title: Uptake by blood components and by subcellular platelet fractions of 1-14C-acetylsalicylic acid.
abstract: 1-14C-Acetylsalicylic acid was used to study the distribution and the kinetics of the acetyl group in blood components. Tests were carried out in 4 patients in vivo and on four blood samples in vitro. At various intervals after tagging, whole blood, plasma, platelets and platelet fractions were examined. In vitro, relative activity was found to be higher in platelets than in all other blood components. When platelet fractions were examined, the highest specific activity was found in membranes. In vivo, rapid disappearance of activity from circulation was observed. The decrease of activity was slower in platelets than in whole blood and in plasma. The highest specific acitivty was again found in platelet membranes. The half-life of the 14C tag was measured in all components. It was found to be longest in platelet membranes where it corresponded to the half-life of platelets in circulation. From the results obtained, the conclusion was drawn that irreversible acetylation of the platelet membrane must be considered to be one of the main causes of platelet dysfunction induced by acetylsalicylic acid.
mesh_terms: D001241:Aspirin; D001769:Blood / Q000378:metabolism*; D001772:Blood Cell Count; D001792:Blood Platelets / Q000201:enzymology / Q000378:metabolism*; D001798:Blood Proteins; D001810:Blood Volume; D002250:Carbon Radioisotopes; D002462:Cell Membrane / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D013347:Subcellular Fractions / Q000378:metabolism
chemical_list: D001798:Blood Proteins; D002250:Carbon Radioisotopes; D001241:Aspirin