A. L. Melo; L. H. Pereira
ABSTRACT
Sitice most studies on the cercaria-schistosomulum transformation have been carried out in vitro, the authors used the inoculation ofcercariae into the peritoneal cavity of mice tofollow the steps involved in this progressive adaptation of cercarie to the vertebmte host. The main conclusions were: 1. Most cercariae reach the schistosomular stage between 90-120 min after intraperitoneal inoculation. 2. Changes usuallystart with detachment of the tail followed by loss, rupture or changes of the glycocalix. 3. After 120 min most larvae loss their tails and present water sensitivity. 4. Acetabular grands depletion usually does not occur in cercaria-shistosomulum changes in the peritoneal cavity of mice. These steps differ in some way from those described in the kinetics of the in vitro observations performed by other investigators, and is more like those described in the penetration in the skin of living vertebrates.
Keywords: Schistosoma mansoni. Cercariae. Schistosomula. In vivo transformation.
RESUMO
Uma vez que a maioria dos estudos da transformação cercária-esquistossômulo têm sido realizados in vitro, os autores usaram a inoculação de cercárias na cavidade peritoneal de camundongos para seguir as etapas envolvidas nesta adaptação progressiva das larvas ao hospedeiro vertebrado. conclusões principais foram:
1. A maioria das cercárias atinge 0 estádio de esquistossômulo entre 90 – 120 minutos após a inoculação intraperitoneal.
2. As modificações usualmente são iniciadas com a perda da cauda, seguidas pela perda, ruptura ou modificações do glicocálice.
3. Após 120 minutos do inóculo, a maioria das larvas perde sua cauda e apresenta intolerância à água.
4. A depleção das glândulas acetabulares habitualmente não ocorre durante o processo de transformação cercária-esquistossômulo, na cavidade peritoneal do camundongo.
Os resultados da inoculação intraperitoneal em camundongos aproximam-se mais dos achados da penetração da cercária na pele de hospedeiros vertebrados, e diferem, em parte, das observações realizadas in vitro.
Palavras-chave: Schistosoma mansoni. Cercária. Esquistossômulo. Transformação in vivo.
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Recebido para publicação em 27/4/1984.
Departamento de Parasitologia and Grupo Interdepartamental de Estudos sobre Esquistossomose (GIDE), ICB/ UFMG, Caixa Postal 2486, 30.000 Belo Horizonte, Brasil.
This work received financial support from FINEP, CNPq – Brasil, and the World Health Organization, Switzerland.
