title: Kinetics of In-111-platelets in the baboon: II. In vitro distribution and sites of sequestration.
abstract: The kinetics and sites of sequestration of a fully representative population of In-111-platelets were determined in 11 baboons. The in vivo method of quantification with computer assisted scintillation camera image analysis was validated by sacrificing 5 baboons and measuring and comparing the distribution of organ radioactivity. Recovery of platelets in the circulation was 87% +/- 7, and their mean survival time was 147 hr +/- 15. The mean splenic platelet pool was 16.0 +/- 1.9. At equilibrium 15.8% +/- 2.9 of the In-111-platelets were in the hepatic blood pool. Senescent platelets were destroyed in the reticulo-endothelial system. The major sites of sequestration were: liver (37.6% +/- 6.0), and the spleen (23.3% +/- 4.6). The bone marrow sequestrated 14.4% +/- 1.7 of the labelled platelets, and 15.5% +/- 4.0 were present in various other tissues. We conclude that the in vivo method of In-111-quantification is accurate. Senescent platelets are mainly sequestrated in the reticuloendothelial tissue, with the liver, spleen and the bone marrow important sites of sequestration.
mesh_terms: D000818:Animals; D001792:Blood Platelets / Q000166:cytology / Q000378:metabolism*; D002469:Cell Separation; D002470:Cell Survival; D005260:Female; D007204:Indium; D008099:Liver / Q000032:analysis; D008297:Male; D010215:Papio / Q000097:blood*; D010976:Platelet Count; D011868:Radioisotopes; D013154:Spleen / Q000032:analysis; D014018:Tissue Distribution
chemical_list: D011868:Radioisotopes; D007204:Indium