Comparative study of amino acid production in erythrocytes parasitized by Plasmodium sp. and Babesia hylomysci.

Parasitized red blood cells are incubated in an isotonic buffer and the release of amino acids is determined in the cells and the buffer according to time. Erythrocytes parasitized by P. yoelii nigeriensis showed an intense release of amino acids whereas those parasitized by B. hylomysci behaved almost like the uninfected erythrocytes. A large amount of the amino acids produced by proteolysis are thus released out of the red blood cell. Red blood cells parasitized by P. berghei and P. berghei chloroquino-resistant strains have the same proteolytic activity. Chloroquine does not inhibit proteolysis. The release of amino acids out of parasitized cells has been confirmed in vivo.