title: Direct measurement of the amount of bound collagen which stimulates platelet aggregation.
abstract: The amount of collagen which binds to platelets has been correlated with aggregating activity in a platelet aggregometer. Aggregating activity requires only 0.22 microgram/ml (0.35 microgram/10(9) cells) of collagen bound, the reaction saturating with 4.9 microgram/ml (7.9 microgram/10(9) cells). On the basis of the fraction of collagen bound and its hydroxyproline/proline ratio, it is concluded that the activity resides in the type I collagen component.
mesh_terms: D001665:Binding Sites; D002462:Cell Membrane; D003094:Collagen / Q000494:pharmacology*; D006801:Humans; D006909:Hydroxyproline / Q000378:metabolism; D010974:Platelet Aggregation / Q000187:drug effects*; D011392:Proline / Q000378:metabolism
chemical_list: D003094:Collagen; D011392:Proline; D006909:Hydroxyproline