[Effect of methotrexate on the early stages of immunogenesis in mice].

The data of the study on the effect of a single intraperitoneal administration of methotrexate (0.5 mg/kg) on the early stages of immunogenesis of mice are presented. A single administration of the drug in different periods before immunization (1-10 days) was shown to induce no suppression of the immune response. On the contrary, at the administration of methotrexate 6-9 days before antigen administration a distinct stimulating effect was noted (320-350% of the control level). The administration of the drug daily for 6 days produced no, significant changes in the immune response formation and only 7-8-day administrations led to a significant decrease of the immune response (24-50% of the control level). The results obtained suggest that the time of renewal of the population of immunocompetent cells in the mouse spleen is 6-9 days.