Article
Characterization of the vascular changes in schistosomal portal (pipestem) fibrosis of mice
Registro en:
SILVA, L. M. et al. Characterization of the vascular changes in schistosomal portal (pipestem) fibrosis of mice. Acta Tropica, v. 98, n. 1, p.34-42, 2006.
0001-706X
10.1016/j.actatropica.2006.01.011
Autor
Silva, Luciana Menezes da
Santos, Ricardo Ribeiro dos
Soares, Milena Botelho Pereira
Andrade, Zilton de Araújo
Resumen
Agradecimentos a Sheilla Andrade de Oliveira, Rejane M.C. Menezes, Antonio
Carlos S. Santos e Ana Cristina Gonzalez pelo apoio técnico e Brendan Flannery pela revisão do manuscrito. Este trabalho foi financiado pelo Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) e pela Fundação Oswaldo Cruz (FIOCRUZ). Mice chronically infected with Schistosoma mansoni develop one of two anatomical forms of hepatic lesions: severe, periportal
(pipestem) fibrosis or milder, isolated granulomas. The pathogenesis of periportal fibrosis is poorly understood. In this work we
compared mice with either periportal fibrosis or isolated granulomas to identify specific markers of severe pathology. BALB/c or
Swiss Webster mice were infected with 30 cercarie, once or six times, and liver biopsies were performed to classify the animals
into two pathological groups 16 weeks later. Sixty percent of the animals sacrificed at 20 or 24 weeks had periportal fibrosis,
15–20% had isolated granulomas and the remainder had indeterminate pathology. There was no correlation between frequency of
infections or egg burden (eggs/g liver) at 20 and 24 weeks post-infection and the development of periportal fibrosis. Livers with
periportal fibrosis at 20 or 24 weeks of infection were characterized by larger areas of fibrotic tissue and greater vascularization
compared to livers of mice with isolated granulomas. Plastic casts of the portal vein system showed marked changes in vascular
structure in mice with periportal fibrosis, including collateral vessels sprouting from the main portal branches, amputation of the
more delicate peripheral ramifications, and distortions of the medium and small branches. Vascular changes were not observed in
mice with isolated granulomas. These results suggest that the interaction between schistosome eggs and portal vascular changes is
of paramount importance in the development of pipestem fibrosis.