[Effect of vinblastine and cyclophosphamide on the formation of antigen-induced B-suppressors]

Seven days after administration of sheep red blood cells (SRBC) to CBA and (CBA X C57BL/6) F1 mice antigen-induced B-suppressors are formed in the spleen. These suppressors are capable of inhibiting the unirradiated syngeneic recipients' response to SRBC. Administration to donors to vinblastine (1.5 mg/kg) concurrently with SRBC did not affect and partially reversed, 5 days after SRBC, the formation of antigen-induced suppressors. On the contrary, administration to donors of cyclophosphamide (20 mg/kg) 24 h prior to SRBC or in a dose of 250 mg/kg concurrently with SRBC or 5 days after SRBC completely reversed the formation of antigen-induced suppressors.