SUBCELLULAR-LOCALIZATION OF IN-111 IN INDIUM-111-LABELED PLATELETS

Abstract

Human platelets labeled with [111In]oxine were suggested for use in platelet kinetic studies, thrombus localization, detection of atherosclerotic lesions and other scintigraphic techniques. The subcellular localization of 111In in labeled platelets was demonstrated by subcellular fractionation and was measured by the amount localized in major platelet components. Human platelets were labeled with [111In]oxine and disrupted by N cavitation. The cellular material was fractionated on sucrose density gradients. When the subcellular fractions were analyzed, more than 70% of the 111In was located in the cytoplasmic pool of the platelets. Chromatography on Sephadex G-100 of aliquots of the labeled cytosol material showed that most of the 111In was associated with components of 46,000 daltons. 111In in human platelets labeled with [111In]oxine is located predominantly in platelet cytosol and is associated with cytoplasmic components.