Detection of alpha-macroglobulin in the heart of mice infected with Trypanosoma cruzi

The aim of this work was to investigate the presence of alpha-macroglobulin (AM) in the heart of mice during acute experimental Chagas' disease and to study its localization as related to the presence of the parasite and/or t o their antigens. Frozen heart tissue sections obtained from Swiss albino m ale mice at different days postinfection with Trypanosoma cruzi were examin ed for triple immunofluorescence in response to parasite antigen (green), A M (red), and nuclei (blue) from both cells. AM was found in the heart of al l the infected animals studied. Parasites were seen arranged in nests insid e heart muscle cells. Usually, AM staining corresponded in position to para site nests and to their antigens spread in large areas of the myocardium. T he most intense staining of AM was observed at days 9 and 11 postinfection, when the highest tissue-infection level occurs. These observations relate the presence of AM to that of T. cruzi antigen in the same areas of the inf lamed myocardium of the chagasic animals.