Primaquine: Modes of Action and Mechanisms of Drug Resistance.

Tetrahymena pyriformis, a ciliate protozoan, has been used to study the mechanism of action of the antimalarial drug, primaquine. These studies have been performed using both intact T. pyriformis and several subcellular fractions and organelles from this organism. In vivo studies were utilized to determine the effects of the drug on the uptake and incorporation of macromolecular precursors by the cells. The in vitro preparations made it possible to study the effects of the drug on in vitro protein synthesis, nucleic acid synthesis in vitro and in isolated nuclei, in vitro lipid synthesis, and membrane transport and permeability. In addition, a procedure was developed to differentiate DNA and RNA on filter paper discs. Studies were also performed on a primaquine-resistant strain of T. pyriformis. The studies completed were the initial characterization of the strain. Author