“ In - Oxine - Labeled Rabbit Platelets : In Vivo Distribution and Sites of Destruction

We have studied the kinetics. biodistribution, and fate of autologous platelets labeled with 111ln-oxine in rabbits. The initial recovery was 75% and mean survival time was 2.8 days when the data were analyzed by the multiple-hit gamma function model. Using a modified geometric mean for correction of attenuation. there was good correlation between the values obtained by in vivo quantification and those obtained by postmortem measurements of the radioactivity in the liver and the spleen (i.e., r = 0.854 and 0.899. respectively, n 32). Using this method, it was shown that after infusion, the “In-platelets rapidly accu-