The effect of some thymic extracts on antibody formation in rats and mice.

: The influence of some thymic extracts TP1 and TP2 on the number of hemolytic plaque-forming cells (PFC) in the mouse spleen, on the titre of serum antibodies, S-typhy antiflagelar agglutinins and anti-influenza antibodies, was investigated. The results have shown that the hemolytic plaque-forming cells in the mouse spleen increase significantly, 2.3 times under the influence of the TP2 thymic extract in RAP mice inoculated with sheep red cells. In Wistar rats, inoculated with a formol-inactivated suspension of S. typhy and treated with TP2, the antibody titre increases 3.3 times at most. The increase is in relation to the dose of extract and the thymus batch from which the extract was prepared. TP1 also stimulates serum antibody formation in Wistar rats inoculated with A2 influenza vaccine. The antiinfluenza antibody titre increases 2.7 times under the influence of the thymic extract. The results also depend on the dose of extract and the thymus batch. In irradiated animals, the thymic extract had a protective effect. X-ray exposure of Wistar rats caused a 2.5 times decrease in the antiinfluenza antibodies titre. Under the influence of the TP1 thymus extract, the antibody titre increases 2.9 times as against the irradiated controls.