title: The effects of nitric oxide on the immune response during giardiasis.
abstract: Nitric oxide (NO) is a free radical synthesized from L-arginine by different isoforms NO-synthases. NO possesses multiple and complex biological functions. NO is an important mediator of homeostasis, and changes in its generation or actions can contribute or not to pathological states. The knowledge of effects of NO has been not only important to our understanding of immune response, but also to new tools for research and treatment of various diseases. Knowing the importance of NO as inflammatory mediator in diverse infectious diseases, we decided to develop a revision that shows the participation/effect of this mediator in immune response induced against Giardia spp. Several studies already demonstrated the participation of NO with microbicidal and microbiostatic activity in giardiasis. On the other hand, some works report that Giardia spp. inhibit NO production by consuming the intermediate metabolite arginine. In fact, studies in vitro showed that G. lamblia infection of human intestinal epithelial cells had reduced NO production. This occurs due to limited offer of the crucial substrate arginine (essential aminoacid for NO production), consequently reducing NO production. Therefore, the balance between giardial arginine consumption and epithelial NO production could contribute to the variability of the duration and severity of infections by this ubiquitous parasite.
authors.affiliation: Department of Pathology Science, State University of Londrina, PR, Brazil. wanderpavanelli@uel.br
authors.forename: Wander Rogério
authors.initials: WR
authors.lastname: Pavanelli
authors.forename: Fredy Roberto Salazar
authors.initials: FR
authors.lastname: Gutierrez
authors.forename: Jean Jerley Nogueira da
authors.initials: JJ
authors.lastname: Silva
authors.forename: Ivete Conchon
authors.initials: IC
authors.lastname: Costa
authors.forename: Maria Claudia Noronha Dutra de
authors.initials: MC
authors.lastname: Menezes
authors.forename: Francisco José de Abreu
authors.initials: FJ
authors.lastname: Oliveira
authors.forename: Eiko Nakagawa
authors.initials: EN
authors.lastname: Itano
authors.forename: Maria Angélica Ehara
authors.initials: MA
authors.lastname: Watanabe
mesh_terms: D000818:Animals; D016829:Giardia lamblia / Q000276:immunology* / Q000472:pathogenicity; D005873:Giardiasis / Q000276:immunology* / Q000469:parasitology; D006801:Humans; D018928:Immunity, Mucosal / Q000276:immunology; D007413:Intestinal Mucosa / Q000276:immunology* / Q000469:parasitology; D009569:Nitric Oxide / Q000096:biosynthesis* / Q000276:immunology
chemical_list: D009569:Nitric Oxide