Studies on the Toxic Action of Ricin. ∗

Abstract

Summary

Ammonium, sulfate fractionation of a 0.85% saline solution of ricin obtained from Ricinus communis L. seeds yielded a protein at the 1/3 to 1/2 saturation level which contained the highest hemagglutinating activity and toxicity. This fraction contained at least 4 proteins as shown by dialysis and starch gel electrophoresis. Further purification using an Amberlite CG-50 resin provided 2 major protein components. When the proteins that were obtained from seeds which were 2 years old were injected subcutaneously into rats it was found that the liver and lymphoid tissues were preferentially attacked. The same seeds lost the substances responsible for this target organ specificity after 4 years' aging. There was no effect of the various preparations on mitochondrial respiration nor on the activity of crystalline fumarase. There was an increase in the packed red cell volume of rats injected intraperitoneally with ricin.