[Effect of medium-sized molecules fro uremic serum on hemopoiesis in intact mice].

The effect of a medium-sized molecular fraction (3000--800) isolated from serum of patients with chronic renal insufficiency on erythropoiesis in intact mice was studied. The fraction significantly lowered the erythropoietic count of the bone marrow (maximum by 47%). The absolute number of myelocytes ranged within normal. The number of granulocytopoietic and lymphoid cells remained statistically unchanged throughout the whole experiment. The results indicate that the medium-sized molecular fraction displays activity in the stage of erythroid precursors.