TY - JOUR A1 - Blömer, Nadja A1 - Pachel, Christina A1 - Hofmann, Urlich A1 - Nordbeck, Peter A1 - Bauer, Wolfgang A1 - Mathes, Denise A1 - Frey, Anna A1 - Bayer, Barbara A1 - Vogel, Benjamin A1 - Ertl, Georg T1 - 5-Lipoxygenase facilitates healing after myocardial infarction JF - Basic Research in Cardiology N2 - Early healing after myocardial infarction (MI) is characterized by a strong inflammatory reaction. Most leukotrienes are pro-inflammatory and are therefore potential mediators of healing and remodeling after myocardial ischemia. The enzyme 5-lipoxygenase (5-LOX) has a key role in the transformation of arachidonic acid in leukotrienes. Thus, we tested the effect of 5-LOX on healing after MI. After chronic coronary artery ligation, early mortality was significantly increased in 5-LOX\(^{−/−}\) when compared to matching wildtype (WT) mice due to left ventricular rupture. This effect could be reproduced in mice treated with the 5-LOX inhibitor Zileuton. A perfusion mismatch due to the vasoactive potential of leukotrienes is not responsible for left ventricular rupture since local blood flow assessed by magnetic resonance perfusion measurements was not different. However, after MI, there was an accentuation of the inflammatory reaction with an increase of pro-inflammatory macrophages. Yet, mortality was not changed in chimeric mice (WT vs. 5-LOX\(^{−/−}\) bone marrow in 5-LOX\(^{−/−}\) animals), indicating that an altered function of 5-LOX\(^{−/−}\) inflammatory cells is not responsible for the phenotype. Collagen production and accumulation of fibroblasts were significantly reduced in 5-LOX\(^{−/−}\) mice in vivo after MI. This might be due to an impaired migration of 5-LOX\(^{−/−}\) fibroblasts, as shown in vitro to serum. In conclusion, a lack or inhibition of 5-LOX increases mortality after MI because of healing defects. This is not mediated by a change in local blood flow, but through an altered inflammation and/or fibroblast function. KW - lipoxygenase KW - myocardial infarction KW - extracellular matrix remodeling KW - inflammation Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-132602 VL - 108 IS - 4 ER -