In vivo radiolabeling of platelet proteins: a new method with identification of platelet factor XIII.
A method for radiolabeling platelets in vivo was developed in which 3H-arginine was injected into the bone marrow of normal dogs. On the third day after injection, a maximum of 6%--7% of the radioactivity had been incorporated into the total platelet mass. This method of isotope administration resulted in a 50--60-fold increase in maximum uptake of radiolabel by platelets, as compared to values obtained by others using intravenous injections of various radioactive compounds. Tritium-labeled platelets were harvested from the animals and then were washed to remove unbound 3H-arginine. On polyacrylamide gel electrophoresis 7 labeled protein bands, with molecular weights ranging from 29,000to 132,000, were obtained from the platelet-soluble fraction. One 3H-containing protein with a molecular weight of 81,000 was identified immunologically and enzymatically as platelet factor XIII.
D000818:Animals; D001120:Arginine / Q000378:metabolism; D001792:Blood Platelets / Q000032:analysis*; D001798:Blood Proteins / Q000032:analysis*; D001853:Bone Marrow; D004285:Dogs; D004591:Electrophoresis, Polyacrylamide Gel; D005176:Factor XIII / Q000302:isolation & purification*; D007553:Isotope Labeling / Q000379:methods*; D008970:Molecular Weight; D014316:Tritium
D001798:Blood Proteins; D014316:Tritium; D005176:Factor XIII; D001120:Arginine