Cytochemical localization of NADH and NADPH oxidases during interaction ofTrypanosoma cruzi with activated macrophages

NADH- or NADPH-oxidase activity was cytochemically detected at the ultrastructural level during the process of interaction betweenTrypanosoma cruzi and activated mouse peritoneal macrophages. The reaction product, indicative of enzyme activity, was found in the portion of the plasma membrane of the macrophages to which the parasites attached. It was also found in the membrane which surrounds endocytic vacuoles containing ingested parasites.