Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/313766
Type: DISSERTAÇÃO
Degree Level: Mestrado
Title: Avaliação da capacidade edematogenica do veneno de Bothrops lanceolatus em pata de camundongos
Author: Souza, Ana Olivia de
Advisor: Araújo, Albetiza Lôbo de, 1946-
Abstract: Resumo: A capacidade que os venenos de serpentes possuem de aumentarem a permeabilidade vascular e induzirem edema, através da liberação de substâncias farmacologicamente ativas, é bem conhecida. Investigamos a resposta inflamatória (edema e permeabilidade vascular) induzida pelo veneno de Bothrops lanceolatus (VBL) em camundongos Swiss machos. O edema de pata foi induzido pela injeção subplantar do VBL (125 a 1000 ng/pata) e quantificado pelo aumento do peso da pata. A permeabifidade vascular foi determinada pela quantidade de azul de Evans extravasado. O edema e o aumento de permeabilidade foram máximos dentro de duas horas e estatisticamente insignificantes a partir de 24 horas. A administração de iloprost (20 ng/pata) após a do VBL potencializou o edema e o aumento de permeabilidade vascular aproximadamente em 400%. O tratamento dos camundongos com indometacina (5 mg/kg), dexametasona (1 mg/kg), NDGA (100 mg/kg) ou BW A4C (50 mg/kg) inibiu o edema induzido pelo VBL (43%, 59%, 28% e 43%, respectivamente) e o a(Jmento da permeabilidade vascular (0%, 66%, 48% e 44%, respectivamente). Ao contrário, os antagonistas de histamina, serotonina, e PAF [mepiramina (6 mg/kg), ciproheptadina (5 mg/kg), e WEB 2086 (50 mg/kg), respectivamente não foram efetivos. Estes resultados indicam que os dois fenômenos anteriormente citados são mediados principalmente por produtos da ação de ciclooxigenase e lipoxigenase. A nível histológico, as patas que sofreram injeção de 250 e 500 ng do VBL apresentaram um aumento na região dérmica com espaços intercelulares que são indícios de edema. Houve a presença de infiltrado celular, principalmente neutrófilos, entre as fibras musculares, as quais, morfologicamente não foram afetadas, pelo menos durante as três primeiras horas de observação. Com a dose de 500 ng ocorreu intensa hemorragia registrando grande número de hemácias extravasculares

Abstract: The ability of snake venoms to increase vascular permeability and to induce oedema through the release of pharmacologically active substances is well known. This thesis investigates the inflammatory response (oedema and , vascular permeability) induced by the venom of Bothrops lanceolatus (BL V) in male Swiss white mice (20-30g). Paw oedema was induced by the subplantar injection of BLV (125-1000 ng/paw) and was quantified as the increase in paw weighí. Changes in vascular permeability were assessed by measuring the amount of Evans blue dye extravasation. Oedema and the increase in vascular permeability were maximal within two hours and had resolved afier 24h. The administration of iloprost (20 ng/paw) immediately afier BLV potentiated the oedema and increased the vascular permeability by approximately 400%. Pre¬treating the mice with indomethacin (5 mg/kg), dexamethasone (1 mg/kg), NDGA (100 mg/kg), or BW A4C (50 mg/kg) inhibited the BLV-induced oedema (by 43%, 59%, 28% and 43%, respectively) and the increase in vascular permeability (by 0%, 66%, 48%, and 44%, respectively). In contrast, histamine, serotonin, and PAF-acether antagonists [mepyramine (6 mglkg) , cyproheptadine (5 mg/kg), and WEB 2086 (50 mg/kg), respectively)] were not effective. In histological sections,the venom (250 and 500 ng) was observed to cause thickening of the innerdermal layers which was accompanied by the presence of large intercellular spaces indicative of oedema. In addition, there was a marked infiltration of inflammatory cells, particularly neutrophils, into the underlying muscle layer. The latter, however, remained morphologically unaffected during the three hours of observation. Venom doses of 500 ng or more produced intense hemorrhage in the paw. These results indicate that BL V-induces oedema and increases vascular permeability in the mouse paw as confirmed by histological examination of the injected paws. The principal mediators of this inflammation response are cyclooxygenase and lipoxygenase products
Subject: Cobra - Veneno - Toxicologia
Language: Português
Editor: [s.n.]
Date Issue: 1995
Appears in Collections:FCM - Tese e Dissertação

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