A cysteine protease inhibitor protects dogs from cardiac damage during infection by Trypanosoma cruzi.

Cruzain is an essential cysteine protease of Trypanosoma cruzi and a therapeutic target for Chagas' disease. Eight dogs were infected with T. cruzi; three were treated with an inhibitor of cruzain, K777, for 14 days. Treatment with K777 abrogated myocardial damage by T. cruzi, as documented by histopathological lesion scores and serum troponin I levels.