Malaria: The Effect of Iron and Chloroquine on the Erythrocytic Forms of Plasmodium berghei 1 2

Summary

A novel finding is presented for the in vivo regulation of the growth and multiplication of the erythrocytic forms of the malarial parasite by iron and chloro-quine.

The experimental conditions are as follows: the mice (10 per group) were placed on a low iron diet for 12 days before the administration of the radioactive iron-59 citrate (10 μCi/2.6 μg iron-59 per mouse) by ip injections. The mice in Curve A were injected with normal saline solution on the 12th, 13th, and the 14th day after they were placed on a low iron diet; and Curve B mice were injected with chloroquine base (40 mg/kg body wt) on the same days as the saline.

The water fed to both groups of mice had a specific conductivity of at least 15 Mohms.

The ordinate is the radioactive iron-59 incorporated into the blood cells and is expressed as the counts per minute of iron incorporated into 1.0 cm of packed cells of the mice. The abscissa is the time expressed in hours.

The insert represents the difference in the rates of radioactive iron incorporated between Curves A and B.

Mice treated with iron showed average parasitemias approximately 3-6 times less than in mice kept on a low iron diet. The protective effect of iron is increased approximately 3-8 times by chloroquine injections. Chloroquine is shown to increase the uptake of iron into the blood cells of uninfected mice to suggest another action of chloroquine.