[Immunodepressive properties of antineoplastic agents]

Experiments on CBA mice immunized with sheep red blood cells have shown that paphencyl, promycil, prospidin and imidazole-4-carboxamide decrease the number of IgM-antibody-forming cells in mouse spleens during the primary immune response. The highest immunodepressant effect was exhibited by paphencyl, while the least by prospidin. The maximum inhibition of the immune response was observed on paphencyl and promycil administration 24 hours after the immunization, that on prospidin administration 24 hours prior to antigen exposure, and that on imidazole-4-carboxamide administration 24 hours prior and 48 hours after the antigenic stimulation. The degree of antibody genesis suppression depends on the dose of paphencyl, promycil and prospidin and does not depend on the dose of imidazole-4-carboxamide. Paphencyl significantly diminishes the number of hemopoietic stem cells in mouse spleens, while prospidin was less active in this respect.