title: 20-Hydroxyeicosatetraenoic acid mediates isolated heart ischemia/reperfusion injury by increasing NADPH oxidase-derived reactive oxygen species production.
abstract: BACKGROUND
  It has been reported that 20-hydroxyeicosatetraenoic acid (20-HETE) aggravates myocardial ischemia/reperfusion (I/R) injury, but the exact mechanism of action is still unclear.
  
  
  RESULTS
  Experiments were performed in isolated rat hearts subjected to 35 min of ischemia followed by 40 min of reperfusion in Langendorff preparations. Perfusion with HET0016, an inhibitor of 20-HETE production, significantly improved I/R-induced reduction in cardiac contractility, myocardial infarction, and myocardial apoptosis. In contrast, administration of 20-HETE aggravated I/R-induced myocardial injury and enhanced apoptosis. I/R significantly increased production of reactive oxygen species (ROS) and oxidative stress, both of which were significantly inhibited by HET0016 and enhanced by 20-HETE administration. Apocynin, an inhibitor of NADPH oxidase, blocked 20-HETE-induced ROS production in the I/R hearts. 20-HETE increased the expression of gp91(phox) and p22(phox), the subunits of NADPH oxidase; and stimulated NADPH oxidase activity. In addition, GF-109203 significantly attenuated the 20-HETE-induced increases in the NADPH oxidase expression and activity. Finally, in the Langendorff I/R preparation, both apocynin and tempol, ROS scavengers, significantly blocked 20-HETE-induced myocardial dysfunction.
  
  
  CONCLUSIONS
  All of the results demonstrated that in isolated rat hearts 20-HETE stimulates NADPH oxidase-derived superoxide production, which aggravates I/R-induced myocardial injury via a PKC-dependent mechanism.
authors.affiliation: Laboratory of Molecular & Cellular Physiology, School of Life Sciences, Northeast Normal University, Changchun, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Han
authors.forename: Huiying
authors.initials: H
authors.lastname: Zhao
authors.forename: Hong
authors.initials: H
authors.lastname: Tang
authors.forename: Xinyu
authors.initials: X
authors.lastname: Li
authors.forename: Jiang
authors.initials: J
authors.lastname: Tan
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Zeng
authors.forename: Chengwen
authors.initials: C
authors.lastname: Sun
mesh_terms: D000098:Acetophenones / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D006893:Hydroxyeicosatetraenoic Acids / Q000494:pharmacology*; D008297:Male; D008562:Membrane Glycoproteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D015428:Myocardial Reperfusion Injury / Q000201:enzymology* / Q000473:pathology / Q000503:physiopathology; D009206:Myocardium / Q000201:enzymology*; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D018384:Oxidative Stress / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: D000098:Acetophenones; D004791:Enzyme Inhibitors; D006893:Hydroxyeicosatetraenoic Acids; D008562:Membrane Glycoproteins; D017382:Reactive Oxygen Species; C055987:20-hydroxy-5,8,11,14-eicosatetraenoic acid; C056165:acetovanillone; C500593:Cybb protein, rat; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases; C515768:Cyba protein, rat