title: Trypanosoma cruzi: effect of the absence of 5-lipoxygenase (5-LO)-derived leukotrienes on levels of cytokines, nitric oxide and iNOS expression in cardiac tissue in the acute phase of infection in mice.
abstract: Leukotrienes are important mediators of inflammatory responses. In this study, we investigated the effect of the absence of 5-lipoxygenase (5-LO)-derived leukotrienes on levels of cytokines, nitric oxide (NO) and iNOS expression in cardiac tissue of mice infected with Trypanosoma cruzi, the agent of Chagas' disease. NO is a key mediator of parasite killing in mice experimentally infected with T. cruzi, and previous studies have suggested that leukotrienes, such as LTB(4), induces NO synthesis in T. cruzi-infected macrophages and plays a relevant role in the killing of parasite in a NO-dependent manner. We therefore investigated whether leukotrienes would have a similar role in vivo in controlling the parasite burden by regulating NO activity. We have made the striking observation that absence of 5-LO-derived leukotrienes results in increased NO and IL-6 production in the plasma with a concomitant decrease in the expression of iNOS in the cardiac tissue on day 12 after T. cruzi infection. These findings indicate that endogenous leukotrienes are important regulators of NO activity in the heart and therefore influence the cardiac parasite burden without exerting a direct action on IL-6 production in the acute phase of infection with T. cruzi.
authors.affiliation: Laboratório de Imunopatologia Experimental, Departamento de Ciências Patológicas, Centro de Ciências Biológicas, Universidade Estadual de Londrina, CEP 86051-970 Londrina, Paraná, Brasil.
authors.forename: Carolina
authors.initials: C
authors.lastname: Panis
authors.forename: Tânia Longo
authors.initials: TL
authors.lastname: Mazzuco
authors.forename: Cauê Zortéa Fernandes
authors.initials: CZ
authors.lastname: Costa
authors.forename: Vanessa Jacob
authors.initials: VJ
authors.lastname: Victorino
authors.forename: Vera Lúcia Hideko
authors.initials: VL
authors.lastname: Tatakihara
authors.forename: Lucy Megumi
authors.initials: LM
authors.lastname: Yamauchi
authors.forename: Sueli Fumie
authors.initials: SF
authors.lastname: Yamada-Ogatta
authors.forename: Rubens
authors.initials: R
authors.lastname: Cecchini
authors.forename: Luiz Vicente
authors.initials: LV
authors.lastname: Rizzo
authors.forename: Phileno
authors.initials: P
authors.lastname: Pinge-Filho
mesh_terms: D000208:Acute Disease; D000818:Animals; D001094:Arachidonate 5-Lipoxygenase / Q000235:genetics / Q000378:metabolism*; D002598:Chagas Cardiomyopathy / Q000378:metabolism*; D016207:Cytokines / Q000097:blood / Q000378:metabolism*; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D006321:Heart / Q000469:parasitology; D007150:Immunohistochemistry; D015289:Leukotrienes / Q000378:metabolism*; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009206:Myocardium / Q000378:metabolism; D009569:Nitric Oxide / Q000097:blood / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism*
chemical_list: D016207:Cytokines; D015289:Leukotrienes; D009569:Nitric Oxide; D001094:Arachidonate 5-Lipoxygenase; D052247:Nitric Oxide Synthase Type II