Studies on Thrombopoiesis II Effect of a Non‐Dialyzable Spleen Preparation on the Thrombocyte Level

Abstract

Evidence is presented for the presence in normal bovine and canine spleen of a material that elevates the platelet count of rabbits. An extraction method and bioassay are outlined. The spleen extract is non‐dialyzable, heat and pH resistant, and exhibits an absorption peak at 265 mμ. It is postulated that the extract effects new platelet production by causing the differentiation of precursor cells to megakaryoblasts. Activity was also found in red cells and platelets but not in a variety of other bovine organs.