Growth of Plasmodium falciparum in sodium-enriched human erythrocytes.

Transport of nutrients into animal cells is driven by transmembrane gradient of Na+ across the plasma membrane. The protozoan malaria parasite, Plasmodium falciparum, however, grows within the host human erythrocytes, in which the cytoplasmic concentration of Na+ is maintained low by the membrane Na+, K+-ATPase. Our experiments show that human erythrocytes enriched with Na+ by treatment with ouabain (an inhibitor of the ATPase) will support the growth of P. falciparum in culture.