Figure 9.

Absence of ABCB1-like activity after treatment of epimastigote forms of the T. cruzi Y strain with transport modulators. ABCB1-like activity was evaluated by the Rhodamine 123 (Rho 123) efflux assay. 10⁶ epimastigotes were incubated in medium containing 100 nM Rho 123 in the presence or absence of 2 or 50 μM cyclosporin A (CsA), 10 or 50 μM verapamil (VP) or 2 or 10 μM trifluoperazine (TFP) for 30 min. Parasites were then centrifuged and incubated in medium in the presence or absence of the modulators for another 30 min. After incubation, parasites were centrifuged, suspended in PBS and kept on ice for acquisition by flow cytometry. The graphs in (A,B) represent the median fluorescence intensity (MFI) for Rho 123, (C,D) the percentages of Rho 123+ parasites at 27 and 37°C, respectively. The Friedman statistical test was used with n = 8 independent experiments. Lines represent the median for each group and the significance values were represented by ^*p < 0.05, ^**p < 0.01, and ^***p < 0.001.