Chemotherapy of Rodent Malaria Drug Action Against Exo-Erythrocytic Stages and Drug Resistant Strains.
Final technical rept. 1 Apr 71-31 Aug 72,
LIVERPOOL SCHOOL OF TROPICAL MEDICINE (ENGLAND) DEPT OF PARASITOLOGY
Pagination or Media Count:
The schizontocidal activity of several compounds against the chloroquine resistant RC strain of P. berghei has been confirmed. However, strains that develop resistance to chloroquine also soon become resistant to the initially active quinoline- and phenanthrene-methanols. Preliminary data suggest that emergence of drug resistant strains may be avoided by the use of binary or ternary drug mixtures. A distinction is drawn between drugs, like chloroquine, which induce haemozoin climping and those, like quinine, which inhibit chloroquine-induced clumping. It is suggested that chloroquine resistant parasites survive by stimulating the host cells to produce increased quantities of essential enzymes, and not by a change from anaerobic to aerobic metabolism. Catheptic activity of intraerythrocytic P. berghei is mainly that of the host reticulocytes, although two small bands in gel electrophoresis may be of parasite origin. Tritiated thymidine is not taken up by oocysts adenosine is taken up. Failure to utilize thymidine is thus an intrinsic property of the parasites and not a result of the inability of thymidine to enter the host cell. Author