[Effect of aminoxidase activity regulators on the humoral immune response and proliferation of lymphoid and nonlymphoid cells].

DL-malic acid dibenzylhydrazide (I) and dihydrazide (II), inhibitors of aminoxidases, have been shown to inhibit immune reactions when administered at the phase of initiation but to stimulate the immune response and proliferation of lymphoid and nonlymphoid cells if given on the 2nd and 3rd day following immunization when the immune reaction is in progress. The intensity of local allergic reaction during passive skin anaphylaxis is reduced by I and enhanced by II if the compounds are administered 16 hrs prior to antigen challenge.