THe dynamics of erythropoiesis inhibition in posttransfusion polycythaemia in the rat.

The dynamics of erythropoiesis inhibition as the consequence of polycythaemia induced in rats by four to six transfusions of homologous erythrocytes was studied in detail. It was found, that, in rats with polycythaemia elicited by two transfusions of erythrocytes, erythropoiesis inhibition occurs 67h after the first transfusion and it is most pronounced in the period between 115-187 h. The hemopoietic system is not completely free from the inhibitory influence of polycythaemia up to 283 h after the first transfusion. Maintenance of a state of polycythaemia for 17 days by repeated transfusions strongly and durably inhibits the haemopoietic system. The red blood cell system remained for this whole period under the inhibitory effect.