Response of Plasmodium berghei to Anti-malarial Drugs

Abstract

THE discovery of Plasmodium berghei by Vincke and Lips¹ has provided a valuable new strain of malaria for the laboratory trials of chemotherapeutic drugs. We are grateful to Prof. H. E. Shortt for presenting us with a strain of this organism, which we have used for the investigation of the series of 2 : 4-diaminopyrimidines described by Faleo el al.². One of the compounds, 2:4 diamino-5-p-chloro-phenoxy-6-methyl pyrimidine (48–210), was assayed simultaneously against P. gallinaceum in chicks and P. berghei in mice at the same dose-levels. The chick test was performed by the method of Curd, Davey and Rose³, and the mouse test by a similar procedure. The mice were inoculated intraperitoneally with a suspension of infected blood in heparinized saline. Each mouse received about five million parasitized erythrocytes. Six doses of drug were given by stomach tube, night and morning, for the following three days. Blood smears were prepared on the fifth and seventh days of the disease, and the percentage of parasitized cells determined for each mouse.