Estudo comparativo do comportamento da infecção de camundongos, através da inoculação subcutânea e intraperitoneal, utilizando-se duas cepas do Trypanosona cruzi Comparative study of the behaviour of infection in mice, when inoculated by intraperitoneal and subcutaneous methods, using two strains of Trypanosoma cruzi

Abstract

Foram utilizados camundongos brancos, pesando em média 18g e duas cepas de Trypanosoma cruzi, morfologicamente distintas: Y com predominância de formas sangüíneas delgadas e Bolívia com predomínio de formas largas. Os lotes de animais receberam 2 x 10³, 2 x 10(4) e 2 x 10(5) tripanossomos por animal e as vias de inoculação utilizadas foram a intraperitoneal e a subcutânea. Nos animais foi observado o curso de infecção. Os resultados obtidos revelaram que, nos experimentos em que se utilizou a cepa Y, existem algumas diferenças significantes, com infecções mais uniformes e virulentas, após inoculação subcutânea de 2 x 10³ e 2 x 10(4) formas sangüíneas de T. cruzi. Entretanto, isto não ocorreu com a cepa Bolívia, pois os animais apresentaram o mesmo padrão de parasitemia e os demais caracteres morfológicos, quer se utilizasse a via subcutânea ou intraperitoneal. Tal fato permite sugerir a existência de interrelação entre os fatores via de inoculação traduzida pela maior ou menor presença de macrófagos no sítio de inoculação, e a morfologia das formas sangüíneas representada pela maior ou menor capacidade de penetração celular.By means of comparative studies of the infection of mice with T. cruzi using intraperitoneal and subcutaneous inoculation, it was concluded that more uniform and virulent infections are obtained after subcutaneous inoculation. This is due to an immediate cellular response, when intraperitoneal inoculations are used. With the aim of making comparative studies as between the two methods of inoculation, the intraperitoneal using two, morfologically distinct, strains of T. cruzi: Y with predominance of thin forms and Bolivia with predominance of broad forms. White mice of approximately 18g were required for these tests. The groups of animals received 2 x 10³, 2 x 10(4) and 2 x 10(5) trypanossomes per animal, and the course of the infection was subsequently observed. The results revealed that after subcutaneous inoculation when the Y strain was used in the tests, some significant differences appear, with more virulent and uniform infections. However, these did not appear when the Bolivia strain was used, because the animals showed the same standard parasitemy and other morpho-biological features, whether by subcutaneous or intraperitoneal inoculation. This incident suggests the existence of interrelation between the factors: method of inoculation represented by a greater or lesser presence of macrophages in the inoculated area, and the morphology of the blood forms represented by a greater or lesser capacity for cellular penetration.

Keywords

• Trypanosoma cruzi
• Camundongos
• Macrófagos
• Infecções subcutâneas
• Injeções intraperitoneais
• Trypanosoma cruzi
• Mice
• Macrophages
• Infections, subcutaneous
• Infections, intraperitoneal