Effect of brown spider venom on basement membrane structures

Effect of brown spider venom on basement membrane structures

Autor Veiga, S. S. Google Scholar
Feitosa, L. Google Scholar
Santos, VLP dos Google Scholar
Souza, G. A. de Google Scholar
Ribeiro, A. S. Google Scholar
Mangili, O. C. Google Scholar
Porcionatto, M. A. Google Scholar
Nader, H. B. Google Scholar
Dietrich, C. P. Google Scholar
Brentani, R. R. Google Scholar
Gremski, W. Google Scholar
Instituição Univ Fed Parana
Universidade Federal de São Paulo (UNIFESP)
Ludwig Inst Canc Res
Resumo Loxoscelism or necrotic arachnidism are terms used to describe lesions and reactions induced by bites (envenomation) from spiders of the genus Loxosceles. Envenomation has been reported to provoke dermonecrosis and haemorrhage at the bite site and haemolysis, disseminated intravascular coagulation and renal failure. the purpose of this work was to study the effect of the venom of the brown spider Loxosceles intermedia on basement membrane structures and on its major constituent molecules. Light microscopy observations showed that L. intermedia venom obtained through electric shock, which reproduces two major signals of Loxoscelism in the laboratory, exhibits activity toward basement membrane structures in mouse Engelbreth-Holm-Swarm (EHS) sarcoma. Basement degradation was seen by a reduced periodic acid-Schiff (PAS) and alcian blue staining as well as by a reduced immunostaining for laminin when compared to control experiments. Electron microscopy studies confirmed the above results, showing the action of the venom on EHS-basement membranes and demonstrating that these tissue structures are susceptible to the venom. Using purified components of the basement membrane, we determined through SDS-PAGE and agarose gel that the venom is not active toward laminin or type IV collagen, but is capable of cleaving entactin and endothelial heparan sulphate proteoglycan. in addition, when EHS tissue was incubated with venom we detected a release of laminin into the supernatant, corroborating the occurrence of some basement membrane disruption. the venom-degrading effect on entactin was blocked by 1,10-phenanthroline, but not by other protease inhibitors such as PMSF, NEM or pepstatin-A. By using light microscopy associated with PAS staining we were able to identify that 1,10-phenanthroline also inhibits EHS-basement membrane disruption evoked by venom, corroborating that a metalloprotease of venom is involved in these effects. Degradation of these extracellular matrix molecules and the observed susceptibility of the basement membrane could lead to loss of vessel and glomerular integrity, resulting in haemorrhage and renal problems after envenomation.
Idioma Inglês
Data de publicação 2000-07-01
Publicado em Histochemical Journal. Dordrecht: Kluwer Academic Publ, v. 32, n. 7, p. 397-408, 2000.
ISSN 0018-2214 (Sherpa/Romeo, fator de impacto)
Publicador Kluwer Academic Publ
Extensão 397-408
Fonte http://dx.doi.org/10.1023/A:1004031019827
Direito de acesso Acesso restrito
Tipo Artigo
Web of Science WOS:000088635400002
Endereço permanente http://repositorio.unifesp.br/handle/11600/26339

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