[Mathematical modelling of the action of methotrexate on the kinetics of B-lymphocyte proliferation during the primary response].

A mathematical simulation model for checking hypotheses concerning specific features of methotrexate action on the primary antibody response is described. In general consistent interpretation of 8 experimental curves (an intact immune response and one when methotrexate was injected 72 hr after immunization; the data taken from literature) was obtained: the number of IgM-AbFCs in the mouse spleen in the first 4.5 days of immunization and the AbFC's labeling indices for three different 3H-thymidine injection schedules. It is concluded that methotrexate effects include the drug-induced lethality of the B-cells in G1-phase (early) and S-phase, S-phase blockage of the cell transfer cell retention on the G1/S boundary and also a decrease of the number of non-dividing IgM-AbFCs due to RNA and protein synthesis impairment.