NITRIC-OXIDE IS INVOLVED IN CONTROL OF TRYPANOSOMA CRUZI-INDUCED PARASITEMIA AND DIRECTLY KILLS THE PARASITE IN-VITRO

This study was carried out to determine the role of reactive nitrogen intermediates in Trypanosoma cruzi infection. In vitro, splenocytes ob tained during the acute phase of infection produced elevated amounts o f nitric oxide (NO) that were correlated,vith the resistance or suscep tibility of the animals. In vivo, the levels of NO2- plus NO3- in plas ma during the later phase of infection were higher in C57BL/6 mice tha n in BALBL/c mice. The treatment of infected C57BL/6 mice with inhibit ors of NO synthase increased parasitemia acid mortality. Finally, we f ound that the NO donor drug S-nitroso-acetyl-penicillamine is able to kill trypomastigotes in vitro in the absence of any other cells, sugge sting a direct NO-mediated killing of T. cruzi.