Fig. 4. Hemolysis of infected cells in isosmotic sorbitol solution. (A and B) Hemolysis was sensitive to reduction, NPPB, furosemide, glybenclamide and DIDS. Enriched trophozoite-infected erythrocytes were suspended in isosmotic sorbitol or, for control, in NaCl and incubated in the presence and absence of DIDS, NPPB, furosemide, glybenclamide (each 100 µM) and DTE (100 µM and 1 mM), respectively. Incubation was stopped by centrifugation, and hemolysis was indicated by hemoglobin in the supernatant. In (A) are the scanned images of supernatants from two individual experiments performed in duplicate. (B) Mean hemolysis in isosmotic sorbitol in the absence (control) and presence of DTE (100 µM and 1 mM, respectively), DIDS, furosemide and glybenclamide (each 100 µM), respectively. The hemoglobin concentration of the supernatants was determined photometrically and data were expressed as a percentage of that fraction of total hemolysis that could be inhibited by NPPB (n = 3–16; **P ≤0.01). (C and D) Substrate dependence of the infection-induced isosmotic hemolysis. In (C) are the imaged supernatants (individual experiment) and in (D) the mean relative hemolysis of cells incubated in different isosmotic carbohydrate solutions as indicated (n = 8–9; **P ≤0.01; ***P ≤0.001).