High-resolution autoradiography of malarial parasites treated with 3 H-chloroquine.

Electron microscope autoradiography was performed on the erythrocytic stages of the rodent malarial parasite, Plasmodium berghei, after exposure to (3)H-Chloroquine. (3)H-Chloroquine becomes selectively localized within the parasite food vacuoles 1 hour after it is administered, and remains in this structure for up to 24 hours. This study indicated that the food vacuoles were the primary site of chloroquine concentration within the parasite.