Morphological Findings in Trophozoites during Amoebic Abscess Development in Misoprostol-Treated BALB/c Mice

During amoebic liver abscess (ALA) formation in susceptible animals, immune response is regulated by prostaglandin E2 (PGE2) dependent mechanisms. The aim of this study was to analyze the effect of misoprostol (MPL), a PGE1 analogue, on ALA formation in BALB/c mice. Male mice from BALB/c strain were intrahepatically infected with 7.5×105 trophozoites of E. histolytica strain HM1:IMSS and treated with 10−4 M of MPL daily until sacrifice at 2, 4, and 7 days postinfection (p.i.). ALA formation was evaluated at 2, 4, and 7 days postinfection; trophozoite morphology was analyzed using immunohistochemistry and image analysis. Results showed an increase in frequency of ALA formation in infected and MPL-treated mice only at 2 days p.i. (P=0.03). A significant diminution in the size of trophozoites was detected in abscesses from mice independently of MPL treatment (from 5.8±1.1 µm at 2 days p.i. to 2.7±1.9 µm at 7 days p.i.) compared with trophozoites dimensions observed in susceptible hamsters (9.6±2.7 µm) (P