Deep vascular schizogony in Plasmodium fragile: organ distribution and ultrastructure of erythrocytes adherent to vascular endothelium.

Erythrocytes infected with Plasmodium fragile, like those infected with P. falciparum and P. coatneyi, adhere to vessels in heart, adipose tissue and, to a lesser ex00 nm knob protrusions on the plasma membrane of infected erythrocytes. The close apposition between knobs and endothelium (1 nm or less) excludes macromolecules such as fibrinogen or antibodies as the adhesive force. The components on the membrane responsible for adhesion at the knobs remain unknown.