Myocardiocyte ultrastructure and morphometrical analysis in hamsters experimentally infected with Trypanosoma cruzi.
The aim of this work was the study of ultrastructural morphologic and morphometric changes in myocardiocytes from chronic chagasic hamsters (Mesocricetus auratus), comparatively with changes described in other animal models and in human Chagas disease. Four chagasic animals and three nonchagasic controls were studied. Mitochondria changes were the most conspicuous findings, varying from swelling to complete organelle destruction. Noteworthy, T-tubules appeared tortuous and interrupted at the Z-line level and there was dehiscence in intercalated disks, especially in adherens junctions;in addition, the myofibrils were separated from each other by intracellular edema, with mild to accentuated focal lyses. In morphometric analysis, both the numeric density and the area of mitochondria from chagasic and normal control animals were statistically similar; however, the infected hamsters showed statistically significant enlarged sarcomeres and reduced myofibril thickness. Based on the morphologic and morphometric characteristics observed in these experimental animals, one may conclude that heart changes described at light microscopy in human Chagas disease can have a substrate on electron microscopy. Moreover, the hamster also constitutes a useful animal model to pathology studies in Chagas disease on electron microscopy.
Colmanetti
Francisco Humberto
FH
Department of Biological Sciences, Histology, Embryology and General Pathology Devesions, Pathology Graduation Course, Triangulo Mineiro Medical School (FMTM), Uberaba-MG, Brazil.
Teixeira
Vicente de Paula Antunes
Vde P
Rodrigues
Maria Laura Pinto
ML
Chica
Javier Emílo Lazo
JE
Reis
Maria das Graças
Md
dos Santos
Vitorino Modesto
VM
D000818:Animals; D002467:Cell Nucleus / Q000648:ultrastructure; D014355:Chagas Disease / Q000469:parasitology* / Q000473:pathology* / Q000635:transmission; D006224:Cricetinae; D004195:Disease Models, Animal; D008297:Male; D046529:Microscopy, Electron, Transmission; D008928:Mitochondria / Q000469:parasitology / Q000648:ultrastructure; D032383:Myocytes, Cardiac / Q000469:parasitology* / Q000648:ultrastructure*; D014349:Trypanosoma cruzi / Q000472:pathogenicity* / Q000502:physiology / Q000648:ultrastructure