Abstract

When the normal rabbit is inoculated intravenously with the maximal tolerated dose of potassium antimonyl tartrate there results an immediate leucopenia without secondary leucocytosis, the red blood corpuscle count remains unchanged, and an increased number of normoblasts appear in the peripheral blood. Potassium antimonyl tartrate depresses both the polymorphonuclear neutrophile and the lymphocyte counts, the former more rapidly and more profoundly than the latter. When injections of potassium antimonyl tartrate are given over a long period of time the same quantitative alterations occur in the peripheral blood after each injection, as are noted after the first injection. Potassium antimonyl tartrate does not destroy the leucocytes of the rabbits in vitro. The inoculated antimony disappears from the circulating blood of the rabbit within one-half hour after inoculation. The maximal tolerated dose of potassium antimonyl tartrate (6 mgm. per kilogram) in the rabbit produces a varying grade of periportal fibrosis in the liver, increased phagocytosis in the spleen, and a mild grade of erythropoietic hyperplasia in the bone marrow. The destruction of leucocytes probably takes place in the spleen.