissues. In the human bronchial arteries, 8-iso PGE2 and 8-iso PGF2alpha evoked powerful constrictions (magnitudes several fold greater than the responses to high millimolar KCl) with negative log concentration causing 50% excitation (EC50) values of 6.8 and 6.5, respectively; 8-iso PGE1 was less potent (EC50 not calculated, since a clear peak contraction was not obtained), while the other isoprostanes were largely ineffective. In the porcine arteries, on the other hand, all three F-ring isoprostanes as well as 8-iso PGE2 evoked constrictor responses, although the peak magnitudes were approximately 50% of the KCl-evoked response; 8-iso PGE2 and 8-iso PGF2alpha were the most potent, with negative log EC50 values of 6.5. We next sought to characterize the signaling pathways underlying the vasoconstrictor responses to 8-iso PGE2, since this was the most potent of the isoprostanes we tested. These responses were largely reversed by the thromboxane A2-selective (TP) prostanoid receptor antagonist ICI 192605 (10-8 m; 4(Z)-6-[(2,4,5 cis)2-(2-chlorophenyl)-4-(2-hydroxy phenyl)1,3-dioxan-5-yl]hexenoic acid) as well as by the nonspecific tyrosine kinase inhibitor genistein (10-5 and 10-4 m), and were reversed approximately 50% by the Rho-kinase inhibitor Y27632 (10-5 m; (+)-(R)-trans-4-(1-aminoethyl)-N-(pyridyl) cyclohexanecarboxamide dihydrochloride). We conclude, therefore, that 8-iso PGE2 constricts bronchial vasculature through the activation of TP receptors, which in turn trigger tyrosine kinase and Rho-kinase activities, resulting in powerful vasoconstriction. These findings are highly relevant to lung transplantation and to exercise-induced asthma.
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Affiliation(s)
- Tracy Tazzeo
- Asthma Research Group, Department of Medicine, Father Sean O'Sullivan Research Centre, Firestone Institute for Respiratory Health, St Joseph's Hospital, McMaster University, 50 Charlton Avenue East L-314, Hamilton, Ontario, Canada L8N 4A6
| | - John Miller
- Asthma Research Group, Department of Medicine, Father Sean O'Sullivan Research Centre, Firestone Institute for Respiratory Health, St Joseph's Hospital, McMaster University, 50 Charlton Avenue East L-314, Hamilton, Ontario, Canada L8N 4A6
| | - Luke J Janssen
- Asthma Research Group, Department of Medicine, Father Sean O'Sullivan Research Centre, Firestone Institute for Respiratory Health, St Joseph's Hospital, McMaster University, 50 Charlton Avenue East L-314, Hamilton, Ontario, Canada L8N 4A6
- Author for correspondence:
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