Kinetic studies of 51Cr and DF32P labelled granulocytes.

In vivo kinetic studies of granulocytes labelled in vitro with 51Cr and DF32P were carried out in nine haematologically normal subjects by isolation of the cells in the blood samples by the Ficoll-Isopaque flotation method. 51Cr and 32P specific activity of blood samples made of 93-98% granulocytes was studied. Distribution between marginated and circulating granulocyte pools was identical for both labelled cells and the marginated pool was similar to the circulating pool, except that it was lower in one subject who had a previous splenectomy. The half-disappearance time (T 1/2) was 16.1+/-2.2 h for 51Cr-labelled and 5.4+/-2.1 hr for DF32P-labelled granulocytes. In one case of a normal subject who previously received multiple transfusion homologous 51Cr-labelled granulocytes had a T 1/2 of less than 1 h.