COMPARATIVE-STUDIES OF NIFURTIMOX UPTAKE AND METABOLISM BY DRUG-RESISTANT AND SUSCEPTIBLE STRAINS OF TRYPANOSOMA-CRUZI

1. Nifurtimox uptake and metabolism by epimastigote forms of three strains of Trypanosoma cruzi (Basileu, Y, YuYu) with different drug responsiveness in mice experimental infections were compared. 2. Statistical analysis of the results demonstrated no correlation between the ability of the strains to catalyze nifurtimox redox-cycling (Basileu = Y = YuYu) nor nifurtimox multiple electron reduction (Basileu = Y > Y) and drug susceptibility (Basileu > Y > YuYu). 3. A partial correlation however, was observed between drug responsiveness and nifurtimox uptake (Basileu > Y = YuYu). 4. The results suggest that drug uptake may be more important than drug metabolism in modulating resistance to nifurtimox in T. cruzi strains.