[The effect of ethylenethiurea on hematopoesis in rats]

The influence of single and repeated oral administration of ethylenethiourea (ETU) on hematologic parameters of the peripheral blood and the bone marrow was studied in male and female rats. Effects of single treatment on the erythrocytic system were initially indicated by increase in red blood cell count, hemoglobin concentration and hematocrit of the peripheral blood. The initial polyglobulia was followed by a decrease in the blood hemoglobin concentration and the number of erythroblasts of the bone marrow. Continuous administration of ETU resulted in hyporegenerative anemia. The white blood picture showed leukopenia after single and continuous administration of the substance. This effect resulted from a decline in lymphocyte numbers which occurred both in the peripheral blood and in the bone marrow. The hematologic changes were induced with 50 mg ETU/kg body weight and more using single treatment and 600 ppm (= 70 mg ETU/kg body weight) and more under dietary administration.