[The effect of new synthetic fragments of thymus hormones on the proliferative response of lymphocytes].

Influence of three new artificial fragments of beta-thymosines Phe-Asp-Lys-Ala, Glu-Lys-Phe-Asp-Lys and Thr-Leu-Pro-Thr on phytohemagglutinin-induced proliferative response of human lymphocytes was studied. These peptides studied either stimulated or inhibited incorporation of 3H-thymidine in cell cultures of human lymphocytes. Possible mechanisms of these effects of the peptides on lymphocyte proliferation are discussed.