Alteration of Homograft Reaction by A-methopterin in Lethally Irradiated Mice Treated with Homologous Marrow

Summary Mice which would normally succumb to a homograft reaction following lethal, total-body X irradiation and homologous marrow inoculation, may be spared if they are treated with folic acid antagonist, A-methopterin. Using different treatment schedules, varying degrees of effectiveness from increased survival following a typical reaction, to no detectable reaction, may be obtained. The relationship between drug toxicity and effectiveness in altering the homograft reaction is discussed.