Alterações da matriz extracelular na pele de cães com leishmaniose visceral naturalmente infectados

• Autor(a) principal: Melo, Ferdinan Almeida
• Data de Publicação: 2005
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5008
• topic: Cão; Doenças; Matriz extracelular; Leishmaniose visceral; Dogs; Extracellular matrix; Visceral leishmaniasis; Diseases; CNPQ::CIENCIAS AGRARIAS::MEDICINA VETERINARIA::PATOLOGIA ANIMAL

The objective of this study was to investigate the extracelular matrix changes in skin of dogs naturally infected by Leishmania chagasi. Fourty dogs were selected naturally infected with L. chagasi come from São Luis-MA, contained in agreement with the clinical symptoms, 20 symptomatic dogs with cutaneous lesions (group I), 20 oligosymptomatic with cutaneous lesions (group II) with positive serologically for Leishmania by Indirect Immunofluorescence Assay (IFAT) and by enzyme-linked immunosorbence assay (ELISA), and 20 dogs negative for leishmaniasis (group III), dogs not infected. Skin biopsies were accomplished for analyses of the histological alterations by technique of Hematoxylin and Eosin (HE), analyses of the collagen system for technical Picrus Sirius Red and Reticulin of Gordon & Sweets. The elastic system was evaluated by the technique of Verhoeff. Indirect Immunoperoxidase for detection of Leishmania in the cutaneous tissue. The fibers adhesive fibronectin (FN) and laminin (LN) they were detected by immunohistochemical technique with the use of the monoclonal antibodies anti-fibronectin and anti-laminin, respectively. The averages of the reactivity serologycal of the animals measure for ELISA were: 0,44 ± 0,21, for the group I; 0,23 ± 0,08 for the group II and 0,037 ± 0,007, group III, with cutoff=0,09, results were significant statistically. The largest frequencies of clinical signs presented by the dogs of the group I and II were: weight loss, generalized alopecia, dermatitis, located and widespread ulcers, opaque coat and onychogryphosis, clinical signs have been objectives of great discussions in the literature, observed so much in natural infections as in experimental. The histological alterations observed in the skin of the dogs of the groups I and II were hiperqueratose that varied of accentuated at discreet, acantosys generally accentuated, vacuolization of the basal membrane. In the derme it was observed an infiltrated inflammatory diffuse constituted mainly by neutrophils, lynphocytes, macrophages and in some cases, mast cell associated to the presence of the parasite. It was proven the prevalence of the collagen of the type III in the skin of the dogs of the group I (79,5 ± 10,0), while in the animals of the group II the collagens of the type I and of the type III was observed in variable proportions, results considered statistically significant. The presence of the collagen of the type III was confirmed by the technique of Reticulin of Gordon & Sweets. The elastic fibers of the groups I and II seemed more disforms and thicken when compared the one of the group III. The expression of the fibronectin and of the laminin it was reduced in the skin of the infected animals, being associated to the presence of parasites. These results demonstrate the intense degradation of the extracelular matrix in the skin caused by Leishmania.