THE CORRELATION BETWEEN DISTRIBUTION OF ANTIMONY IN TISSUES AND CHEMOTHERAPEUTIC EFFECT IN EXPERIMENTAL LEISHMANIASIS

¹ Department of Pharmaco1ogy, College of Physicians and Surgeons, Columbia University, New York, N. Y.

The distribution of the antimony of 8 tervalent and 7 quinquevalent antimonials in liver and spleen was studied in hamsters infected with the Khartoum strain of L. donovani for the purpose of correlating tissue distribution with chemotherapeutic effect. Only 3 compounds, all quinquevalent, were effective and in all 3 instances there was a high splenic concentration of antimony (about 90 micrograms per gram). In all the remaining drugs (except one) whether tervalent or quinquevalent, the splenic concentration of Sb was 10 micrograms per gram or less. The behavior of the quinquevalent drug, Stibacetin, was exceptional in that its antimony was deposited in the spleen in very high concentration (226 micrograms per gram) and yet it showed no chemotherapeutic activity. It is concluded that by the chemotherapeutic test used, a high splenic concentration of antimony is a necessary but not a sufficient condition for the cure of experimental leishmaniasis.

The correlation between the structure of quinquevalent antimonials and chemotherapeutic activity is discussed.