title: Qualitative and quantitative immunohistochemical evaluation of iNOS expression in the spleen of dogs naturally infected with Leishmania chagasi.
abstract: Nitric oxide (NO), the product of the nitric oxide synthase enzymes has been detected in Leishmania-infected animals. Besides its role on the immunity to infection, the role of NO and the inducible nitric oxide synthase (iNOS) in the pathogenesis of canine visceral leishmaniasis (CVL) is not well understood. This study aimed at evaluating immunohistochemically the iNOS expression in the spleen of dogs naturally infected (ID) with Leishmania (L.) chagasi compared with non-infected dogs (NID). The ID was grouped according to the clinical form and the parasite load. Symptomatic dogs (SD) presented higher parasite load in relation to oligosymptomatic (OD) and asymptomatic (AD). The qualitative expression of iNOS was observed only in ID. SD presented strong and prominent labeling of iNOS, followed by OD and AD. Quantitatively, the results showed that the median expression of iNOS was higher in SD and OD compared to NID. Also, dog spleens with high parasitism load showed marked iNOS expression. Taken together, the results suggest that the expression of iNOS in the spleen of infected dogs with CVL was associated with clinical worsening of the disease and with high parasitism.
authors.affiliation: Universidade Presidente Antonio Carlos, Teófilo Otoni, MG, Brazil.
authors.forename: Fernando Rocha
authors.initials: FR
authors.lastname: dos Santos
authors.forename: Paula Melo Abreu
authors.initials: PM
authors.lastname: Vieira
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Correa-Oliveira
authors.forename: Rodolfo Cordeiro
authors.initials: RC
authors.lastname: Giunchetti
authors.forename: Claudia Martins
authors.initials: CM
authors.lastname: Carneiro
authors.forename: Alexandre Barbosa
authors.initials: AB
authors.lastname: Reis
authors.forename: Luiz Cosme Cotta
authors.initials: LC
authors.lastname: Malaquias
mesh_terms: D000818:Animals; D004283:Dog Diseases / Q000201:enzymology* / Q000469:parasitology; D004285:Dogs; D005260:Female; D005455:Fluorescent Antibody Technique; D007891:Leishmania; D007896:Leishmaniasis / Q000201:enzymology / Q000662:veterinary*; D008297:Male; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II / Q000096:biosynthesis*; D013154:Spleen / Q000201:enzymology* / Q000469:parasitology
chemical_list: D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II