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Schistosomiasis mansoni: evidence for a milder response in germfree mice

Esquistossomose mansônica: evidência de menor resposta nos camundongos isentos de germes

Abstracts

Germfree (GF and conventional (CV) mice were infected intraperitoneally with GF cercariae of Schistosoma mansoni and kept for six weeks. Twenty four hours before killing, they were injected with [³H]-thymidine. Schistosoma worms, harvested after perfusion of portal system, were counted as well as eggs from liver and intestines. Liver was also used for DNA, protein, and collagen determinations. [³H] -Thymidine incorporation and collagen determinations were used to establish the indices given by the difference between their contents in infected and control animals and expressed per thousand eggs in liver. The recovery of worms in GF mice was around twice as much as in CV ones, and the total number of eggs was higher in the liver of GF animals. No hypertrophy of liver cells was observed by the ratio protein/DNA, but [³H]-thymidine incorporation into DNA was higher than in controls in both GF and CV infected animals. The [³H]-thymidine and collagen indices were lower in GF animals which indicate a more discrete cellular replication and smaller collagen content in relation to the number of eggs present in livers of these mice. It was concluded that the disease seems to be less severe in GF animals.

Schistosomiasis mansoni; Axenic cercariae


Camundongos isentos de germes (GF) e convencionais (CV) foram infectados intraperito-nealmente com cercárias GF de Schistosoma mansoni e mantidos por seis semanas. Vinte e quatro horas antes do sacrifício, eles foram injetados com [³H]-timidina. Vermes de Schistosoma, recolhidos através de perfusão do sistema porta, foram contados, assim como os ovos no fígado e intestino delgado. O fígado foi também usado para determinações de DNA, proteínas e colágeno. A incorporação de [³H]-timidina e as determinações de colágeno foram usadas para calcular os índices dados pela diferença entre seus conteúdos nos animais infectados e controles e expressos por mil ovos no fígado. A recuperação de vermes nos camundongos GF foi cerca de duas vezes aquela dos CV. O número total de ovos foi maior no fígado dos animais GF. Nenhuma hipertrofia das células hepáticas foi observada pela relação proteína/DNA mas a incorporação de [³H]-timidina em DNA foi maior que nos controles em ambos animais infectados (GF e CV). Os índices de [³H]-timidina e colágeno foram menores nos animais GF indicando uma replicação celular mais discreta e um conteúdo de colágeno menor em relação ao número de ovos presentes nos fígados destes camundongos. Concluiu-se que a doença parece ser menos se vera em animais GF.


ARTIGOS ORIGINAIS

Leda Q. Viera; Tasso Moraes-santos

Department of Biochemistry Immunology, Institute of Biological Sciences, Federal University of Minas Gerads, CP 2486, 31270 Belo Horizonte, MG, Brazil

ABSTRACT

Germfree (GF and conventional (CV) mice were infected intraperitoneally with GF cercariae of Schistosoma mansoni and kept for six weeks. Twenty four hours before killing, they were injected with [3H]-thymidine. Schistosoma worms, harvested after perfusion of portal system, were counted as well as eggs from liver and intestines. Liver was also used for DNA, protein, and collagen determinations. [3H] -Thymidine incorporation and collagen determinations were used to establish the indices given by the difference between their contents in infected and control animals and expressed per thousand eggs in liver. The recovery of worms in GF mice was around twice as much as in CV ones, and the total number of eggs was higher in the liver of GF animals. No hypertrophy of liver cells was observed by the ratio protein/DNA, but [3H]-thymidine incorporation into DNA was higher than in controls in both GF and CV infected animals. The [3H]-thymidine and collagen indices were lower in GF animals which indicate a more discrete cellular replication and smaller collagen content in relation to the number of eggs present in livers of these mice. It was concluded that the disease seems to be less severe in GF animals.

Key words: Germfree mice; Schistosomiasis mansoni; Axenic cercariae.

RESUMO

Camundongos isentos de germes (GF) e convencionais (CV) foram infectados intraperito-nealmente com cercárias GF de Schistosoma mansoni e mantidos por seis semanas. Vinte e quatro horas antes do sacrifício, eles foram injetados com [3H]-timidina. Vermes de Schistosoma, recolhidos através de perfusão do sistema porta, foram contados, assim como os ovos no fígado e intestino delgado. O fígado foi também usado para determinações de DNA, proteínas e colágeno. A incorporação de [3H]-timidina e as determinações de colágeno foram usadas para calcular os índices dados pela diferença entre seus conteúdos nos animais infectados e controles e expressos por mil ovos no fígado. A recuperação de vermes nos camundongos GF foi cerca de duas vezes aquela dos CV. O número total de ovos foi maior no fígado dos animais GF. Nenhuma hipertrofia das células hepáticas foi observada pela relação proteína/DNA mas a incorporação de [3H]-timidina em DNA foi maior que nos controles em ambos animais infectados (GF e CV). Os índices de [3H]-timidina e colágeno foram menores nos animais GF indicando uma replicação celular mais discreta e um conteúdo de colágeno menor em relação ao número de ovos presentes nos fígados destes camundongos. Concluiu-se que a doença parece ser menos se vera em animais GF.

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Recebido para publicação em 16/4/1986.

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  • Schistosomiasis mansoni: evidence for a milder response in germfree mice

    Esquistossomose mansônica: evidência de menor resposta nos camundongos isentos de germes
  • Publication Dates

    • Publication in this collection
      17 Feb 2011
    • Date of issue
      Feb 1987

    History

    • Received
      16 Apr 1986
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