Figure 5
Effects of known transport inhibitors. (A) Mean ± S.E.M. Ca++ uptake by Dd2-infected cells in the presence of 15 μM ISPA-28, 10 μM verapamil, 100 μM CdCl2, or 10 μM nifedipine, normalized to 100% for control measurements over 12 hours without inhibitor. Cd++ increases parasite-associated fluorescence, but none of the agents block the parasite-induced erythrocyte Ca++ permeability. (B) Mean ± S.E.M. fluorescence change associated with 100 μM CdCl2 for uninfected cells in media without probenecid. At these concentrations, extracellular Cd++ does not contribute significantly to the signal.