Blood leukocyte responses to extracorporeal circulation. II. Medium term extracorporeal circulation without and with extracorporeal irradiation in normal and splenectomized dogs.

Medium term (6-8 h) extracorporeal irradiation without and with irradiation of blood was performed in normal and splenectomized dogs to reveal the changes of blood leukocytes including CFU-C. A regular but transitory decrease of granulocytes and a longer lasting diminution of lymphocytes in the blood were observed. The CFU-C level became and mostly remained very low during the procedure. Splenectomy did not influence significantly the changes of peripheral leukocyte counts. No marked difference of leukocytes was seen in the blood samples taken from the arterial or venous side of the shunt or even from the cubital vein. Also, the irradiation did not produce any difference in the alterations of blood cell counts compared to those without irradiation. The possible explanations of these results are discussed.