(Eh) y metanólico (Em) de Pera distichophylla sobre un aislado de ...
(Eh) y metanólico (Em) de Pera distichophylla sobre un aislado de ...
(Eh) y metanólico (Em) de Pera distichophylla sobre un aislado de ...
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Artículo Original<br />
Rev. Ibero-Latinoam. Parasitol. (2012); 71 (1): 23-33<br />
Edad <strong>de</strong>l hospe<strong>de</strong>ro en la evolución <strong>de</strong><br />
la infección experimental con Trypanosoma cruzi<br />
en <strong>un</strong> mo<strong>de</strong>lo murino<br />
ZÚÑIGA C. 1 , BINDER N. 1 , PALáU M.T. 4 , LARENAS J. 2 y VERGARA U. 1,3<br />
1 Departamento <strong>de</strong> Medicina Preventiva, Facultad <strong>de</strong> Ciencias Veterinarias, Universidad <strong>de</strong> Chile. Avenida Santa<br />
Rosa 11735. La Pintana, Santiago - Chile.<br />
2 Departamento <strong>de</strong> Patología Animal, Facultad <strong>de</strong> Ciencias Veterinarias, Universidad <strong>de</strong> Chile. Avenida Santa Rosa<br />
11735. La Pintana, Santiago- Chile.<br />
3 Escuela <strong>de</strong> Postgrado, Facultad <strong>de</strong> Medicina, Universidad <strong>de</strong> Chile. In<strong>de</strong>pen<strong>de</strong>ncia 1027, Santiago - Chile.<br />
4 Escuela <strong>de</strong> Nutrición, Universidad Autónoma <strong>de</strong> Chile.<br />
ABSTRACT<br />
AGE EFFECT IN EVOLUTION OF EXPERIMENTAL TRYPANOSOMA CRUzI INFECTION<br />
IN A MURINE MODEL<br />
Two and eight months old Balb/c mice, were infected with 2000 Dm28c trypomastigotes of Trypanosoma.<br />
cruzi. Two weeks after initial infection the yo<strong>un</strong>g males showed parasitemia of 5.1 x 10 5 parasites/mL<br />
and 50% of accumulated mortality, which reached 100% at 40 days after infection. Aged males reached<br />
3.2 x 10 5 parasites/mL and 40% survival longer than four months. Histopathology showed differential<br />
distribution and severity of tissue lesions between the mouse groups. Increased damage and pseudocysts<br />
were fo<strong>un</strong>d in heart of aged mice, which showed a long term tissue repair while lesions seemed to increase<br />
in the striated muscle of yo<strong>un</strong>g mice, <strong>de</strong>spite of the absence of <strong>de</strong>tectable tissue or blood parasites. The<br />
differences in parasite bur<strong>de</strong>n, tissue damage and accumulated mortality observed in our infected mice,<br />
suggest that age may affect the effectiveness of the imm<strong>un</strong>e response in controlling parasite-<strong>de</strong>pen<strong>de</strong>nt<br />
and/or imm<strong>un</strong>e-mediated damage in specific organs. Although there is no evi<strong>de</strong>nce for the pathogenic<br />
role of parasite persistence and/or autoimm<strong>un</strong>ity in the evolution of the disease, the 100% of accumulated<br />
mortality observed in the yo<strong>un</strong>g mice may be explained by neurological disturbances as those associated<br />
to malignant arrhythmias and sud<strong>de</strong>n <strong>de</strong>ath observed in humans. These disturbances may not be triggered<br />
in the eight months old mice as a consequence of the <strong>de</strong>creased effectiveness of the imm<strong>un</strong>e system which<br />
comes with age.<br />
Key words: Trypanosoma cruzi, aged mice, parasitemia, histopathology.<br />
Recibido: 5 <strong>de</strong> Marzo <strong>de</strong> 2012. Aprobado: 28 <strong>de</strong> <strong>de</strong> Mayo <strong>de</strong> 2012.<br />
Correspon<strong>de</strong>ncia: U. Vergara<br />
<strong>Em</strong>ail: uvergara@uchile.cl<br />
C. Zuñiga<br />
<strong>Em</strong>ail: clz<strong>un</strong>iga@uchile.cl<br />
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