Trypanosoma cruzi: experimental Chagas' disease in rhesus monkeys. II. Ultrastructural and cytochemical studies of peroxidase and acid phosphatase activities.

Ultrastructural and cytochemical studies of peroxidase and acid phosphatase were performed in skin, lymph node and heart muscle tissue of rhesus monkeys with experimental Chagas' disease. At the site of inoculation there was a proliferative reaction with the presence of immature macrophages revealed by peroxidase technique. At the lymph node a diffuse inflammatory exudate with mononuclear cells, fibroblasts and immature activated macrophages reproduces the human pattern of acute Chagas' disease inflammatory lesions. The heart muscle cells present different degrees of degenerative alterations and a striking increase in the number of lysosomal profiles that exhibit acid hydrolase reaction product. A strong inflammatory reaction was present due to lymphocytic infiltrate or due to eosinophil granulocytes associated to ruptured cells. The present study provides some experimental evidences that the monkey model could be used as a reliable model to characterize histopathological alterations of the human disease.