The released proteins from avian thrombocytes.

The effect of aggregating agents on the amounts and nature of released proteins from washed goose and chicken thrombocytes was studied. The released protein material was separated on Sepharose 4B. Protein fractions with low molecular weight were next chromatographed on Sephadex G-200. The released proteins from thrombin aggregated pig platelets were analysed in the same way. It was shown that during aggregation avian thrombocytes release protein material containing a well separated fraction (the major component) which seems to correspond to a platelet specific beta-thromboglobulin.