[Effect of prolonged continuous external irradiation on humoral immunity indices of mice].

Changes in the content and function of cell populations and subpopulations involved in the humoral response of mice to the thymus-dependent antigen were investigated. The effect was followed during a prolonged continuous exposure to 137Cs gamma-emitter (total dose--5 Gy and daily dose--12 cGy for 22 hours) and after its termination. The data obtained give evidence for a decrease of the pool of polypotent lymphocyte precursors (CFUs), stable moderate hypoplasia of central and peripheral organs of the immune system, distinct inhibition of antibody production at the expense of reduced activity of precursors of lymphocytes, B-lymphocytes and T-helpers. In the remote postirradiation period residual radiation damage was seen in polypotent and committed precursors of lymphocytes and T-helpers which was responsible for the trend towards the decline of antibody production, hypoplasia in the spleen and lymph nodes being persistent.