[Studies with radiolabeled autologous and heterologous thrombocytes to determine life-span and destruction sites].

The kinetic of 51Cr-labelled autologeous and heterologeous thrombocytes was studied in 12 healthy volunteers. The mean recovery value was 63% (SX = +/- 15%). The survival times (t50% and t10%) were determined as 94 hrs. (SX = +/- 11 hrs.) and as 202 hrs. (SX = +/- 13 hrs.) respectively. The "excess counts" over spleen and liver were measured and the spleen to liver ratio calculated. In every parameter investigated no significant difference between autologeous and heterologeous labelled thrombocytes could be found. The "excess counts" over spleen and liver were calculated on the basis of the radioactivity of blood and of the heart surface area. The values obtained from the blood radioactivity calculations showed significant lower variation coefficients than the corresponding values derived from the heart measurements.