Influence of Spleen on Thrombocytopenia Induced by Humoral Factor(s) of Experimental Hypersplenism

The influence of the spleen on the thrombocytopenia induced in normal rats by intragastric administration of humoral factor or factors [HF(s)] was studied. Splenectomized rats showed the same thrombocytopenia associated with administration of HF(s) as rats with intact spleen. Thrombocytopenia established by two separate and disconnected periods of intragastric administration of HF(s) and followed by splenectomy was not modified. It is concluded that the spleen is not required by HF(s) to induce thrombocytopenia in the normal rat, and also that the spleen does not participate in the maintenance of thrombocytopenia observed after discontinuation of HF(s).