[Natural factor splenin and mechanisms of its action].

The search of biologically active chemical compounds of the drug was carried out basing on the revealed lymphocytotropic property of splenin. A non-protein factor of the nucleoside origin was isolated from splenin by precipitation with mercury. It had a pronounced direct mitogenic effect on splein and thymic T-lymphocetes, being an active component of the drug. This factor increases the mass of lymphoid organs, promotes restoration of postradiation and steroidogenic lymphocytopenias.