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PubMed · 6421332

Platelet activation studied by fluorescence polarization.

M Steiner·E F Lüscher
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Abstract

Platelet activation was elevated by changes in the fluorescence anisotropy of the sulfhydryl-reactive fluorescent probe, (5-[2-(iodoacetyl) aminacetyl]aminonaphthalene-1-sulfonic acid. The membrane-permeable fluorophore was shown to bind to a multitude of cytoplasmic and membrane proteins. Platelets were stimulated by addition of thrombin, arachidonic acid or ADP under conditions that did not induce aggregation. A sudden increase in the fluorescence anisotropy, r of moderate degree (25-33%) occurred during the first 60 s after exposure of platelets to the aggregating agents and was sustained during the entire period of observation (15-18 min). Phenylmethylsulfonyl thrombin was unable to produce these changes in fluorescence anisotropy. Preincubation of platelets with colchicine reduced r within 30-60 s after platelets were exposed to thrombin. These findings are interpreted as an indication of a general decrease in the 'motional freedom' of the fluorophores and indirectly their ligand molecules.

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Adenosine DiphosphateArachidonic AcidArachidonic AcidsBlood PlateletsColchicineFluorescence PolarizationHumansMolecular WeightPlatelet AggregationSulfhydryl ReagentsThrombinJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, P.H.S.

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M Steiner, E F Lüscher. 1984-02-17. Platelet activation studied by fluorescence polarization.. https://doi.org/10.1016/0167-4889(84)90053-3

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